Polycarbonate (PC) injection molding process newmaker polycarbonate is a non-crystalline engineering plastic, odorless, odorless, non-toxic, transparent amorphous plastic. It has excellent toughness, high heat distortion temperature and excellent transparency. There are also good dimensional stability and electrical properties. Molding: 1 The raw materials are strictly kept to prevent moisture, and the polycarbonate is very sensitive to trace moisture at high temperatures. The drying temperature is generally 110 to 120 ° C for 24 hours. 2 polycarbonate has no obvious melting point, and the injection molding temperature can be formed from 240 ° C to 310 ° C. When it exceeds 320 °C, it starts to decompose. When molding, it is more effective to adjust the temperature than to adjust the pressure. Generally, in order to gradually melt the plastic, a lower temperature is set in the rear/feed zone of the feed pipe, and a higher temperature is set in the front section of the feed pipe. However, if the screw design is improper, or the L/D value is too small, the reverse temperature setting is better. 3 The mold temperature is too low, the production is easy to produce stress concentration, causing cracking, and the mold temperature is required to be 70 ° C ~ 110 ° C. The high mold temperature provides a better surface appearance, less residual stress, and is easier to fill for thinner or longer molded articles. However, low mold temperatures can shorten the molding cycle. 4 Injection pressure: In order to fill the mold cavity as soon as possible, the injection pressure is as high as possible, generally about 850 ~ 1400kg / cm2, and up to 2400kg / cm2. The lower the back pressure, the better, but the feed is required to be uniform. It is recommended to use 3~14kg/cm2. 5 injection speed has a great relationship with the gate design. When using direct gate or edge gate, to prevent the phenomenon of daylight and wave current, the slower rate of fire is applied, and the thickness of the finished product is more than 5mm; to avoid bubbles and Depression, slow rate of fire will help, in general, the principle of rate of fire is thin, fast, thick, screw speed is 40 ~ 70RPM, but need to adjust the machine and screw design. 6 barrel cleaning At the molding temperature of the polycarbonate, the cleaning material (general-grade polystyrene or benzene-permeable benzene) is continuously injected until the injected cleaning material starts to rise and foam, and then the barrel temperature is reset to 200-230 ° C. Continue to air the cleaning material until the appearance of the cleaning material looks clean and transparent. 7 injection molding machine requirements: Clamping force: multiply 0.47~0.78t per square centimeter of projected area of ​​the finished product (or 3~5t per square meter) Injection volume: about 40% to 60% of the capacity of the injection molding machine. Screw: The length is at least 15 diameters long, and the L/D20:1 is the best, and the compression ratio is 1.5:1~3.0:1. ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsir-valves.com