Table of Content

15 April 2023, Volume 44 Issue 04

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Fiber Materials

Preparation and properties of poly(butylene succinate)/silk sericin blend fiber

XIA Yu, YAO Juming, ZHOU Jie, MAO Menghui, ZHANG Yumei, YAO Yongbo

Journal of Textile Research. 2023, 44(04):  1-7.  doi:10.13475/j.fzxb.20211111107

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Objective Poly (butylene succinate) (PBS) is a synthetic biodegradable polymer and silk sericin is a natural biodegradable polymer. PBS fiber can be prepared by melt spinning process, which is applied in textile industry as raw material. Silk sericin can be used as moisturizer in skincare and textile industries. To improve the skin-friendliness of PBS fiber, PBS and silk sericin was mixed by melt blending, then the blend fiber was prepared by melt spinning process.
Method After vacuum drying at 80 ℃ for 4 h, the PBS and silk sericin were melt blended using an internal mixer at the rotation rate of 60 r/min for 25 min. The mixing temperature of the PBS/silk sericin blends was set to 140 ℃, and the weight ratio of PBS/silk sericin is shown in Tab. 1. After that, the PBS/silk sericin blend fibers were spun through a single-screw extruder at 160 ℃. Then, the fiber was cooled in a water bath at room temperature. The extrusion speed was 1.95 g/min, the drawing speed was 3.60 m/min, and the draw ratio was 4.
Results The scanning electron microscopy (SEM) of the cross-section of the PBS/silk sericin blend fiber is shown in Fig. 1. The rough cross-section of PBS/silk sericin blend fiber indicates poor compatibility between PBS and silk sericin. There were small voids on the cross-section of the blend fibers, the number of voids would increase with the rise of silk sericin mass fraction. The XRD pattern of PBS/silk sericin blend fiber is shown in Fig. 3 and the crystallinity of PBS is listed in Tab. 2. With the increase of silk sericin mass fraction, the crystallinity of the blend fiber decreases. It seems that the crystallization process of PBS was obstructed by the dispersion of silk sericin in the fiber. The mechanical property of PBS/silk sericin blend fiber is shown in Fig. 4. Tensile strength and elongation at break of the blend fiber decrease when the silk sericin mass fraction increases, and the elongation at break of PBS fiber is 212.1%. However, for the blend fiber when the mass fraction of silk sericin became 15%, the elongation at break of was only 8.9%, this value meets the requirement of textile requirement. Hence, the overlarge elongation at break of PBS fiber can be reduced with the existence of silk sericin. The saturated moisture regains of the PBS/silk sericin blend fibers is shown in Fig. 6. It can be found that the saturated moisture regain of the blend fiber is improved with the increase of silk sericin mass fraction. For the blend fiber when the silk sericin mass fraction is 15%, the saturated moisture regain is 3.90%. This value is similar to the saturated moisture regain of polyamide 6 fiber (saturated moisture regain is 3.95%) with good hydrophilic property. The improved saturated moisture regain of the blend fiber is not only related to the hydrophilic group of silk sericin, but also associated with the increase of amorphous region area in the blend fiber. The weight loss rate of PBS/silk sericin blend fibers after soil burial test is shown in Fig. 7. The weight loss rate of the blend fiber after 6 weeks during the soil burial test is up to 53.6%. When silk sericin is degraded by microorganisms firstly, the specific surface area increases, which is beneficial to the contact between PBS and microorganisms. Then, the degradation rate of PBS is also accelerated.
Conclusion In this research, the PBS/silk sericin blend fibers were prepared by melt spinning method. The effect of PBS/silk sericin weight ratio on the morphology, mechanical strength and biodegradability was studied. The main findings are as follows,the small voids can be found on the cross-section of the PBS/silk sericin blend fibers, which is related to the weak interface force between PBS and silk sericin. For the PBS/silk sericin blend fiber when the mass fraction of silk sericin is 15%, the elongation at break is 8.9%, the saturated moisture regain is 3.90%. By contrast, the elongation at break of PBS fiber is 212.1%, the saturated moisture regain is 2.26%. The existence of silk sericin not only reduces the overlarge elongation at break of PBS fiber, but also improves the hydrophilic property. For the PBS/silk sericin blend fiber when the mass fraction of silk sericin is 15%, the weight loss rate after 6 weeks during the soil burial test is up to 53.6%. The biodegradability of PBS/silk sericin blend fiber of PBS is better than that of PBS fiber. Hence, the PBS/silk sericin blend fiber degrades quickly after use.

Preparation and properties of plasticized polyvinyl alcohol for sea-island fiber production

WANG Shuanghua, WANG Dong, FU Shaohai, ZHONG Hongtian, DONG Peng

Journal of Textile Research. 2023, 44(04):  8-15.  doi:10.13475/j.fzxb.20220306908

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Objective Sea-island fibers, which are mostly prepared by melt composite spinning, are favored by the textile industry due to the excellent properties and high added value. Alkali-soluble polyester (COPET) is the common sea component of PVA to be removed by alkali decrement method that will cause environmental pollution. Polyvinyl alcohol (PVA) is expected to replace COPET as the sea component to solve environmental pollution, because it is green, non-toxic and water-soluble.
Method Due to amounts of strong intermolecular/intramolecular hydrogen bonds of PVA, the melting point is approximate to the thermal decomposition temperature, which leads to difficulty for melt processing. Modified PVA with high thermal decomposition temperature was prepared by melt blending with compound plasticizers, which consisted of dipentaerythritol, calcium stearate and irganox B225. The effects of compound plasticizers on thermal properties and fluidity of PVA were investigated by DSC, TG and melt flow rate. The suitable processing temperature of PVA was obtained by torque rheometer. The intermolecular hydrogen bonds, crystallinity and compatibility of modified PVA were analyzed by FT-IR, XRD and SEM.
Results The melt-forming property and thermostability of PVA were improved obviously via introducing compound plasticizers. When the contents of dipentathritol, calcium stearate and irganox B225 were 15%, 3%, and 1%, respectively, the thermal decomposition temperature of modified PVA was up to 301.3 ℃ and the melting point reduced to 178.2 ℃ (Fig. 1, Fig. 3 and Fig. 5), providing a thermal processing window of 123.1 ℃. The modified PVA showed a transparent appearance due to its good melt fluidity and outstanding oxidation resistance (Fig. 2, Fig. 4 and Fig. 6). The plasticization and melt fluidity of modified PVA were significantly enhanced with the increase of melting processing temperature (ranging from 195 to 210 ℃). Obviously, when the processing temperature reached up to 200 ℃, the modified PVA could be well plasticized (Tab. 2). The compound plasticizers could effectively destroy the intramolecular and/or intermolecular hydrogen bonds of PVA and reconstructed the fresh hydrogen bonds with PVA, reflected by the shift of absorption peak (Fig. 7). Interestingly, the compound plasticizers improved greatly the activity of PVA molecular chain, thereby reducing its crystallinity (Fig. 8). Addition, the cross section of the modified PVA was observed by scanning electron microscope (SEM). There were almost no obvious plasticizer particles precipitation, and some tiny particles were dispersed uniformly in PVA matrix without agglomeration, which indicated good compatibility between the composite plasticizers and PVA (Fig. 9). Furthermore, the resulting modified PVA could still be melt extruded smoothly at 250 ℃, which provided feasibility for melt composite spinning with PET. Particularly, it is unexpected that the modified PVA could be dissolved at 25 ℃ (Tab. 3), which demonstrates good water solubility, creating many opportunities for the subsequent alkali-free fiber opening process of sea-island fiber.
Conclusion The modified PVA was prepared by melting process and its compound plasticizer composed of dipentaerythritol, calcium stearate and irganox B225.The effects of compound plasticizers and processing temperature on the properties of PVA were investigated to optimize its plasticizing modification process. The compound plasticizers can effectively destroy the hydrogen bonds among PVA molecules and enhance the activity of PVA molecular chain to reduce its crystallinity and melting point. Meanwhile, the fresh hydrogen bonds between PVA and the compound plasticizer enhance the stability of PVA hydroxyl group, thereby improving the thermal stability of PVA. In conclusion, the modified PVA has excellent thermostability and melt fluidity as well as water solubility, providing reference and technical support for the preparation of sea-island fiber with PVA as the sea component.

Preparation of bacterial cellulose/Au film loaded with tungsten trioxide and its catalytic performance

ZHOU Tang, WANG Dengbing, ZHAO Lei, LIU Zuyi, FENG Quan

Journal of Textile Research. 2023, 44(04):  16-23.  doi:10.13475/j.fzxb.20220401908

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Objective Highly toxic and refractory trace antibiotics in agricultural and medical wastewater seriously affect the ecological environment, which makes it necessary to develop efficient antibiotic removal methods. Photocatalytic technology can use solar energy to degrade pollutants in water. However, in most studies, photocatalysts are usually used in powder form for photocatalytic degradation of pollutants, which is difficult to remove from water. This research sets out to investigate the natural nanofiber network of bacterial cellulose (BC) as a support skeleton for supporting nano-catalytic materials, with potential applications in water purification.
Method Biocultured bacterial cellulose nanofiber membranes were made into nanofiber dispersion, and Au nanoparticles were deposited on the dispersed nanofibers by chemical reduction to obtain flexible BC/Au conductive nanofiber materials. After that, the tungsten trioxide (WO₃) photocatalyst was fixed by adsorption method, and the BC/Au-WO₃ nanofiber membrane was formed by vacuum-assisted filtration.
Results A large number of adherent WO₃ nanoparticles were found on BC nanofibers, as a good flexible support role for photocatalytic materials (Fig. 2). BC showed standard cellulose crystals and the composite nanofibers show obvious diffraction peaks of Au and WO₃. No other impurities were found in the sample by XRD (Fig. 3). The electrochemical impedance and mechanical test indicated that the addition of Au could improve the electron transfer resistance and mechanical properties of nanofiber membrane and the interface charge transfer impedance of BC/Au nanofiber membrane was 32.353 Ω (Fig. 4). The light absorption capacity of BC/Au-WO₃ nanofiber membrane for visible light was improved with the addition of Au, and there was a distinct characteristic absorption peak at 550 nm, consistent with the local surface plasmon resonance effect of Au nanoparticles in the visible light (Fig. 5). In this work, tetracycline hydrochloride was used as the target substrate to study the catalytic degradation of nanofiber membrane. The results showed that the addition of Au was beneficial to improve the photocatalytic degradation rate of the material (Fig. 6(a)). The photocatalytic and photoelectrocatalytic degradation rates of tetracycline hydrochloride by nanofiber membrane in 3 h were 60.2% and 78.4%, respectively (Fig. 6(b)). Compared with photocatalytic degradation alone, the catalytic degradation efficiency was greatly improved after adding additional electric fields, and the photoelectrocatalytic efficiency was greater than the sum of the efficiency of photocatalysis and electrocatalysis (Fig. 6(c)). Coupling was shown between photocatalysis and electrocatalysis. With the addition of additional electric field, the photogenerated electrons generated by the photocatalytic reaction were controlled by the voltage and transferred from the fiber membrane side to the platinum electrode side through the external circuit, thus playing the role of separating the photogenerated electrons and hole pairs. In addition, BC/Au-WO₃ nanofiber membrane also showed the good reusability, and the results showed that its catalytic degradation performance remained unchanged after 6 times of reuse (Fig. 6(d)).
Conclusion BC can play a good support role for WO₃ as a three-dimensional biomass flexible skeleton. Au nanoparticles modification can effectively improve the photocatalytic efficiency of BC/Au-WO₃ composite nanofiber membrane. After light radiation, the Au nanoparticles and the WO₃ Photocatalyst on the nanofiber network can form Mott-Schottky barriers to trap photogenerated electrons, thus reducing the recombination of photcogenerated electron-hole pairs. Moreover, Au nanoparticles can generate local plasma resonance effects in visible light and inject thermal electrons into WO₃ to improve photocatalytic efficiency. Under light excitation and additional electric field, the catalytic degradation rate of tetracycline hydrochloride by composite nanofiber membranes was greatly improved. This is because the directional movement of photogenerated electrons under an additional electric field can force photogenerated electron hole pairs to efficient separate. When the additional voltage is 2.0 V, the photocatalytic degradation rate of tetracycline hydrochloride can reach 78.4% within 3 h. Compared with the single photocatalytic reaction, photoelectric catalytic reaction can accelerate the reaction and improve the degradation rate, which has potential application value in the water treatment of antibiotic.

