At N & P Thermoplastics (Acton) Ltd we have our own in-house Toolroom complete with latest technology providing our customers a complete service from design to product manufacturing with fast delivery times and cost effective.
Our factory is equipped with a wide range of modern micro-processor-controlled injection moulding machines.
Printing and finishing are completed in house using special paint-inks which are key to the plastic surface. Mouldings can also be finished in variety of metallic or other paints and varnished.
Light Guides for Industry by using fibre optic cables connected to custom made plastic lenses – These lenses can be produced in SAN Acrylic Polycarbonate depending on final installation.
Injection Moulding is a manufacturing for producing parts by injecting material into a mould. Injection moulding can be performed with a host of materials, including metals, glasses elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed, and forced into a mould cavity where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mouldmaker or toolmaker from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Advances in technology now also allow for 3D printing of injection moulds for certain applications, using photopolymer plastics which do not melt during the injection process. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars.
Parts to be injection moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be considered. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.
An Injection moulding machine, also known as an injection press, is a machine for manufacturing plastic products by the injection moulding process. It consists of two main parts, an injection unit and a clamping unit.
Injection moulding machines can fasten the moulds in either a horizontal or vertical position. The majority of machines are horizontally oriented, but vertical machines are used in some niche applications such as insert moulding, allowing the machine to take advantage of gravity. Some vertical machines also don't require the mold to be fastened.
There are many ways to fasten the tools to the platens, the most common being manual clamps (both halves are bolted to the platens); however hydraulic clamps (chocks are used to hold the tool in place) and magnetic clamps are also used. The magnetic and hydraulic clamps are used where fast tool changes are required.
The person designing the mold chooses whether the mold uses a cold runner system or a hot runner system to carry the plastic from the injection unit to the cavities. A cold runner is a simple channel carved into the mold. The plastic that fills the cold runner cools as the part cools and is then ejected with the part as a sprue.
A hot runner system is more complicated, often using cartridge heaters to keep the plastic in the runners hot as the part cools. After the part is ejected, the plastic remaining in a hot runner is injected into the next part.