Research And Development Of Carbon Fiber Knitted Fabric Composites

Carbon fiber knitted fabric composite is a kind of material made of carbon fiber knitted fabric as a reinforcement and resin as a matrix.Because of high specific strength and specific modulus,carbon fiber composites were not only widely used in the aerospace sector,but also paid highly attention to in other areas.This project aimed to develop a kind of carbon fiber knitted composite,the research were as follows:The knitting properties of carbon fiber were explored based on hand-knitting machine,and with stitch depth of 13,smaller yarn tension and traction force,carbon fiber could be knitted smoothly and carbon fiber knitted fabrics came out.In order to improve the surface properties of carbon fiber,Low-temperature plasma treatment was used to the surface modification of carbon fiber.And by single factor analysis and orthogonal test,solutions were put forward.The best solution of plasma treatment was 5#A₂B₂C_3,?40Pa,100W,120S?.With 5#,the carbon fiber breaking strength was 6.82cN,static friction coefficient was 0.7062,capillary weight change rate was52.84%,and fiber surface structure and functional groups were also observed and analyzed with the aid of scanning electron microscopy?SEM?and Fourier transform infrared spectroscopy?FTIR?.Finally,the optimum plasma treatment process was used to the surface modification of carbon fiber knitted fabric.In this paper,with molding method and vulcanizing machine,carbon fiber knitted fabric and E-44 epoxy resin were compounded into a kind of carbon fiber composite.After plenty of tests,and the optimal molding process parameters were given:when the E-44 epoxy resin/hardener according to ratio of 150:60,with Vaseline for stripping machine,temperature of 40?and molding pressure of 1.5MPa,the heating time was 1h,insulation2h,and then the molding is cooled to room temperature,the carbon fiber knitted fabric composite finally came into being.Finally,the mechanical tests of carbon fiber knitted fabric composites were done on CMT5304-30KN microcomputer controlled electronic universal testing machine,and the following conclusions:After plasma treatment,the carbon fiber knitted composite longitudinal stretch strength increased by 23.74%,transverse tensile strength increased by28.88%;longitudinal bending strength increased 20.90%,transverse bending strength increased by 18.97%;longitudinal compressive strength increased by 28.78%,transverse compressive strength increased by22.92%.It is indicated that plasma treatment have some etching effect on the surface of carbon fiber,so that the surface of carbon fiber was more actively,and naturally combined more closely with resin after fiber modification treatment,the composite behaved better afterwards.