Preparation and adsorption analysis of sodium alginate/graphene oxide microporous aerogel fiber

SUN Jianghao, SHAO Yanzheng, WEI Chunyan, WANG Ying

Journal of Textile Research. 2023, 44(04):  24-31.  doi:10.13475/j.fzxb.20211109208

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Objective The pollution of dye wastewater to the environment is the main factor restricting the large-scale production of the textile industry. Sodium alginate (SA) and graphene oxide (GO) both have good adsorption on residual dyes in dye wastewater. This paper reports a research that combines sodium alginate and graphene oxide are for fiber spinning, and studies the adsorption of dye wastewater of the composite fiber for the optimal absorption effect and recovery of adsorbent materials.
Method In this research, graphene oxide was used as an additive, sodium alginate was used as the main material of the gel, where graphene oxide was grafted with maleic anhydride for modification. SA/MAH-GO (modified graphene oxide) composite adsorbent material was prepared by wet spinning, microscopic pore-forming, freeze-drying, and so on. Fourier infrared spectrometer, differential scanning calorimeter, scanning electron microscope, X-ray diffractometer, particle size analyzer and other instruments were used to test and characterize the product. Additionally, an ultraviolet spectrophotometer and a fiber tensile breaking strength meter were used to compare its adsorption properties and physical and mechanical properties.
Results At the microscopic level, the chemical structure and particle size of GO have changed after grafting with maleic anhydride. FT-IR test showed that the infrared spectrum of MAH-GO particles illustrated an ester base vibration peak at 1 101 cm^-1, which proved that maleic anhydride was successfully grafted onto the GO surface lamellar (as shown in Fig. 1). After ultrasonic dispersion, the particle size of MAH-GO in the water medium is mainly distributed within 191.2 nm, much smaller than GO particle size (9 669.8 nm), and the dispersion of MAH-GO is obviously better than GO particle. The experimental results show that trace amounts of modified graphene oxide (MAH-GO) have a certain optimization effect on the physical and mechanical properties of SA/MAH-GO microporous aerogel fibers. On the other hand, the special structure of microporous aerogel fibers has improved its adsorption capacity of methylene blue dyes. When the mass fraction of MAH-GO is 0.5%, the maximum tensile breaking strength is 0.513 cN/dtex, the breaking strength is increased by 11.51% compared with unmodified GO, and the breaking strength is increased by 81.27% compared with the microporous SA aerogel fiber (as shown in Fig. 4). Microporous aerogel fibers containing 0.75% MAH-GO demonstrated a higher removal rate of methylene blue, and the removal rate is always above 80% in the mass concentration range of 200 mg/L to 1 800 mg/L, and the maximum adsorption capacity can reach 2 400.6 mg/g (as shown in Fig. 6 and 7).The fitting results of the quasi-secondary kinetic adsorption model and the Langmuir isotherm adsorption model prove that the adsorption process involves electron sharing or transfer between the adsorbent and the adsorbate.
Conclusion Composite adsorption materials have good development prospects for adsorption of polluted wastewater. The raw materials such as calcium carbonate particles and sodium alginate used in the preparation of micro-porous adsorption fiber are cheap. When the mass fraction of MAH-GO is controlled within 0.75%, the cost actual treatment of low concentration methylene blue pollutants can be further controlled. To sum up, there are some suggestions for the next research of this topic. Firstly, the organic solvent DMF is used in the esterification process of graphene oxide, which can be recycled by vacuum distillation, but it is time-consuming and energy-consuming. Environmental friendly solvents and modified catalytic methods such as ultraviolet photocatalysis should be selected. Secondly, besides the pore-forming method, mineral materials such as bentonite, montmorillonite and diatomite can also expose more potential adsorption sites for sodium alginate composites and improve the adsorption potential of composites for cations, which deserves further exploration.

Influence of electrode loading mode on preparation in polymer melt electrowriting

LI Haoyi, JIA Zichu, LIU Yuliang, TAN Jing, DING Yumei, YANG Weimin, MU Wenying

Journal of Textile Research. 2023, 44(04):  32-37.  doi:10.13475/j.fzxb.20220303106

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Objective In recent years, melt electrowriting has attracted wide attention in biomedicine, especially in tissue engineering. The loading mode of electrodes in melt electrowriting may effluent the electrostatic distribution thus further effluent the jet deposition controlling. Relatively few studies have been conducted at home or abroad, and the difference in the effect of positive and negative high voltages loading is not completely clear. In this paper, the electric fields under two kinds of high voltage electrostatic loading are simulated, and the specific experiments are analyzed and compared to determine the influence of the two conditions on the performance parameters of melt electrowriting preparation.
Method In order to explore the difference between the positive electrode connection and the reverse electrode connection in the preparation process of melt electrowriting, ANSYS was employed to simulate the magnitude, distribution and direction of the electric field in the spinning area under different high-voltage electrostatic loading. Experimental investigation was conducted to analyze the critical voltage of jet generation, jet velocity, fibers diameter, and fibers deposition accuracy.
Results The simulation and the experimental results confirm each other. In the case of positive electrode connection, the electric field strength at the nozzle is about 14% higher than that of the reverse connection (Fig. 3), the fibers are thinner (Fig. 7), and the jet velocity is faster (Fig. 8). The critical voltage required to generate a jet at the same distance is only 35% to 74% of the reverse connection (Fig. 5). In the case of reverse electrode connection, the electric field strength of the receiving plate is about 35% higher than that of the positive connection (Fig. 3), the distribution of electric field strength is more uniform, and the direction of electric field is more consistent, which is more conducive to improving the stability of the fibers in the electric field,and the fibers deposition deviation is reduced by 35%-51% compared with that in condition positive connection (Tab. 2).
Conclusion Method that high voltage was loaded on the spinning head, enabled higher electric field intensity at the spinning area, which is more conducive to jet generation and tensile refinement, and the use of this method could improve the adaptability of melt electrowriting to materials with high viscosity. Method that high voltage was loaded on the receiving plate, enabled higher electric field intensity near the receiving area, more uniform electric field distribution and smaller component of electric field vector along the horizontal direction near the receiving plate, which could reduce the instability of jet flow and improve the deposition accuracy. These results suggested that we could connect the spinning head and the receiving plate with the opposite high voltages at the same time, taking the advantages of the two electric fields loading modes.

Quantification and evaluation of carbon footprint based on traditional test and electronic test of raw silk

XU Jianmei, PAN Lulu, WU Dongping, BIAN Xing'er, HU Yifeng, DAI Jiayang, WANG Yujing

Journal of Textile Research. 2023, 44(04):  38-45.  doi:10.13475/j.fzxb.20211100808

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Objective In response to our national goal of "achieving a carbon peak by 2030, and carbon neutrality by 2060", the silk industry urgently needs to carry out life cycle assessment, carry out carbon footprint accounting, and guide silk enterprises to conduct energy-saving and emission reduction green production. Although raw silk inspection is a small part of the entire silk product industry chain, it is also an important part. Research on the carbon footprint assessment of this stage is also necessary.
Method The life cycle assessment (LCA) method under the framework of ISO14067 and ISO14040/44 was used to calculate and compare the carbon footprint of the traditional and electronic inspection of raw silk. The primary activity data including the electricity, material and other additive inputs were collected in the most representative silk inspection agency in China. The Monte Carlo method was used to assess the uncertainty of the accounting results through computer simulation.
Results The system boundaries of traditional and electronic raw silk tests were established as shown in Fig. 1 and Fig. 2, where the main inputs for the two testing methods were almost the same with only slight differences in unit processes. The primary activity data of each unit process are collected and recorded, as shown in Tab. 1. The GHG emission factors of different energy and material inputs were listed(Tab. 2). The carbon footprint (CFP) was calculated by multiplying the quantity of the material input and GHG emission factor of the material. The CFP distribution of raw silk inspections consisting of different unit processes, as well as corresponding CFP percentages of different inputs for different inspections(Fig. 3). The results indicate that the proportion of electricity consumption was the largest, followed by gasoline used for transportation, and the electricity consumption was mainly due to the operation of standard atmosphere maintained in the test room. CFP quantification result shows that there are no big differences between the CFPs of the electronic test and traditional inspection, which are 0.233 6 and 0.235 5 kgCO₂e/kg respectively. The difference between the two test methods is mainly the difference between the seriplane test, the cohesion test and the electronic test. The total test time and electricity consumption are basically the same, so the GHG emissions of the two methods are also similar. Greenhouse gas (GHG) emissions mainly come from electricity consumption for maintaining the standard atmosphere in the inspection room. As the winding machine is huge compared with other test devices, the winding tests occupied a larger space in the room with a standard atmosphere, which contributed to 53.07% of the total emissions of the traditional raw silk inspection. Among the three entrusted inspection items, the GHG emissions of the pile test are the highest, reaching 0.014 5 kgCO₂e/kg, and the sericin content test is 0.010 8 kgCO₂e/kg, while the emissions of monofilament tenacity test are small enough to be neglected. The uncertainty analysis shows that the impact of the total weight of each batch of silk on the total emissions is within 3.95% (95% confidence interval). In raw silk inspection, the two unit processes of appearance inspection and weight inspection are conducted on the whole batch of raw silk. Thus the inspectors need to go to the factory to conduct the inspection. Thus, the distance between the inspection center and the factory varies from miles to hundreds of miles. The GHG emissions of the inspector transportation are estimated according to the average distance, and the uncertainty of this estimation was computed using the Monte Carlo method through Visual C++ programming. The uncertainty percentages of this estimation to the total CFPs of the two test methods are 0.41%, and 0.4%.
Conclusion The calculation results showed that the two test methods yielded almost the same results in GHG emissions, and the GHG emissions during raw silk inspection were largely from electricity consumption. Therefore, effective ways to reduce GHG emissions seem to improve the space utilization rate of the standard atmosphere room, increase the inspection batches and control the cooling or heating temperature of the air conditioner. This study established the estimation and allocation methods of primary activity data collected, CFP accounting and the uncertainty analysis method in the process of raw silk inspection, which provided data and a method reference for CFP accounting in the silk industry.

Textile Engineering

Process optimization of novel silk reeling technique

LUO Hailin, SU Jian, JIN Wanhui, FU Yaqin

Journal of Textile Research. 2023, 44(04):  46-54.  doi:10.13475/j.fzxb.20220606009

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Objective To shorten the raw silk process and improve the existing silk reeling techniques onto bobbins, a novel type of silk reeling machine was developed based on the automatic silk reeling machine. The new type of silk reeling machine was equipped with a single thread-controlled winding device and an active overfeeding device with an electromechanical integrated and compact structure. This research was set to investigate the optimization of the process parameters of the novel silk reeling machine and the properties of the raw silk.
Method The process parameters were optimized using the orthogonal analysis method. We selected the winding speed, overfeeding ratio, drying temperature, and oil concentration as test factors, and the breaking strength, breaking elongation rate, and cohesion property of the raw silk prepared by the new silk reeling machine as test indexes. After the optimization, the differences between the raw silk on bobbins prepared by the new silk reeling technique onto bobbins, the raw silk on small reels prepared by the automatic silk reeling machine, and the traditional raw silk on bobbins prepared by processes such as re-reeling, finishing, foaming, winding were investigated.
Results In the optimization experiment of parameters, the winding speed showed a very significant effect on the breaking strength and breaking elongation rate of the raw silk. The overfeeding ratio and drying temperature have a significant or very significant effect on the breaking strength, breaking elongation rate, and cohesion property of the reeled raw silk. However, the oil concentration has no significant effect on the breaking strength and breaking elongation rate of the raw silk. It only has a very significant effect on the cohesion property of the raw silk. For the selected raw material cocoons, when the winding speed is 130 m/min, the overfeed ratio is 1.15, the drying temperature is 90 ℃, and the oiling concentration is 5%, that is, when they are used as the optimal process parameters, the raw silk on bobbins prepared by the new type of silk reeling machine has relatively good breaking strength, breaking elongation rate and cohesion property at the same time. In the comparative experiment of the three kinds of raw silk, the surface morphology of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins is similar to that of the traditional raw silk on bobbins, better than that of the raw silk on small reels. The molecular composition, crystallinity, and other microstructures of the three kinds of raw silk are similar(Fig. 4, Fig. 5). The breaking elongation rate, softness, and other properties of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins are similar to those of the traditional raw silk on bobbins, while the breaking strength and cohesion property of the raw silk on bobbins prepared by the new silk reeling technique onto bobbins are significantly better than those of the traditional raw silk on bobbins.
Conclusion The research provides a practical basis for the development of silk reeling techniques onto bobbins. The raw silk on bobbins prepared by the new silk reeling technology onto bobbins has similar properties to the traditional raw silk on bobbins, which can meet the subsequent weaving needs of raw silk. Moreover, the new silk reeling technique onto bobbins can reduce the raw silk processing process, such as rewinding, finishing, soaking, and other steps, improving production efficiency, reducing production costs, reducing energy consumption, and protecting the environment. Therefore, the new silk reeling technique onto bobbins has a good application prospect.

