Effects Of Processing Parameters On Quality Of Polycarbonate Product By Injection-compression Molding

Polycarbonate (PC) is a large class of polymer with carbonic ester in its molecularchain which is amorphous, non-toxic and odorless general engineering thermoplastics.PC with excellent overall performance, which is characterized by both the transparency,excellent impact toughness, dimensional stability, creep resistance and electricalinsulation, has a high tensile strength, flexural strength, elongation and rigidity. It hasbeen widely used in construction, packing, automotive, electrical, electronics andmedical equipment industry.Injection compression molding is an advanced forming method, developed from theconventional injection molding and compression molding, which can effectively reducethe defects of the injection molding products, such as large warpage and high residualstress. Its products have a high dimensional accuracy, stability and lower residual stress.But at present, both researches on injection compression molding and its equipment andresearches on the injection compression molding processing parameters’ effect on thequality of the molding products are still less in our country.In order to study the injection compression molding processing parameters’ effecton the forming quality, the main job of this paper is as follows:Firstly, three kinds of gating running systems and four kinds of cooling systems areproposed according to the shape to the product and principles of mold designing, thenthese systems are simulated in the Moldflow software. After that the best running andcooling system are selected based on the analysis of the simulation results. Finally, aninjection-compression mold is designed and made according to the selected systems.Secondly,injection-compression finite element model of PC product is built inMoldflow based on the simulation results. Then processing parameters’ effects onqualities such as warpage and residual stress are simulated in the software by orthogonalexperimental method. According to the analysis of the results, six processing parameterswhose effects are significant. On the basis of the six processing parameters,injection-compression experiment is conducted by single factors experiment method.Finally,experiments such as the measurement of the volume shrinkage, tensileproperties experiments, impact strength experiment and photoelastic experiment aremade with the injection-compression products. Then the processing parameters’ effect onthe volumetric shrinkage, yield strength, elongation, impact strength and residual stressare obtained.