Study On Microporous Molding Technology Of Polycarbonate And Its Composites In General Injection Machine

Polymer foam products are widely used in real life,with high heat deformation temperature and good impact strength.The traditional polycarbonate foaming method adopts intermittent foaming,molding foaming,extrusion foaming and other equipment processes and processing environment,which restricts the wide application of polycarbonate foaming materials.This article uses a common injection machine combined with micro-pore injection technology to prepare PC foam material injection parts,PC composite material injection parts and corresponding proportions of foam material injection parts.The foaming agent is prepared through extrusion and pelletizing process,and is prepared into small particles that are almost the same as the particle size of the injection material,so that it can be blended,injected and foamed according to the mass ratio.Considering the method that can be used to increase the foaming effect in mass production,the polymer is blended and modified by adding a polymer with poor compatibility with polycarbonate,the purpose is to add other phases to promote the heterogeneous formation of cells The core,and by adding a compatibilizer,improve the compatibility of PC and PMMA,PC and PP to a reasonable degree,in order to help obtain a better foaming effect.Simplify the processing equipment,conditions,processes,and verify the effect of polycarbonate microcellular injection molding in combination with actual production applications.The internal cell size of the PC foam injection parts made by foaming with a general injection machine is about 220μm,but it is clearly visible that the foaming effect of the PC/PMMA system based on PC has improved,PC/PMMA=At 3:1,the cell density is 1.412×10~5cells/cm~3,and the average cell size is 84μm.It is improved by continuing to blend thermoplastic rubber.PC/PMMA=3:1 Add 5%thermoplastic rubber and then perform micropores After injection,the cell density reached 5.343×10~5 cells/cm~3,and the average cell size was about70μm.The phenomenon of cell merging inside the main shot of the composite material was reduced,and the cell distribution was more uniform.Using PC as the base material,after adding PP in proportion,perform micropore injection.When PC/PP=3:1,the cell density is 1.273×10~5 cells/cm~3,the cell size is 90μm,PC/PP=1:1 When the cell density is 0.776×10~5 cells/cm~3,the cell size is 127.5μm,because the compatibility of PC and PP is poor,the foaming effect is not very obvious,when PC/PP=3:1 After adding MA to the system,the foaming effect of the injection parts was obviously improved,the cell density was 7.113×10~5 cells/cm~3,and the cell size was about 88μm,which indicated the feasibility of preparing PC foam material with a common injection machine.Through the DMA test,with the introduction of PMMA,the loss factor of the PC/PMMA composite system is closer to 1,when 25%is added,it approaches 1 to about 0.3,which increases the damping performance of the composite system.After adding thermoplastic rubber,the composite The loss modulus of the system increases by about 50Mpa,indicating that the viscosity of the composite system is increased and the plasticity is enhanced,which helps to improve the microcellular injection foaming effect of the system.Through the torque rheometer test,after adding the thermoplastic rubber,the maximum torque of the PC/PMMA foam system is increased by about 10N/m.After the PC/PMMA system is added with SBS blend,the balance torque of the blended system is In pure PC foaming system,the viscosity is increased by 3N/m.For PC/PP composite materials,after adding the compatibilizer MA,the balance torque is slightly increased by about 3N m,which increases the compatibility of PC and PP,increases the viscosity of the composite,and helps improve the foaming performance.The distance between the plasticizing peak and the thermal decomposition peak becomes longer,which can make the PC/PP composite material have a longer processing time period.The method of preparing polycarbonate injection parts by micro-hole injection adopted in this paper further simplifies the process flow,is more convenient for actual production and application,and can be directly applied to actual production.All experiments are in line with actual production,avoiding the use of complex equipment and harsh processing conditions.In order to broaden the use of PC,more efficient and stable preparation of PC foam materials,preparation of ideal injection molding microporous materials,blending modification It provides reference and reference for improving the foaming performance of polycarbonate.