Fractal-based modeling of whiskers and simulation of drafting process

XIE Penghao, LI Yong, CHEN Xiaochuan, WANG Jun

Journal of Textile Research. 2023, 44(04):  55-62.  doi:10.13475/j.fzxb.20220403708

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Objective In order to analyze and calculate the changes in the drawing force of cotton whiskers and improve the quality of the cotton drawing process, this paper analyzes and researches the drawing force. Using the finite element analysis to calculate the drawing force can greatly simplify the calculation process of the drawing force and improve the efficiency of the drawing process. The drawing force is the most important process parameter in the drawing process of cotton whiskers, and it has an important influence on the final yarn quality of the spinning process.
Method Fractology is an effective method used to describe the structure of irregular objects. Fractal theory is used to construct the complex form of whisker fibers, which can better reflect the structural characteristics of the whisker. Using the relationship between static stretching and dynamic drawing, static stretching is used instead of dynamic drawing to simulate and solve the drawing force. The simulated drawing force is fitted with the experimental data to obtain the fitting equation, which can be used to solve the drawing force.
Results The fractal whisker bar model constructed by the fractal method can better simulate the complex pore structure of cotton whiskers. The fractal graph generation algorithm used in this paper is the iterative function system algorithm (IFS). At the same time, the model uses a fiber bundle to represent the existence of several fibers, and the fiber bundle has a circular cross-sectional structure. ANSYS is used to perform finite element analysis and calculation of the fractal whisker bar model, and the simulation-calculated drawing force is obtained based on the post-processing results. (Tab. 4). The comparison results of the simulated drawing force and the experimental drawing force show that the average error between the static drawing force and the dynamic drawing force of the whisker strip is 5.66%, the maximum relative error is within 12%, and the relative error is within a reasonable range. These prove that the simulated drawing force can better reflect the drawing force in the drawing process to a certain extent. Using curve fitting, the relationship between the experimental drawing force and the simulated drawing force is obtained, and the size of the drawing force of the whiskers under different quantifications is successfully predicted. Under the quantitative 25.60 g/m whisker model, the simulated drawing force of the model under different drawing multiples is analyzed, and it is found that the simulated drawing force reached the critical maximum value when the drawing multiple was about 1.5, and then the drawing force decreased rapidly with the increase of the drawing multiple. The curve of the simulated drawing force with the multiple of drawing is also basically the same as the experimental curve. Finally, the comparison between the simulation results of the drawing force and the experimental data shows that the fractal whisker bar model can effectively solve the drawing force, and the model is reasonable.
Conclusion In this paper, the fractal method is used to construct a cotton whisker strip model, which provides a new idea for the three-dimensional modeling of the whisker strip. The fractal model can reflect the nonlinear structure of the whisker strip. The use of finite element simulation to solve the drawing force of the whisker strip can greatly improve the efficiency of solving the drawing force and save manpower and material resources. The simulation results of the drawing force of the whisker strip show the effectiveness of the fractal whisker strip model. The relationship between the simulated drawing force and the experimental drawing force can be used to predict the size of the drawing force and to pre-calculate the drawing force, which provides a reference for the setting of the drawing force in spinning. The curve of the simulated drawing force on the drawing multiple also proves the rationality of the fractal whisker model.

Model analysis on structure of ring spun Sirofil wrapped yarn and its property optimization

LIU Shuai, GUO Chenyu, CHEN Hewen, YANG Ruihua

Journal of Textile Research. 2023, 44(04):  63-69.  doi:10.13475/j.fzxb.20211200707

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Objective Compared with the traditional ring spinning, Sirofil two-component yarn possesses higher strength and smoother surface. In order to optimize the performance of Sirofil wrapped yarn, including hairiness, evenness and strength, the influence of the relative position and spacing distance of filament and staple strand on the yarn properties was explored. Additionally, the combination of theoretical modeling and experiment were employed to quantitatively analyse and predict the performance of ring spun Sirofil wrapped yarn in practical manufacturing.
Method To analyze the twisting process and characteristics of the Sirofil wrapped yarn, the numerical analysis of the twisting triangle were carried out, and the model is established based on the geometric relationship of filament and staple strand in the twisting triangle and the force analysis of the twisting triangle. The hairiness, evenness and strength of sirofil wrapped yarn were tested by experiments, the results of which were used to validate the model.
Results The relationship between the offset distance of the centroid of the Sirofil wrapped yarn relative to the spindle axis and the yarn twisting angle in the triangle area was deduced and the equation for calculating the quality of half twisted yarn was established. In accordance with the force analysis of the twisting triangle, the moment balance equation was attained and the twist transfer rule of Z-twisting yarn was explained. The analysis results showed that with the increase of the distance, the offset distance of the centroid of the twisting triangle relative to the spindle axis was increased, and the twist angle of the staple strand was decreased(Tab. 3). Therefore, the slippage length of the staple fibers became longer and the proportion of the strength of the short fiber bundles in the axial direction of the yarn got larger, making greater contribution of the fiber to the yarn strength leading to improved yarn strength. Torque contributed by filament and staple strand shows that the twist angle of the filament was smaller than that of the staple strand, and the proportion of the torque in the axial direction of the yarn was larger(Tab. 4). Therefore, the filament is regarded as the main contributor to the strength of the Sirofil wrapped yarn. Furthermore, when the filament position was on the right, the staple strand would obtain a larger number of twists with better wrapping effect which is conducive to enhance the yarn quality. Through the comparison of 3 mm, 4 mm and 5 mm spacing distances, it was seen that 5 mm was the best spacing distance between filament and staple strand of Sirofil wrapped yarn. It is evident that the experimental results showed good consistency with the conclusion of model analysis(Fig. 5).
Conclusion In this paper, the force model of twisting triangle zone is established based on results from mechanical analysis and experimental investigation, and the influence of the relative position and distance between filament and staple fiber on the yarn properties is studied. The calculation and verification results show that the larger the yarn centroid offset distance is, the smaller the twist return angle is, and the twist direction above the convergence point is the same as the real twist direction below the convergence point. The twist of the staple filament is greater when it is on the left side of the filament. The model provides theoretical and experimental guidance for practical quantitative analysis and process design.

Feature extraction method for ring-spun-yarn evenness online detection based on visual calibration

TAO Jing, WANG Junliang, XU Chuqiao, ZHANG Jie

Journal of Textile Research. 2023, 44(04):  70-77.  doi:10.13475/j.fzxb.20211111008

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Objective The appearance quality of yarn is directly related to its mechanical properties and even economic value. However, manual inspection is still the dominant method in most factories, which are lagging and subjective. Based on machine vision and other emerging technology, in the ring spinning yarn production process of online detection of fine yarn evenness, hairiness and other indicators, so as to drive the classification of yarn drop and other emerging industry, has important theoretical significance and engineering value.
Method Accurate contour extraction during online visual inspection of ring spun yarn is difficult because of high speed yarn rotation and interweaving of the hairiness. To solve this problem, a method that fused deep-learning with morphological operations is proposed. Firstly, an online image acquisition system and focusing method are designed to provide high quality input for contour feature extraction; Secondly, a model based on holistically-nested edge detection(HED) neural network and morphological operations is constructed to achieve accurate online contour extraction under the interference of hairiness.
Results The camera was deployed to acquire 1 600 images of the yarn, whose resolution is 2 448 pixel×2 048 pixel, to calculate the optimal focal plane with the acquisition parameters. Compared with the images acquired under other focal plane parameters, the images acquired under the calculated focal plane parameters are of higher quality, which obviously improves the accuracy of contour extraction. 500 images of yarn were collected using the calibrated image acquisition system and processed with the proposed contour extraction method and other SOTA(state of the art) methods. The proposed method achieves OIS-F (optimal image scale), ODS-F (Optimal Dataset scale) of 0.91 and AP (average precision) of 0.89, which is more than 7% better than the current method. From the visual comparison results, it can be seen that the proposed method is based on the output of HED network, combined with morphological operations to remove the interference of hairiness and fiber texture, and reconstruct the yarn stem contour based on Cubic spline interpolation with good consistency. Finally, the extracted yarn contours were further processed using the proposed reconstruction method to calculate the CV value of yarn unevenness. In this paper, five groups of image data collected from different groups are processed using the proposed algorithm (experiments are performed using a Tesla V100 with 32 GB video memory GPU) to calculate the CV values for each group of 4 000 images. The average processing speed is about 24 frame/s, higher than the current experimental maximum image acquisition frequency of 20 frame/s. As shown in Fig. 6, the calculated results were compared with those of the laboratory high-precision electronic yarn evenness tester (CT3000), with an average error of less than 4% and a minimum accuracy of 92% and a maximum of 99% for a single group of tube yarn measurements.
Conclusion The image acquisition system calibration method improves the quality of the acquired data and facilitates the processing of subsequent algorithms. The designed deep learning and morphological operations fusion method for the extraction and reconstruction of yarn evenness effectively removes the interference of hairiness and improves the accuracy of the calculated CV values. In terms of processing speed, the proposed method can meet the current demand of online detection. And from the comparison results of the CV value of yarn unevenness, the detection accuracy also reaches the standard of practical application. The good application of the proposed method in the online detection of ring-spun-yarn evenness has been verified and the hardware system design as well as algorithm optimization can be further investigated for different application scenarios.

Influence of starting point setting of triple-weft compound structure on woven fabric color display

HU Yili, ZHOU Jiu

Journal of Textile Research. 2023, 44(04):  78-85.  doi:10.13475/j.fzxb.20211101408

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Objective The setting of starting point position in combination of three full-color basic weaves forms the basis of the full-color weave database, and the diversified basic weaves starting point position setting methods affect the design of the entire shaded-weave database with full-color weaves, thereby affecting the color rendering effect of the fabric. In order to explore the internal law of the setting of starting point position in combination of three basic full-color weaves on color rendering effect of fabric, different starting point positions were used to design the combination of three basic weaves with full-color weaves, and the characteristics of color development of the structure were studied.
Method Using a 16-end 3-step number sateen weave as the basic weave, 4 different positional relationship of basic weaves starting point position were set to design the combination of three basic full-color weaves, and 4 groups of shaded-weave database were formed with the combination of three basic full-color weaves. Color card design and weaving and color measurement analysis were carried out to obtain color data. The fabric was measured by the Color i7 spectrophotometer to obtain the color data for structural color development, and the uniformity of the gradient color was obtained by comparing the variance of chromatic difference. In addition, by comparing the relationship between the weave and the fabric structure on the surface of the fabric, the reason for the sudden change in color development of the fabric surface was obtained.
Results Through the comparative analysis of color rendering characteristics, the results showed that the fabric gradient color rendering transition with uneven distribution at the combination of three basic weaves starting point position produces polarization, and the fabric with uniform distribution at the base weaves start point has a more uniform fabric gradient color rendering effect(Fig. 8). Based on the color data of four groups of samples collected by color measurement, the color difference formula was used to calculate the color difference of each adjacent two pieces of fabrics with different base weaves starting point positions in the four groups, and it was obtained that the combination of three basic weaves with evenly distributed starting point position settings had the smallest color difference value and the gradient color rendering transition was the best(Tab. 1). The analysis of fabric surface texture and fabric brightness value revealed that the full-color weaves of the combination of three basic weaves with evenly distributed of the starting point position showed small variation in fabric brightness(Tab. 2) and increase oblique obviousness of the texture in the area with large fabric brightness(Fig. 9). Finally, by comparing the color relationship of the fabric and the surface texture effect, it is concluded that the position setting of the starting point in the full-color weaves of the combination of three basic weaves will affect the position change of the floating length of the color weft, which not only affects the saturation of the fabric color and the obviousness of the texture oblique, but also the root cause of the color mutation(Fig. 11).
Conclusion In this paper, the basic principle of the starting point position setting affecting the color rendering of the combined full-color weaves is analyzed, and the method of optimizing the starting point position of the full-color weaves of the combination of three basic weaves is proposed, and the effectiveness of the optimization design method on the gradient color rendering effect of the fabric is verified by experiments, and the following conclusions are drawn through research: 1) In the three basic weave combined full-color weaves, the position setting of the starting point of the basic weaves will affect the position relationship between the color developing weft in the combined full-color weaves, and finally affect the gradient color rendering effect of the fabric. Synchronization will produce different accumulation of warp lengths, forming a clear texture oblique direction, which affects the color saturation of the fabric structure. 2) Under the method of increasing the point in the unified direction, the more uniform the distribution of the starting point position of the basic tissue, the more uniform the color mixing transition of the color development weft, and the optimal gradient color rendering effect. The results of this research provide a technical reference for the digital optimization design of the combination of three basic weaves with full-color weaves jacquard fabrics.

