PC has high performance, high transparency, good impact toughness, creep resistance, wide temperature range, PC process characteristics: melt viscosity is less sensitive to shear rate, and sensitive to temperature, no obvious melting point, The melt has a high viscosity, and the resin is easily hydrolyzed at a high temperature, and the product is easily cracked.
Due to the high viscosity of PC melt, it is beneficial to plasticize and facilitate exhaust. It is beneficial to the maintenance of the plastic machine and prevent the screw load from being too large. The rotation speed of the screw should not be too high. Generally, it is suitable for 30-60r/min. The back pressure control is preferably between 10-15% of the injection pressure.
Plastic machine requirements for the production of PC products: the maximum injection volume (including runners, gates, etc.) of the product should be no more than 70-80% of the nominal injection volume.
The screw should be a single-thread thread with a pitch, with a gradient of the check ring. The compression type screw has a length to diameter ratio L/D of 15-20 and a geometric compression ratio C/R of 2-3.