PC polycarbonate can be injected, extruded, moulded, blow moulded, hot moulded, printed, bonded, coated and machined. The most important processing method is injection moulding.
Pre-drying is necessary before forming. The moisture content should be less than 0.02%. Processing at high temperature will make the product white and turbid, silver wire and bubbles. PC has considerable ability of forcing high elastic deformation at room temperature. Because of its high impact toughness, it can be processed by cold pressing, cold drawing and cold roll pressing. Molecular weight of PC for extrusion should be more than 30,000. Gradual compression screw should be used with length-diameter ratio of 1:18-24 and compression ratio of 1:2.5. Extrusion blow moulding, injection-blow and injection-pull-blow moulding can be used to produce high quality and transparent bottles. There are many kinds of PC alloys, which can improve the defects of high melt viscosity (processability) and easy stress cracking of PC products. PC can form alloys or blends with different polymers to improve material properties. There are PC/ABS alloy, PC/ASA alloy, PC/PBT alloy, PC/PET alloy, PC/PET/elastomer blend, PC/MBS blend, PC/PTFE alloy, PC/PA alloy and so on, which have two advantages of material performance and lower cost. For example, PC/ABS alloy mainly contributes to high heat resistance, good toughness and impact strength, high strength and flame retardancy, while ABS can improve formability and apparent quality. Quantity, reduce density.
