According to the burns caused by different reasons such as machinery, mold or molding conditions, the solutions are also different.
(1) Mechanical reasons
For example, due to the overheating of the material barrel caused by abnormal conditions, the resin is decomposed at high temperature, burned and injected into the product, or due to the stagnant flow of the resin in the nozzle and screw thread, check valve and other parts of the material barrel, the resin is decomposed and discolored and then brought into the product, with black and brown burn marks in the product. At this time, the nozzle, screw and barrel should be cleaned.
(2) The reason for the mold
It is mainly caused by poor exhaust. This kind of burn usually occurs in a fixed place, which is easily different from the first case. At this time, it is necessary to take measures such as adding exhaust slots and anti-exhaust rods.
(3) In terms of forming conditions, when the back pressure is more than 300MPa, the material barrel will be overheated, causing burns. When the screw speed is too high, overheating will also occur, which is generally within the range of 40~90r/min. When there is no exhaust slot or the exhaust slot is small, too high injection speed will cause overheating gas burn.