Design and structure optimization of warp knitted unidirectional moisture conducting fabrics

YIN Ang, CONG Honglian

Journal of Textile Research. 2023, 44(04):  86-91.  doi:10.13475/j.fzxb.20211008006

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Objective This research is carried out in order to explore the influence of warp knitting structure and raw material configuration on the wet performance of fabrics.
Method This paper took differential capillary effect as the design principle, 5.6 tex (14 f)tex polyester, 8.3 tex (288 f)polyester, 9.7 tex cotton, 4.5 tex spandex as raw materials, and 8 sample fabrics were made on the HKS4EL knitting machine, with manufacturing specifications E28, width 1 066 mm, knitting machine speed is 550 r/min. In terms of structure, four warp structures were designed, GB1 used warp velvet structure and warp flat tissue, and GB2 used warp structure and warp satin tissue to form four structural configurations.
Results Water absorption rate shows that the lowest water content of the eight samples was higher than the top for most of the time in 120 s. The timely transfer of the liquid from the inside to the outside of the fabric reflects the better unidirectional conductive ability of the fabric. Moisture time shows that the wetting time at the top of the eight samples was greater than that at the bottom, which shows that the inner layer of the fabric can remain dry for a long time. It can be seen in the water absorption rate at the top of the samples is higher than that at the bottom(Fig. 5). The maximum wetting radius and propagation speed of the top of the fabric are basically greater than those at the bottom of the fabric(Fig. 6, Fig. 7), which reflects the fabric's good single-guide wet ability. In general, the maximum wetting radius and propagation speed of the fabric are affected by the fabric structure, fabric thickness and yarn type and the cumulative one-way transport index reflects how easily liquid wets in a fabric. The highest index of f6 of the eight types of fabrics, the maximum wetting radius and propagation speed of f6 were significantly higher than those in the other samples(Fig. 8). This is due to the relatively loose fabric structure used in the f6, The gap between the yarn is relatively large, and the line density of the two yarn materials used can form a poor capillary effect, it allows the liquid to quickly transmit to the outer layer; the overall water management capability of the fabric is shown in Fig. 9, the results fluctuate between 0.2 and 1.0. The overall water management capacity of f1, f3 and f5 is higher than that of f2, f4 and f8, which indicates that the inner layer is better than the satin structure, and the less the number of the fabric inner layer is beneficial to enhance the wet performance of the single guide.
Conclusion Through the comparison and evaluation of 8 samples, it is found that the factors affecting the wet performance are the difference of the inner and outer yarn, the yarn density difference, and the structure and thickness of the fabric. In different raw material configurations, although the sample containing cotton yarn has good wetting time and absorption rate, its low wetting time difference, maximum wetting radius and diffusion speed will affect the comfort of the fabric to the human body, the fabric containing spandex will increase the tightness of its fabric, and the overall water management ability is reduced by about 10% under the same structure. In the configuration of different structures, it can be found that the overall water management performance of the inner layer is better than the inner layer using the satin tissue, which reduces the obstruction of moisture transport, and enhances the conduction of water in the fabric. Among all samples, the outer layer is closed horizontal tissue, and the inner layer is open horizontal tissue, the wet performance of single guide is best.

Analysis on pore characteristics of braided geotextiles based on topological sorting method

TANG Xiaowu, LI Keyi, ZHAO Wenfang, CHEN Shihua, LIN Weikang, LIANG Jiaxing

Journal of Textile Research. 2023, 44(04):  92-99.  doi:10.13475/j.fzxb.20211110108

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Objective It is evident that the traditional digital image methods are prone to errors in sorting pores in braided geotextiles. Current studies have used statistical methods to analyze pore changes, which do not allow the morphological and dimensional changes of each pore to be traced during the tensioning process. The method of characterizing the pores in braided geotextiles is investigated to address this problem.
Method Topological sorting was used to correct the sorting error of braided geotextiles digital image method, and then the area, length, and width of each pore were accurately obtained based on pixel statistics and minimum area bounding rectangle (MABR). Finally, the sorting results of the digital image method and topological image method, three-dimensional area distribution, and length-width statistics diagram are compared.
Results The error rate associated with the digital image method for braided geotextiles in the initial state was found to be the highest, at 19.5% (Fig. 7), and it can be seen that the error rate of the digital image method for all three geotextiles gradually decreases with increased strain. The digital image method was found to produce errors in the ordering of the geotextile pores, which would have an impact on the subsequent experimental analysis and processing, and would not truly reflect the changes in the pore parameters of the braided geotextile during the stretching process. The improved image sorting method based on topological sorting can correct the sorting errors of the digital image method for geotextiles with different masses and tensile strains per unit area, thus achieving accurate acquisition of the sorting of geotextile pores.
The topological image method was used to correct the area of the upper ten pores in the first column on the left side of W₁₅₀(Fig. 6). The area of the pore obtained by the digital image method under different tensile strains was corrected, and accurate tracking of the area was achieved.
The three-dimensional distribution of the area is plotted according to the location and area of each pore in W₁₅₀, with the X and Y coordinates representing the location of the pores and the Z axis representing the area of the pores(Fig. 8), which depicts the distribution of pore area and its variation with strain over a large area range. It is shown that the improved image method based on the topological principle can improve the accuracy of the pole area acquisition results and enable large-scale tracking of geotextile pore areas.
The effectiveness of the topographic image method for tracking the length and width of geotextile pores over a wide area is verified(Fig. 11). As the geotextile stretches, it causes some of the pores to tilt or come back into alignment. The improved image method based on the topological principle can identify and locate pores in woven geotextiles at any angle and accurately track the length and width of pores on a large scale.
Conclusion 1) Comparison of the sorting results of the digital image method and the improved image method based on topological sorting shows that topological sorting can correct the sorting errors of the digital image method for geotextiles with different unit area masses and tensile strains to obtain the sorting of geotextile pores accurately. 2) The area correction of geotextile pores and the three-dimensional distribution of the area show that the topological image method can visually reflect the distribution of pore areas and their variation with strain over a large area of geotextile and achieve large-scale accurate tracking of geotextile pore areas. 3) The comparison of the area of each pore and the geotextile length and width statistics chart shows that the MABR method can improve the accuracy of the pore length and width acquisition, and based on this method, the topological image method can accurately acquire and track the changes of pore length and width from any angle on a large scale.

A method for improving mechanical properties of needled fabrics based on synergy of pre-needling and main needling

CHEN Xiaoming, REN Zhipeng, ZHENG Hongwei, WU Kaijie, SU Xingzhao, CHEN Li

Journal of Textile Research. 2023, 44(04):  100-107.  doi:10.13475/j.fzxb.20220505908

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Objective The purpose of this paper was to study a needling process, proposed the concept of needling prefabricated holes and the synergistic needling method of prefabrication and needling, and strengthened the connection of needled bundles through the synergistic method of pre-needling and main needling, while reducing the needled on the fabric surface. The damage of the inner fibers could improve the interlaminar peeling performance and the in-plane tensile performance of the needled fabric at the same time, which provided a new idea and method for the preparation of high-performance needled fabrics.
Method In this paper, carbon fiber non woven fabric and carbon fiber felt were used to prepare needled preforms in the form of carbon cloth/felt lamination. Under the same conditions, traditional needled fabrics and pre-needling and main needling synergistic needled fabrics were prepared using the traditional needling process and the pre-needling and main needling synergistic process. The mechanical properties of the two fabrics were characterized through a series of experiments, and the strengthening principle of the pre-needling and main needling synergistic process was revealed.
Results In the pre-needling and main needling synergistic process, pre-needling formed prefabricated holes, and the main needling was in situ needled at the pre-needling point. The synergistic effect of the two played a role in strengthening interlaminar connection and reducing in-plane fiber damage. The interlaminar peeling properties of the two were characterized by performing the interlaminar peeling experiment on the prepared needled fabrics. The interlaminar peeling property of the latter under different total needling densities were improved by 56.16%-58.46% compared with the former(Fig. 6). The 3-D profiler was used to observe the fiber bundle morphology on the interlaminar peeling surface, and the fiber bundle volume was counted. It could be seen from interlaminar peeled fabric that the pre-needling and main needling synergistic process had less shearing of the inner fibers, and less and larger needling holes were formed. The needled fabric bundles of the pre-needling and main needling synergistic needled fabric were thicker and longer and the distribution were sparse; the needled fabric bundles of the traditional needled fabric were shorter and thinner, but the distribution were denser. Compared with the traditional needled fabrics, the maximum fiber bundle volume of the interlaminar peeling observation surface of the synergistic needled fabrics increased by 349.1%-445.1%, and the total fiber bundle volume increased by 63.1%-93.2%(Fig. 9). Therefore, it could be seen that the pre/main pre-needling and main needling synergistic process increases the needled fiber bundles brought in during the main needling process and reduced the damage to the fibers in the face through the pre-needling to form the needled prefabricated holes, and improved the interlaminar of the needled fabrics peel performance. Then, tensile experiments were performed on each layer of carbon cloth of the needled fabrics to characterize the in-plane tensile property. It could be seen that the in-plane tensile strength of the pre-needling and main needling synergistic needled fabrics was 8.8%-15.7% higher than that of the traditional needled fabrics. According to the previous analysis, synergistic needled fabrics could improve the in-plane tensile property of the fabric by reducing the shear damage of the in-plane fibers.
Conclusion The new synergistic process of pre-needling and main needling significantly improved the interlaminar peeling performance of needled fabrics. For the needled preforms prepared with different total needling densities, the interlaminar peeling strength of the synergistic needling process increased by 56.16%-58.46% compared with the traditional needled fabric; the transferred in-plane fiber content increased by 63.1%-93.1%, this was because the pre needling process generated pre-fabricated holes, which was beneficial to the subsequent main needling process to bring more short fibers into the thickness direction to form needled fabric bundles. The in-plane tensile property of the synergistic needled fabricss were improved by 8.8%-15.7%. This was because the synergistic needling process adopted the idea of halving the needling density, doubling the number of times of needling, and in-situ needling, which effectively reduced the area of the damaged area of needling and improved in-plane tensile strength of needled fabrics.

Dyeing and Finishing & Chemicals

Bioremediation dyeing of keratin hair fibers with dopamine hydrochloride catalyzed by laccase

JIA Weini, WANG Tao, BAO Jie, LIANG Zhijie, WANG Haifeng

Journal of Textile Research. 2023, 44(04):  108-114.  doi:10.13475/j.fzxb.20211108707

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Objective In order to solve the problems of keratin hair fibers damage and allergy caused by the oxidant and keratin hair colorants in the current routine of keratin hair fibers dyeing process, the keratin hair fibers were dyed in situ by laccase catalyzed polymerization of dopamine hydrochloride to achieve blackening effect, accompanied by ecological restoration, health and fastness features.
Method The in-situ dyeing process was performed in one step with 2.5 g/L dopamine hydrochloride, 0.9 U/mL laccase at 50 ℃ for 4 h. Factors, such as reaction time, temperature and laccase concentration, were investigated on the influence on determining the binding of pigment molecule to keratin hair fibers. Besides, the structure and properties of the dyed keratin hair fibers were characterized and analyzed by color parameter, single fiber strength, Fourier-transform infrared spectroscopy, scanning electron microscope, anti-UV and color fastness test.
Results To understand the effect of pre-bleaching on keratin hair fibers coloring, the untreated natural white keratin hair fibers and white keratin hair fibers pretreated with hydrogen peroxide were dyed (Fig. 5, Fig. 6). After the pre-processing, more binding points were exposed to facilitate the penetration of the pigment formed in the in-situ dyeing process into the keratin hair fibers, reaching a darker color and good fastness. The results of SEM and K/S value as well as color fastness showed that the dyeing process was more suitable to the pretreated white keratin hair fibers, owing to the weaken cuticle layer of pretreated white keratin hair fibers. After dyeing, the cuticle layer of the keratin hair fibers was not clear, attributing to the uniform and dense polydopamine coating formed by a reaction catalyzed by laccase covering on the surface of the keratin hair fibers (Fig. 7). Comparing to the IR spectra of keratin hair fibers before dyeing (Fig. 8), fibers after dyeing showed a broad peak at 3 273 cm^-1, indicating that there were polydopamine pigments on the surface of keratin hair fibers. Peaks at 1 634 and 2 921 cm^-1 could be ascribed to the stretching vibration of C=O and C—H, revealing that the coupling reaction occurred between benzene ring carbon radicals. On the other hand, the K/S value of keratin hair fibers after dyeing reached to 22.1, while the K/S value is 21.7 after treated with DMF. The slight variation indicated pigment combines with keratin hair fibers by covalent bonds. Therefore, the color fastness on rubbing stress under dry and wet conditions were very well and reached 4 and 3-4, respectively. The color fastness on washing can reaches 4-5. Besides, owing to the formation of polydopamine on the surface of the keratin hair fibers, the dyed keratin hair fibers exhibited excellent anti-ultraviolet property (UPF: 100⁺, Fig. 9). In addition, in order to test the mechanical robustness, the tensile strengths of non-dyed and dyed keratin hair fibers were reported with a 7.8 % increase, which results from the generation of polydopamine pigment. It is clear that the pigment plays a certain role in repairing the damaged spots of the bleached keratin hair fibers, further improving the strength of keratin hair fibers.
Conclusion Laccase was chosen to be a catalyst for the oxidative polymerization of dopamine hydrochloride to produce polymeric colorants for the dyeing of keratin fibers and shows a dark black color. The colored keratin hair fibers were characterized fully. Besides, the dyed keratin hair fibers exhibits excellent anti-ultraviolet property, color fastness on rubbing stress and washing, which can be attributed to the polydopamine coating and the strong covalent binding between polydopamine and keratin hair fibers. It is important to note that the dyed keratin hair fibers undergoing chemical modification remains the natural physical feature. The proposed eco-friendly enzymatic polymerization provides an efficient and green strategy for biological dyeing of keratin hair fibers. These good characteristics make the dyeing strategy a promising candidate for textile dyeing and even other field. Therefore, this study could lead to the successful development of biologically dyed materials with multiple functions.

