Research On UV-curing Resin Toughening And Composite Molding Process

UV curing fiber-reinforced resin composites technology has the advantages of high molding speed,high production efficiency,environmental friendly and energy saving.Hence,it has a huge application prospect in the automotive industry.However,the UV curing resin typically has low toughness,and is hard to manufacture structures with unregular shapes or with thick-walls,etc.In this paper,toughening of UV curing epoxy resin and typical structures of glass fiber reinforced composites manufactured through UV curing process were studied.(1)Effects of the content of TPGDA on the tensile,bending properties and glass transition temperatures(T_gs)of UV curing E-51 epoxy resin were investigated.The results showed that when the content of TPGDA is 10 wt%,the tensile fracture energy is the highest.Tensile strength and modulus are 66.2 MPa and 2.9 GPa respectively,which are 89.6%and 124.5%of thermo curing epoxy resin,respectively.Flexural strength and flexural modulus were 114.8 MPa and 3.0 GPa,respectively,which were107.6%and 129.7%of thermo curing epoxy resin.The UV curing epoxy resin had a T_g of about 130?.(2)The mechanical properties and interfacial bonding strength of glass fiber reinforced UV curing epoxy resin composites were studied.The results showed that the tensile,flexural and inter-laminar shear strengths of UV curing epoxy resin composites with 10 wt%TPGDA were 560.2 MPa,545.2 MPa and 30.33 MPa,respectively.Compared with unmodified UV curing composites,they were inncreased by 10.6%,18.2%and 3.4%respectively.(3)Feasibility of the molding of automobile hood by UV curing composite material is studied.The hood specimen includes the typical structural features such as the curved surface structure and the bending structure.Meanwhile,the UV curing composites manufacturing process for the thick-walled parts was explored,and a method combining UV curing and heat curing process was proposed.The results indicated that the molded composite specimens have high dimensional accuracy,uniform thickness,uniform solidification and high curing degree.What's more,the thick-walled parts of UV curing composite specimens can be completely cured after a post-heat-curing treatment.