Common problems of injection molding (Part 2)

Injection Mold technology is being widely used in plastics production, creating a variety of products used in daily life or industries. However, during the usage, we would still be having some problems, and here are some fundamental problems with the causes and proposed remedy.

Short Shots error, the cause of this problem may be due to cold molding which makes frozen too quickly and higher resistance to flow. Other cause that we can consider is too low pressure or too small gates. Or if the mold is not balanced with appropriate flow which will also cause this problem.

To solve this, we can raise the temperature or pressure accordingly. In case if the gate is too small, we ca expand the area up, either add or increase venting. In addition, we should also adjust to a mold runner system become balanced.

The next problem that we're talking about is Sink Marks. This occurs when there is not enough plastic in the mold to pack appropriately. Also, too hot plastic or too low injection pressure is a cause of this problem

The workaround is to increase the speed, increase the size gate. In addition, we can also reduce the temperature of the cylinder, increase the injection pressure.

Another problem is Warpage. When the part is ejected too hot which might cause this problem. Plastic is too cool or gates are not balanced which is also the reason for it. We can reduce the plastic temperature in order to solve this. Modifying the gates is to make it balanced, or getting the cylinder temperature hotter is also a good way to handle.

The last, but not least, is Surface Marks. When we use cold material or the injection is so slow which might be the reason. Other reason we can think about is that the flow in the gates and runner is unbalanced. To solve, we can: increase the plastic or mold temperature; increase speed of the injection or balance the gates and runners.