This is a manufacturing process for producing parts from plastic materials.  Molten plastic is forced into a steel mould and allowed to cool.  The plastic sets in place and the part is removed from the mould.

Most polymers may be used, including all thermoplastics, some thermosets, and some elastomers.  Common materials are Nylon, Acetal, Polyethylene, Polystyrene, Epoxy's, and PVC.  Nybro can manufacture in an extensive range of materials.  Food grade materials and compliance or products for medical use are available.

Standard two plate tooling in a simple split die is the most economical.  Multiple parts included in the same die further reduces costs.  This is called a gang die.

Complex parts with deep cavities, undercuts and moulded threads or clips are possible, but require careful design to allow for tooling to operate.  Nybro has extensive experience at manufacturing complex parts.

Co-Moulded parts, such as brass threaded inserts are also possible.

The standard material properties can be enhanced by adding reinforcements such as glass fibres or aluminium powders.  In this sense they become a composite.  Glass fibres assist in increasing the tensile strength of the plastic and can be added in varying amounts up to 50% without problems.  UV inhibitors, colours, pigments, pearlescents, can all be added to increase the aesthetic qualities and durability of the product.

Before commencing production, die trials are produced to ensure that the parts meet the design requirements.  Extensive testing is conducted to determine if the tooling design is a success.  All of the mould parameters are determined for production including temperature, injection time, cooling time etc.

To modify the material properties after moulding, post treatments can be conducted such as stress relieving, pressurised impregnation of lubricants, surface treatments and finishes such as enamelling, screen printing, chrome plating and polishing.