Injection Molding Design Plastic Molding Design Design Resources Plastic injection molding is the primary process for manufacturing plastic parts. Plastic is known to be a very versatile and economical material that is used in many applications. Although the tooling is expensive, the cost per part is very low.
Complex geometries are possible and limited only to mold manufacturability.
Your computer monitor, mouse and keyboard are injection molded plastics. Injection molding involves taking plastic in the form of pellets or granules and heating this material until a melt is obtained. The mold is then opened and the part is ejected, at which time the cycle is repeated. Depending surface length draft angles down to half a degree are reasonable. Typical draft angles should be about 1 too 2 degrees for part surfaces not exceeding 5 inches.