Abstract:

Objective Domestic research on reusable decontamination primarily focuses on the relationship between fabric processing techniques and the number of reuse cycles. However, there remains a lack of systematic investigation into the influences of varying decontamination conditions on the reusability and decontamination resistance of protective fabrics. Further in-depth study on the synergistic influence of decontamination parameters, particularly decontamination conditions and frequency, is an important direction for future research. This study investigates how repeated application of different decontamination and sterilization methods would affect the decontamination and sterilization resistance of reusable protective fabrics, aiming to provide scientific references and a theoretical foundation for advancing research in this field. Additionally, this study supports the development of reusable non-surgical medical composite protective clothing that comprehensively ensures the safety of both patients and healthcare personnel.

Method Two self-developed materials, i.e., nylon-based laminated composite fabric and polyester-based laminated composite fabric, were selected for evaluation. Four decontamination and sterilization methods were designed for repeated treatment testing, which are high-temperature moist heat decontamination and sterilization (80 ℃), steam (121 ℃), 500 mg/L sodium hypochlorite solution decontamination and sterilization, and 2 000 mg/L sodium hypochlorite solution. Through analysis of protective performance, comfort-related properties, and mechanical characteristics after multiple washing and decontamination cycles, the durability and resistance of the composite fabrics were assessed. By comparing the impacts of repeated decontamination and sterilization using different methods on fabric performance, recommendations were provided for optimal decontamination strategies tailored to specific types of protective fabrics.

Results Following repeated decontamination and sterilization using different methods, the polyurethane (PUR) adhesive dots of the composite fabric exhibited a certain degree of bonding strength reduction due to exposure to water, disinfectants, and elevated temperatures. No significant changes were observed in the inner layer fabric, and no delamination occurred in the composite structure after decontamination and sterilization. For nylon laminated composite fabric, the outer fabric structure underwent displacement and deformation after multiple washing and decontamination and sterilization cycles, resulting in increased exposure of the polytetrafluoroethylene (PTFE) film and a consequent reduction in protection for the film layer. In contrast, the outer structure of polyester laminated composite fabric remained tight and stable after repeated treatments, effectively preserving the integrity of the PTFE film layer. After repeated decontamination and sterilization, both nylon and polyester composite fabrics showed varying degrees of change in protective performance, comfort properties, and mechanical characteristics. The test results are summarized as follows. For protective performance, no delamination was observed in the composite fabric after 25 cycles of high-temperature wet heat decontamination and sterilization (80 ℃), steam decontamination and sterilization at 121 ℃, and repeated washing with sodium hypochlorite. Dimensional stability remained largely unchanged and filtration efficiency remained above 99.99%. However, hydrostatic pressure demonstrated a decrease, indicating reduced resistance to liquid penetration. The solid-liquid contact angle of the fabric surface was diminished, although it remained above 90°after repeated treatments, confirming that the fabric retains its surface water-repellent functionality. In terms of comfort performance, air permeability showed no significant variation after repeated decontamination and sterilization. Moisture permeability of nylon-based composites exhibited a declining trend, whereas that of polyester-based composites increased slightly. Some curling or deformation may occur after high-temperature wet heat (80 ℃) and steam decontamination and sterilization treatments, but this can be corrected through ironing or similar post-processing methods. Fading caused by repeated sodium hypochlorite treatment was found irreversible. With regard to mechanical properties, repeated sodium hypochlorite decontamination and sterilization resulted in the most pronounced degradation of breaking strength, with a maximum reduction of 66.44%, significantly exceeding the 27.07% maximum loss observed under high-temperature wet heat and steam decontamination and sterilization conditions.

Conclusion After 25 cycles of repeated decontamination and sterilization via high-temperature moist heat decontamination and sterilization, steam decontamination and sterilization, and sodium hypochlorite decontamination and sterilization treatments, evaluations on dimensional stability, air permeability, filtration efficiency, moisture permeability, and hydrostatic pressure indicate that the composite fabrics could still meet relevant standards for protective apparel. Based on a comprehensive comparison of performance degradation across different decontamination and sterilization methods, it is recommended that for low-risk contamination involving bacterial vegetative cells, high-temperature moist heat decontamination and sterilization (80 ℃) be prioritized. For high-risk scenarios involving prion-contaminated materials, pressure steam decontamination and sterilization is strongly recommended.

Key words: decontamination and sterilization method, protective fabric, lamination composite fabric, protective performance, high-temperature decontamination and sterilization, steam decontamination and sterilization, sodium hypochlorite decontamination and sterilization