Study On The High-temperature Hot-pressing Technology Of Polytetrafluoroethylene Membrane Filter

With the excellent performance of high temperature and chemical resistance,the Polytetrafluoroethylene(PTFE)membrane filter was widely applied to the area of hightemperature filtering industry.There are several problems of the membrane filter produced by traditional adhesive technology,such as weak adhesive strength between the PTFE membrane and the basic fabric.It effects the properties of PTFE membrane filter.To solve the problems above,it need to update the traditional adhesive technology and study on how the different parameters gives different impacts to the performance of PTFE membrane filter.This study could be the theoretical basis for the application of the membrane filter.First of all,this paper analyzed the surface coating composition of the glass-woven fabric produced by a professional factory.The average pore of filter,permeability and the laminating strength of filter are discussed to evaluate the performance of filter by the single-factor analytical method.And it can help to study the various effects of the different experimental parameters on the membrane filter.Secondly,the silane coupling agent was applied to improve the adhesion between the glass fiber and PTFE polymer.In order to put forward the coating formulation of basic fabric coating,the different ratio between the PTFE emulsion and acrylic emulsion was prepared.The film forming ability,stability and adhesive strength was discussed to evaluate the performance of finishing agent produced by the particular coating formulation.It can improve the surface property glass fiber and the adhesive strength between basic fabric and PTFE membrane.Thirdly,the glass felt was dipping in the finishing agent produced by the particular formulation and manufactured the membrane filter with the high-temperature hot-pressing technology.It can further investigate the effect of the hot-pressing time,pressure and temperature on the performance of PTFE membrane filter.Finally,in order to the best technology to produce to membrane filter through the performance comparison between different samples with different basic fabric and manufactured process.The results show that the acceptable parameters of high-temperature hot-pressing technology between glass fiber fabric and PTFE membrane as follows: the hot-pressing time is about 10~15s,the hot-pressing temperature is about 220~240 ?,the hotpressing pressure is about 1~3MPa.The acceptable ratio of the coating formulation of basic fabric coating between the PTFE emulsion and acrylic emulsion is 75/25.Besides,after the drying in the condition of 120? about 1h,the adhesive strength of PTFE between glass yarn and PTFE membrane can improve 66.9% using the 1% of KH550.With regard to the technological parameter of high-temperature hot-pressing technology,the acceptable parameters as follows: the hot-pressing time is about 7~10s,the hot-pressing temperature is about 220~240?,the hot-pressing pressure is about 1~2MPa.The permeability of membrane filter can reach 56.98mm/s and the laminating strength between PTFE membrane and basic fabric can reach 30.7k Pa as the hotpressing time is 10 s,the hot-pressing temperature is 220 ? and the hot-pressing pressure is 1MPa.It can apply to high-temperature dust-cleaning area with desirable properties.