Dyeing and Finishing & Chemicals

Preparation and properties of self-dispersed nanoscale carbon black for in-situ polymerization of spun-dyed polyester fiber

SONG Weiguang, WANG Dong, DU Changsen, LIANG Dong, FU Shaohai

Journal of Textile Research. 2023, 44(04):  115-123.  doi:10.13475/j.fzxb.20220201209

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Objective The traditional polyester fiber spun-dyed mostly uses in-situ polymerization method to prepare high-performance colored polyester chips, where the carbon black grinding is dispersed in the ethylene glycol, and the carbon black ethylene glycol color paste is applied to the in-situ polymerization of polyester. However, conventional carbon black ethylene glycol color paste have poor storage stability and high transportation cost. In view of this problem, this study uses spray drying method to make self-dispersed nanoscale carbon black, aiming to effectively decrease transportation cost and improve the storage stability of carbon black in ethylene glycol.
Method In this study, nanoscale carbon black paste was prepared into self-dispersed nanoscale carbon black by a spray-drying method. The effects of carbon black, dispersant and dispersion process on self-dispersed nanoscale carbon black were parametrically studied. The effects of mass fraction of dispersant, grinding time and grinding speed on the particle size of self-dispersed nanoscale carbon black were discussed based on the response surface optimization experiment in order to obtain the optimal grinding and dispersion conditions. In addition, transmission electron microscope (TEM), thermogravimetric analysis (TGA) and contact angle meter were employed to study the apparent morphology, heat resistance and hydrophilicity.
Results Parametrical study was carried out to investigate the influence of dispersant and carbon black on the particle size of self-dispersed nanoscale carbon black. When the dispersant SUA-305 and the carbon black AP-104H were selected, the particle size of self-dispersed nanoscale carbon black was found to be the smallest (Fig. 2). The same method was used to study the influence of process conditions on the particle size and PDI (polydispersity index) of self-dispersed nanoscale carbon black. When the mass fraction of dispersant was 30%, the grinding time was 2 h, and the grinding speed was 3 500 r/min, the minimum particle sizes of self-dispersed nanoscale carbon black was 85 nm, and the minimum PDI was 0.163 (Fig. 3). The response surface was used to optimize the experiment, and the particle size was taken as the response value to further optimize the experimental results. The F-value in the model was 23.98 and the P-value was 0.000 2(Tab. 1). The minimum particle size of self-dispersed nanoscale carbon black were found on the three groups of response surfaces, and there were extreme values in the contour map, which were consistent with each other (Fig. 4). In order to determine the feasibility of the test, five groups of validation tests were conducted on the response surface model. The normalized deviation was 2.92%, and the normalized standard deviation was 1.544% (Tab. 2). The optimum process parameters were identified to be as follows: the mass fraction of dispersant is 30%, the grinding time is 2 h, and the grinding speed is 3 500 r/min. The original carbon black has a large particle size of 15.007 μm (Fig. 5). In comparison, the particle size of self-dispersed nanoscale carbon black is 0.085 μm, the contact angle between the original carbon black and ethylene glycol is 147°, and the contact angle between the ethylene glycol of self-dispersed nanoscale carbon black is 7° (Fig. 6). The original carbon black shows multiple agglomerations, and the self-dispersed nanoscale carbon black particles are small and evenly distributed. In Fig. 8, the self-dispersed nanoscale carbon black meets the requirement of decomposition resistant at 280 ℃ (Fig. 7). The self-dispersed nanoscale carbon black ethylene glycol color paste was centrifuged for 19 h at 4 000 r/min, its color paste sedimentation rate is 0.772 %/h, and the estimated storage period is 26.8 months (Fig. 9).
Conclusion This study evaluated the influence of five factors (dispersant, carbon black, dispersant mass fraction, and grinding time, grinding speed) on the particle size of self-dispersed nanoscale carbon black. Response surface methodology was used to optimize the three factors (mass fraction of dispersant, grinding time and grinding speed) in the preparation process of self-dispersed nanoscale carbon black. The variance analysis results of the optimization process show that the regression model is significant, which indicates that the reliability of the response surface model fitting equation is high, and the best process obtained from this model is feasible. Under the technological conditions that the mass fraction of dispersant is 30%, and the grinding time is 2 h, and the grinding speed is 3 500 r/min, the minimum particle size of self-dispersed nanoscale carbon black is 85 nm. The self-dispersed nanoscale carbon black demonstrates good hydrophilicity, good self-dispersion in ethylene glycol solution, and good heat resistance, meeting the preparation requirements of in-situ polymerization polyester fiber chips. The self-dispersed nanoscale carbon black ethylene glycol color paste has good storage stability with an estimated storage period of 26.8 months under the simulated natural sedimentation conditions.

Preparation and waterproof properties of fluorine-free polyacrylate latex composites

LIU Xinyu, LI Jianhao, WANG Zhen, SHEN Junyan, YANG Lei

Journal of Textile Research. 2023, 44(04):  124-131.  doi:10.13475/j.fzxb.20220202508

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Objective Textiles with water repellent function have attracted great attention. At present, the water repellent function is generally achieved by finishing textiles with fluorine-containing chemical agents, but this technique was deemed to cause biological toxicity problems. It research aims to investigate environment-friendly fluorine-free water repellent agent for textiles coating.
Method Two types of stearyl acrylate (SA) copolymer latex (PSA) were prepared by mini-emulsion polymerization of SA with ethyl hexyl acrylate (2-EHA) and cyclohexyl methacrylate (TMCHMA), respectively. These two types of latex were used for fluorine-free waterproof finishing of fabrics. The morphologies of composite latex films were investigated by atomic force microscope. The effects of composite ratio and dosage on the surface structures and waterproof performances of the finished fabrics were studied.
Results To start with, the PSA latex were spin-coated onto glass sildes, and followed by baking at 170 ℃ for 90 s. A relatively smooth surface was observed for latex prepared by copolymerization of SA and 2-EHA, with root mean square roughness (R_q) of only 5.0 nm (Fig. 2) and contact angle(WCA) of 88°. Submicron bulges appeared on the surface of composite latex films containing PSAh obtained by the copolymerization of SA and TMCHMA. Furthermore, with the growth of PSAh fraction, R_q of latex film increased accordingly and attained 13.8 nm as PSAh mass fraction increased to 100%. It led to the water contact angle increasing to 110.0° (Fig. 3). During fabric finishing, the dosage of PSAs-PSAh composite latex was kept at 20 g/L. By adjusting the proportion of composite latex, the contact angle of finished Oxford fabric reached a maximum of 144.8° at the PSAh mass fraction of 40% (Fig. 5). Then, Oxford fabric was replaced by Chun-Ya-Fang with high waving density. When the mass fraction of PSAh in the composite latex is 80%, the water contact angle (WCA) of finished Chun-Ya-Fang reached a maximum value of 152° (Fig. 6). When the dosage of composite latex is increased to 30 g/ L, the WCA of Oxford fabric after finishing were further increased and maintained to be higher than 150° (Fig. 6). The water repellent efficiency of composite latex was higher than either PSAs or PSAh. When attaining the same WCA, the dosage of finishing agent made of solo PSAh was 1.7 times of that of composite latex (Fig. 7). In addition, the composite latex-finished fabric exhibited improved performance of abrasion resistance. After 50 times of abrasion, the static water contact angle of the composite latex-finished fabric retained 148° (Tab. 2). The composite latex-finished fabric exhibited Grade 5 water repellency (Tab. 3) and excellent air permeability (Tab. 4).Conclusion The results showed that the copolymerization of SA and 2-EHA improved the latex film forming capacity, while the introduction of TMCHMA enhanced the shape retention of latex. After the two types of latex were compounded, a micro-nano hydrophobic structure was formed on the surfaces of the finished fabrics, and the waterproof performance of the finished fabrics were significantly improved. The maximum static contact angle reached 152°, and the waterproof grade attained Grade 5. After 50 times of wear resistance tests, the finished fabrics still retained good hydrophobic performance. In addition, the fabric structure exerted a great impact on the water repellency, so the composition of auxiliaries or finishing process should be adjusted during finishing: increasing the amount of auxiliaries, especially the content of PSAh, would improve the water repellency performance. At the same dosage of finishing agent, the best water repellency of fabrics with dense waving structure was generally found at high percentage of PSAh, contrasting that of fabrics with loose structure.

Preparation and properties of functional cotton knitwear modified by two-dimensional titanium carbide

GE Jiahui, MAO Zhiping, ZHANG Linping, ZHONG Yi, SUI Xiaofeng, XU Hong

Journal of Textile Research. 2023, 44(04):  132-138.  doi:10.13475/j.fzxb.20211003207

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Objective Through preparation of conductive cotton fabrics with washable properties and application of two-dimensional titanium carbide to cotton fabrics, this research aims to obtain conductive cotton fabrics with a new method.
Method By cationic modification of cotton fabric, two-dimensional nanomaterial Ti₃C₂T_x was adsorbed on the surface of cationic cotton fabric to obtain new conductive cotton fabrics. The morphologies and elements of cotton knitted products before and after cationic modification and Ti₃C₂T_x loading were analyzed by X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The surface resistance of conductive cotton fabric was tested by using RTS-9 four probes, and the cationic modification technology and adsorption conditions of Ti₃C₂T_x were optimized, so as to obtain the optimal scheme.
Results Ti₃AlC₂ is a three-dimensional solid, and the product after etching by hydrofluoric acid becomes a two-dimensional nanomaterial. This conclusion has been confirmed in the electron microscopy (Fig. 1), and it is also confirmed that the etched material contains F, O and other groups (Fig. 2), making the two-dimensional material negatively charged. Cationic modifier is a polymer nitrogen-containing compound. After cationic modification, the surface of cotton knitted fabric is grafted with positive amino group (Fig. 3). After ultrasonic treatment with Ti₃C₂T_x, there are Ti, F, O and other groups on the surface of the fabric, which proves that Ti₃C₂T_x is successfully loaded on the surface of the fabric (Fig. 4). Following the experimental design (Tab. 1), the optimal processing conditions are that the cationic modifier is 10% o.w.f(Fig. 6), the concentration of sodium hydroxide is 10 g/L (Fig. 5), the modification time is 30 min, and the ultrasonic time of Ti₃C₂T_x is 60 min (Fig. 8). Under optimized conditions, the surface resistance of cationic modified cotton knitted material loaded with Ti₃C₂T_x can be as low as 84.5 Ω/□. After 20 times of washing, the surface resistance of conductive cotton knitted material increases from 84.5 Ω/□ to 95.6 Ω/□, still below 100 Ω/□ (Fig. 9).
Conclusion This paper provides a method for fabric-loaded Ti₃C₂T_x nanosheets for fabric-based flexibility with excellent preparative properties. After cationic modification of cotton fabric, conductive nanosheets are applied to the fabric by adsorption. The composite cotton fabric has good electrical conductivity. The conductive fabric obtained by this method is simple and has excellent electrical conductivity textiles offer new ideas, and Ti₃C₂T_x/cation-modified cotton knitted fabrics can still maintain certain conductivity after washing for many times, but there are still many shortcomings and unsolved problems. For example, the preparation of Ti₃C₂T_x/cation modified cotton knitted fabric has good water resistance, but composites conductivity needs to be improved. Subsequent experiments can further explore the use of other cationic modifiers for comparison, or use adhesives to attach nanosheets to fabrics to observe whether the conductivity of composite materials is improved, and the application of nanomaterials in fabrics can be expanded by trying other fabrics.

Preparation of carbonized three-dimensional spacer cotton fabric and its electrical heating properties

HUANG Jinbo, SHAO Lingda, ZHU Chengyan

Journal of Textile Research. 2023, 44(04):  139-145.  doi:10.13475/j.fzxb.20211108407

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Objective In order to develop functional textiles used in piezoresistive sensing and electric heating, the effects of different carbonization processes on the conductivity and electric heating properties of cotton fabrics were studied.
Method Using cotton fiber as the raw material, a three-dimensional spacer fabric was prepared using a double-shed weaving machine. The fabric was then carbonized to achieve the conductive and heating properties. The fiber structure in the carbonized cotton fabric was characterized by scanning electron microscopy, Fourier infrared spectroscopy and Raman spectroscopy. The conductivity and electric heating performance of the fabric were characterized by multimeter and infrared thermal imager, and their internal relations were analyzed.
Results The fabric can be carbonized by high temperature inert gas (N₂)(Fig. 3). In the carbonization process, with the increase of carbonization temperature, the fiber scale layer structure was obvious seen, and the fiber surface structure became more porous. When the carbonization temperature of the fabric was set to 900 ℃, obvious punctate broken holes appeared on the fiber surface, and carbon particles falling off were observed. By analyzing the conductivity of the fabric, it was found that the resistance of the carbonized fabric decreased with the increase of carbonization temperature. The resistance of the charred fabric gradually increases with increasing measurement distance, the fabric resistance is linearly related to the plane distance and can be seen as similar to a uniform resistance. At a lower carbonization temperature or a higher current, the heating performance of the carbonized fabric is better, but there will be a lot of heat radiation and air heat exchange during the heating process of the fabric. The actual temperature rise curve of the fabric does not agree with the theoretical calculation of electric power(Fig. 8). The carbonized fabric was found to be heated and cooled fastest at 750 ℃. When the heating temperature of the carbonized fabric was lower than 62.4 ℃, the heating temperature of the fabric demonstrated proportional increases to the value of the theoretical electric power(Fig. 11). In the case where the heating temperature was higher than this temperature, the theoretical power of the fabric was significantly lower than the temperature of the fabric.
Conclusion The three-dimensional space carbonized cotton fabric demonstrated good electrical conductivity and it can be regarded as a uniform resistance medium, and the resistance rate decreases exponentially with the increase of carbonization temperature. At lower carbonization temperature, the change rate of resistance is larger, and with the increase of carbonization temperature, the change rate of resistance gradually decreases. Through the analysis of the heating effect and the heating property of the fabric, it is found that the theoretical heating efficiency of the fabric is proportional to the heating temperature when the temperature is below 62.4 ℃, and it can be applied to the electrically heated fabric with precise and controllable temperature.

