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Journal of Textile Research
(Started in 1979,Monthly)
Authority in Charge: China Association for Science and Technology
Sponsor: China Textile Engineering Society
Edited and Published by: Periodical Agency of Journal of Textile Research
ISSN 0253-9721
CN 11-5167/TS
Table of Content
15 April 2024, Volume 45 Issue 04
    
  • Academic Salon Column for New Insight of Textile Science and Technology: Green Functional and Smart Textiles
    Preparation of cellulose hydrogel fiber and its flame retardancy and sensing property
    LIU Yide, LI Kai, YAO Jiuyong, CHENG Fangfang, XIA Yanzhi
    Journal of Textile Research. 2024, 45(04):  1-7.  doi:10.13475/j.fzxb.20230907201
    Abstract ( 69 )   HTML ( 15 )   PDF (7816KB) ( 53 )   Save
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    Objective Lyocell fiber is a novel eco-friendly fiber produced through solvent spinning techniques with excellent flexibility and mechanical strength. Due to the outstanding performance, Lyocell fiber is extensively utilized in the textile, household, and medical sectors, rendering it an ideal substrate for fabricating functional fibers. However, Lyocell fiber is composed entirely of cellulose, poses a significant flammability risk. Simultaneously, its inherent insulating properties also impede the advancement of Lyocell fiber in the realm of flexible electronics. Therefore, enhancing the flame retardancy and electrical conductivity of Lyocell fiber is imperative to expand their functional applications.

    Method In order to address the issues of flammability and limited functionality in cellulose fiber, this study utilized Lyocell fiber as the primary research material and employed a typically etherification reaction strategy to modify. By introducing carboxyl groups and metal ions (Na+), flame retardancy and water absorption properties were imparted, resulted in the formation of an ionic conductive hydrogel fiber upon water absorption. The surface morphology of the modified fiber was characterized, and flame retardancy of the carboxymethylated fiber as well as the sensing performance of the hydrogel fiber were investigated.

    Results The carboxymethylation modification of Lyocell fiber had excellent flame retardancy and water absorption properties. The morphology of modified fiber remains similar to original fiber, exhibited a smooth outer surface. In thermogravimetric analysis, due to the introduction of carboxyl and Na+, the residual carbon content of the modified fiber was significantly increased from 17.0% to 24.4%. The limiting oxygen index (LOI) of original Lyocell fiber was merely 17.8%. However, the LOI of fiber can be significantly enhanced to reach an impressive 35.3% through carboxymethylation modification, thereby ensuring its non-ignitability even over prolonged periods in fire. The presence of metal ions exerted a flame retardant effect, resulting in a significant reduction in the peak heat release rate (PHRR) of Lyocell-Na from 184.4 W/g to 55.2 W/g. Moreover, the total heat release (THR) and heat release capacity (HRC) also decreased by 49.4% and 40.7%, respectively. It is noteworthy that Lyocell-Na exhibited a characteristic double heat release peak. This phenomenon arose from the promotion of carbonization in the fiber matrix by Na+, resulting in the formation of a dense barrier carbon layer on the fiber surface during the initial stage of combustion. Once sufficient heat accumulated within this carbon layer, it eventually breaches, leading to the second heat release peak. Compared to pure Lyocell fiber, the tensile strength of the fiber slightly decreased after carboxymethylation, from 3.9 cN/dtex to 3.2 cN/dtex. This could be attributed to that the reaction was carried out in an alkaline environment, and NaOH would decrease the crystallinity of Lyocell fiber, consequently impacted its mechanical strength. The hydrogel fiber showed a sensitive cyclic response to changes in finger bending angle. When the hydrogel fiber was attached to the finger joint for bending cycle action, it underwent deformation to yield and exhibited varying rates of current change corresponding to different bending angles.

    Conclusion Cellulose-based hydrogel fiber was successfully prepared from Lyocell fiber by etherification reaction. By introducing carboxyl groups and metal ions into the molecular chain, the flame retardancy and water absorption of Lyocell fibers were significantly improved. Moreover, the gelled fiber exhibits a certain level of ionic conductivity upon water absorption. By considering the flame retardant performance, different degrees of deformation can generate corresponding changes in current signals, enabling identification of the operational state. Therefore, this work holds promising prospects for advancement in the field of flexible sensing.

    Preparation and properties of flexible thermal insulating cellulose aerogel
    SHI Jilei, TANG Chunxia, FU Shaohai, ZHANG Liping
    Journal of Textile Research. 2024, 45(04):  8-14.  doi:10.13475/j.fzxb.20230906101
    Abstract ( 52 )   HTML ( 13 )   PDF (6168KB) ( 23 )   Save
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    Objective New generation of cellulose aerogel has become a research hotspot in recent years because of its wide source of raw materials, good biocompatibility, low density and low thermal conductivity, and has been widely used in civil, military, aerospace and other fields. However, cellulose-based aerogel has some disadvantages such as poor skeleton strength, brittleness, which seriously limit its development and application in the field of thermal insulation. Therefore, a cellulose-based aerogel with high strength and high compressive resilience was studied by introducing silane coupling agent to covalent crosslinking with cellulose.

    Method A cellular-network aerogels with cellular-network structure was constructed by freeze-drying by using in situ covalent cross-linking of silane coupling agent 1,2-di (trimethoxysilyl) ethane (BTMSE) and cellulose nanofibers (CNF) to form strong interfacial interaction. By adjusting the content of silane coupling agent, the thermal insulation aerogel with high strength and good compressive resilience was obtained. The relationship between the amount of BTMSE added and the mechanical properties and thermal conductivity of aerogel was studied. The microstructure, chemical structure and thermal insulation properties of aerogel were analyzed.

    Results Chemical bonding was considered first in studying the forming mechanism of CNF/BTMSE aerogel. Under acidic conditions, BTMSE was hydrolyzed to form reactive silanol, and covalently was polycopated with the hydroxyl group on cellulose to form Si—O—C bond, which acted as the cross-linking point between CNF. Chemical bonding enabled cross-linking and entangling among CNF to form network structure. The second was the investigation of the temperature-induced effect. In the process of low temperature freezing, water continuously formed ice crystals, and layered ice crystals gradually grew and squeezed nanofibers, so that the nanofibers gathered among the ice crystals, and the fibers were tightly stacked and intertwined to form a three-dimensional network structure. Finally, after freeze drying, the ice crystals were directly sublimated to form a honeycomb cell structure. Due to chemical crosslinking with siloxane, the CNF/BTMSE aerogel demonstrated a more regular pore structure. After BTMSE modification, the pore size of cellulose aerogel showed a decreasing trend, proving the formation of crosslinking network. Infrared spectroscopy and XPS spectroscopy confirmed the successful introduction of silane coupling agents in 3# aerogel (the mass ratio of CNF and BTMSE is 2∶3) and the covalent force with the hydroxyl group on cellulose. Under 60% compression strain, the strength of CNF aerogel was 13.1 kPa, and the strength of 3# aerogel was 34.8 kPa, and the deformation recovery rate was 97% after the external force was removed, indicating good resilience. In addition to higher compressive stress and resilience, the aerogel modified by silane coupling agent also showed excellent cyclic compressibility resistance. After 200 cycles of cyclic compression, the aerogel still maintained 90.4% of its initial height, and the strain loss was less than 10%. The regular pore structure formed by silane modification and the mesopole formed by crosslinked network make the aerogel demonstrated low thermal conductivity. The thermal conductivity of 3# aerogel was 31.90 mW/(m·K), representing good thermal insulation stability, and the thermal conductivity increase was kept below 1% after 60% compression strain, which is well below the 20% increase in CNF aerogels. The 3# aerogel produced a temperature difference of about 70 ℃ on a 130 ℃ platform, showing good thermal insulation performance.

    Conclusion High strength and superelastic cellulose based aerogel materials were prepared by in situ covalent crosslinking and freeze-induced assembly. It improves the problems that the structure of pure cellulose aerogel with poor resilience is easy to collapse and the thermal insulation performance is decreased in real environment. It has great application value in flexible thermal insulation field.

    Preparation and performance of ion sensors based on composite nanofiber membranes
    LIANG Wenjing, WU Junxian, HE Yin, LIU Hao
    Journal of Textile Research. 2024, 45(04):  15-23.  doi:10.13475/j.fzxb.20231200101
    Abstract ( 28 )   HTML ( 3 )   PDF (13672KB) ( 13 )   Save
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    Objective In order to develop a flexible ion sensor with high stability and sensitivity, polyvinylidene fluoride ionic liquid ((PVDF)/IL) composite nanofibrous membranes were prepared by electrostatic spinning, and assembled with electrode materials to form an ion sensor with a sandwich structure.

    Method The effects of spinning liquid mass fraction and IL content on the spinning process and fibrous membrane morphology were investigated using scanning electron microscopy, and the elemental distribution and chemical structure of the composite nanofibrous membranes were characterized using energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The effects of nanofibrous membranes with different IL contents and thicknesses on the sensor performance were investigated using the flexible sensor test system (FSTS), and the ion sensors were attached to human skin and clothes for body signals and motion monitoring, and the real-time output electrical signals were recorded using the FSTS.

    Results When the mass ratio of PVDF was 18%-19% and the dosage ratio of ionic liquid was 2∶1 and 3∶1, the composite nanofibrous membranes had a regular surface, fewer beads, and a uniform distribution of fibre diameters. The addition of ionic liquid increased the number of charged ions in the PVDF nanofibre membranes and made them uniformly distributed. The pressure sensing sensitivity of the ion sensor in the detection range of 0-40 kPa was 32.471 pF/kPa at a PVDF mass fraction of 18% and an ionic liquid dosage ratio of 2∶1. The increase in ionic liquid content in the composite nanofibrous membrane ion sensor resulted in a significant increase in the sensitivity of the sensor. As the thickness of the nanofibre membrane increases, the detection range of the sensor gradually increases and the sensitivity gradually decreases. The hysteresis of the ion sensor was 6.64% with no significant delay or dependence at different pressure levels, with compression rate of 5 000 loading cycles. Ion sensors attached to the surface of human skin and clothing was able to distinguish the motion of the human body by the output pressure-capacitance curves.

    Conclusion The composite nanofibre membrane-based ion sensor exploits the supercapacitive property of the electric double layer (EDL) to accurately detect small-amplitude human motion and large-amplitude joint motion. Meanwhile, the composite nanofibre membrane ion sensor has a pressure sensing with a sensitivity of 32.471 pF/kPa in the detection range of 0-40 kPa, maintains outstanding mechanical stability after 5 000 loading-cycles, has a low hysteresis rate (6.64%) and has no significant delay and dependence. The membrane can be applied in the future to communication with deaf people, human-computer interaction, intelligent control and other fields.

    Application of MXene-loaded cobalt-nitrogen doped carbon nanofibers in lithium-sulfur batteries
    SONG Beibei, ZHAO Haoyue, LI Xinyu, QU Zhan, FANG Jian
    Journal of Textile Research. 2024, 45(04):  24-32.  doi:10.13475/j.fzxb.20231002001
    Abstract ( 29 )   HTML ( 4 )   PDF (9162KB) ( 21 )   Save
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    Objective With its high theoretical specific capacity and high energy density, lithium-sulfur batteries stand out from many energy storage systems. However, the shuttle effect of polysulfides and the slow redox reaction kinetics are serious challenges in the development of lithium-sulfur batteries. Therefore, the adsorption limiting polysulfide and the catalytic conversion of polysulfide have become the research focus of lithium sulfur batteries. Functional interlayers can be endowed with high electrical conductivity, strong adsorption and catalytic capabilities, so interlayer insertion is a simple and effective strategy. The electrospun carbon nanofiber network has a three-dimensional porous structure, which can effectively intercept polysulfide and promote electron conduction inside the battery. In order to enhance the interaction between the material and polysulfide and catalyze its transformation, the introduction of functional material MXene is to be explored in this research.

    Method Using polyacrylonitrile (PAN) as carbon source, 1, 10-Philolin as nitrogen source, polymethyl methacrylate (PMMA) as pore-making agent, cobalt acetate tetrahydrate as cobalt source and MXene as functional material, electrostatic spinning nanofibers were prepared. After pre-oxidation and high temperature carbonization under specific conditions, flexible self-supporting carbon nanofiber interlayer (MX-Co/N-PCNFs) embedded with cobalt single atom was obtained.

