plastic injection molding solidworks

During injection molding, the molten plastic form meets multiple chains in the cavity due to hole insertion, the area of flow is discontinuous, and the place where the flow of the filler is interrupted, a linear weld is generated because it cannot be fully fused. In addition, the gate injection molding, will also form a weld, weld strength and other poor performance. The main reasons are as follows:
Processing:
Injection pressure and speed are too low, barrel temperature and mold temperature are too low, resulting in premature cooling of molten material entering the mold and weld.
When the injection pressure and speed are too high, the injection will occur and the weld will appear. Should increase the speed, increase the back pressure, in order to reduce the viscosity of plastic, increase the density. Plastic should be good dry, recycled materials should be economical use, release agent dosage is too much or poor quality, may appear weld. Reduce clamping force and facilitate exhaust.
2. Injection mold:
When there are too many sprue in the same cavity, the sprue should be reduced or set symmetrically, or as close as possible to the weld. Poor exhaust at the weld shall be provided with an exhaust system. The gate is too large, the size of the pouring system is improper, the gate is opened to prevent the melt from flowing around the insert hole, or the insert piece is used as little as possible. If the wall thickness changes too much or the wall thickness is too thin, the wall thickness of the workpiece should be uniform. If necessary, weld holes should be opened at the weld to separate the weld from the workpiece.
3. Plastics:
For plastics with poor fluidity or heat sensitivity, lubricants and stabilizers should be appropriately added. Plastic contains a lot of impurities, if necessary to replace good quality plastic.