Dyeing and Finishing & Chemicals

Synthesis of silicon phosphorus modified calcium carbonate and its application in polyamide coating

CHEN Zhijie, JIANG Jikang, YU Yihao, FU Ye, WU Jindan, QI Dongming

Journal of Textile Research. 2023, 44(04):  146-153.  doi:10.13475/j.fzxb.20220203208

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Objective The wet coating technology based on the use of waste polyamide fiber is the main means to prepare coated textiles such as trademark webbing, and also an important way to physically recycle polyamide fiber. This technology is characterized by low production cost and excellent product performance. In order to solve the problems associated with calcium carbonate powder in polyamide 6 coating, such as easy accumulation and lack of flame retardant function, calcium carbonate was grafted onto the surface with self-made coupling modifier containing silicon phosphorus flame retardant components to improve its dispersion and facilitate flame retardant function.
Method Calcium carbonate powder was modified by coupling grafting with the reaction product of vinyl trimethylsilane and DOPO as a modifier, which was applied to the preparation of polyamide 6 wet-coated fabric. The effect of calcium carbonate modification degree on its dispersion state in polyamide 6 coating and the surface morphology of the coated fabric was investigated, and the flame retardancy of the coated fabric with different modified degree of calcium carbonate was characterized and compared
Results It was proved by FT-IR and elemental analysis that the coupling modifier was successfully grafted onto the surface of calcium carbonate, and the graft reaction kinetics and hydrophilicity and lipophilicity of the modified calcium carbonate were further studied. The infrared spectrum of calcium carbonate powder before and after the grafting reaction is tested, and the results are shown in Fig. 2. It can be seen that new peaks appear at 1 238 cm^-1 and 765 cm^-1 of the modified calcium carbonate, of which the peak at 765 cm^-1 represents the stretching vibration of Si—O in the coupling modifier molecule, and the peak at 1 238 cm^-1 reflects to the stretching vibration of P=O in the coupling modifier. The results of EDS test of calcium carbonate powder before and after modification are shown in Tab. 1. It can be seen that after the grafting reaction, a small amount of P and Si elements can be detected in the energy spectrum of the cleaned modified calcium carbonate surface. Combined with the infrared spectrum in Fig. 2, it shows that the coupling agent containing silicon and phosphorus is successfully grafted on the surface of calcium carbonate.
The calcium carbonate modified by different dosage of modifier is added to the wet coating slurry to test the limiting oxygen index (LOI) of the polyamide 6 coated fabric. It can be seen that the LOI of the modified calcium carbonate polyamide 6 coated fabric is positively correlated with the mass fraction of the modifier. When the mass fraction of the modifier reaches 40%, the LOI reaches the highest value of 25.1% (Fig. 6). The unmodified calcium carbonate does not have any flame retardancy, while the P and Si components in the modifier can endow calcium carbonate with better flame retardancy. Therefore, with the increase of grafting ratio, the LOI of the modified calcium carbonate polyamide 6 coated fabric will gradually increase, and the flame retardancy will gradually increase. When the grafting ratio is not increased, LOI cannot be further improved. Tab. 2 shows the vertical burning performance of the modified calcium carbonate polyamide 6 coated fabric with different modifier mass fraction. It can be seen that the polyamide 6 coated fabric using unmodified calcium carbonate and low modified calcium carbonate is completely burnt and damaged, with long afterburning time and no smoldering time. 7-8 molten droplets are generated and these molten droplets can ignite the absorbent cotton. When the mass fraction of the modifier exceeds 20%, the vertical damage length gradually decreases, and the afterburning time starts to decrease, with a smoldering time of 2.7 seconds. At this time, the number of melt droplets is still large and the degreased cotton can be ignited, and the flame retardant effect is poor. When the mass fraction of modifier is 40%, the vertical damage length reaches the minimum value of 5.3 cm, the afterburning time is 1.6 s, the smoldering time is 0.7 s, and the number of droplets decreases to 0-1.
Conclusion The effects of calcium carbonate on the morphology and flame retardancy of the polyamide 6 coated fabric before and after modification were compared and characterized. The results showed that when the modification time was 30 h and the mass fraction of the modifier was 40%, the fully modified calcium carbonate with good lipophilicity could be obtained, and the polyamide 6 coated fabric had good flame retardancy with the highest limiting oxygen index of 25.1%, vertical damage length of 5.3 cm, afterburning time of 1.6 s and smoldering time of 0.7 s.

Apparel Engineering

Clothing development based on flexible selective laser sintering 3D printing technology

GU Liwen, RUAN Yanwen, LI Hao

Journal of Textile Research. 2023, 44(04):  154-164.  doi:10.13475/j.fzxb.20220105911

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Objective Flexible and complex 3-D structure forming is one of the main difficulties of concern in the field of clothing 3D printing technology. The selective laser sintering (SLS) process and thermoplastic polyurethane (TPU) materials have obvious advantages in addressing this difficulty. However, there is a lack of more systematic research on the 3D printing clothing development process based on this technology combination. This study carry out an empirical research which combines case studies and summaries of universal problems to address this issue.
Method As the initial attempt, a digital model of a 3D printed corset was designed and generated by comprehensive usage of the soft-ware including DAZ 3D, Blender, CLO and Materialise Magics. Then, the study produced a physical model of a flexible 3D printed corset with wearability by using an EOS P700 3D printer and TPU powder material. Eventually, the development process of this case was designed and generated in detail, from which extracted a universal 3D printing clothing development process.
Results The produced flexible 3D printing corset was made of the TPU material with Shore hardness of 88A and has a maximum wall thickness of 4 mm, resulting in a clothing with good shaping ability as well as the expected flexibility, which contains complex 3-D structures such as layered, overhang and hollow for testing the capabilities of SLS-TPU technology in the forming of complex 3-D structures(Fig. 11). A rear central non through-body invisible zipper placket was used to enable the clothing to be put on and taken off(Fig. 7), which was divided into upper and lower parts with a waist division line and is manufactured separately, and assembled together with boss-groove structure and a sewing process by using 0.12 mm transparent nylon wire(Fig. 6, Fig. 8). The universal process of 3D printing clothing based on SLS process, TPU material and thin wall structure obtained through this study includes 5 major steps, which are digital 3-D base model modelling, digital 3D printing model modeling, digital 3D printing model data preparation, physical 3D printing model manufacturing, and physical 3D printing model post-processing, as well as the 20 sub-steps under them(Tab. 1). The fourth step was not discussed in detail because the work was carried out by a third party manufacturer.
Conclusion The study shows that the initial shape of the 3-D digital model, the fit between the hardness of the TPU material and the wall thickness of the model have a significant impact on the variable and flexible shape of the 3D printed clothing, and also demon-strates the feasibility of using the sewing process for piecing together 3D printed models of clothing. The study proposed a series of solutions for 5 key generic issues in this case development process, including 1) the initial shape setting of the digital clothing 3-D base model, 2) the setting of the clothing 3D printed model's wall thickness and material hardness, 3) the matching of the clothing 3D structure to the 3D printing process, 4) the design of the 3D printing clothing putting on and taking off method, and 5) the disassembly and assembly of the clothing 3D printing model. In the future, the various steps of the clothing 3D printing process involved in this study can be studied in more depth in terms of material performance, process technology, cost control and sustainability by using quantitative measurements and lateral comparisons.

Leg style perception evaluation and personalized customization of women's sports trousers

CAI Liling, REN Qianbin, JI Xiaofen, XIAO Zengrui, ZHANG Yiling

Journal of Textile Research. 2023, 44(04):  165-171.  doi:10.13475/j.fzxb.20220104907

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Objective In recent years, consumers' demand for clothing has turned to be more individualized, diversified and intelligent. The purpose of this paper is to help enterprises accurately grasp the emotional preference of consumers in the customization process, so as to match the personalized recommendation of product core components with users' emotional needs, thus achieving successful personalized customization. This paper takes the female tracksuit bottom as an example to establish a personalized recommendation model based on Kanseiengineering, and to help consumers customize personal schemes based on their needs.
Method Based on the principle of Kansei engineering, this paper firstly collected the bottom styles and design elements. Adjective words were selected to describe the style, and semantic difference method was used to obtain consumers' perceptual evaluation in seven dimensions and build a perceptual image space. Then, the author set up a mapping model between design elements and consumer perception through partial least square(PLS) method. Analytic hierarchy process (FAHP) was applied to quantify the perceptual needs of consumers, and a personalized recommendation model combining with mapping modelwas established.
Results Through a preliminary screening, literature review and expert consultation of 100 tracksuit bottom designs, the quantifiable factors wereset including looseness, closing method and slitting method. Morphological analysis was used to decompose the three elements twice to obtain 12 sub elements. The design elements and coding table are shown in Tab. 1. After preliminary screening, questionnaire survey and expert screening of 120 perceptual adjectives werecollected, 7 pairs of adjectives were finally obtained which were used to establish the perceptual image space of female tracksuit bottoms. The vocabulary and its definition angle are shown in Tab. 2. According to the principle of Kanseiengineering, a 7-level scale was designed by semantic difference method. 70 female college students with exercise habits were randomly invited for questionnaire survey, and 64 valid questionnaires were obtained. The average score of sample styles are shown in Tab. 3. Minitab software was used to conduct regression analysis on the average scores of style design elements and adjectives. The regression coefficient table is shown in Tab. 4. According to the regression coefficient, a mapping model between design elements and consumption perception was established. Through questionnaire, users wereasked to choose the perceptual image words of preference to describe individual needs. For example, user I's perceptual image acquisition and demand emphasis are shown in Tab. 5 and Tab. 6. The weight of perceptual image wascalculated by FAHP, thus obtaining user one's perceptual image weight expression. Based on weight, clothing set distance sortingwas adopted, and recommendations were made according to the sorting results. For the case of user I, the comprehensive evaluation distance P was sorted of each experimental sample, and four styles that meet the perceptual needs of user I were generate(Fig. 4). 15 consumers were invited at random again to make recommendations, and the recommendation results were obtained, and the consumers were asked to conduct emotional evaluation on the recommendation results. The similarity of the score matrix between the recommendation results and the perception evaluation was compared by calculating the cosine similarity of formula 4. The average similarity reached 0.902, which was relatively high. The average absolute value error (R_MAE) of formula 5 was used to evaluate the accuracy of recommendation results(Fig. 5). R_MAE was all less than 0.75. The recommendation algorithm was found able topredict and recommend accurately and has certain application value.
Conclusion Based on Kansei engineering, this paper proposed a personalized recommendation model for tracksuit bottom, and demonstrates the algorithm and process of the recommendation. Through testing, it shows that this model can effectively transform the emotional needs of consumers into design elements, so that the recommendation results can be matched with user needs, thus realizing personalized recommendation for tracksuit bottom based on the emotional needs of users, and improving the efficiency of personalized customization. At present, only the styles of female tracksuit bottoms have been evaluated and recommended. In the future, more comprehensive studies can be carried out based on fabric comfort and color. Besides, the tracksuit bottom is only one part of a garment, and the research object can be expanded to other parts.

