Plastic injection molding is a common process to make plastic products. This technique proceeds in four steps and each one is important. Depending on the size and complexity of the item being made, this process takes between 2 seconds and 2 minutes. Here is a look at the four stages of injection molding.
Proper Clamping
Molding a plastic item via injection requires a mold divided into two halves. These halves are clamped together to hold the molten plastic as it is injected. The force used keeps the two halves together while the material is injected and prevents massive spilling.
Plastic Injection
A quick inspection confirms the two mold halves are clamped properly, then the molten plastic is injected. Raw pellets are fed into a heating unit which melts them down and forces the melted material into the mold. The amount injected must be measured precisely and depends on the item being made. This amount is called a “shot.”
Cooling
Before the two mold halves can be separated, the plastic must cool and harden. For large items, some shrinkage may occur so the injection device stays connected to the mold in order to press more material into the space and lessen the visible signs of shrinkage. A specific cooling time is calculated in advance and the two mold halves will not be opened until that time expires.
Product Ejection
When the cooling process is complete, the newly molded plastic can be removed from the mold. Depending on the size of the item, this could be as simple as popping open the mold and allowing the item to fall through or could be a more complex process. Finally, any excess material is removed.
Plastic injection molding is a common practice to create custom molded items. Many different shapes and sizes can be created with this process and multiple different materials may be used. For your custom plastic molding needs, look for a company that had experience handling high amounts of heat and pressure in their manufacturing process.
