Study On Wearability And Application Of PTFE Membrane Materials

Polytetrafluoroethylene film(PTFE)is a kind of macromolecule material prepared by biaxial stretching technology.It is observed by electron microscopy that the film is made of interlaced filaments,and the voids between filaments and filaments form the micropore of the film.The micropore diameter of the film is mainly distributed in the range of 0.8um to 1um,and the micropore size of the PTFE film is only 0.6um.Even the largest pore size is only about 1.6umm.The diameter of water vapor is 0.0004um and the diameter of liquid water droplets is 20um.Therefore,water vapor can pass through the micropore of the PTFE film and liquid water can not pass through it.PTFE film has the ability of waterproof and moisture permeability.In this paper,polytetrafluoroethylene(PTFE)films and fabrics are compounded by using binders.Polyacrylate coated adhesive(PA)and polyurethane water-borne adhesive(PU)are used to laminate the films and fabrics.The peeling strength is taken as an index to study the optimum process of film-fabric compounding.The optimum range of PU water-borne adhesive is 10g/m~2-20g/m~2,the pressing temperature is 150℃~170℃,and the pressing time is 50s-70s.The orthogonal experiments of four factors and three levels are carried out to test the peeling strength,air permeability,moisture permeability and washing resistance.The main influence factors on the peeling strength of composite fabrics are obtained.The best composite fabric can be obtained by blanching at 170℃for50 seconds with PU water-borne adhesive as binder at 20g/m~2.Polytetrafluoroethylene(PTFE)film and polyurethane(PU)film were laminated to make composite film materials.Polyacrylate coating adhesive,polyurethane water-borne adhesive and polyurethane oil-borne adhesive were selected as binders.Peeling strength was taken as index and air permeability,moisture permeability and water washing resistance were tested to study the optimum composite process.The Optimum Blanching Temperature and blanching time of the three adhesives are 160℃~200℃and 35s~60s respectively.Polytetrafluoroethylene(PTFE)film has the ability of waterproofing and moisture permeability,which affects the moisture permeability of PTFE film.Four kinds of films with different grades were selected and tested by hygroscopicity method in GB12704.1-2009 and inverted cup method in GB12704.2-2009.It was concluded that the different pore size,thickness,porosity and detection methods of the films themselves would affect the moisture permeability rate of the films.Among them,the difference of film itself has the greatest influence on the moisture permeability,which is 765.92 g/m~2.24h.The average difference of the influence of different detection methods on the moisture permeability is 3414.02 g/m~2.24h,which is much higher than the difference of the moisture permeability caused by the difference of film itself.