To makeplastic seals, we need let the plastic be molded. The plastic molding is a process use various forms of plastic (powder, pellets and the solution, dispersion) change into the products or blanks of desired shape which customer need. There are more than thirty kinds of molding method can achieve this process.

To choice the plastic molding method is mainly determined by the type of plastic (thermoplastic or thermosetting), the starting morphology and dimensions of the products. The commonly used methods of processing thermoplastics extrusion, injection molding, calendaring, blow molding and thermoforming. Processing thermosetting plastic generally used compression molding, transfer molding injection molding. In these methods, extrusion and injection molding is the most used and the most basic method of molding plastic.

Theplastic seals often use injection molding. This method is let the molten plastic rapid inject to the mold by injection machine, and make it solidified to obtain a variety of plastic products. Almost all thermoplastics (except fluorine plastic) can be used this method, also be used for some thermosetting plastics molding too.

Injection molding accounted about 30% of the plastic production. It can be primary molding a complex shape with precise size, and high productivity advantages. But the cost of equipment and mold is higher, so this method is mainly used for product a large quantities of plastic parts.

The principle of injection molding is put the powder and granular material of plastic into the barrel by hopper. Then when the machine’s plunger be impelled, the raw material is pushed into the heating zone, and through the die cone, then the molten plastic is injected into the mold cavity by nozzle, after cooling we can get the plastic product we need.

This is the process that how to makeplastic seals.