Due to the different materials of each product, it is often the case that defective products may occur during the injection molding process. For example, vibration marks often appear on rigid plastic products, so what is the reason? Is there a good solution?
Causes of Product Ripples in Injection Processing
On the surface near the gate of a rigid plastic part such as PS, dense corrugations are formed around the gate, sometimes referred to as vibration marks. The reason is that when the melt viscosity is too large and the mold is filled in the form of stagnation, the front-end material will quickly condense and contract as soon as it touches the surface of the cavity, and the subsequent melt expands and the contracted cold material continues to advance Constant alternation causes the flow to form surface vibrations as it progresses.
The solution to the occurrence of chatter marks in the injection molding process:
- (1) Increase the barrel temperature, especially the nozzle temperature, and also increase the mold temperature.
- (2) Increase the injection pressure and speed to make it fill the model cavity quickly.
- (3) Improve the dimensions of runners and gates to prevent excessive resistance.
- (4) The mold exhaust should be good, and a sufficiently large cold well should be set up.
- (5) Do not design the part too thin.