Injection moulding requires three essencial ingredients: plastic, an injection moulding machine and an injection moulding tool. You do not really need to concern yourself with this technology. We have put it here purely for your benefit.
The tool/mould is clamped into the injection moulding machine and hot molten plastic is forced into the cavity of the mould. The plastic is then cooled and finally the plastic product is released from the mould.
Plastic granules are fed into the injection moulding machine’s hopper. The plastic melts in the barrel. Heat is applied by friction of the screw and by heaters. While the screw turns the screw moves backwards and the molten plastic moves to the front of the barrel. The mould closes and plastic is forced into the mould by the forward moving force of the screw. The mould is then cooled by water circulation. Once the product has crystallized or hardened the mould can be opened to release the product.
Plastic products are usually a thermoplastic material. The most common are polystyrene PS, polypropelene PP, polyethelene HDPE or LDPE, polycarbonate PC and polyamide (nylon) PA.
The tool is normally made from tooling steel and the force excerted on the tool is many tons of force. For example: it would take about 100 tons to injection mould a CD cover. The mould is clamped together with 100 tons of force and the injection is also done with an equivalent force. A chair would typically require about 1000-1200 tons of force.
Big Boy Plastic owns many injection moulding machines and tools. Our range of machines will be suited to make your products. We can take your product from design stage to production. See our product design section.