| As a high-tech fiber,polyimide(PI)fiber has the characteristics of high temperature resistance,corrosion resistance,flame retardancy and excellent biocompatibility.It can be woven into fabrics and used in special protective clothing such as fire and flame retardant.The development of laminated fabrics with both waterproof and moisture permeability and special protective functions has been a research hotspot in recent years.Polytetrafluoroethylene(PTFE)microporous membrane with stable chemical properties,good heat resistance and excellent waterproof and moisture permeability has obvious advantages in this field.This subject uses polyimide(PI)fabric,polytetrafluoroethylene(PTFE)microporous membrane,copolyamide(COPA)hot melt adhesive as raw materials to prepare a three-layer structure laminated composite fabric,and optimizes the lamination process,PTFE film surface modification process,and laminated fabric single-sided water repellent finishing process.This subject develops a waterproof and moisture permeable laminate product with excellent comprehensive performance,which provide a reference for the development and application of special protective clothing fabrics.The main content includes the following points:Plain weaving was performed using PI filaments,and the specifications and waterproof and moisture permeability of the fabric were tested and analyzed.The results show that the PI fabric obtained by experiments is thin,compact,and has good moisture permeability,which is suitable for the fabric layer of laminated fabrics.Laminated composite fabric was prepared by using PI fabric,PTFE microporous film and COPA hot melt adhesive.The laminated fabric composite process was optimized,and the adhesive property and waterproof and moisture permeability of the laminated fabric were tested and analyzed.The results show that with the increase of hot pressing temperature,the prolongation of hot pressing time and the increase of hot pressing pressure,the peel strength of the laminated fabrics all show a tendency to rise first and then fall;As the amount of the glue increases,the peel strength of the laminated fabric gradually increases,but the moisture permeability is obviously lowered.The optimum process conditions for the polyimide/polytetrafluoroethylene film lamination are as follows:hot pressing temperature is 150℃,hot pressing time is 25s,hot pressing pressure is 0.3MPa,and glue amount is 12g/m~2.Under this condition,the laminated fabric has good waterproof and moisture permeability,but the peel strength does not meet the relevant standard requirements,and the laminated fabric has poor adhesive properties.In order to improve the bond strength of the laminated fabric,the PTFE film was subjected to sodium naphthalene modification treatment,and the influence of the treatment time on the PTFE film and the laminated fabric thereof was investigated.The results show that with the prolongation of the modification time of naphthalene sodium,the thickness of PTFE film increases,the micropores become smaller,and the tensile strength decreases;Naphthyl sodium modification treatment can significantly improve the surface wettability of the film,and the PTFE film can be transformed from a hydrophobic surface to a hydrophilic surface;After the PTFE film is modified by sodium naphthalene,the moisture permeability and air permeability are slightly reduced;The hydrostatic resistance of PTFE film is closely related to the hydrophilic/hydrophobicity of the surface.When the surface of the film becomes hydrophilic,its hydrostatic pressure resistance decreases significantly;After the PTFE film is modified by sodium naphthalene,the adhesive property of the polyimide/polytetrafluoroethylene film laminated fabric are significantly improved.When the treatment time of naphthalene sodium is 10s,the laminated fabric has the highest adhesive force and good waterproof and moisture permeability,and the best overall performance is obtained.In order to improve the waterproof performance of the laminated fabric,the laminated fabric was subjected to one-sided water-repellent finishing,and the water repellent performance,adhesive property,waterproof and moisture permeability and washing resistance of the laminated fabric were tested and analyzed.The laminated fabric was subjected to one-side water repellent finishing,and the water repellency,adhesive property,waterproof and moisture permeability were tested and analyzed.The results show that with the increase of the concentration of the finishing agent,the water-repellent grade of the PI fabric layer of the laminated fabric gradually increases,and finally tends to be stable;After the laminated fabric is treated with water repellent,the adhesive strength and air permeability are unchanged,but the moisture permeability is slightly reduced;Water repellent finishing is beneficial to improve the waterproof performance of the laminated fabric.The optimum concentration of the water repellent finish is 7%.Under this condition,the initial water repellency level of laminated fabric reaches the highest level of 5,and has excellent waterproof moisture permeability and water washing resistance. |
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