    Results The morphology, structure, and impact of MXene addition on the adsorption of polysulfides and electrochemical performance were studied. After 180 degrees of twisting and bending, the surface of the sample showed no cracks and damage, and demonstrated excellent flexibility. The test results show that the total XPS spectrum analysis and peak fitting confirmed the introduction of MXene and the doping of cobalt nitrogen, and that the high degree of graphitization of the sample could be seen through the analysis of Raman spectrum. The specific surface area of MX-Co/N-PCNFs was 257.5 m2/g when the concentration of MXene dispersion was 90 mg/mL and the carbonization temperature was 800 ℃. The dynamic and static adsorption of sulfur proved that MX-Co/N-PCNFs intermediate layer achieved both physical and chemical adsorption to limit the shuttle effect of polysulfide, and also showed that it had the best catalytic activity. By testing the cyclic voltammetry curve (CV), the potential difference between the oxidation peak and the reduction peak of the MX-Co/N-PCNFs intermediate layer was 0.27 V respectively, which proved that it had a small polarization and a strong redox reaction kinetics. It is used as a polar plate and assembled into a symmetrical battery to characterize the liquid-liquid conversion process between liquid sulfur species. At a sweep speed of 50 mV/s, MX-Co/N-PCNFs based symmetric cells exhibit excellent REDOX current response among the three, indicating significant catalytic performance in liquid-liquid conversion processes. The electrochemical impedance spectroscopy results showed that the introduction of MXene nanosheets further promoted the conductivity and wettability of the middle layer of cobalt-nitrogen doped carbon nanofibers, resulting a very small interface impedance and charge transfer impedance. The battery assembled with MX-Co/N-PCNFs as the interlayer showed a capacity of 971.5 mA·h/g after 100 cycles at 0.2 C. The capacity decay was only 0.063% after 400 cycles at 1 C, and the capacity was still 853 mA·h/g after 50 cycles at 0.5 C with high sulfur loading (4 mg/cm2), which was better than that of the interlayer without the addition of MXene nanosheets.

    Conclusion MXene was added to the middle layer of nitrogen-doped carbon nanofibers embedded with cobalt single atom. Through electrochemical comparison, it is confirmed that MXene could improve the electrochemical and electrocatalytic properties of porous electrostatic spinning carbon nanofibers, promote the adsorption and catalytic conversion of polysulfide in lithium-sulfur batteries, and improve the energy density of the positive electrode. The inclusion of non-active materials in the binder is avoided, and the influence on the energy density of the lithium-sulfur battery is reduced.

    Research progress in fiber-based transistors
    QING Xing, XIAO Qing, CHEN Bin, LI Mufang, WANG Dong
    Journal of Textile Research. 2024, 45(04):  33-40.  doi:10.13475/j.fzxb.20231202402
    Abstract ( 29 )   HTML ( 5 )   PDF (12958KB) ( 13 )   Save
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    Significance The flourishing development of emerging industries including the Internet of Things, artificial intelligence, brain-like computing has promoted the miniaturization of electronic devices. To integrate them into daily life, e-textiles which can seamlessly combine the electronic components with functions like energy supply, perception, computing, communication, execution and display with fiber and fabrics have aroused great interest. As one of the basic components for signal processing and computing, transistor is an indispensable part in e-textiles. Meanwhile, fiber material featured with light, soft and diverse forms is regarded as the first choice for making wearable electronic devices. Hence, it is of great significance to develop high-performance fiber-based transistor for E-textile.

    Progress In order to study comprehensively the application prospects of fiber-based transistors in E-textiles, this review summarizes the composition, classification and working principle of fiber-based transistors, especially the fiber-based field effect transistor (FET) and fiber-based organic electrochemical transistor (OECT). Comparing to the fiber-based FET, the fiber-based OECT assembled with a solution or gel electrolyte exhibits various advantages such as ionic-electronic transport characteristic, low processing temperature and operating voltage (< 1 V), large transconductance (in mS range) and good biocompatibility. Moreover, the research progress of fiber transistor in wearable and implantable biochemical sensors, brain-like neuromorphic devices, such as memristor, artificial synapse, and logic circuits is reviewed. The fiber transistor promotes the development of national strategic industries such as e-textiles, human-computer interaction, intelligent medical treatment and is expected to driving the human society to the era of pan-intelligence.

    Conclusion and Prospect Fiber transistors have made great progress in recent decades, but the problems and challenges in device integration, performance optimization and practical application are still serious. The materials and fabrication processes for the mainstream thin-film transistor are not compatible with the porous and highly deformable fiber or textile substrates. The mechanical mismatch between the fiber electrode and organism tissue, the inflammation and biofouling all limit the fiber transistor application for chronic and stable in-vivo monitoring. The structure, energy consumption and synaptic functions of brain-like neuromorphic devices is still far from the human brain. More works need to be done.

    Review on self-powered triboelectric textiles for wearable electronics
    WANG Ning, GONG Wei, WANG Hongzhi
    Journal of Textile Research. 2024, 45(04):  41-49.  doi:10.13475/j.fzxb.20231000902
    Abstract ( 34 )   HTML ( 1 )   PDF (6446KB) ( 19 )   Save
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    Significance Numerous energy conversion methods have evolved one after another to address the issue of energy supply for wearable electronic items as public demand for smart wear grows. Power plants' conventional energy delivery method is unsuitable for the development of functional electronics connected to wearable technology. The shortcomings in capacitance, safety risks, environmental risks, and inconvenience make rechargeable energy storage battery systems unsuitable for use in wearable electronics. Triboelectric textiles excel in low-frequency mechanical energy harvesting and self-driven sensors, making them a leader in the field of energy fabrics.

    Progress Triboelectric nanogenerators (TENG) based on contact electrification and electrostatic induction effects have proliferated since researchers introduced an energy transfer technique that transforms kinetic energy into electrical energy. Multiple preparation procedures for triboelectric fabrics have been increasingly refined as a result of extensive research and development on the functionality and application of TENG. Triboelectric textiles are categorized into two primary types based on variations in their macroscopic morphology: fiber structure and fabric structure. Triboelectric fiber is the fundamental building block of triboelectric textiles, as well as the cornerstone of scientific research and industrial transformation of triboelectric textiles. Triboelectric fibers fall into three types: yarn-based TENG, fabric-based TENG, and nonwoven-based TENG. Tribostatic charges in yarn based TENGs can be produced by contact electrification of a single fiber alone, without the need for external media. The fabric based TENG is easy to integrate with conventional clothes because of its broad variety of material alternatives and relatively basic construction. More atomic-level contact area is available for triboelectric electrification in nonwoven-based TENGs due to their greater specific surface area.

    Conclusion and Prospect There is still a long way to go before triboelectric textiles are used in commercial settings, despite tremendous advancements in theoretical research and practical demonstrations. The physical mechanism of contact electrification was addressed based on the theoretical basis of triboelectric technology to increase the energy conversion efficiency and comfortable and natural wearing feeling of triboelectric fabrics. The development in yarn-based TENGs, fabric-based TENGs, and nonwoven-based TENGs is outlined from the perspectives of materials, structures, operating modes, and functionality. Triboelectric fiber applications in flexible sensing, electronic skin, intelligent robots, and interactive devices are also discussed. The current obstacles and future potential for triboelectric textiles are highlighted to provide some theoretical reference for the high-value combination of triboelectric technology and the traditional textile sector.

    Fiber Materials
    Synthesis kinetics and properties of phosphorus containing flame retardant polyethylene terephthalate
    YUAN Ye, ZHANG Anying, WEI Lifei, GAO Jianwei, CHEN Yong, WANG Rui
    Journal of Textile Research. 2024, 45(04):  50-58.  doi:10.13475/j.fzxb.20221101001
    Abstract ( 31 )   HTML ( 4 )   PDF (4063KB) ( 9 )   Save
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    Objective Polyethylene terephthalate (PET) is a very widely used polyester fiber material, but PET-based materials have problems of being flammable or combustible, so low toxicity, low smoke and flame retardant lasting [(6-oxygen generation-6H-dibenzo [c, e] [1,2] -6-group) methyl] butanedioic acid (DDP) is selected as a flame retardant to PET. The purpose of studying the synthesis kinetics of PET is to effectively regulate the reaction rate, reaction conditions, product quality and other process parameters, and explore the internal law of polyester synthesis reaction, so as to guide the actual production process of polyester.

    Method This study chose copolymeric flame retardant PET as an example of trace modified polyester, prepared different DDP added flame retardant polyester, studied the two phases of esterification and condensation, explored the different condensation temperature, different flame retardant added on the synthetic reaction kinetics, in order to achieve the purpose of process regulation through production amplification. The thermal properties, crystallization properties, flame retardant properties and mechanical properties of flame retardant PET were characterized by testing differential scanning calorimetry, extreme oxygen index, conical calorimeter, scanning electron microscope, energy dispersive spectrometer and microinjection molding instrument.

    Results The activation energy (Ea) of the flame retardant PET with different phosphorus contents of the esterification reaction was gradually decreased from 81.37 kJ/mol to 59.52 kJ/mol with increasing amount of DDP addition at the same reaction temperature. For the same polymerization system, the increase in condensation temperature led to greater reaction rate constant and faster reaction speed. At the same condensation temperature, for different polymerization systems, the reaction rate was constantly decreased and Ea was significantly increased from 69.67 kJ/mol to 223.49 kJ/mol. With the increase of DDP addition, the cold crystallization temperature (Tcc) was increased from 121 ℃ to 143 ℃, the melting temperature (Tm) from 249 ℃ to 224 ℃, and the thermal crystallization temperature (Tmc) from 198 ℃ to 169 ℃. At the same condensation temperature, with the increase of DDP addition, LOI was gradually increased. When the phosphorus content was 1.10%, LOI reached 34%, and LOI did not change significantly. At the same condensation reaction temperature, the ignition time (TTI) was gradually increased to 57 s with the increase of DDP addition, and when the condensation reaction temperature was 270, 275, and 280 ℃, the peak heat release rate (pHRR) and the total heat release amount (THR) were significantly reduced. C and O were the residual carbon of PET, while the residual carbon of flame retardant PET was composed of C, O and P elements, and with the increase of DDP addition, the content of O and P were increased to 13.69% and 9.18%, respectively. PET showed more and denser residual carbon holes, while after DDP with phosphorus content of 0.65% was added, the holes of the residual carbon surface were significantly smaller, but the number of holes was not significantly improved. When the phosphorus content was increased to 1.10%, the number of residual carbon holes was greatly reduced, and the surface of the carbon layer became smoother and more compact with certain isolation effect. After the addition of flame retardant DDP, the elastic modulus of the polymer was increased from 947.3 MPa to 1 103.1 MPa, and with the addition of flame retardant DDP, the fracture elongation of the polymer was decreased from 247% to 190%.

    Conclusion Compared with PET, the addition of DDP promoted the positive esterification reaction but hindered the polycondensation reaction, and the flame retardancy of PET-DDP was significantly improved, and the change of polycondensation reaction temperature had less influence on the flame retardancy. In conclusion, the study on the kinetics of esterification and polycondensation reactions and the flame-retardant properties of PET-DDP provides data support for the adjustment of process parameters in the later industrial production of flame retardant polyester.

    Preparation and performance of polycaprolactone/MgO composite nanofibrous filter membrane
    JIA Lin, DONG Xiao, WANG Xixian, ZHANG Haixia, QIN Xiaohong
    Journal of Textile Research. 2024, 45(04):  59-66.  doi:10.13475/j.fzxb.20221101801
    Abstract ( 35 )   HTML ( 3 )   PDF (7929KB) ( 13 )   Save
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    Objective At present, the pollution of particulate matter is still serious, and hence preparation of fiber filter materials with multiple functions such as ultraviolet(UV) protection, antibacterial, high comfort and biodegradability is imperative and important in various application prospects. Magnesium oxide (MgO) nanoparticle is one type of nanostructured metal oxides, it had been chosen as antibacterial materials because of its broad-spectrum antibacterial property, biocompatibility, non-toxicity, high thermal stability, high chemical stability, and high surface reactivity. Polycaprolactone (PCL) possess good biodegradation, biocompatibility and non-toxicity. As an environmentally friendly polymer, PCL is often used in biomedical materials such as tissue engineering. This paper reports on a research that nanofibrous filter membrane with higher filtration efficiency, lower pressure drop, improved antibacterial property and excellent ultraviolet protection performance.

    Method In this work, MgO nano-particles were added into polycaprolactone solution before preparing PCL/MgO nanofibrous filter membrane through electrospinning. The fibre characteristics including fibers morphologies, chemical group, crystalline texture and hydrophilic performance were tested and analyzed through scanning electron microscope, Fourier infrared spectrometer and X-ray diffraction. In addition, the filtration performance, antibacterial properties, UV protection performance and the mass fraction of MgO nanoparticles on the properties of nanofiber membrane were also studied and evaluated.

