Study And Development Of UHMWPE Fiber Knitted Fabric Composites

UHMWPE fiber is emerged after carbon fiber and Kevlar fiber and becomes the third high strength and high modulus fiber in the world.At present the researches of UHMWPE fiber knitted fabric / epoxy resin composites are very few,especially the three-dimensional molding of UHMWPE fiber knitted reinforced composite materials has not been studied by anyone.This study aims to determine the optimal process of plasma modification of UHMWPE fiber,and test the mechanical properties of UHMWPE knitted fabric / epoxy resin composites before and after plasma treatment.Finally,the three-dimensional forming UHMWPE knitted fabric composite model were researched and developed.Through the single factor experiments,the effects of the different processing pressure,processing power and processing time on the static friction coefficient and breaking strength of UHMWPE fiber treated by plasma were discussed,the results show that: after processing the static friction coefficient of UHMWPE fiber was increased by 1.04% ~40.48%,the breaking strength decreased by 4.27% ~ 23.47%.The orthogonal test three factors levels of UHMWPE fiber treated by plasma were determined: processing pressure is 30 Pa,40Pa,50 Pa,processing power is 75 W,100W,125 W,processing time is 120 s,150s,180 s.Through orthogonal test,the optimal process of UHMWPE fibers treated by plasma was determined: pressure 50 Pa,power 100 W,time 180 s.The optimal plasma process was used to treat UHMWPE fibers,then the performances of UHMWPE fibers before and after treatment were tested.The results show that: the wettability of UHMWPE fibers has increased after treatment,the roughness and etching of fiber surface has also increased and the fiber specific surface area has been larger,the fiber surface became more uneven,and more active groups appeared on the fiber surface.The mechanical properties of UHMWPE knitted fabric / epoxy resin composite materials were tested,the results show that: the warp tensile strength and bending strength of UHMWPE fabric / epoxy resin composites before and after treatment are always greater than the weft,the compression strength is approximately equal in warp and weft direction.the mechanical properties of UHMWPE knitted fabric / epoxy resin composite materialafter plasma treatment is always greater than the untreated,which shows that the plasma treatment can improve the adhesion between UHMWPE fiber and epoxy resin,thus the mechanical properties of the composites can be improved.The knitting process of radar cover,rocket,submarines and some other models were calculated.All the modals were knitted on knitting machine by using three-dimensional molding technology,then the UHMWPE fiber knitted fabrics and epoxy resin were composited,and the three-dimensional UHMWPE fiber knitted fabric reinforced composites were manufactured,which provides a theoretical foundation and basis for applying the knitting three-dimensional molding technology in UHMWPE fiber reinforced composite material.