Custom injection molding materials can be selected to meet or exceed your specifications and enhance your products performance properties, such as appearance, durability, chemical resistance and corrosion resistance.
Injection molding is a manufacturing process that creates objects by injecting a desired material into a custom mold. It is the most preferred method for producing high volumes of plastic parts and products. Injection molding has an infinite number of applications. It is used to create bottle caps, automotive parts, wire spools, storage containers, one-piece furniture, and most other plastic products.
Manufacturers can use a variety of materials in injection molding. The most common are thermoplastic resins and thermosetting polymers, but elastomers, types of glass and metals (though this process is referred to as die-casting) can also be used. One of the most versatile and popular resins used for injection molding are PEEK plastic, also known as polyetheretherketon and TORLON.
Thermoplastic is the best material used for injection molding because of its versatility. Not only does it easily soften and flow into molds when heated, it is generally more forgiving than other materials. Thermosetting polymers, for example, need to be used quickly after heating. If not, it can seize and damage injection molding machines.
Injection molds are typically made from tool steels, however, stainless steel or aluminum molds may be better suited for certain applications. Aluminum molds are more susceptible to deformation during injection and clamping cycles, and therefore aren’t suitable for high-yield jobs. Steel molds are far more expensive but have impressive durability, capable of producing upwards of a million items in their lifespan.
For custom molding with thermoplastic resins, raw pellets of material are fed into a heated barrel with a reciprocating screw. As the temperature of the barrel increases, the viscosity—or thickness—of the pellets decreases, which enables it to travel through the check valve and creates a shot.
A shot is the volume of material needed to fill the cavity of the mold. The material is forced in the mold, allowing for the shrinkage when set. Finally, the items are efficiently chilled by the external temperature controller and a series of lines that circulating chilled water or oil around the molds. Once the desired temperature is achieved, the molds open and the parts are removed by pins or strippers, so the entire process can be repeated.