Research On The Influence Of Thecnological Parameters On Proerties Of Polycarbonate Product Fabricated By Injection-Compression Molding

Polycarbonate (PC) is a kind of engineering thermoplastics which is nontoxicand transparent, duo to its outstanding impact resistance, good transmittance andsmaller density, it is widely used in auto industry, electronic and electrical appliances,aerospace and so on. For the producing of PC products, the traditional methods areplate hot forming, injection molding and so on, but they will induce many defects,such as large buckling deformation and large residual stress. Injection-compressionmolding is a new processing method which can solve the above problems. There aremany factors which affect the properties of the injection-compression moldedproducts in the injection-compression molding, such as mold structure, materialproperty and processing technological parameters, so getting an ideal product throughrepairing and testing a die and parameters repeatedly by using an experimentalmethod will cost many manpower, material and financial resources, and thedevelopment cycle will become longer, so numerical simulation technology can beadopted. Among the numerous influencing factors, the effects of technologicalparameters are obvious, so it is much significant to research the influence oftechnological parameters on the properties of PC products fabricated byinjection-compression molding by using numerical simulation method andexperimental method, it can provide certain reference for the producing of PCproducts.This paper firstly built an injection-compression finite element model of PCplate by using the software MOLDFLOW, and optimized the running gate system andthe cooling system according to the warping deformation, welding scar, cooling effectand so on. Based on this, the mould was designed and manufactured.The injection-compression simulations and experiments of PC plates were doneunder the same technological conditions. The maximum relative deviation of the totalwarping deformation obtained from experiment and the one obtained from simulationis 4.62%, so they fitted well with each other, this indicated that the established modelis right, and it provided the foundation for the further study on the simulation ofinjection-compression molding.The influence which mold temperature, compression speed, compression forceand other four process parameters have on the total warping deformation andvolumetric shrinkage of PC injection-compression molded plate was researched byusing orthogonal experimental method. The primary and secondary relations ofvarious factors were determined by using range analysis, so the optimum process parameter combinations. Variance analysis was adopted to identify the significance ofinfluence which various factors have on the test indexes. On the basis of theoptimized process parameter combinations, the effects which main factors have onthe qualities of PC plates were also studied by using single factor analysis method.Injection-compression experiments of PC plates under different moldingconditions were conducted on the basis of the optimized process parametercombinations, and the tensile experimental study of PC plates was done to get theinfluence of various factors on the mechanical properties of injection-compressionmolded parts.