Study On The Fabrication Of Porous Carbon Fiber Mat By Paper Making-heat Pressing Process And Its Physical Performance

In recent years,with the advent of smart fabrics such as wearable electronics,conductive fabrics obtain rapid development and wide attention,its fabrication involved nonwoven technology has a good application prospect due to high efficiency and low cost.This work proposed a paper making-heat pressing nonwoven technology in which carbon fiber(CF)and polyethylene/polypropylene core/sheath bi-component fiber(ESF)are dispersed into porous preform by paper making process and then strengthened into porous carbon fiber composite mat(CEF-NC)by heat pressing process.The influences of heat pressing parameters and structural parameters on the several basic physical properties of CEF-NCs including micro structure,tensile strength,electrical and wetting performance are then investigated thoroughly.On micro structure,the spatial distribution of CFs and ESFs was observed from scanning electron microscope(SEM)images,finding two types of bonding points,i.e.ESF-CF and ESF-ESF bonding points,are formed inner the CEF-NC and the forming process of these bonding points was analyzed.On mechanical performance,uniaxial tensile test and flexibility test were conducted to systematically evaluate the mechanical performance of CEF-NC.The macro and micro fracture structure of tensile species were observed to investigating the influence of heat temperature and fiber mass fraction on fracture mode of CEF-NC.On electrical performance,the four-points probe method are used to measure the electrical conductivity of CEF-NC to investigate the relation between process parameters and electrical conductivity.In addition,a theoretical model is established to express the relation between the electrical conductivity and conductivity percolation threshold of a CEF-NC is obtained(5.45 wt%).On wetting performance,this work puts forward an infrared(IR)image testing method to visualize the wetting process of droplets.The experimental platform was designed and established to observe the wetting process of droplets(deionized water)on CEF-NC and the wetting performance is evaluated by the area of wetting region.Then the the influence of process parameters on wetting performance of CEF-NC was investigated.