Analysis on in-cavity residual stress of crystalline polymer plastics based on orthogonal experiment
SUN Guo-dong;LIU Chang-hua;School of Mechanical and Materials Engineering,Jiujiang University;Surface Green Remanufacturing Engineering Technology Center of Jiangxi Province,Jiujiang University;
The effects of mould temperature, melt temperature, pressure holding time and cooling time on in-cavity residual stress of mobile phone back cover that was made from crystalline polymer were analyzed by using Moldflow software and combining with orthogonal method and variance and significant analysis. The simulation results showed that the cavity residual stress of part on the direction of the thickness was tensile stress. For crystalline polymer plastics, the mould temperature has a significant influence on in-cavity residual stress, the rest of the factors have a little influence on it. The reason was that the mould temperature affects on the crystallization process of polymer plastics, the stress of plastics in the cooling process was released. Process parameters were optimized by orthogonal method, namely, the mould temperature was 20 ℃, cooling time was 10 s, the melt temperature was 220 ℃, the pressure holding time was 20 s. The optimized in-cavity residual stress was 21.80 MPa, which was reduced 15.8% than before.