Equipment aspect (1) The equipment is not clean. Dust or other dust deposits on the hopper to contaminate the material. (2) Temperature control failure due to thermocouple, temperature controller or heating system imbalance. (3) There are obstacles in the barrel, which tends to promote the degradation of plastics; metal foreign objects are stuck in the barrel or the screw groove, and the plastic is continuously ground to discolor the plastic. Mold aspect (1) The mold is poorly exhausted, the plastic is adiabatically compressed, reacts with oxygen at high temperature and high pressure, and burns the plastic. (2) The mold gate is too small. (3) Too much lubricant or mold release agent in the material or in the mold. If necessary, the cylinder should be cleaned regularly to remove additives such as antistatic properties that are inferior to the heat resistance of plastics. (4) The size of the nozzle hole, the main flow path and the branch passage are too small. Process aspect (1) The screw speed is too high and the pre-plastic back pressure is too large. (2) The temperature of the barrel and nozzle is too high. (3) The injection pressure is too high, the time is too long, and the injection speed is too fast to cause discoloration of the product. Raw material (1) The material is contaminated. (2) High moisture and volatile matter content. (3) Decomposition of coloring agents and additives. Black spot or black liquor The main reasons for this defect are in equipment and raw materials: Equipment aspect (1) There is a blackened material in the barrel. (2) The barrel has cracks. (3) The screw or plunger is worn. (4) The vicinity of the hopper is not clean. Mold aspect (1) There is oil in the cavity. (2) Infiltration of oil from the ejector. Raw materials: (1) The raw materials are not clean. (2) Insufficient lubricant. Burnt dark lines Equipment: After the injection of heat sensitive plastic, the barrel is not cleaned or there is a mat at the nozzle that causes the exhaust to be poor at the beginning of the injection. Mold aspect: (1) Poor exhaust. (2) The gate is small or the gate is not in the proper position. (3) The local resistance of the cavity is large, which makes the exhaust of the flow slower and makes the exhaust difficult. Process aspect: (1) The temperature of the barrel and nozzle is too high. (2) The injection pressure or pre-plastic back pressure is too high. (3) The injection speed is too fast or the injection cycle is too long. Raw materials: (1) The particles are uneven and contain a powder. (2) The volatile content of the raw material is high. (3) Too much amount of lubricant and mold release agent. 2016 Biological Microscope,Celestron Biological Microscope,Biology Corner Microscope,Radical Biological Microscope Ningbo Beilun Kalinu Optoelectronic Technology Co.,Ltd , https://www.nbyxmicroscope.com