Plastic mold manufacturing weld lines are visible stripes or linear traces on the surface. They are formed by not completely fusing at the interface when two streams meet. In the mold filling method, the weld line refers to a line when the front sections of the fluids meet. . The mold factory pointed out that especially where the injection mold has a highly polished surface, the weld line on the product looks like a scratch or a groove, especially on darker or transparent products.
The following is a brief analysis of the factors that affect the welding line of injection mold products as follows:
1. The mold manufacturer analyzes from the aspect of equipment: Poor plasticization, uneven melt temperature, increase the amount of plasticization, and replace the machine with large plasticization capacity if necessary.
2. The mold manufacturer analyzes from the mold aspect:
a. If the mold temperature is too low, the mold temperature should be appropriately increased or the local temperature of the weld line should be increased purposefully.
b. The flow channel is small, too narrow or too shallow, and the cold material well is small. The size of the runner should be increased to improve the efficiency of the runner, and at the same time increase the volume of the cold slug well
c. Enlarge or reduce the gate section and change the gate position. The gate opening should try to avoid the melt flowing around the inserts and cavities. The gate where injection mold filling occurs should be corrected, migrated, or buffered with a stopper. Try not to use or use more gates as much as possible.
d. Poor exhaust or no exhaust holes. Exhaust channels should be opened, expanded or dredged, including the use of inserts and thimble gaps for exhaust.
The position of the weld line is always in the direction of the material flow. This is because the place where the weld line is formed is the place where the trickle of the melt is branched in parallel. It is typically the melt flow around the core or the use of multiple gates. Products. Where the trickle meets again, weld lines and stream lines are formed on the surface.
Post time: Dec-17-2021