| Packaging materials require special properties such as flame retardancy,flexibility,moisture barrier and other advantages.At present,the current packaging film has high surface density,poor flame retardancy and flexibility,which limits its application in the aerospace industry.In this paper,Nylon66/VMPET(Polyester aluminized film)/PVF(Polyvinyl fluoride)composite film was prepared by dry composite method and hot pressing composite method.The effects of fiber bundle,grid area,hot pressing temperature and pressure on the mechanical properties of the composite film were studied,analyzed the strengthening structure and mechanism of the composite films,solved the problem of fiber bundle binder non-uniformity,overcome the bonding problem caused fiber bundle spacing;The effects of heat-sealing temperature,heat-sealing time and heat-sealing pressure on the heat-sealing strength of the composite film were investigated.The Nylon66/VMPET/PVF composite film as the research object,the microscopic mechanism of the sealing process was analyzed,and established a BP neural network model based on MATLAB for heat-sealing strength of the composite film,the simulation of the heat sealing process parameters was optimized,and successfully prepared.the composite films.Thirdly,after coating the composite film,the thermal conductivity is reduced by 13%-16.4% at the same temperature,and the sound insulation is increased by 4.5-14 dB in the frequency range of 3.15-6.3kHz.Fourthly,the BP neural network model was relatively accurate,the simulation error was 5%,and determined the parameters to meet the standard heat-sealing strength,which provide guidance for the practical application of Nylon66/VMPET/PVF composite film.The surface density of Nylon66/VMPET/PVF composite film was about 66.76g/m2.It had excellent mechanical properties,heat-sealing performance,thermal,sound insulation properties,and improved the thermal insulation performance and service performance of aerospace cotton felt. |
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