    Results The morphologies of PCL and PCL/MgO nanofibers demonstrated smooth and interconnected fiber characters, and that when the MgO mass fraction was 1.5% and 2.0%, MgO nanoparticles gathered on the surface of PCL/MgO composite nanofibers. The average fiber diameter of PCL nanofiber were 147 nm, while the diameter of PCL/MgO composite nanofiber ranged from 216 to 285 nm. The addition of MgO increased the diameter of nanofiber, decreased the standard deviation of diameter, and PCL/MgO composite nanofibers showed more uniform fiber distribution. Pure PCL nanofiber membrane had lower air permeability and higher water vapor permeability, with the air permeability of 77.61 mm/s and the water vapor permeability of 3 095 g/(m2·d). The presence of MgO nanoparticles in PCL/MgO nanofibers increased the air permeability of nanofiber membranes, while decreased the water vapor permeability of nanofiber membranes. PCL and PCL/MgO nanofibers had the characteristic carbonyl peaks at 1 724 cm-1, CH2 stretching peaks at 2 945 cm-1 (asymmetric) and 2 865 cm-1 (symmetric), C—O stretching peaks at 1 050 cm-1, C—O—C stretching peaks at 1 240 cm-1 (asymmetric) and 1 163 cm-1 (symmetric). PCL nanofiber membrane showed the characteristic diffraction peaks at 21.4° and 23.8°, relating to the semi-crystalline structure of PCL macromolecular. On the pattern of PCL/MgO nanofiber membrane, three characteristic diffraction peaks at 43.2°, 62.5° and 78.7° corresponded to the (200), (220) and (222) crystal planes of the face central cubic structure of MgO, indicating that the MgO NPs still maintained their crystalline structures. The UV protection factor (UPF) of pure PCL filtration membrane was 21.37, the transmittance to UVA was 5.36%, while the UPF of PCL/MgO composite filtration membranes were 53.86-76.21, the transmittance to UVA were 2.01%-1.45%. The insertion of MgO nanoparticles in PCL nanofibrous membranes enhancend the UV protection performance of PCL/MgO composite membranes significantly. The filtration efficiency of pure PCL nanofiber membrane was 92.11% and the pressure drop was 77.42 Pa, while the filtration efficiency of PCL/MgO nanofibrous filter membranes were 97.57%-98.87% with the pressure drop being 91.18-99.96 Pa. Compared to pure PCL nanofibrous filter membrane, the filtration performance of PCL/MgO nanofibrous filter membranes demonstrated effictive increases because of the higher surface reaction and higher absorption of MgO nanoparticles to particulate matters. When the mass fraction of MgO nanoparticles was 1.0%, the filtration performance of composite PCL nanofiber membrane was best with 98.87%, filtration efficiency, while its resistance pressure drop was 99.96 Pa. The maximum quality factor was 0.044 85. All PCL/MgO composite nanofibrous membranes possessed significant antibacterial efficiency in comparison with pure PCL nanofibers. When the MgO mass fraction was 0.5%, 1.0%, 1.5% and 2.0%, the antibacterial activities of PCL/MgO nanofibers membrane against Escherichia coli were 73.78%, 83.75%, 95.13% and 98.55% respectively, while the antibacterial activities against staphylococcus aureus were 53.61%, 62.63%, 93.02% and 97.56%. Antibacterial activity against Escherichia coli was stronger than that against staphylococcus aureus, which is mainly due to the intrinsic cell wall structure of these two bacterial. In addition, there were many lattice defects on the surface of MgO nanoparticles with positive charge, which were more likely to form strong interaction with negatively charged Escherichia coli, so as to inhibit the growth of bacteria.

    Conclusion PCL/MgO composite nanofibrous filter membranes were prepared through electrospinning technology, the addition of MgO nanoparticles significantly increased the filtration performance, antibacterial performance and UV absorption protection performance of PCL/MgO composite nanofiber filter membrane, which can be developed as a multifunctional nanofiber filter material. This work showed the promise of PCL nanofibers and metal oxide antibacterial membrane in various biomedical applications, including in protective filter membranes. It laid a foundation for the further industrial development of biodegradable multifunctional mask filter materials.

    Preparation and photocatalytic performance of titanium dioxide/porous carbon nanofibers composite material
    LU Yaoyao, YE Juntao, RUAN Chengxiang, LOU Jin
    Journal of Textile Research. 2024, 45(04):  67-75.  doi:10.13475/j.fzxb.20230403001
    Abstract ( 22 )   HTML ( 1 )   PDF (4657KB) ( 7 )   Save
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    Objective With the widespread use of organic dyes, the residue of which have gradually become the main component of industrial wastewater and caused serious water pollution. As an environmentally friendly photocatalyst, titanium dioxide (TiO2) nanoparticles have been used in dye degradation, wastewater treatment and other fields due to their high photocatalytic activity, large specific surface area and easy preparation, but they also have problems such as wide band gap and difficult separation and recovery. Therefore, it is urgent to find a suitable carrier material to achieve effective separation and recovery of TiO2 without reducing its photocatalytic activity and stability.

    Method Porous carbon nanofibers (PCNF) were prepared by electrospinning, high-temperature calcination, and acid dissolution. Then anatase TiO2 was loaded onto its surface by secondary nucleation method to obtain photocatalytic TiO2/PCNF composites. The morphology, structure, composition, and light absorption properties of TiO2/PCNF nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV-Vis diffuse reflection spectroscopy, and the photocatalytic properties of TiO2/PCNF nanocomposites were tested by degradation methylene blue (MB) solution.

    Results SEM results showed that TiO2 nanoparticles were uniformly loaded on porous CNF surfaces, while it was difficult to be loaded on smooth CNF surfaces. This showed that the mesoporous surface of carbon nanofibers was the key to the loading of TiO2. XRD results indicated that the three samples prepared, i.e., TiO2, TiO2/PCNF and TiO2/CNF were of anatase phase TiO2. Compared with rutile phase and titanite phase, anatase phase TiO2 had better photocatalytic activity, so it was beneficial to improve the photocatalytic performance of TiO2/PCNF. The full spectrum of XPS showed that Ti, O, C, F and N elements existed in TiO2/PCNF composites, which further proved that TiO2 had been successfully loaded onto the surface of porous carbon nanofibers. The UV-Vis DRS results showed that significant redshift could occur when TiO2 was loaded onto both PCNF and CNF surfaces, which not only increased the utilization rate of visible light, but also reduced the band gap value. Brunauer-Emmett-Teller(BET)results suggested that the prepared TiO2/PCNF composites had mesoporous structures, and the specific surface area was as high as 331.9 m2/g, providing abundant active sites for adsorption and surface reaction. The photocatalytic tests showed that the removal efficiency of TiO2/PCNF composites was higher than that of the control group with the same TiO2 content. After 30 min illumination of TiO2/PCNF composite material, the removal rate of MB solution of 5 mg/L was 98.6%, and after 60 min illumination, the removal rate of MB solution could reach 99.6%. However, the removal rates of TiO2 and TiO2/CNF composites in the control group were only 93.3% and 73.2% for MB solution after 30 min illumination. After repeated use for 5 times, the removal rate of TiO2/PCNF on MB solution remained at 95.0%. All these indicated that TiO2/PCNF composites have excellent photocatalytic and reusable properties.

    Conclusion The TiO2/PCNF composite was successfully prepared by secondary nucleation method, and the composite had excellent photocatalytic and reusable properties. Compared with CNF, it was found that PCNF with mesoporous structure was more conducive to the loading of TiO2. The improvement of photocatalytic performance of TiO2/PCNF composites was mainly attributed to the following reasons. ①All the prepared TiO2 were anatase phase, which has better photocatalytic activity than rutile phase and plate titanite phase. ②The TiO2/PCNF composite increased the response range of TiO2 to visible light, which was conducive to improve the utilization rate of TiO2 for visible light. ③PCNF had excellent electrical conductivity, which was conducive to accelerating the separation of TiO2 photogenerated electrons and holes. ④PCNF had a large specific surface area, which providing more active sites both for MB adsorption and surface reactions.

    Textile Engineering
    Influence of roving performance on back drafting of ring spinning frame
    WU Jiaqing, HAO Xinmin, WANG Meihui, GUO Yafei, WANG Ying
    Journal of Textile Research. 2024, 45(04):  76-82.  doi:10.13475/j.fzxb.20220805101
    Abstract ( 30 )   HTML ( 2 )   PDF (3854KB) ( 13 )   Save
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    Objective The purpose of this paper is to explore the shape change of roving whisker in the back drafting area of spinning frame and the influence of roving performance on the drawing effect of the back drafting area of spinning frame. It has certain beneficial effect for producers to set the roving production process and optimize the spinning production parameters.

    Method In this research, polyester fiber (1.67 dtex×38 mm) and viscose fiber (1.67 dtex×51 mm) were used as raw materials to prepare roving samples with different roving weights, roving twist and fiber length. The roving section was observed by resin embedding method, and the roving mechanical properties were measured by stretching method. The drawing experiment was carried out on the digital spinning machine SSP-01 to observe the shape change of the roving whisker and cut off the drawing sample. The drawing effect of the back area of the spinning yarns was analyzed, based on the isometric cutting and weighing method.

    Results The section of roving whiskers in the rear drafting area was round at first, became a flat ribbon after extrusion by roller pliers, and then gradually shirked and recovered to a circular shape with a certain tightness. Roving (450 tex, 4.01 twist/m or 4.48 twist/m) had better mechanical properties than another samples. The additional friction boundary generated by roving twist back was found to control effectively the movement of fibers, so that the fiber accelerated points was concentrated and close to the clamp mouth of the middle roller, and the drafting effect was stable. The variation of roving strength indirectly proved that the roving strength was better at the twist of 4.01 twist/m and 4.48 twist/m, indicating that the additional friction boundary generated by roving twist back could effectively control the fiber movement. The drafting effect of 350 tex roving whisker met the draft requirement of concentration of the fiber accelerated point and as close as possible to the jaws of the middle roller when the draft multiple of the back area was 1.1 times and the draft spacing was 50 mm. However, under the same drafting conditions, the fiber accelerated points of 600 tex roving fiber was in region Ⅰ, even earlier, which seriously affect yarn quality. Furthermore, without increasing the pressure of the roller, the high weight of the roving was not conducive to the drafting of the roving, while the speed difference between fast fiber and slow fiber leads to more and more obvious delamination behavior with the increase of roving weight. At small drafting multiples (1.10 times and 1.22 times), the fiber weight ratio of each block in the whole post-drafting area changed slightly, indicating that only a small relative displacement occurred between fibers. When the draft ratio was 1.36 times, the fiber weight ratio of each block decreased greatly, indicating that the fiber accelerating points occurred earlier. Even at large draft multiples (1.50 and 1.65 times), the proportion of fiber weight was decreased sharply between zone Ⅲ and zone Ⅳ, indicating that the relative displacement between fibers was too large, resulting in draft instability.

    Conclusion The shape of the roving whisker section was constantly changing during the drafting process in the back area, which was accompanied by a slight twist redistribution. The additional friction boundary created by roving twist can effectively control the movement of the fiber, so that the fiber accelerated points were concentrated and closed to the jaws of the middle roller, which was beneficial to the stable drafting. In addition, the small weight of roving facilitated stable drafting. As for heavy roving, it was recommended to increase the roller pressure and roving twist to control fiber movement. The draft factor of the back area should be small, within 1.10 to 1.36 times was appropriate.

    Preparation and properties of flame-retardant acrylic/phenolic resin fabrics
    DING Qian, WU Junlin, JIANG Hui, WANG Jun
    Journal of Textile Research. 2024, 45(04):  83-88.  doi:10.13475/j.fzxb.20220900301
    Abstract ( 33 )   HTML ( 4 )   PDF (5298KB) ( 14 )   Save
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    Objective Phenolic resin fiber has attracted extensive attention owing to its unique flame retardant properties. However, the difficulty in spinning limits the garment applications of phenolic resin fibers due to low fiber strength. In order to solve this problem, this paper proposes a novel method of blending phenolic resin fiber and flame-retardant acrylic fiber and exploring their feasibility in garment.

    Methods During spinning process, the ratio of phenolic resin fiber and flame retardant acrylic fiber were set to 20∶80, 40∶60, 60∶40 and 80∶20, respectively. Then, the blended yarns were weaved into fabrics with plain weave structure, and their structure, flame retardant, mechanical properties, wear resistance, thermal and wet comfort properties of the fabric were characterized according to national standards.

    Results With the increased of the phenolic resin fiber from 20% to 80%, the fabric exhibited yellow, from light to deep, because the natural color of the phenolic resin fiber is golden yellow, while that of acrylic fiber is white. Notably, the thickness and surface density were gradually increased, as the content of phenolic resin fiber in fabric increased. According to GB/T 5455—2014 "Textiles-Burning behaviour-Determination of damaged length, afterglow time and afterflame time of vertically oriented specimens", the damaged length of blended fabrics should be less than 10 cm, and no afterglow and melt dripping phenomenon should occur. Although, with the increase of phenolic resin fiber, the afterflame time and damaged length of the fabric gradually decreased, but it still meet the standard requirements of flame retardant fabrics.

    With the increase of phenolic resin fiber content in the samples, the breaking strength and the work of fracture of the four fabrics were gradually decreased due to the low breaking strength of the phenolic resin fiber, but the breaking elongation remained unchanged. The thermal and wet comfort properties of the fabrics were also studied and the results were summarized. As the content of phenolic resin fiber increased from 20% to 40%, the thermal insulation effect of the fabrics gradually enhanced. However, there was no significant change in thermal insulation as the content of phenolic resin fiber further increased to 60% and 80%. With the increase of phenolic resin fiber proportion, the moisture absorption rate gradually enhanced, and the permeability of the samples demonstrated a decrease and then an increase. The fabrics with the content of the phenolic resin fiber at 40% and 60%, had the same moisture conductivity. The pilling grades of four fabrics were 1.5, 3, 3.5 and 4, suggesting increased wear resistance of the fabrics with the increasing content of phenolic resin fiber.

