ERKA Technik Gmbh

Injection Moulding

Injection moulding is a process for producing parts from both thermoplastic and thermosetting plastic materials it is used to create most of the plastic products available today.

The process is ideal for producing high volumes of the same object where repeatable high tolerances, the ability to use a wide range of materials, maintaining minimal scrap losses, and little need to finish parts after moulding is required.

Injection moulding can be used to manufacture a variety of parts, from the smallest of components to entire body panels of cars.

The injection moulding process

Once a product is designed moulds are precision-machined in metal, usually in either steel or aluminium to form the features of the  part to be created during the injection moulding process.

During the Injection moulding process thermoplastic or thermosetting plastic materials are fed into a heated barrel, mixed, and forced into the mould cavity where it cools and hardens to the configuration of the mould cavity to produce a solid or open-ended shape which conforming to the contour of the mould.  

The moulding Cycle

The sequence of events during the injection mould of a plastic part is called the injection moulding cycle. The cycle begins when the mould closes, followed by the injection of the heated materials. Once the cavity of the mould is filled, a holding pressure is maintained to compensate for material shrinkage.

In the next step, the screw turns, feeding the next shot to the front screw causing the screw to retract as the next shot is prepared. When sufficiently cool, the mould opens and the part is ejected. Metal inserts can also be introduced into the mould cavity prior to the injection of the heated materials. These metal inserts are left imbedded as part of the final product.

Available Matterials

Most polymers are available for moulding, including all thermoplastics, some thermosets, and some elastomers.

There are over 19,000 different materials available for injection moulding where the available materials are alloys or blends of previously developed materials meaning that our designers can choose from a vast selection of material blends to create a product that has exactly the right properties required.

The selected materials are chosen based on the strength and function required for the final part.