Reasons for Weld Line on Plastic Part
Apr 04, 2019
When we get the plastic parts during mold test, we will see some weld lines on them. What's the main reasons for the weld lines?
1. The surface temperature of the injection mold is too cold, and the surface temperature of the mold should be appropriately increased or the local temperature at the welded joint should be changed.
2. The runner is too small, too narrow or too shallow. The diameter of the runner should be increased to improve the efficiency of the runner, at the same time increasing the area and depth of the slag well.
3. Change the gate position. the gate should away from the weld zone, and need adjust the gate position or incease the quantity of auxiliary gates, and added buffer to the injection rate. Also we need try to reduce the number of mold gates.
4. Insufficient venting or the vent hole is not manufactured at the welding area. If so, the venting passage should be opened and expanded. we need increase vent holes and the size in the welded area.
5. The TPE product is too thin in the welding zone, and it needs to be modified to thicken the material.