    Conclusion Phenolic resin fiber based yarns via blending with flame retardant acrylic fiber were prepared, and 4 types of yarns with different content of phenolic resin fiber were woven with plain weave structure. Their mechanical properties, flame retardant and thermal and wet comfort properties were carefully investigated. The results suggested that all types of blending spinning yarn based fabrics meet the acquirement of flame retardant, mechanical and air permeability. Besides, the fabrics with the content of phenolic resin fiber at 40% and 60% could reach the needs of flame retardant textiles and have good wear performance. Our blending spinning strategy will provide reference for the development of phenolic resin based wearable products.

    Interlaminar shear properties of composites with Ni-Cr alloy weft knitted electric heating layer
    FENG Ya, SUN Ying, CUI Yanchao, LIU Liangsen, ZHANG Hongliang, HU Junjun, JU Ao, CHEN Li
    Journal of Textile Research. 2024, 45(04):  89-95.  doi:10.13475/j.fzxb.20221002801
    Abstract ( 27 )   HTML ( 2 )   PDF (9121KB) ( 6 )   Save
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    Objective In order to ensure the helicopter can operate safely in all weather, especially at low temperature, the engine inlet anti-icing protection is necessary. Therefore, it is of great significance to develop electrothermal composites that can not only meet the requirements of lightweight helicopter inlet structure, but also realize the heating function. Due to the structural complexity of the multi curvature of the helicopter inlet, a glass filer/epoxy laminated composite with integrated structure and function is developed based on the weft knitted fabric with excellent formability performance.

    Method Three kinds of nickel chromium alloy wires of different fineness are selected to design and prepare 9 kinds of fabrics with three kinds of weave structures: plain, rib and interlock. Based on the principle of minimum thickness, six kinds of weft knitted electrically heated fabrics were selected. The glass filer/epoxy laminated composite was prepared by using nickel chromium alloy weft knitted fabric as the intermediate electric heating layer and the autoclave composite molding process was preferred. The electrothermal properties and interlaminar shear properties of the composites were tested by infrared thermography and universal testing machine.

    Results The results showed that under 8 V direct current(DC) voltage, the temperature of the six kinds of electrothermal composites can rise above 37 ℃, up to 72 ℃, taking 30 s, and the heating rate can reach 1.58 ℃/s. The composites showed that the maximum equilibrium temperature is positively related to the fineness of Ni-Cr alloy wire. Under 8 V DC voltage, the maximum equilibrium temperature of plain composite samples with nickel chromium alloy wire fineness of 0.08 mm, 0.06 mm and 0.04 mm in 30 s is 72.8 ℃, 67.1 ℃ and 49.0 ℃respectively. Compared with rib and interlock, the maximum equilibrium temperature of plain structure composite is the highest. Based on the fineness diameter of nickel chromium alloy wire is 0.04 mm, the maximum equilibrium temperature of plain, rib and interlock electrothermal composite samples reached in 30 s is 49.0 ℃, 37.2 ℃ and 45.7 ℃ respectively. The electric heating surface temperature of the six electric heating composite materials is evenly distributed, and the temperature difference is within 7 ℃. The surface temperature uniformity of interlock composite is better than that of plain and rib composites, and the surface temperature difference is only 3 ℃. The interlaminar shear strength of glass/epoxy laminated composite without electric heating layer is 74.18 MPa. The interlaminar shear strengths of the longitudinal and transverse specimens of the electrothermal composite materials are higher than 54.97 MPa and 63.01 MPa, respectively. The retention rate of interlaminar shear strength of electrothermal composites is about 74%-97% compared with that of composites without electrothermal layer. The damage morphology of composite sample after was analyzed. According to the analysis of the damage morphology of the electrothermal samples after interlaminar shear test, the longitudinal and transverse shear samples mainly failed because of the bending failure of the outermost prepreg on the lower surface, and a little interface delamination occurred in the middle layer due to the shear failure, but the structure of electrothermal weft knitted reinforced fabric was not damaged.

    Conclusion The preliminary research work shows that the glass filer/epoxy laminated composite material with nickel chromium alloy wire weft knitted fabric as the intermediate electric heating layer prepared by the autoclave composite molding process can achieve both the electric heating function and the bearing mechanical properties of the composite material at the same time, which is expected to meet the design requirements of the helicopter engine inlet anti-icing/deicing system. In addition, it broadens the application range of weft knitted fabric, and also provides a new way for the diversification of the composite electric heating layer used for electric anti-icing, which has the significance of engineering practical application.

    Fabric defects detection algorithm based on multi-scale Laws texture energy and low-rank decomposition
    WANG Zhenhua, ZHANG Zhouqiang, ZAN Jie, LIU Jianghao
    Journal of Textile Research. 2024, 45(04):  96-104.  doi:10.13475/j.fzxb.20230201001
    Abstract ( 28 )   HTML ( 1 )   PDF (9150KB) ( 12 )   Save
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    Objective In order to improve the universality and accuracy of fabric defects detection algorithm for simple textured fabric, pattern textured fabric and stripe textured fabric. A fabric defects detection algorithm based on multiscale Laws of texture energy and low-rank decomposition was proposed.

    Method Firstly, the fabric image is equalized by histogram, and the image is evenly divided into sub-image blocks. Secondly, 28 texture energy features were extracted from each sub-image block (7 Laws filter templates were used to extract the features on 4 scales), and the mean values of all sub-image blocks were calculated, and the feature matrix was formed. Then, the low-rank decomposition model is constructed by the feature matrix, and the low-rank and spare parts are obtained by the direction alternation method (ADM). Finally, the defect saliency maps are generated from the sparse part, which is segmented by iterative threshold segmentation method, and the fabric defect detection results are obtained.

    Results To validate the effectiveness of the proposed algorithm, the ZJU-Leaper colored fabric dataset is used for experiments. Three images, including simple textured fabric, patterned textured fabric, and striped textured fabric, were selected for the experiment, including common defects such as wrong weft, broken warp, flaking and holes. The image size is 512 pixels × 512 pixels. First, the key elements of the algorithm are analyzed. In the feature extraction section, the saliency maps generated with different numbers of Laws filter templates are compared. In the low-rank decomposition part, the saliency maps generated by choosing different balance factors are compared. The experimental results show that 28 Laws filter templates have the best detection effect, and the fabric defect saliency maps is the best when λ values of simple texture, pattern texture and stripe texture fabric are 0.02, 0.12 and 0.05, respectively. Secondly, the defect saliency maps generated by the proposed algorithm in this paper is compared with Gabor combined with low-rank decomposition algorithm (the following content is expressed in Gabor+LR), HOG combined with low-rank decomposition algorithm (the following content is expressed in HOG+LR), and Gabor combined with HOG combined with low-rank decomposition algorithm to generate saliency maps (the following content is expressed in GHOG+LR). Experimental results show that: in the detection of simple texture fabrics, impurities exist in the detection results of Gabor+LR algorithm and HOG+LR algorithm, and the results of GHOG+LR algorithm and the results of the algorithm in this paper are satisfactory. In the detection of pattern-texturing fabrics, the results of the proposed algorithm in this paper are ideal. However, error detection occurs in the detection results of Gabor+ LR algorithm and HOG+LR algorithm, and a small number of impurities also occur in the detection results of GHOG+LR algorithm. In the detection of striped texture fabrics, the results of the proposed algorithm in this paper also are relatively ideal. A small number of impurities appears in the detection results of the GHOG+LR algorithm, while the Gabor+LR algorithm will have error detection when the fabric image does not have obvious defects, and a large number of impurities still appear in the detection of the HOG+LR algorithm. Finally, the timeliness analysis of the algorithm is carried out, and the results show that the detection speed of the proposed algorithm has certain advantages.

    Conclusion In this paper, we propose a fabric defect detection algorithm based on multiscale Laws texture energy and low-rank decomposition. In the feature extraction part, 28 Laws texture energy features are extracted based on four image scales to generate the feature matrix. In the low-rank decomposition part, the low-rank decomposition model is established, and the direction alternation method (ADM) is used to optimize it to get the low-rank and sparse parts of the feature matrix. Experimental results show that the proposed algorithm performs better than other algorithms in detecting simple textured fabrics, patterned textured fabrics, and striped textured fabrics, with some advantages in detection speed. Therefore, the proposed algorithm has better generality, accuracy and detection efficiency.

    Technique for generating knitting parameters from 3-D model of socks and applications
    RU Xin, YE Xiao, YAN Caijie, PENG Laihu, SHI Weimin
    Journal of Textile Research. 2024, 45(04):  105-110.  doi:10.13475/j.fzxb.20221102801
    Abstract ( 29 )   HTML ( 5 )   PDF (4314KB) ( 10 )   Save
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    Objective For customized socks, such as medical socks and sports socks, the existing customized design techniques can only ensure the accuracy of key data for foot length and foot height, but cannot meet the accuracy requirements for the target user's foot that needs to be better fitted. In such cases, a trial-and-error excercise would be necessary to meet the needs of users after obtaining the parameters, which makes the hosiery customization process inefficient.

    Method According to the actual knitting process based on the circular sock machine, the yarn starts from the top and is knitted circularly along the direction of the tube until the sock toe part is knitted. For the proposed technique, the sampling point also started from the top and was iteratively knitted along the sampling axis until the toe part was sampled. The model sampling axis was obtained as the first step. Since the model skeleton was represented the direction of the model, it was selected as the sampling axis. The Shapira L method was adopted and simplified as sampling axis extraction method. The model surface was iteratively sampled to obtained the knitting path graph including the coil size. In this research, the sock top ring was used as the initial sampling ring, the sampling axis was used as the sampling direction for vertical iterative sampling, and the coil height was adjusted during sampling according to the angle between the normal vector of the model surface point and the sampling axis. When calculating the next sampling row, if the number of vertices on the model surface was small, the sampling row would be uneven. Therefore, the weighted average method was used to smooth the sampling points. Since the upper and lower loops were essentially the same yarn during the knitting process of the circular socks machine, it was necessary to connect the sampling point at the end of the current row with the sampling point at the beginning of the next row during iterative sampling. When the position of the next sampling line exceeded the current sampling axis segment, the sampling axis segment was switched to a new sampling axis segment. Since the actual weaving process was cyclically knitted by a single yarn, the end point of the current sampling row was connected to the beginning point of the next sampling row during the sampling process.

    Results In this research, the model of socks was selected, and the number of stitches input was 144 stitches. The knitting parameters were then calculated by the system for the WLF-6F fully formed circular sock machine for knitting. The needle number of the needle cylinder was set to 144 needles, and the yarn material was cotton yarn. The generated results from the model was compared with the dimensions of each part of the knitted socks, and the error was below 4.1%.

    Conclusion Based on the idea of simulating knitting, The model created in this research can output the knitting path diagram that simulates the actual hosiery knitting process after inputting the hosiery model and the required number of stitches. After seelcting the hosiery model and specifying the number of stitches, the parameters required for knitting on the circular hosiery machine can be generated. The modeled sample socks are produced by knitting on the machine with good accuracy, improving the production design rate for customized hosiery.

    Dyeing and Finshing Engineering
    Preparation of cotton fabrics with both double-sided structural colored effect and high hydrophobicity by one-step method
    XIANG Jiaojiao, LIU Hao, OUYANG Shenshen, MA Wanbin, CHAI Liqin, ZHOU Lan, SHAO Jianzhong, LIU Guojin
    Journal of Textile Research. 2024, 45(04):  111-119.  doi:10.13475/j.fzxb.20230405701
    Abstract ( 21 )   HTML ( 4 )   PDF (12669KB) ( 11 )   Save
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    Objective Cotton fabrics are widely used in the textile industry due to their excellent moisture absorption and breathability. However, the hydrophilic properties of cotton fabrics may limit their application in some hydrophobic and anti-fouling clothing. The coloring and hydrophobic effects of cotton fabrics can be achieved by a one-step method, which uses hydrophobic colloidal microspheres as the basic unit of photonic crystals to construct photonic crystals with both structural colored effect and high hydrophobicity on cotton fabric. This approach not only helps to reduce the processing process, but also generates new ideas for the development of multifunctional integrated cotton fabrics.

    Method In this work, hydrophobic poly(trifluoroethyl methacrylate)(PTFEMA)colloidal microspheres were prepared by soap-free emulsion polymerization method. The microspheres were used as the building blocks of photonic crystals. The cotton fabric with double-sided structural colored effect and high hydrophobicity was obtained by a one-step method of dipping and baking.

    Results The size distribution of PTFEMA colloidal microspheres synthesized by soap-free emulsion polymerization was found uniform, the particle dispersion index (PDI) was less than 0.08, the colloidal microspheres had hydrophobic functional group-CF3, and the water contact angle can reach 98.65°. When the mass fraction of PTFEMA colloidal microsphere assembly solution was 20%-30%, the cotton fabrics with obvious color and strong hydrophobicity were able to be prepared via one step method of dipping and baking. The photonic crystal structural colored cotton fabrics showed iridescent effect, and the water contact angle reached about 140°. The results showed that the high hydrophobicity of cotton fabrics with photonic crystal structural coloration was mainly caused by two aspects, i.e., the fluorine-containing group-CF3 carried by the PTFEMA microsphere, and the roughness of the cotton fabrics increased by the photonic crystal structural layer constructed by the PTFEMA microsphere.