Research and design of temperature-control intelligent thermal gloves with wearing comfort

DU Jihui, SU Yun, LIU Guangju, TIAN Miao, LI Jun

Journal of Textile Research. 2023, 44(04):  172-178.  doi:10.13475/j.fzxb.20220306807

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Objective When working in a cold environment, people usually wear intelligent cold-proof gloves to compensate the lack of physiological heat regulation. The previous studies on electric heating gloves showed that there had been no temperature regulation based on skin temperature, and it was difficult to control accurately the heating pad. In addition, there had been few studies regarding simulation of the real operation of pressure states for cold contact state. In this research, a temperature-control system was designed and the thermal comfort performance of the cold-proof gloves was targeted for investigation.
Method The designed intelligent temperature-control system rapidly adjusts the heating power of the heating pad by comparing the skin temperature with the comfortable temperature of the human body. The skin-simulant sensor of the cold-contact test device was used to measure heat transfer through fabric system. The skin temperature changes during the cold contact were analyzed to explore the influence of modes of temperature control, heating temperatures, fabric layers and cold contact conditions on the thermal comfort performance of the cold-proof gloves.
Results As for the heating effect of the intelligent cold-proof gloves, skin discomfort, even frostbite occurred for no heating pad (Fig. 4). However, when the intelligent heating pad was used, the skin temperature was more stable. In terms of design factors of heating pad, when the mode of temperature control for human skin (STC) was adopted, the final skin temperature was stable around the comfort range. Compared with the mode of temperature control for the heating pad (HPTC), the skin temperature was more stable and closer to the comfortable temperature range (Tab. 4). At the same time, the temperature of the heating pad was reduced to a certain extent on the premise of ensuring the thermal comfort of the skin. Therefore, energy consumption was considered to be effectively reduced (Fig. 6). In an extremely low temperature environment, the intelligent heating pad greatly improved the thermal comfort performance of the gloves and reduced the number of fabric layers, meeting the requirements of skin comfort and flexible operation (Fig. 7). With decrease of the contact temperature, the physiological discomfort was aggravated and the time to reach the skin discomfort gradually became shorter (Fig. 8(a)). After using the heating pad, the final skin temperature is basically stable within the comfortable temperature range of the skin, which ensures the long-term thermal comfort requirements of the skin (Fig. 8(b)). The final stable skin temperature was higher for 0 kPa pressure than that for 3 kPa pressure. When the heating pad was used, the change of the skin temperature was contrary to no heating pad. Besides, the skin temperature was higher for 3 kPa pressure than that for 0 kPa pressure (Fig. 9). However, the intelligent heating pad for the double-layer fabric system worked to maintain the skin temperature and ensure the skin thermal comfort under 0 kPa and 3 kPa pressures.
Conclusion An intelligent temperature control system was developed and the influence of heating pad design and fabric layer number on skin temperature change in different cold contact conditions was investigated based on the cold-contact test device of fabric. The designed intelligent cold-proof gloves with the STC mode can keep the skin temperature stable in the comfortable temperature range during cold contact. Two modes of temperature control for the heating pad (HPTC) and human skin (STC) were compared, considering the thickness, temperature control and power consumption, and the STC mode seems to be the better heating choice. With the increase of fabric layers, the thermal comfort performance of the intelligent cold-proof gloves is improved. However, according to the different fabric layers, the intelligent cold-proof gloves with skin temperature control mode can achieve thermal comfort. Furthermore, the intelligent cold proof gloves can keep the skin temperature in the comfortable temperature range under different experimental pressures to ensure the thermal comfort of the skin.

Virtual restoration of ancient costumes based on 3-D costume modeling technology

DENG Kehui, WEI Yilin

Journal of Textile Research. 2023, 44(04):  179-186.  doi:10.13475/j.fzxb.20220301508

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Objective 3-D virtual restoration technology has become an important method in the research of digital conservation and restoration of common hard cultural relics such as terracotta warriors and horses, Buddha sculptures and bronzes, but it is less applied in textile and clothing soft cultural relics. In order to better realize the non-contact restoration of mutilated ancient costume artifacts and provide detailed costume engineering data reference for their virtual restoration, this paper proposes a method for digital virtual restoration of ancient costumes based on 3-D costume modeling technology.
Method Taking "Yellow ground silk robe with clamp resist dyeing technology" (Warehouse in the South 139-1) of Tang Dynasty in Shosoin Museum of Japan as the research object, the stained pattern of the robe were extracted and repaired by using Canny graphic detection algorithm in MatLab, before restoring the style and structure of the defective part of the robe by using the garment CAD software ET System. 3-D modeling technology based on CLO3D platform was adopted to make a digital 3-D virtual restoration of the robe, and the restoration scheme were tested through the performed pressure simulation and dynamic simulation.
Results This digital virtual restoration method of textile soft cultural relics based on 3-D garment modeling technology was formulated by combining computer graphics detection technology and 3-D visualization technology, enabling successfully the high-precision 3-D virtual restoration of ancient costumes. The damaged decorative pattern (Fig. 3) of "Yellow ground silk robe with clamp resist dyeing" (Warehouse in the South 139-1) in the collection of Shosoin Museum in Japan was restored using Canny graphic edge detection algorithm (Fig. 2), based on which the pattern was proved to be a popular early Tang Dynasty Buddhist, revealing that the pattern is "Complex open space type baoxiang flower", the composition is "Diagonal eight-petal flower" (Fig. 4) with the center of the flower in "Persimmon pattern" and the inner and outer petals in "Double leaf pattern" and "Cloud Curved petal pattern" (Fig. 6), and the artifact can be further clarified as "Yellow ground baoxiang flower silk robe with clamp resist dyeing". On the basis of the pattern recovery, using CorelDraw, ET System and other software on the "Yellow ground silk robe with clamp resist dyeing" style and structure of the recovery, the production of the style recovery and structure recovery diagram (such as Fig. 7-8) was facilitated. Combined with the detailed size data of the robe, 3-D modeling technology based on COL3D platform was used on top of the pattern, size, style and structure restoration, and systematic 3-D virtual digital restoration of the robe was carried out in steps of modeling, plate making (Fig. 9), virtual sewing and fitting (Fig. 10-11), fabric pattern simulation (Fig. 12), which provided detailed information for further heritage conservation and the work of physical restoration provided a detailed data reference.
Conclusion The results show that the method is able to facilitate the high-precision 3-D virtual restoration of ancient costume cultural relics, effectively restore the 3-D dynamic shape of ancient costumes, and provide reliable technical support for the digital conservation and restoration of textile and costume soft cultural relics. With the continuous progress of the 3-D modeling technology of clothing, the method can be widely used in the field of digital conservation and restoration of textile and clothing soft cultural relics, providing clothing engineering data reference for its restoration work, and at the same time bringing help to the promotion and display of textile non-heritage and the construction of digital museums.

Machinery & Accessories

Design of automated board shoveling system under non-stop-spinning condition

DING Caihong, ZUO Jinzhao, SHI Yi

Journal of Textile Research. 2023, 44(04):  187-193.  doi:10.13475/j.fzxb.20211006207

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Objective Board shoveling is an essential process in chemical fiber spinning production, in which the shovel blade is used to clean residual polymers from the spinneret surface. Automated board shoveling operation under stop-spinning condition was prone to causing pressure fluctuations in the extrusion pump which would affect the stability of spinning quality. Therefore, an automated shoveling system under non-stop-spinning condition was proposed with no negative influence on spinning quality. It could clean the spinneret surface and at the same time collect and discharge the flowing waste wires. However, the narrow space of spinning box greatly increased the difficulty of structural design of shoveling mechanism. In this paper, the structure layout design and detailed structural design were carried out to solve the structural design problem of the automated shoveling system above.
Method Referring to the design method of mechanical power distribution, a compact structure design scheme combining two functions of board shovel and wire discharge was proposed (Fig. 1), where the structure layout was in the form of the discharge assembly in the center and the shovel assembly on the side. A cantilever beam and series-parallel spring buffer technology was applied to the offset structure design of the shovel assembly, and the slip ring design technology was applied to solve the structural connection between the rotating wire collecting funnel and the stationary wire discharging pipeline in the wire discharge assembly. Numerical calculation methods, including mechanical modeling, finite element analysis, kinematic analysis, fluid mechanics, were applied to carry out the calculation and design of specific structural parameters of the two parts. Eventually, practical test methods were used to verify the correctness of the structural design through the development of the actual experimental device.
Results The linear motion performance of the shovel assembly was investigated in details through ANSYS simulation, where a contact force of 50 N was applied to the blade. The displacement difference of the cantilever structure at the three sets of guides supported by the spring K1 was within a few micrometer(Fig. 3). It was proved that the offset shovel assembly could move smoothly in line. Through further analysis of the contact stress distribution between the scraper blade and the spinneret surface, the scraper blade could be in full contact with the spinneret surface and keep pressed upon the surface. In order to avoid the rigid impact when the blade approached fast to be pressed on the spinneret surface, the mechanical modeling of the shovel setting movement was carried out, and the numerical calculation was performed to get the elastic coefficients of springs K1 and K2 in the buffer structure of the shovel assembly as 9 N/mm and 4 N/mm. Finally, through the development of the test device, the experiments of board shoveling and wire discharge were carried out under the laboratory simulation conditions. The actual shovel force in experiment was collected in real time to learn the influence of shovel force and shovel time on shovel effect. A more reasonable experimental result was shown in Fig. 11, during the spinneret surface was scraped with a preset force of 40 N, the actual shovel force converged gradually and stabilized after 2 s, and effective cleaning was completed within 5 s. Simultaneously, the functional experiments of wire discharge were carried out with the parameters of negative pressure and flow velocity obtained through Fluent fluid simulation. The simulated spinning objects flowing out of the spinneret could be all collected in the collecting funnel with a tendency to converge towards the center and then discharged downward(Fig. 12). Later the pipeline was opened to observe that no remains were hung on the wall inside the pipe.
Conclusion Through mechanical modeling, numerical calculation, simulation analysis and experimental research, the related analysis and calculation of the automated shoveling system with integrated structure have been done for the achievability of board shoveling and wire discharge, and the correctness of the structure layout and design were verified. Thus a new automated shoveling system under non-stop-spinning condition is provided for the spinneret cleaning without stopping the extrusion pump in the fiber spinning production, and the relevant design parameters are given to guide the development of the actual system design. That will be beneficial to ensure the stability of spinning quality.

Control on dynamic delivery of spandex yarns in knitting under constant tension

PENG Laihu, LUO Chang, DAI Ning, HU Xudong, NIU Chong

Journal of Textile Research. 2023, 44(04):  194-203.  doi:10.13475/j.fzxb.20211107810

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Objective Due to the friction between spandex yarn and guide nozzle and the variation of knit loop feeding length in knitting production process, the conveying tension of spandex yarn is uneven, often resulting in fabric horizontal strips, uneven elasticity, and even yarn breakage, wire turning and other phenomena. At present, the use of dynamic constant tension method for the transport control of spandex yarns is a new trend. In this paper, the friction mechanism and spandex conveying process characteristics are analyzed in depth, and a constant tension spandex conveying control scheme based on the double closed-loop method of speed and tension is proposed.
Method Based on the analysis of spandex conveying related processes, spandex tension model and hybrid stepper motor mathematical model were constructed with the proposed tension fuzzy PID control strategy. Simulink simulation and Recurdyn/Colink electromechanical joint simulation as carried out, and the implementation of constant tension spandex yarn transmission algorithm was elaborated.
Results The single-phase excitation transfer function of the two-phase hybrid stepper motor was calculated from the relevant parameters of the stepper motor, the syringe speed was set to 558.292 r/min, and the preset tension value was calculated according to the difference between the syringe speed and the spandex yarn conveyor. Setting the step signal input as 0.32 and a unit step disturbance at the 10th second to obtain the tension control step response curve(Fig. 12), it was found that spandex tension control using fuzzy PID had better performance, faster response time, and stronger anti-interference ability. In this paper, 30.8 tex spandex bare filament was used as the conveying object, the basic parameters were obtained by consulting the relevant reference manuals and literature, and the simulation parameters were set and the simulation was run. The overall tension fluctuation of spandex yarn using constant tension conveying control was small, and the vibration of spandex yarn was significantly suppressed during simulation, and the spandex yarn without constant tension conveying control (only let the spandex yarn conveyor follow the movement of the syringe barrel at a certain rotational ratio) showed large tension fluctuations as a whole, and the vibration of spandex yarn was obvious during simulation. Through the analysis, it can be seen that the spandex yarn controlled by the constant tension spandex conveying control in this paper was more stable, and the yarn vibration was suppressed to a certain extent, which has better performance. In order to further verify the reliability of the simulation and the feasibility of this scheme, an experimental platform was built for verification, as shown in Fig. 14 where the tension fluctuation of the control force without constant tension transmission was large and cannot be restored to the preset tension when encountering external disturbances (change of friction, touch of the adjustment master's hand). Using constant tension conveying control, the spandex tension basically fluctuates around 3 g, and can return to the preset tension in a short time when encountering external disturbances. Through experimental verification analysis, the reliability of the simulation and the feasibility of this scheme were proved.
Conclusion The tension control device has been installed on the RFSM20 seamless underwear machine of a manufacturer, and after several debugging, the spandex conveying control system operates correctly, and the spandex elastic fabric can be knitted normally. The woven spandex elastic fabric has excellent elasticity and the elasticity of each part is basically the same, and the cloth surface is flat and meets the elastic fabric standard. Experiments verify the adaptability and superiority of the control strategy, and the dynamic constant tension spandex transport control scheme has engineering application value.

