Shaping: Plastic Injection Molding

Depositphotos_32449559_lPlastic Injection Molding enables the production of high volumes of thin-walled plastic parts in a variety of shapes and sizes; this makes it the most common method of manufacturing plastic parts. Injection molding is used to create parts for everything from household appliances, containers, and automotive interiors, to any number of mechanical parts.

The injection process involves an injection molding machine (“press”), raw plastic material, and a mold (“die”) which is usually made of steel or aluminum. The process takes less than 2 minutes and occurs over four stages: Raw plastic material is melted and injected into the mold.  The two halves of the mold are pressed together and held with pressure while the plastic is injected. As the plastic cools, it solidifies into the shape of the mold. When it’s completely cooled, the part is pushed out of the mold.

Many different types of materials may be used including all thermoplastics, some thermosets, and some elastomers. There are a few things to consider when choosing a material; strength and function of the final product, and the material’s molding limits.

Cost is determined by different factors, such as complexity, size, and wall thickness. Fewer cavities and thinner walls will result in lower costs, however you should take into account the requirements of the final product before trying to cut costs.