    Conclusion Photonic crystals composed of PTFEMA colloidal microspheres with excellent monodispersion were constructed by the one-step method of dipping and baking, facilitating the color enhancement and high hydrophobicity of double-sided structure of cotton fabrics. The effect of mass fraction of PTFEMA microsphere assembly solution on the structure color and hydrophobicity of cotton fabric was studied, and the results show that 20%-30% microsphere assembly solution is suitable for forming cotton fabric with obvious structural color and high hydrophobicity. In addition, the hydrophobic mechanism of cotton fabric with photonic crystal structural coloration is discussed. It is found that the hydrophobic group-CF3 carried by the PTFEMA colloidal microspheres, and the photonic crystal array constructed by the microspheres increase the roughness of the cotton fabric, which results in the high hydrophobicity of the structure. Therefore, the combination of the one-step method of dipping and baking, cotton fabric and photonic crystal structure can achieve the structure color of cotton fabrics and provides strategic support for the preparation of highly hydrophobic cotton fabric.

    Preparation and application of durable and multifunctional photothermal flame retardant fabrics
    WANG Xiaomeng, LI Tingting, SHIU Bingchiuan, LIN Jiahorng, LOU Chingwen
    Journal of Textile Research. 2024, 45(04):  120-125.  doi:10.13475/j.fzxb.20220809901
    Abstract ( 24 )   HTML ( 3 )   PDF (5027KB) ( 11 )   Save
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    Objective In order to maintain human body temperature in harsh cold environments, there is a need for green and safe photothermal conversion textiles to convert renewable free solar energy into heat to obtain safe and efficient personal heating materials for human body heat management. At the same time, there is also a need for fire retardant properties in order to prevent fire emergencies during the photothermal conversion process. Therefore, it is of great practical importance to prepare photothermal flame retardant fabrics that can be used for long-term service.

    Method Herein, to prepare multifunctional photothermal flame retardant fabrics that can be self-heated during daytime and have excellent fire resistance, polydopamine (PDA)-assisted aramid (PSA) nonwoven fabrics were used as hydrophilic substrates, Fe3O4 as the photothermal functional material and ammonium polyphosphate (APP) as the flame retardant functional material. The multifunctional flame retardant photothermal fabric obtained by wrapping the Fe3O4 microspheres prepared by co-precipitation method with the help of viscous ammonium polyphosphate APP with a functional coating using simple impregnation. The structure and properties of the flame retardant photothermal fabric were characterized by means of scanning electron microscopy, Fourier transform infrared spectroscopy, time-temperature curves and ignition experiments, and the durability of the flame retardant photothermal fabric was characterized by observing the fabric morphology before and after placement in acid and alkali solutions.

    Results After the PDA treatment, the fabric surface became rougher, providing more active sites and allowing Fe3O4 and APP to be fully loaded on the fabric surface. The characteristic peaks belonging to PDA are still present in addition to those of Fe3O4, indicating that Fe3O4 does not change the original structure of the PSA nonwoven fabric. The temperature change of PSA/PDA fabric and PSA/Fe3O4/APP fabric within 720 s of IR light irradiation. It can be seen that compared to the dopamine treated fabric which warmed up to 49.2 ℃, the PSA/Fe3O4/APP fabric can rise from 27 ℃ to 63.2 ℃ in the same period, indicating that the PSA/Fe3O4/APP fabric had excellent photothermal. It showed that PSA/Fe3O4/APP fabric has excellent photothermal conversion ability and Fe3O4 played a major positive role in photothermal conversion. The temperature change of the PSA/Fe3O4/APP fabric over five cycles, demonstrating the recyclability of the fabric's photothermal response, which would help extend the practical application of self-heating garments. A digital image of the fabric during simulated vertical combustion showed that the fabric was not easily ignited and was self-extinguishing after leaving the fire source. The SEM image of the PSA/Fe3O4/APP fabric after combustion clearly showed the fibre and charcoal layer structure, indicating that the functional coating formed by Fe3O4 and APP established a physical barrier that isolated heat and oxygen, effectively inhibiting further combustion of the fabric. The fabric did not significantly change the colour in different acid and alkali solutions, indicating that the PSA/Fe3O4/APP fabric has excellent durability and resistance to oxidation.

    Conclusion Overall, the photothermal flame retardant fabric combined the excellent photothermal properties of Fe3O4 with the flame retardant properties of APP while maintaining the good flexibility of the fabric, which can heat up to over 60 ℃ in daytime, was difficult to ignite when first encountered with flame, and the fabric was self-extinguishing after 12 s away from the fire source, and the fabric still maintained good form in acidic and alkaline environments. This lightweight, soft, durable and versatile photothermal flame retardant fabric showed its potential application in harsh environments as a smart wearable, self-heating garment.

    Synergistic flame retardant finishing of polyester/cotton blended fabric with phytic acid/chitosan
    HU Ziqiang, LUO Xiaolei, WEI Lulin, LIU Lin
    Journal of Textile Research. 2024, 45(04):  126-135.  doi:10.13475/j.fzxb.20230403301
    Abstract ( 19 )   HTML ( 2 )   PDF (10908KB) ( 7 )   Save
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    Objective Polyester/cotton fabric (PC) combines the comfort, air permeability of cotton and stability, high mechanical of polyester, and it is widely used in aerospace, home decoration and other fields. However, the PC produces heat and smoke when burning, accompanied by a serious melting phenomenon, which seriously endangers people's life and health and property safety. The combustion will produce a "wick effect", making the combustion process more intense. Therefore, it is essential to improve the flame retardant performance of PC.

    Method To improve the flame retardant property of PC, by using phytic acid (PA) from biology to provide a phosphorus source and chitosan (CS) to provide nitrogen source and carbon source, the expansion flame retardant system was constructed on the surface of PC by the impregnation-baking process to prepare flame retardant polyester/cotton fabric (PC-PA/CS) which improved the flame retardant property of PC.

    Results The optimal preparation process of PC-PA/CS was determined by the limiting oxygen index (LOI) value: baking temperature was 160 ℃, baking time was 120 s, CS concentration was 30 g/L, and PA concentration was 400 g/L. The LOI value of flame retardant polyester cotton fabric reached to 28.7%. Infrared spectrum analysis showed that the flame retardant finishing liquid composed of PA and CS was successfully deposited on the surface of polyester/cotton fabric. From the scanning electron microscopy images, the fibers in PC showed obvious dents after pretreatment. After flame retardant treatment, the dents on the fiber of PC-PA/CS surface disappeared and the surface became smooth, with a uniform coating on the surface. Compared with PC, after flame-retardant finishing, the decomposition temperature of cotton with PC-PA/CS was advanced from 377 ℃ to 256 ℃, the maximum decomposition rate of fabric was reduced, and stable char layer can be formed. And the char residual rate is increased to more than 25% at 800 ℃ in N2. Flame retardant finishing has succeeded in improving the thermal stability of polyester and cotton fabric. The results of cone calorimetry test showed that the maximum heat release rate (PHRR) and total heat release (THR) of PC were 145.86 kW/m2 and 2.75 MJ/m2, respectively. The PHRR and THR of PC-PA/CS were 96.96 kW/m2 and 2.06 MJ/m2, respectively, which decreased by 33.53% and 25.10%, respectively, showing that the coating had good thermal inhibition ability. The combustion growth rate index (FGR) was decreased from 6.34 kW/(m2·s) to 3.88 kW/(m2·s), and the fire safety of the fabric was increased. The breaking strength of PC was 50.62 N, while that of PC-PA/CS decreased to 48.86 N which remained above 95% of original fabric. The introduction of CS reduced the influence of thermal and acidic environment on the mechanical properties of fabrics. The introduction of flame retardant coating formed a stable expanded carbon layer on the surface during the combustion process of the fabric, which improved the flame retardant performance of the fabric and has a condensed phase flame retardant mechanism.

    Conclusion PC-PA/CS was successfully prepared by dipping-baking method, using PA and CS of biomass to form an expansion flame retardant system together with PC. The LOI value of PC-PA/CS increased significantly from 17.8% to 28.7%, and the droplet phenomenon disappeared, showing excellent flame retardant property. The introduction of flame retardant coating improved the thermal stability and char residual rate of the fabric. Flame retardant finishing effectively reduced the heat release and improved the fire safety of PC. When the fabric was burned, it can form a stable expanded char layer, increased the degree of graphitization of the char layer, and improved the flame retardant performance of PC, which had the flame retardant mechanism of condensed phase.

    Effects of loading different polar drugs on structure and properties of viscose fabrics
    ZHU Weiwei, SHU Wei, GU Wenjuan
    Journal of Textile Research. 2024, 45(04):  136-141.  doi:10.13475/j.fzxb.20220500701
    Abstract ( 22 )   HTML ( 1 )   PDF (4201KB) ( 5 )   Save
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    Objective It is reported that supercritical CO2 fluid (SCF-CO2) can solubilize many drugs and carry them onto the polymer matrices, which allows to process with thermosensitive drugs and it enables to recover a final impregnated implant free of any solvent residue just by depressurization. Therefore, SCF-CO2 can be used to process functional viscose fabric. To achieve good drug loading performance, it is necessary to study the structure and property of different drugs-loaded viscose fabrics impregnated by SCF-CO2.

    Method Viscose fabrics loaded with different polar drugs of nicotinamide, resveratrol were processed by SCF-CO2 at 80 ℃, 20 MPa, 90 min. Scanning electron microscope (SEM) was utilized to analyses the surface morphology of drug-loaded viscose fabric. Fourier transform infrared spectroscopy (FT-IR) was used to monitor the change of the chemical structure of viscose fibre. X-Ray Diffraction (XRD) was applied to measure the crystallinity of drug-loaded viscose fibre. Thermogravimetry (TG/DTA) and INSTRON was respectively utilized to analyse the thermostability and tensile property of viscose fibre.

    Results The results showed that the surface morphology of viscose fibre did not change after SCF-CO2 treatment, and Nicotinamide and resveratrol were observed on the fiber surface in the form of small particles, but the distribution quantity of nicotinamide was more than that of resveratrol. The loading drugs had no effect on the chemical structure of viscose fibre, but it weakened the interaction between viscose fiber molecular chains. As a results, SCF-CO2 impregnation showed a plasticizing effect on viscose fiber. After the treatment of the pure SCF-CO2 the crystallinity was virtually changeless, but after being loaded with nicotinamide and resveratrol the crystallinity of viscose fiber was decreased from 41.37% to 29.28%, 23.37%, respectively. It was found that after the viscose fiber was treated with pure SCF-CO2, the aggregate structure did not change significantly. However, after loading nicotinamide and resveratrol, parts of molecular chains of viscose fiber were changed from the ordered structure into disordered structure and the destruction of the ordered structure of viscose fiber loaded with resveratrol was more significant. It was observed that it had a significant degradation at 300 - 400 ℃ for viscose fibre samples and the quality retention rate was about 10%. The initial decomposition temperatures were 319.8 ℃, 320.2 ℃, 317.3 ℃ and 317.4 ℃, respectively, for untreated viscose fibre, treated viscose fibre by pure SCF-CO2, viscose fibre loaded with nicotinamide, and viscose fibre loaded with resveratrol. The corresponding thermogravimetric loss rates were 94.29%, 93.69%, 95.36% and 95.67% respectively and the maximum mass loss rate were 30.5%/℃, 30.6%/℃, 31.2%/℃ and 32.2%/℃, respectively. The initial decomposition temperature of viscose fabric was decreased slightly after drug loading, and the thermogravimetric rate and maximum mass loss rate were increased slightly, indicating that the thermal degradation performance of viscose fabric loaded with drugs decreased to a certain extent, but it was not distinctive. The tensile breaking strength and elongation at break of viscose fabric after SCF-CO2 treatment did not demonstrate distinctive variations.

    Conclusion The variations in structure and property of drug-loaded viscose fabrics impregnated by SCF-CO2 were charactered. It is found that a higher loading capacity of nicotinamide in viscose fibre results in a higher distribution quantity on the surface of viscose fibre than resveratrol. Under the effect of the swelling, penetrating of SCF-CO2 and the interaction between drugs and viscose fibre molecular chains viscose fibre is plasticized to certain extent, but its chemical structure has no change. The interaction between nicotinamide, resveratrol and viscose fibre molecular chains causes the decreasing of the crystallinity of drug-loaded viscose fibre from 41.37% to 29.28%, 23.37%. After SCF-CO2 impregnation viscose fabric can still maintain good thermal stability and mechanical property.

    Preparation of durable superhydrophobic coatings on polyester fabric surfaces and its water-oil separation properties
    SHAO Mingjun, JIAN Yulan, TANG Wei, CHAI Xijuan, WAN Hui, XIE Linkun
    Journal of Textile Research. 2024, 45(04):  142-150.  doi:10.13475/j.fzxb.20221104201
    Abstract ( 28 )   HTML ( 2 )   PDF (7691KB) ( 11 )   Save
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    Objective Superhydrophobic polyester fabrics have been widely used for the fields of self-cleaning and oil-water separation. However, the preparation methods for superhydrophobic fabrics usually involve complex processes and use of fluorine-containing compounds. Fabric finishes with nonfluorinated chemical coatings to attain durable water repellency have attracted broad attention in both academic and industry. This research aims to explore a green and efficient process for preparing durable superhydrophobic polyester fabrics with fluorine-free compounds.

