Injection molding is a commonly used manufacturing technique. A material is melted and then “injected” into a mold which as the desired dimensions of the final part. This process is done under high pressures in order to force the material into all parts of the mold prior to the material cooling. The injection mold design plays a critical part in the quality and reproducibility of the finished product. These molds have a limited work life depending on the material used to make the mold. Hardened steel makes the longest lasting molds but is also the most expansive and time consuming to make. For lower volume products, an aluminum mold may be sufficient. Injection molding can be used for making parts out of both plastic and metal (MIM). The best plastic injection molding companies have experience working with many different types of plastics and part designs. To injection mold more complicated parts, multi-part molds and automated inserts might be necessary.
There are some specialized molding techniques to consider when looking to make products such as bottles and jars. Blow molding is typically used to create hollow plastic parts with a uniform wall thickness. The process involves inflating a plastic preform inside of a closed mold so that the final shape of the part conforms to the mold cavity. Many blow molding company reviews can be found on VendOp.
Extrusion process is quite different from molding and is used to create objects that have a fixed cross sectional profile. The process can be continuous and produce products of great length such as tubing. Because during the process, the material only experiences shear and compressive forces, brittle materials such as ceramics can be used for extrusion as well as metals and plastics. Extrusion is used to make tubing and parts with a fixed cross sectional geometry. Multi-lumen tubes can also be made with very intricate details. The best extrusion companies have many techniques and skills they have developed over the years to be able to make your product quickly and accurately.
Rubber extrusion, plastic extrusion and metal extrusion are common processes.