| With the development of society,people’s awareness of safety and protection has gradually increased.China has formulated strict firearms management regulations to reduce the occurrence of shooting cases,but in daily life,cases of people being hurt by knives and sharp objects occur from time to time,and the demand for stab-proof products is growing.Para-aramid fiber has excellent mechanical properties,and nonwoven fabric has the characteristics of soft,breathable and light weight,which has good anti-stabbing effect for conical knives,and there is less research on the antistabbing performance of nonwoven fabric.In this paper,we take aramid nonwoven fabric as the research object and compound it with hard silicon carbide particles and modified polycarbonate resin sheet to make the prepared anti-stabbing composite with certain softness and breathability on the basis of enhancing the anti-stabbing performance,and the main conclusions obtained are as follows:(1)Structure and puncture resistance of para-aramid nonwovens.The mechanical properties(tensile,top-break,tear)of para-aramid nonwovens of different gram weights were tested,and it was obtained that the longitudinal and transverse mechanical properties of para-aramid nonwovens differed greatly due to the directional distribution of fibers,which had some influence on their puncture resistance.In addition,quasi-static puncture tests were conducted on single-layer,stackedlayer and different angles(0°,45°,90°)of the aramid nonwoven.The results showed that the puncture resistance of the aramid nonwoven with high grammage in the single-layer puncture resistance test was good,and the puncture strength of the aramid nonwoven increased nonlinearly after stacking.The best puncture resistance was achieved at puncture angles of 0° and 45°.Finally,the morphological observation of the punctures showed that the deformation of the aramid nonwoven and the fracture of the fibers by the tensile shear of the tool mainly occurred during the puncturing process.(2)Preparation of silicon carbide reinforced sandwich aramid nonwoven composites.Firstly,bicomponent polyester fiber is selected as the binder,and the nonwoven fabric is obtained by the net laying and needling process.The sandwich structure is adopted,and the arrangement of aramid nonwoven/bicomponent polyester nonwoven/silicon carbide particles/bicomponent polyester nonwoven/aramid nonwoven is used,and the silicon carbide particles are uniformly sprayed through the powder spraying machine,and finally the skin layer of bicomponent polyester fiber is melted by hot pressing,so as to fix silicon carbide particles.The effects of different hot pressing pressure,particle mesh and particle content on the anti-puncture performance were investigated.The results showed that the addition of silicon carbide particles significantly improved the puncture resistance with certain softness,in which the maximum puncture strength was 78.4 N,which was improved by124%.The dynamic puncture test showed that the puncture resistance standard of GA 68-2019 could be achieved when the number of stacked layers was 11.(3)Preparation of polycarbonate resin sheet composites.In order to further reduce the thickness of the puncture-resistant composite material that meets the puncture resistance standard,a polycarbonate/aramid nonwoven composite material was prepared by laminating a circular polycarbonate resin sheet with high stiffness and impact resistance with an aramid nonwoven fabric using polyurethane as the adhesive.Through quasi-static puncture test,dynamic puncture test and breathability and stiffness performance test,it was found that the material could meet GA 68-2019 puncture resistance standard with only 5 layers,and its thickness was reduced by 68.4% compared with that of silicon carbide puncture resistant composite with good breathability and softness. |
PDF Full Text Request