    Method Polyester fabrics pretreated with oxygen plasma were finished by impregnation method using hydrolyzed solution of methyltrimethoxysilane (MTMS), ammonia water and anhydrous ethanol at the volume ratio of 3∶50∶50. The effect of solution hydrolyzed time on the surface wettability and morphology of the fabrics was analyzed by contact angle measurement and scanning electron microscopy. The surface elemental composition and chemical structure of the polyester fabrics before and after finishing were analyzed by Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the mechanical properties, stabilities, durability and water-oil separation characteristics of the superhydrophobic polyester fabrics were evaluated.

    Results The pretreated polyester fabric by low temperature oxygen plasma was finished by MTMS solution with different hydrolytic times. The results showed that the surface of polyester fabric finished with MTMS presented different rough coatings at different hydrolytic times of MTMS solutions, and additional Si elements were found on the surface with the EDX observation. In FT-IR spectrum of the polyester fabric surface before and after MTMS finishing, it was showed that the bending and stretching vibration absorption peaks of Si—CH3 appeared on the finished polyester fabric surface at 1 262 and 779 cm-1 respectively, and the XPS test showed obviously signal peaks of Si2p and Si2p. The FT-IR and XPS analysis indicated that the MTMS was successfully finished on the surface of the polyester fabric. In the contact angle test, the MTMS-coated polyester fabrics were all hydrophobic, especially the polyester fabrics with 120-180 min hydrolyzed MTMS treatment reached superhydrophobicity, and the water contact angles were all greater than 150° and the sliding angle was less than 10°. Compared with the untreated polyester fabric, the tensile strength of the polyester fabric with 120 min hydrolyzed MTMS treatment was increased by 8.31% and 11.61% in the warp and weft directions, respectively. After 600 min ultrasonic washing, 10 000 abrasion tests, 24 h acid and alkaline solution immersion, and 24 h UV aging, the water contact angle of the surface of the superhydrophobic polyester fabric was still greater than 150°. In the five water-oil separation cycle tests, the separation efficiency of polyester fabrics with 90-210 min hydrolyzed MTMS treatment was above 97.0%. Moreover, it also showed good absorption performance in the absorption test with light and heavy oil in water.

    Conclusion The surface wettability and micro-morphology of polyester fabrics were controlled by MTMS hydrolytic time. The hydrophobic properties of the polyester fabric were enhanced after MTMS finishing, and when the hydrolytic time was 120 min, a rough micro-nanostructure was formed on the surface of the polyester fabric, exhibiting a superhydrophobic state for the polyester fabric. The MTMS-coated polyester fabric had good mechanical properties, and the superhydrophobic coating had excellent resistance to ultrasonic washing, abrasion, acid-alkali corrosion and UV aging, as well as good anti-fouling and water-oil separation properties. This process is green and efficient, and the prepared polyester fabric has a great application potential in water-oil separation, water purification and other fields.

    Preparation and stab-resistance of composites fabricated by aramid fabric impregnated with SiO2/poly(ethylene glycol)200/ multi-walled carbon nanotube shear thickening solution
    JIA Xiaoya, WANG Ruining, SUN Runjun
    Journal of Textile Research. 2024, 45(04):  151-159.  doi:10.13475/j.fzxb.20220802501
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    Objective In recent years, flexible stab-resistant materials have gradually replaced traditional hard stab-resistant materials, and high-performance fabrics become an important research object for flexible stab-resistant materials. In order to optimize the stab resistance of high-performance fabrics, reduce the number of stacked layers and the quality, it is necessary to prepare composites with both flexibility and stab resistance properties.

    Method In this study, multi-phase shear thickening fluids (MSTFs) were prepared by polyethylene glycol 200, SiO2 and multi-walled carbon nanotubes (MWCNTs), and the effects of the aspect ratio and addition amount of MWCNTs on rheological properties of STF were studied. A MSTFs composite fabric was prepared by dipping and drying, and a composite fabric was fabricated by coated silicon carbide/thermoplastic polyure-thanes(SiC/TPU) on the aramid fabric. Yarn pull-out test and quasi-static stab test were conducted to evaluate the stab resistance of the composite fabrics. In addition, double layer composite fabrics with the two different composite fabrics were prepared to investigate the effect of the stacking sequence on the stab resistance.

    Results The study shows that the carbon nanotubes with larger aspect ratio were better in improving the thickening effect of STF, the maximal viscosity of MSTFs(0.4%MWCNTs-A) increased by 52 Pa·s over MSTFs(0.4% MWCNTs-B). and with the increase of the content of MWCNTs, the critical shear rate of the MSTFs became smaller, and the maximum viscosity value was gradually increased. In addition, from the results of yarn pulling-out test and the quasi-static stab resistance test, the performance of composite fabrics were seen to be improved greatly compared to neat fabrics. The MSTFs composite fabrics have more interyarn friction than the pure 68%STF composite fabric, and with the increase of the MWCNTs addition in the MSTFs, the maximum pull-out load between the yarns of the composite fabric increases first and then decreases, and the friction between yarns of MSTFs composite fabric is related to the yarn pull-out speed. the study found a pronounced effect of the MSTFs on the ability of stab resistance was noticed, the maximum puncture load of MSTFs composite fabrics was greater than that of the pure 68%STF composite fabric under unit areal density, and the maximum puncture load demonstrated a gradual increase as the content of MWCNTs increased in MSTFs. However, When the content of MWCNTs is 0.6%, the initial viscosity of MSTF was larger, the weight-growth rate of the composite fabric was increased, and most of the liquid remained on the surface of the fabric, affecting the performance of the composite fabric. According to the experiments, the penetration velocity of tested long nails was 25 mm/min, the maximum puncture load of MSTFs(0.4% MWCNTs-A)-impregnated aramid fabric was 154.33% higher than that of pure 68%STF-impregnated aramid fabric. In the experiments to explore the influence of the laminated structure of different composite materials on the anti-stab performance, the study found that, the double-layer fabrics which the shear thickening liquid impregnated fabric as the surface layer and the SiC/TPU coated fabric as the back layer (S/T) has the biggest maximum puncture load, which is 786.26% higher than that of the double-layer pure fabric.

    Conclusion The study shows that the addition of MWCNTs improve the rheological properties of MSTFs, and the fabrics impregnated with MSTFs optimize the stab resistance performance of neat aramid fabrics effectively. When the fabric is impacted, the viscosity of MSTFs increases quickly, and composite fabric has a tighter bond between the fibers, further improving the puncture resistance of composite fabrics. Moreover, experiments show that since the stab-proof mechanism of MSTFs composite fabric and SiC/TPU coated fabric is not exactly the same, the laminated composites of shear thickening liquid impregnated fabric as the surface layer and SiC/TPU coated fabric as the back layer demonstrates excellent puncture resistance performance, offering ideas for design of the laminated structure of the multi-layer stab-resistant material.

    Degradation of polyester/cotton blended fabrics in hydrothermal system
    ZHANG Yongfang, GUO Hong, SHI Sheng, YAN Zhifeng, HOU Wensheng
    Journal of Textile Research. 2024, 45(04):  160-168.  doi:10.13475/j.fzxb.20230503801
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    Objective Hydrothermal process is a new way of recycling of waste textiles that will reduce environment pollution and resource waste thereof. With the characteristics of low cost, no pollution and controllable products, hydrothermal degradation technology is suitable for chemical degradation and high valued recycling of waste textiles. Most waste textiles are blended fabrics of polyester/cotton, which have different chemical properties and compact twisting structures, and therefore it is always a difficult problem in the recovery of blended textiles. Research on degradation behavior of blended fabrics in a hydrothermal system is believed to provide the necessary theoretical and numerical evidence for the hydrothermal degradation, regeneration and recycling of blended textiles.

    Method Hydrothermal degradation of high polymer could be achieved by utilization of the special character of water as a solvent, a catalyst and a reactant in the subcritical water. Hydrothermal process was applied in the research of blended fabrics of polyester and cotton with the addition of copper sulfate to identify the hydrothermal degradation behavior of cotton fiber and polyester fibers, followed by characterization of the yield, microstructure, chemical structure, crystal structure, and mechanical properties of the cotton and polyester blended fabrics under different temperatures.

    Results It was indicated that polyester and cotton featured different hydrothermal behaviors in the copper sulfate hydrothermal system. In particular, the cotton fiber of the blended fabrics was selectively hydrolyzed and degraded in the temperature range of 130-190 ℃, and the fiber structure of the cotton disappeared after hydrolysis, and some of the cotton fiber was hydrolyzed to becoming powdered cellulose and some to monosaccharides. The polyester fiber, on the other hand, maintained its morphology unchanged in the temperature range of 130-190 ℃, while the structures of chemistry, crystal, and mechanical properties were almost the same as the original polyester fiber, which could be reused directly as the polyester fiber for recycling. When the temperature rose above 210 ℃, dehydration and carbonization happened to cotton fiber and the hydrothermal products were carbonized products of carbon element in the main. As for polyester fiber, when the temperature elevated to 210-250 ℃, the polyester fiber was gradually hydrolyzed. When the temperature was increased to 270 ℃, the polyester fiber was completely degraded to terephthalic acid(TPA) with a theoretical yield over 91%. The TPA was found to decompose at higher temperature. The retention rate of TPA was about 78% of the theoretical yield at 330 ℃. During the high temperature hydrothermal treatment of polyester/cotton blend fabric, the presence of TPA does not essentially affect the crystal structure of the carbonated products of cotton fibers. However, due to the presence of a large amount of terephthalic acid, complete degradation and carbonization of the hydrolyzed products of cotton fiber were hindered, and the carbonated products were in the form of block structure rather than the expected ball structure.

    Conclusion In the hydrothermal environment of copper sulfate, hydrothermal separation of polyester/cotton can be achieved at low temperature due to degradation of cotton fiber into cellulose powder that disintegrated the fabric structure and hydrothermal stability of the polyester, while at high temperature, polyester and cotton can be degraded together in the same system. The cellulose powder generated from the separation of polyester/cotton at low temperature can be applied to the preparation of modified cellulose or other cellulose materials in a wide range of applications. Besides, the soluble sugar in the hydrolysate can be further recycled as well. At high temperature, polyester degrades into terephthalic acid, which can be recycled and used as the raw material for industrial production of polyester monomer and others. The carbon products formed through cotton fiber carbonization at high temperature, rich in hydrophilic oxygen-containing functional groups and of high functional values, can be grafted and modified to prepare functional materials, or applied in the areas of sewage adsorption materials, catalytic carriers, materials of electrode, and so on. The research offers a certain reference to the recycling of polyester/cotton blended fabrics and of a certain practical value.

    Acute toxic effects of antimony contaminants on green algae and cyanobacteria
    LI Fang, ZHANG Yili, WANG Man, MENG Xiangzhou, SHEN Chensi
    Journal of Textile Research. 2024, 45(04):  169-179.  doi:10.13475/j.fzxb.20230307401
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    Objective Antimony (Sb) is utilized as a catalyst during the polymerization process of polyethylene terephthalate (PET) and it remains in PET fibers or textiles. When printing and dyeing PET, Sb will leach into wastewater and cause contamination, and it commonly exists in aquatic environments in two oxidation states: +3 and +5. Investigating their toxicological effects on aquatic ecosystems is highly necessary. Microalgae are the primary producers in aquatic ecosystems, and their short growth cycle and ease of isolation make them highly suitable for studying the toxic effects of Sb pollutants on aquatic ecosystems.

    Method Representatives of green algae, Raphidocelis subcapitata and Chlamydomonas reinhardtii, and representatives of cyanobacteria, Synechococcus and Dolichospermum sp., were selected for investigation. The growth status of the microalgae was evaluated by measuring algal cell concentration, chlorophyll a, and soluble protein. The potential oxidative stress caused by exposure to Sb(Ⅲ) and Sb(V) was assessed by measuring the activities of superoxide dismutase (SOD) and catalase (CAT). The potential damage to microalgal was determined through subcellular structure observation by TEM. Additionally, the adsorption or absorption of Sb(Ⅲ) and Sb(V) by microalgae were quantified to determine the extent of adsorption relative to their growth status.

    Results The results revealed that under different concentrations of Sb(Ⅲ) and Sb(V) stress for 72 h, Hormesis effect was observed in four algae species, i.e. Raphidocelis subcapitata, Chlamydomonas reinhardtii, Synechococcus, Dolichospermum sp. Sb(Ⅲ) had a more potent inhibitory effect on microalgae, with up to a 76.6% reduction in growth, compared to Sb(V) which only resulted in a 41.0% decrease. Green algae were found to be more vulnerable to Sb-induced stress compared to cyanobacteria. The toxic impact of Sb on microalgae was primarily attributed to the impairment of their photosynthetic machinery and the occurrence of oxidative damage. Alterations in the synthesis of chlorophyll a and soluble protein content in microalgae indicated similar trends in response to growth inhibition, but the impact on cyanobacteria was less pronounced. Additionally, the activities of SOD and CAT in green algae exhibited a pattern of promotion at low concentrations and inhibition at high concentrations, while cyanobacteria showed a variable pattern of changes. Subcellular examination of microalgae revealed that Chlamydomonas reinhardtii experienced damage to the cell wall, nucleus, chloroplasts, and other organelles, whereas Synechococcus suffered damage mainly to the photosynthetic system. Further, all four microalgae had greater sorption and uptake of Sb(Ⅲ) than Sb(V), but there was no clear correlation between the uptake or sorption of antimony by microalgae and their tolerance to antimony stress.