Vibration analysis of high speed warp knitting machine based on fast empirical mode decomposition

CHEN Zhihao, BAO Wenjie, LI Fucai, JING Bo, HUANG Chaolin, SUN Jianwen

Journal of Textile Research. 2023, 44(04):  204-211.  doi:10.13475/j.fzxb.20210907408

Abstract ( 133 )   HTML ( 3 )   PDF (4938KB) ( 48 )   Save

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Objective Warp knitting machine is one of the most important machines used widely in the textile industry. Aiming at the problems that excessive vibration of a high-speed warp knitting machine at high speed and the overlapping of mechanism motion signal and structure vibration signal, which makes it difficult to separate fault characteristics, a vibration fault diagnosis method for high speed warp knitting machine based on fast empirical mode decomposition (FAEMD) algorithm is proposed.
Method Firstly, the original vibration signal was decomposed into finite intrinsic mode functions (IMFs) by FAEMD algorithm. Then, the correlation between each IMF component and the original signal was calculated. Combining with the motion characteristics of the warp knitting machine, an analysis was carried out to determine the most relevant intrinsic mode function and its removal. Finally, the remaining components are recombined to extract the structural vibration signal. The specific process is shown in Fig. 3.
Results The proposed method was applied to the vibration analysis of a high speed warp knitting machine. Abnormal sound caused by excessive vibration occurred when a certain type of high-speed warp knitting machine runs at the speed of 1 700 r/min, 1 900 r/min and 2 000 r/min. To tackle this, the location of measuring points and the directions of measuring signals were determined according to the structural characteristics of the warp knitting machine. The measuring points were bed, comb bed, slotted needle bed, needle core bed and settler sheet bed, and the directions were vertical and length(Fig. 5). Then static test was carried out to determine the natural frequencies of the main parts of the warp knitting machine in three directions i.e. length, front, back and vertical, before the dynamic test was carried out. The speed change started from 1 600 r/min and increased to 2 000 r/min at a 50 r/min step to obtain vibration signals of main components at different speeds. According to the structural characteristics of the drive crankshaft of the warp knitting machine(Fig. 6), the main frequency of analysis was determined to be three times the frequency of the speed. The original signal features and the features extracted by the traditional EMD algorithm were not consistent with the fault phenomena. The proposed method was applied to the vibration signals of warp knitting machines, and the signal features consistent with the fault phenomena were successfully extracted (Fig. 7). By combining the static test results with the dynamic test results, it was finally determined that the reason for the excessive vibration of the structure was that the frequency of the driving force was close to the natural frequency of the bed, the settler sheet bed and the comb bed in the vertical direction at some specific speed, so as to produce the resonance phenomenon.
Conclusion In order to solve the problem of excessive vibration of high-speed warp knitting machine at a specific speed, a new vibration analysis method of warp knitting machine is proposed in this paper. The FAEMD algorithm and Pearson correlation coefficient are innovated to remove the mechanism motion signals of warp knitting machine and keep the structural vibration signals for analysis. In practical application, it is found that for the same signals, the number of IMF decomposed by EMD algorithm is more than that obtained by FAEMD algorithm, and the correlation of signals is poor. This method can improve the problem of end-point effect and mode aliasing of traditional EMD algorithm, and can effectively extract the fault characteristics of vibration acceleration signal of warp knitting machine, which provides a feasible method for vibration fault diagnosis of warp knitting machine.

Comprehensive Review

Research and application of structural color fibers with photonic crystals

GU Jia, ZHANG Zhenxiong, HAN Ying, HU Jianchen, ZHANG Keqin

Journal of Textile Research. 2023, 44(04):  212-221.  doi:10.13475/j.fzxb.20220303310

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Significance Structural color is formed by utilizing microstructures to produce color through visible light scattering or interference. In the researches for fabrication of colorful fibers with high color saturation which are not easy to fade and are environmentally-friendly, formation of structural color fibers based on photonic crystals is an effective method. The application of structural color in the textile field mainly target at obtaining fabrics with highly color saturation and reducing the pollution caused by chemical dyeing, and for this reason structural color fibers have received much attention in recent years due to their significant potential applications in sensor and wearable device. This paper is set to review the research activities and applications of structural color fibers.
Progress The review covers the color generation principles of the multidimensional photonic crystals that make up structural color fibers, and focuses on the main methods of preparing structural color fibers based on photonic crystals, including traditional fiber external coloring, template assembly and other different spinning technologies (Fig. 1). The method of structural color fibers formed by traditional fiber external coloring is to coat photonic crystal on the surface of fibers with external conditions to form structural color fibers. Among them, the most commonly used methods are convective self-assembly (Fig. 2), electrophoretic deposition, atomic layer deposition and magnetic assembly. The template assembly method (Fig. 3) is different from the structural color fibers formed by traditional fiber external coloring, in which colloidal microspheres are assembled on the template through capillary force and other effects with the help of the template to form photonic crystal fibers. An example is the formation of structural color fibers by rapidly self-assembling colloidal silica nanoparticles in capillary tubes. Electrostatic spinning (Fig. 4(a)) and microfluidic spinning (Fig. 4(b)) are common spinning techniques, and are also studied in the researches on formation of structural color fibers. In particular, microfluidic spinning technology is a spinning technology that can precisely control and manipulate micro-nano scale fluid. As shown in Fig. 4(b), point-aligned colloidal crystal fibers and structural color-coded fibers by integrating injectable photonic hydrogels with microfluidic assisted assembly methods are developed. Besides, the paper reviews the progress of researches and applications of multifunctional structural color fibers in the fields of wearability, detection and sensing.
Conclusions and Prospect The advantages of photonic crystal structural color fibers are summarized. The bottlenecks in the design and applications of structural color fibers are analyzed, and their future developments are prospected. It can be concluded that photonic crystals, as the basic material of structure color generation technology, promote the vigorous development of photonic crystal structure color fiber researches. Structural color fibers with a certain mechanical properties, excellent optical properties and size uniformity show application potentials in wearable, sensing, biological detection, environmental response and other fields. There are several aspects about the future development of photonic crystal structural color fibers that need to be further explored and studied. Firstly, when assembling photonic crystals onto conventional fibers or forming photonic crystal structure color fibers by the template method, the assembly stability of photonic crystals has not been satisfactory. In order to improve the structural stability of photonic crystals on fibers, the material can be chemically modified to effectively enhance the bonding between the microspheres. Secondly, Use of optimal photonic crystal materials and addition of adhesive polymer materials would improve the mechanical properties of structural color fibers. Finally, the simpler and cheaper preparation process allows for industrial production. The exploration and improvement of these points will make the development and application of photonic crystal fibers more realistic.

Research progress in recycling of waste polyphenylene sulfide fibers

XING Jian, ZHANG Shucheng, YU Tianjiao, TANG Wenbin, WANG Liang, XU Zhenzhen, LIANG Botao

Journal of Textile Research. 2023, 44(04):  222-229.  doi:10.13475/j.fzxb.20211007208

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Significance High-temperature dust is the characteristic of air pollutants discharged by industry. Bag-type dust removal systems have been widely used in high-temperature dust treatment of waste incineration plant, steel plant, cement plant and coal-fired power plant, due to effectiveness and low cost. Filter bags are the key material of bag dust removal system. Polyphenylene sulfide (PPS) fiber is one of the most widely used thermoplastic fibers in the field of high-temperature filter bags due to the good mechanical properties, outstanding thermal stability and excellent flame retardancy. With the upgrade of flue gas emission standards, the quantity demand and replacement of PPS filter bags both greatly increases. However, most of waste PPS filter bags are disposed by incineration or landfill. A large quantity of smoke, acid or alkaline gas and carcinogens can be produced during the incineration process. Meanwhile, the dust particles, acid and alkaline substances and carcinogens contained in the waste PPS filter bags can also cause pollution of soil and groundwater through the landfill. Therefore, these two traditional treatment methods not only waste resources but also cause serious damage on the environment. Moreover, the most important thing is that PPS fibers cannot be recycled. Therefore, it is of great social significance and economic value to recycle waste PPS fibers and filter bags.
Progress In order to promote the efficient and high-value recycling of waste PPS fibers and filter bags, a detailed overview on the current research advances was carried in this study, where the methods, processes, advantages and disadvantages of recycling PPS fibers were compared, analyzed and summarized. The technical difficulties affecting the recycling use of waste PPS filter bags were also analyzed from the aspects of deashing treatment, complex fiber composition and high recycling cost. Finally, a tripartite linkage mechanism of PPS filter bags manufacturer, user and recycling enterprise was proposed to manage and recycle waste PPS filter bags in different working conditions to provide reference for the high-value recycling. Currently, the commonly used recycling methods can be roughly divided into chemical recovery method and physical recovery method. The chemical recovery method refers that the PPS macromolecular chains are dissolved or decomposed using the corresponding organic solvent, and then the high polymer solid or polymer monomer are separated and reused. The technology of chemical dissolution method is relatively mature and the recovery rate is high, and it can be used for PPS filter bags with different components. Moreover, the chemical dissolution method has a high application value if the recovery rate of organic solvent can be improved and the separation and purification process can be simplified during the process of industrialization. Physical recovery method refers that waste PPS filter bags are generated into the initial state and reused by mechanical processing. It can be divided into mechanical pulverization, melt reprocessing, fiber disassembly and direct utilization. The mechanical pulverization method has been industrialized because of its simple process and low cost. The other three methods are still in the stage of experiment due to the limitation of multiple factors.
Conclusions and Prospect Recycling use of waste PPS filter bags is an effective and imperative way to protect the environment and preserve the resources, which will benefit both the society and the economy significantly. However, the industrial scale of waste PPS filter bags recycling is small in our country, and the industrial cluster has not yet formed. Mechanical pulverization is the only recycling method that has been industrialized, but the industrial scale is still small. The chemical solution method has been studied extensively and has entered the stage of small trial. It will become the main recycling method for waste PPS filter bags on the condition of solving the high price and recycling of chemical solvent. In short, the recycling process of waste PPS filter bags is still immature and it is fraught with technical difficulties and high coasts. This paper puts forward some suggestions in the following areas. 1) A professional recycling system for waste PPS filter bags and other waste filter bags should be established. 2) Advanced and mature recycling processes and methods need to be developed to solve the technical difficulties by increasing R&D investment. 3) It is urgent to have the standards, laws and regulations for the recycling of waste PPS filter bag shall be formulated.

Research progress and application of new graphene based antibacterial materials

LI Yang, FENG Yan

Journal of Textile Research. 2023, 44(04):  230-237.  doi:10.13475/j.fzxb.20211103808

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Significance Variety of bacteria in the nature pose a great threat to animals and plants, as well as human beings leading to gradual emergence of various antibiotics. However, due to the large use of antibiotics, many pathogenic bacteria have developed strong resistance to them, leading the decreased efficacy of antibiotics, and it is hence urgent to develop more effective antibacterial materials. The graphene family materials themselves have certain antibacterial properties, but the effect of a single graphene material in exerting its antibacterial properties is not ideal. In this case, the synergistic antibacterial effect between components can be better played by combining graphene materials with other antibacterial materials. In view of this, in order to better overcome the limitations faced by single materials in the antibacterial field, the research progress in graphene based new antibacterial materials is reviewed and discussed, with the aim to provide reference for research and development of new antibacterial materials with strong antibacterial properties, long antibacterial aging properties, and stable antibacterial properties.
Progress The characteristics of graphene materials in antibacterial such as broad-spectrum antibacterial, physical and chemical effects were introduced, and the antibacterial mechanisms of graphene and its derivatives including contact cutting, coating, and oxidative stress were emphatically elaborated. Then, the research progress of graphene compounded with nanomaterial, chitosan, quaternary ammonium salts, haloamines, etc. was analyzed. The image of Escherichia coli cells was showed before and after a sandwich type antibacterial material treatment under the scanning electron microscope(Fig.1). The sandwich type antibacterial material was prepared by directly growing silver nanoparticles on the surface of graphene based nano sheets. The image shows that the bacterial cell membrane structure was damaged after the sandwich type antibacterial material were treated with Escherichia coli cells for a period of time. The difference diagram of antibacterial performance was showed between graphene and composites with different copper nanoparticles loading by colony count method(Fig. 2). The results show that, within a certain range, the loading of copper nanoparticles significantly improved the antibacterial performance of graphene. When the loading of copper nanoparticles was 10%, the antibacterial effect of the composite reached the best state. The application of graphene based composite antibacterial materials in the textile field was analysed, problems challenging research are summarized, and the future development direction of graphene based composite antibacterial materials is prospected.
Conclusions and Prospect The literature review shows that in the field of antibacterial, graphene materials exhibit broad-spectrum antibacterial activity that can inhibit a variety of pathogenic bacteria. When graphene materials exert their antibacterial activity, there are physical and chemical action modes, including physical damage caused by nanoknife contact cutting, reactive oxygen mechanism generated by oxidative stress, and coating effect. When graphene materials are compounded with other materials, such as nano silver particles, nano copper particles, titanium dioxide, nano zinc oxide particles, chitosan, quaternary ammonium salts, haloamines, and so on, the prepared graphene based new antibacterial materials demonstrate excellent antibacterial properties, and the composite materials show more excellent antibacterial properties than a single component. This is because the graphene based new antibacterial materials can give full play to the synergistic effect between components, and reduce the reunions between components. When graphene based composite antibacterial materials are applied in the textiles, the developed composite fibers and functional fabrics have good antibacterial activity, and the modified fibers and fabrics can inactivate gram-positive bacteria, gram-negative bacteria and other pathogens. However, during the development of functional fabrics, there are still problems such as the defects of graphene fibers and the difficulties in the combination of graphene materials and fabrics, calling for solutions. To sum up, the materials obtained by compounding graphene materials with other antibacterial materials can give full play to the synergistic antibacterial effect of each component and develop rapidly. However, despite the rapid development of graphene based new antibacterial materials, their industrialization still faces many challenges. In the future, focuses should be placed on optimizing their preparation process, antibacterial mechanism and other aspects to make them green and environmentally friendly.