Research And Preparation Of Modified PTFE Membrane And Laminated Fabrics

PTFE microporous membrane waterproof and moisture permeable laminated fabric,which combines a variety of functions in one fabric, has obvious advantages. So it is widely favored by consumers, having been long a research hotspot. In this paper, PTFE membranes with excellent hydrophobicity and adhesion were prepared by means of high temperature modification method, thus solving the problem that strong hydrophobicity and adhesion couldn’t be obtained simultaneously; Then, high-density polyester fabrics were treated by calendering at different temperature and optimized. Finally, the selected PTFE membranes and high-density polyester fabrics were made into laminated fabric. The composite process was optimized and the related properties were tested and analyzed. The influence of high temperature modification on the adhesion of PTFE film and heat pressure process on the performance of the final fabric was mainly discussed, and this can provide a theoretical basis and rationalization proposals for the Design and Development work of laminated fabric in the future. The main contents and conclusions of the research are shown as below.The property of wetting and adhesion of PTFE membrane modified by high temperature were signicantly different from the orginal sample. The PTFE membranes’ surface morphology, roughness and crystallinity were charactered with many testing methods, such as scanning electron microscope(SEM), differential scanning calorimetry(DSC) and atomic force microscope(AFM). The surface wettability and adhesive force were studied with the aid of optical video contact angle measuring instrument and DCAT 21 surface tension meter. The results showed that with the increase of temperature, the contact angle had an increasing tendency, so did adhesion; The crystallinity and surface roughness decreased when modification temperature increased. The PTFE membranes were preliminarily screened and the films modified at temperatures of 260 °C, 320 °C and 380 °C were selected as the inner layer of the laminated fabrics.12 kinds of density fabrics were prepared by different calendaring process. The properties of the above-mentioned fabrics were measured and charactered by means of many instruments such as digital type moisture meter, water permeability tester and homemade rolling angle measuring instrument. And then the influence of setting temperature and calendaring temperature on high-density fabric’s performance was further explored. The results indicated that contact angle first increased and then decreased with setting and calendaring temperature increasing. Taking the index, such as contact angle, adhesive force,moisture permeability and resistance to water pressure, etc. into consideration for optimizing,the high-density polyester fabric, which was made at the condition of setting temperature of150 °C and calendaring temperature of 180 °C, was the best choice. In addition, the effect ofpore size on wetting and adhesion was studied by shrink-finishing at different temperatures.The chosen PTFE membrane and high-density polyester fabric were laminated for composite fabric, and PTFE membrane was selected by peel strength test. Moreover, the effect of the laminating process on product property was studied mainly by controlling the paramaters which included glue amount, hot-pressing temperature, and hot-pressing pressure.Meanwhile, the relationship between adhesion and laminating process was discussed. The results showed that PTFE membrane modified at the temperature of 260 °C was the best choice for the inner layer of laminated fabric; For PTFE microporous membrane laminated fabric, the optimal laminating process was hot-pressing temperature of 100 °C, hot-pressing pressure of 0.3 MPa and glue amount of 31.8 g/m2; The stronger the adhesion of the material,the stronger the bond. In the case of the same bond fastness, less gule amount may be used,which may less clog the gap within the materials, and this was conducive to moisture permeability. Meanwhile, the hand feeling and drape of the final laminated fabric were excellent.PTFE laminated fabric, which was prepared under the optimum conditions, had excellent waterproof and moisture permeability, the moisture permeability reached 5108 g/(m2·24h),and it had good hand feeling and drapeability. It was suitable for functional protective clothing.