    Conclusion Antimony contamination has become an increasing concern, and it is essential to comprehend the toxicity and toxic mechanisms of Sb of different valence. This study found that the toxicity of Sb(Ⅲ) to microalgae is significantly higher than that of Sb(V), and that green algae are more sensitive to Sb stress than blue algae. When the exposure concentration of Sb(Ⅲ) is below 0.05 mg/L and the exposure concentration of Sb(V) is below 0.2 mg/L, the toxicity impact on microalgae is relatively small. The mechanisms by which Sb affects microalgae are primarily associated with harm to the photosynthetic system and oxidative stress. Under Sb(Ⅲ) stress, the cell wall, nucleus, chloroplasts, and other organelles of green algae are damaged, while in blue-green algae, the photosynthetic system is primarily affected. The above research results are expected to provide certain basis for a comprehensive assessment of the ecological risks of Sb pollutants.

    Apparel Engineering
    Classification and discrimination of waist-abdomen-hip morphology of young women based on space vector length
    WU Jinying, LI Xin, DING Xiaojun, QIU Wenchi, ZOU Fengyuan
    Journal of Textile Research. 2024, 45(04):  180-187.  doi:10.13475/j.fzxb.20230405301
    Abstract ( 31 )   HTML ( 4 )   PDF (11785KB) ( 24 )   Save
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    Objective The current research on body shape uses classification indexes for body shape such as circumference, width, thickness, ratio and angle, which are not able to fully reflect the curved shape of body. In order to establish classification and discrimination of three-dimensional surfaces of female body and improve the fit of pants, a method of body shape classification based on space vector length characterization of waist-abdomen-hip morphology is proposed.

    Method The 3-D point cloud data of 323 young women aged 18-25 years were collected by TC2 3D scanner, and the 10-layer cross-sectional curves of the waist-abdomen-hip were extracted. The center of mass of hip circumference was used as the origin to reconstruct the point cloud coordinate system. The space vector length of 130 feature points was calculated by Euclidean distance to construct the modulus length matrix to characterize the morphology of body surface. The eigen dimension was determined by using maximum likelihood estimation, and Laplace feature mapping was introduced. The body type segmentation based on space vector length was achieved by K-means clustering. The discriminative model of waist-abdomen-hip morphology of young women was established by random forest algorithm. The garment samples (SVP) corresponding to four types under size 160/66A were obtained and compared with the basic women's suit pants benchmark sample (BTP) to evaluate their fit.

    Results Based on the 3-D point cloud data, 10 feature cross-sections reflecting the morphology of the waist-abdomen-hip surfaces were extracted, and 130 feature points were extracted. A modal length matrix of 323 samples, each with 130 space vector lengths was constructed. The maximum likelihood estimation was used to determine the eigen dimension as 18. The modal length matrix 323 18 characterizing the body surface morphology was obtained by dimensionality reduction. The elbow method was used to determine the number of clusters as 4. Through cluster analysis, the waist-abdomen-hip of young women were subdivided into four types by combining the national standard body type, i.e., mass, flat, convex abdomen and convex hip, which accounted for 58.82%, 27.86%, 8.36% and 4.95% of the total number of samples respectively. In order to perform the discrimination test for the independence of different body types, a discriminative model of waist-abdomen-hip morphology of young women was established with a decision tree number of 100, a classification number of 4, a training and testing sample of 8∶2. The model was continuously trained by Random Forest(RF) algorithm, and the discrimination accuracy reached 96.92%. Using the virtual fitting, it can be seen that the SVP sample pants are blue and green areas at the waist and crotch. The garment stretch is between 100%-110% in a normal stretch state, with moderate dressing pressure and a good garment fit. Through virtual fitting and physical verification, the fit of SVP sample pants became better than that of BTP sample pants.

    Conclusion The space vector length is used as a classification index to characterize the surface morphology of the waist-abdomen-hip of young women and to perform body type segmentation to achieve the classification and discrimination of female body 3-D surface. The discrimination test of the independence of different body types shows that the four types classified by the space vector length as the index show strong independence. Through virtual validation and physical validation, it is shown that the body type classification method based on space vector length has a good effect on improving the fit of pants. The application of this method can effectively facilitate the body type segmentation and further improve the matching degree of clothing and human body, which can be applied to the scale customization of garment.

    Influence of heating area distribution of electrical heating clothing on human thermal comfort
    KE Ying, LIN Lei, ZHENG Qing, WANG Hongfu
    Journal of Textile Research. 2024, 45(04):  188-194.  doi:10.13475/j.fzxb.20230205501
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    Objective Applying thermal stimulation to different parts of the human body can affect human thermal comfort. This research aims to further investigate and compare the performance of heating area distribution of electric heating clothing at low temperature (5 ℃). The influence of the heating area distribution on the thermal comfort of electric heating clothing is analyzed, aiming to assist the design of electric heating clothing.

    Method Seven healthy male university students were recruited for this trial, which was conducted in an artificial climate chamber (ESPEC Corp, Japan). Three heating areas were designed, i.e., the torso (HA1), the torso and legs (HA2), and the torso and thigh and upper arm heating (HA3). Carbon nanotube heating pads were selected for the trial. The human dressing experiments were carried out under the conditions of the ambient temperature of (5 ± 0.5) ℃ and relative humidity of (50 ± 5)%. The subjects' objective physiological data and subjective feelings were recorded and analyzed during the trial.

    Results The experimental results showed that HA1 significantly increased the mean torso temperature, while had little effect on the mean skin temperature. In contrast, HA2 effectively increased the mean skin temperature by more than 0.8 ℃, and HA3 increased the mean skin temperature by more than 0.5 ℃. The skin temperature of the chest and waist of HA1 was significantly higher than that of HA2 and HA3. On the other hand, HA2 and HA3 significantly affected leg temperatures. Significantly higher thermal sensation vote(TSV) was found in HA2 as compared to HA1 at 10 min and 30-60 min (P < 0.05). Only at 10 min, the TSV of HA3 and the thermal comfort vote(TCV) of HA2 were significantly higher than that of HA1 (P < 0.05). HA2 had the highest thermal acceptability. More importantly, HA2 had the lowest percentage of people who wanted to be warm. There was a negative linear correlation between the mean torso temperature and overall thermal sensation and a positive linear correlation between the mean skin temperature and overall thermal sensation for HA1. There is a negative linear correlation between the mean torso temperature and overall thermal comfort for the three heated area distributions. The mean skin temperature of HA1 positively correlated with overall thermal comfort. Overall thermal sensation and thermal comfort decreased with increasing mean torso temperature and increased with increasing mean skin temperature.

    Conclusion Under a specific heating area, centralized torso heating can significantly increase the mean torso temperature, but it fails to increase the mean skin temperature effectively. The excessively high mean torso temperature can also reduce the thermal comfort of the body. The mean skin temperature is linearly correlated with the overall thermal sensation and comfort within a certain range. Distributing heating pads to the legs and arms can not only effectively increase the mean skin temperature but also improve the thermal comfort of the human body. The heating combination of the torso and legs is more beneficial to improve the thermal comfort of the whole body than the heating combination of the torso, thigh and upper arm. It is suggested to distribute heating pads to the torso and leg positions with the same heating area, which can give the electrical heating clothing better retention of warmth.

    Knowledge graph construction technology for provision of sewing process information
    ZHENG Xiaohu, LIU Zhenghao, LIU Bing, ZHANG Jie, XU Xiuliang, LIU Xi
    Journal of Textile Research. 2024, 45(04):  195-203.  doi:10.13475/j.fzxb.20230204901
    Abstract ( 26 )   HTML ( 4 )   PDF (5129KB) ( 10 )   Save
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    Objective The sewing process is characterized by long processing chains, diverse production elements and scattered processing information. Using knowledge graph technology for the management of design, operation and maintenance data generated during the sewing process, this research proposed a knowledge graph construction method for sewing process information management to achieve standardized knowledge representation.

    Method Modelling methods for the organisation of sewing process information were investigated. The process information generated during the fabric sewing process was classified, and a sewing process knowledge ontology model was established based on the classification results to realise the construction of a knowledge graph. The process recommendation method was established based on the graph. Experiments were carried out on fabric structure, fabric mechanical parameters and fabric sewing process to establish a knowledge system and to analyse the mechanical properties of fabrics before and after sewing. Based on the analysis, a regression model of fabric mechanical properties and sewing flatness and a theoretical model of fabric sewing shrinkage were established. An ontology model of the sewing parameter knowledge system was created for sewing parameter recommendation based on knowledge graph.

    Results According to the requirements of sewing process corpus and knowledge graph, a process recommendation method based on knowledge graph was established by combining the characteristics of industry knowledge structure and knowledge management requirements.The developed ontology and knowledge graph contains a total of 2 865 entities and 52 relations, with wide knowledge coverage and strong generalization, facilitating the standardized representation of unstructured knowledge. The relationship between mechanical parameters and sewing parameters were modelled for common fabrics in the flat sewing process, the flatness of the sewn fabric and the maximum sewing shrinkage were predicted and recommendations for sewing parameters, bonding parameters and processing instructions for the corresponding fabrics were achieved. The technical architecture for intelligent recommendation of sewing parameters was established. The knowledge system was interconnected with other sewing process knowledge and enabled integration of process information.

    Conclusion The established knowledge graph is characterized by strong integration and interconnection of sewing process knowledge, which enables data integration and facilitates the maintenance and expansion of knowledge at a later stage. The research provides a useful supplementary case for process information management paths in the sewing industry, showing that knowledge graph technology has good application prospects in the sewing industry and has a certain reference value.

    Association rules mining for non-compliant items in children's clothing quality inspection
    WANG Yuxian, WEI Mengyuan, XUE Wenliang, MA Yanxue
    Journal of Textile Research. 2024, 45(04):  204-210.  doi:10.13475/j.fzxb.20230302101
    Abstract ( 23 )   HTML ( 1 )   PDF (2658KB) ( 9 )   Save
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    Objective Children's curiosity and vulnerability have raised high demands for the quality of children's clothing. The government has accordingly introduced a series of strict standards, but quality issues in children's clothing still frequently occur. Facing the huge children's clothing market, regulatory authorities cannot conduct comprehensive inspections and can only adopt a spot-checking approach for quality supervision. The key to improving spot-checking efficiency is to make it more targeted by focusing on the frequently occurring problems in children's clothing.

    Method Apriori is a classic algorithm of association rules to mine the correlation between labels in a dataset. Core of Apriori idea is iterative searching layer by layer. Multiple rounds of scanning were performed and filtered by minimum support and minimum confidence to obtain strong association rules. The research used the inspection reports on imported and exported children's clothing provided by Shanghai Customs from 2018 to 2022 as the input data for association rules. These data were used to mine the association between the brand and the quality, as well as the correlation between unqualified color fastness, mechanical safety, and components.

    Results The confidence of the association rule between Brand A and unqualified pH reaches 75%. Five brands were involved with the association rules relating to unqualified mechanical safety, whose confidence reached more than 67.39%. Three brands were in the strong association rules with unqualified color fastness. The top 10 strong association rules related to unqualified color fastness include nylon and acrylic. Main strong relations had more than one type of fiber. The confidence of the association rules between denim clothing and color fastness to wet rubbing was up to 69.70%. The lift of association rule between infant pajamas and unqualified saliva-resistant color was 5.24. Confidence of the rule between children’s paints and unqualified color fastness to wet rubbing was 16.81%. The black and blue dyed garments tended to be poor in color fastness. The lift of the association rule between printed children's clothing and unqualified color fastness to rubbing was 2.77. Nylon, viscose and three varieties of the fiber marked in the children's clothing had a strong relation with unqualified component. Children's underwear and daily tops had a strong relation with unqualified mechanical safety.

    Conclusion Given the identified strong association rules, we have pinpointed Five brands with mechanical safety issues, Three brands with color fastness problems, and 3 low-risk brands. Particular attention should be given to these problematic brands during spot inspections. Color fastness of children's clothing is heavily influenced by component, category, as well as color. In terms of component, nylon and acrylic fiber, due to their dyeing mechanisms, bind weakly with dye. Different types of fiber usually affect each other during dyeing processes resulting in floating colors. Therefore, close supervision is required for clothing made from nylon, acrylic, especially those containing more than one type of fiber. As for category, different categories of children's clothing have different usage scenarios. Baby pajamas, which are often chewed on by infants, require high saliva fastness. Pants, which constantly rub against children's bodies when moving, require excellent rubbing fastness. Consequently, great attention should be paid to saliva and rubbing fastness of these two categories respectively. Considering color, black and blue children's clothing, especially denim clothing often uses vulcanized dyes and indigo dyes. However, these two dyes have to undergo slow oxidation before dyeing and use weak mechanical force to bind with fabric, leading to poor friction color fastness. Printed clothing requires adhesive to bind pigment with fabric together, so rubbing color fastness is defective. According to the strong association rules, the clothing labeled with nylon, viscose and three kinds of component tend to have poor quality in component check. Underwear and daily tops are key categories for mechanical safety supervision of children's clothing.

    Machinery & Equipment
    Multi-fault feature adaptive extraction method for textile typical equipment
    REN Jie, ZHANG Jie, WANG Junliang
    Journal of Textile Research. 2024, 45(04):  211-220.  doi:10.13475/j.fzxb.20221106801
    Abstract ( 25 )   HTML ( 2 )   PDF (5713KB) ( 9 )   Save
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    Objective Chemical fiber winder is the core equipment in chemical fiber production. The failure of winder will seriously affect the quality and production efficiency of chemical fiber products, so it is necessary to accurately diagnose the fault of chemical fiber winder. Fault feature extraction is the premise of winder fault diagnosis. It is mainly divided into empirical knowledge-based methods and data-driven methods. Aiming at the problem of low accuracy of empirical knowledge features in fault diagnosis of winder and poor interpretability of data-driven features, this paper proposes a data-driven method for adaptive extraction of multiple fault features of chemical fiber winder.

    Method The proposed adaptive feature extraction method of chemical fiber winder fault based on improved gene expression programming (GEP) with multi-fault feature correlation analysis and subset evaluation method, which includes gene encoding and decoding of feature initialization, feature subset correlation analysis and decision tree evaluation, roulette screening and Elite retention strategies, feature optimization method based on genetic evolution. Among them, the multi-feature correlation analysis method is combined with the experience and knowledge features to select the advantages of strong correlation, low redundancy and high complementarity. When the last iteration is completed, the dominant feature subset output forms the final feature.

    Results In order to verify the effectiveness of the proposed improved GEP feature extraction method in industrial applications, the measured vibration data of POY-1800 winder in a chemical fiber enterprise in Zhejiang province are used to test the performance of the proposed feature extraction method. The fault characteristics of 14 winders in the production process of one kind of fiber are extracted. The vibration acceleration sensor was used to collect the vibration data during the rotation of the winder, and the feature extraction test was carried out under the instantaneous linear speed of 1 000 m/min, 2 000 m/min and 3 000 m/min. The sampling frequency is 51 200 Hz, and the collection time of each class is 1 s. There are 4 categories in total, each of which is a binary classification task. The verification was carried out by using the multi-round cycle data set, and the original data was processed in segments according to every 20 points. The number of individuals in the population is set to 100, the number of iterations is 50, and the outermost cycle is 3 rounds to set the optimal individual retention mechanism. In the experiment, the proposed method was compared with the method based on empirical knowledge features and the general GEP method without using multi-feature association analysis. The extracted features are input into the classifier formed by C4.5 decision tree algorithm, and the effect of each method is compared by classification accuracy. To facilitate the observation of the results, the average classification accuracy AVG and the BEST classification accuracy best during GEP are recorded. The experimental results show that compared with the fault features generated by the traditional feature extraction method and the general GEP method, under the line speed of the winder in 1 000 m/min, 2 000 m/min, 3 000 m/min, the fault diagnosis accuracy of the proposed improved GEP method is increased by 8.959%, 3.87%, 3.77% respectively 2.601%, 3.2%, 2.018% respectively, which effectively solves the problem of fault feature extraction of the winder.

    Conclusion In this study, a data-driven multi-fault feature adaptive extraction method for chemical winder is proposed. Contrast experiment results demonstrate the proposed GEP-based interpretable feature extraction method with experience and knowledge features is effective in improving the accuracy of fault diagnosis; The outcomes of classification accuracy at various speeds illustrate the proposed multi-feature correlation analysis method is validate in augmenting the adaptability of winding scenarios; Subsequent experimental results in feature engineering affirm the proposed enhanced GEP feature extraction method is effective in diagnosing multiple faults of chemical fiber winders.

    Moisture content measurement technology of two-component fabrics by microwave resonant cavity method
    XIANG Zhong, ZHAO Wei, HE Shiwei, WANG Yuhang, QIAN Miao
    Journal of Textile Research. 2024, 45(04):  221-228.  doi:10.13475/j.fzxb.20221006101
    Abstract ( 27 )   HTML ( 1 )   PDF (3333KB) ( 8 )   Save
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    Objective For detecting the moisture content of fabric accurately, it is critical to understanding the relationship between moisture content and dielectric constant of fabrics. The objective of this study is to establish the relationship between moisture content and dielectric constant for two-component fabrics with different materials, thicknesses and component ratios, aiming for accurate measurement of moisture content in different types of textiles.

    Method Based on the Bruggeman-Hanai dielectric mixing model, the relationship between the dielectric constant model of water content of two-component fabric was developed by considering the influence of fabric thickness and the pro-portion of multi-component fabric components under different material, thickness and component ratio was obtained. The dielectric constant measurement experiments of cotton, chemical fiber and blended fabric with uniform humidity were carried out, and the coefficient of the dielectric constant model of the two-component fabric was obtained.

    Results For the theoretical prediction model, when the depolarization factor coefficient of pure cotton fabric L1=0.35 and the depolarization factor coefficient of chemical fiber fabric L2=0.23, the comparison results of the moisture content prediction model of pure cotton and chemical fiber cloth and experimental data were able to be obtained. The root mean square error(RMSE)calculation was carried out and it was found that the theoretical model RMSE of different fabric materials was less than 3%, and hence the prediction on the relationship between moisture content and dielectric constant, for pure cotton and chemical fiber fabrics, was proven reliable. When the cotton fabric coefficient C1 (the ratio of the thickness coefficient of pure cotton fabric to its thickness) was 1.475, B1 (the correction factor for pure cotton fabric)was 0.683 3; and when polyester fiber fabric C2 (the ratio of the thickness coefficient of blending textiles to their thickness)was 1.567, and B2(the correction factor for synthetic fabrics) was 0.743 2. For cotton fabrics, the RMSE ≤4.6%. Comparison of the prediction results of the model to the experimental results showed that the model enabled a good prediction on the permittivity related to the thickness of cotton fabrics. For chemical fiber fabrics where RMSE ≤ 3.8%, the prediction of fabrics with larger thickness and lower moisture content was not as good. However, when the moisture content of the fabric was greater than 3%, the prediction was generally better. When the determinant of blended fabric α =0.67, for fabrics with cotton content between 20%-35%, the prediction results of the two-component fabric theoretical model were close to the experimental results, and the prediction was better.

    Conclusion In order to accurately measure the moisture content of fabrics with different materials, varying thickness and diversified components, this research explores the influence of changes in fabric material, thickness and composition ratio on moisture content and permittivity based on the microwave resonator method, and then establishes a theoretical model of fabric moisture content permittivity. After comparing and analyzing the predicted value of the model and the experimental value, results show that the model has good prediction accuracy, the RMSE is less than 5%.

    Comprehensive Review
    Structural regulation and biomedical applications of polyvinylidene fluoride nanofibers
    LI Chaowei, CHENG Yue, SU Xin, CHEN Pengfei, LI Dawei, FU Yijun
    Journal of Textile Research. 2024, 45(04):  229-237.  doi:10.13475/j.fzxb.20230700402
    Abstract ( 29 )   HTML ( 6 )   PDF (4341KB) ( 9 )   Save
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    Significance Polyvinylidene fluoride (PVDF) possess excellent electrical properties, which is currently one of the strongest piezoelectric polymers discovered. Among various preparation methods of PVDF piezoelectric nanofibers, PVDF nanofibers prepared by electrospinning have more advantages, including large specific surface area, high porosity, good biocompatibility and better piezoelectric property, etc. In addition, the structure of electrospun nanofibers is similar to that of extracellular matrix, which is beneficial for promoting cell proliferation and differentiation. At present, there have been numerous reports on the application of electrospun PVDF piezoelectric nanofibers in biomedical fields such as wound dressings, drug carriers, and tissue engineering, proving their enormous potential in biomedical applications.

    Progress In this paper, the piezoelectric characteristics of PVDF were analyzed. four types of electrospun PVDF nanofibers, consisting of random type, oriented type, hollow type, and patterned type were introduced and their process methods, structures, properties, and preparation principles were analyzed. The influence of the doping of fillers such as graphene, zinc oxide, barium carbonate, carbon nanotubes, etc and the creation of multi-layer composite structures on the structure and piezoelectric property of electrospun PVDF nanofibers were described. The results showed that these doped materials not only changed the original morphology of PVDF nanofibers, but also significantly improved their piezoelectric property. The multilayered composite structure nanofibers created by combining electrospinning PVDF fibers with nanofibers generated by another method (such as vapor phase polymerization, point spraying and extended flow method) exhibited higher voltage output. Because of outstanding biocompatibility and piezoelectricity, electrospun PVDF nanofibers are widely used in biomedical fields such as wound dressings, drug carriers and tissue engineering. It could be demonstrated that PVDF based piezoelectric scaffolds presented excellent piezoelectric performance, which were able to provide piezoelectric signals similar to the internal electric field of the human body and generate sufficient piezoelectric output to stimulate cell differentiation and proliferation, thereby promoting tissue formation and bone growth. Moreover, PVDF electrospun nanofibers were used as a drug carrier to targeted therapy of the lesion site to achieve sustained drug release.

    Conclusion and Prospect The PVDF nanofibers prepared by electrospinning technology with high specific surface area, high porosity, good biocompatibility and excellent piezoelectric property can output enough voltage to promote cell proliferation and differentiation, which is conducive to their application in the biomedical field. The current methods used to improve electrospun PVDF based nanofibers mainly focus on structural design and filler doping. Structural changes will face the challenge of reducing mechanical strength, and the addition of fillers may bring biocompatibility and uniformity issues. On the one hand, it is necessary to explore more effective structures and additives to improve the mechanical, piezoelectric and other comprehensive properties of PVDF nanofibers while ensuring that they are non-toxic to the human body in future research. On the other hand, structural design can be combined with filler doping to prepare PVDF composites with better performance.

    Current situation and development in applying metaverse virtual space in field of fashion
    WANG Xuewei, YU Xiaokun
    Journal of Textile Research. 2024, 45(04):  238-245.  doi:10.13475/j.fzxb.20230300202
    Abstract ( 32 )   HTML ( 5 )   PDF (6349KB) ( 20 )   Save
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    Significance Under the dual influence of Web3 and AIGC, the content and form of virtual spaces are gradually converging towards the shape of the Metaverse, holding substantial commercial and economic value for the textile and fashion industry. This paper reviews and discusses the strategies and methods for constructing virtual spaces for textile and fashion. It is advantageous for textile and fashion brands, manufacturers, and designers to adapt to the dramatic shifts in economic and creative models brought about by the rapid development of Web3 and artificial intelligence. This adaptation would enable these enterprises to better understand the future direction of the market, respond to market demands, innovate more rapidly, enhance production efficiency, reduce costs, and ultimately improve their competitiveness and market share.

    Progress Virtual spaces serve as vital mediums in the Metaverse, enabling fashion brands to engage in activities such as AR try-ons, NFT issuance, digital game development, digital avatar creation, and the establishment of Metaverse communities. Mass-oriented virtual spaces include open-world spaces originating from video games, online 3-D galleries, and digital twins. This paper outlines three methods for establishing fashionable virtual spaces, integration within existing Metaverse projects, the development of standalone fashion virtual spaces, and the creation of pop-up event spaces. It summarizes virtual space applications in the textile and fashion industry, encompassing brand promotion, virtual try-ons, clothing customization systems, digital clothing design tools, and more. By studying and reviewing current operational models of fashion spaces, the paper identifies shortcomings in terms of commercial viability, practicality, and interactivity, such as inadequate technical support, low audience engagement, poor user experiences, and insufficient traffic conversion. The advantages of physical commercial centers over virtual spaces in terms of government support, historical and cultural significance, and interactivity are discussed. Additionally, the rapid development of artificial intelligence is noted for its transformative effect on fashion creative models.

    Conclusion and Prospect The next phase of focus in the textile and fashion sector's virtual spaces is the development of fashion integrated business complexes. Fashion virtual spaces should be grounded in successful physical integrated business complexes, creating spaces that mirror physical entities to achieve a profound integration of the physical and digital economies. This paper provides specific implementation pathways and approaches to build a fashion integrated commercial complexes in virtual space. This includes leveraging virtual reality and artificial intelligence to cultivate culturally rich, real-world-connected fashion business centers within the Metaverse. Specific strategies involve drawing inspiration and investment from successful physical businesses, establishing digital twins, creating fashion business centers that amalgamate fashion concepts, artistic creativity, lifestyles, culture, and history, and deploying, expanding, and promoting them through curation. Employing AR and MR technologies to project virtual scenes into the physical world is recommended, as is using physical scanning or encouraging user participation in space co-creation activities to enrich virtual space content. Leveraging artificial intelligence to develop digital roles such as digital fashion designers and digital shopping assistants can bridge the gap between physical and virtual spaces. Making effective use of Web3's advantages in confirming creative ownership, encouraging collaborative user content creation, and employing incentive mechanisms like collection, rewards, and competition can attract user participation in content creation and sharing within virtual spaces, leading to traffic growth and realization. Ultimately, this will facilitate the deep integration of the physical and digital economies.

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