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Injection Moulding (Injection Molding)

This process page is kindly sponsored by the Battenfeld Group. For more info. Email sales@vuk.battenfeld.com

Typical Materials Used

Most thermoplastics can be processed by Injection Moulding. The table below lists some of the commonly used materials.

Acrylonitrile-Butadiene-Styrene	ABS
Nylon	PA
Polycarbonate	PC
Polypropylene	PP
Polystyrene	GPPS

Typical Products Produced

Power-tool housings	Safety helmets
Telephone handsets	Television cabinets
Washing-up bowls

Components produced using Injection Moulding

Overview

Along with extrusion, injection moulding ranks as one of the prime processes for producing plastics articles. It is a fast process and is used to produce large numbers of identical items from high precision engineering components to disposable consumer goods.

The Process

The injection moulding machine consists of a heated barrel equipped with a reciprocating screw (usually driven by a hydraulic motor), which feeds the molten polymer into a temperature controlled split mould via a channel system of gates and runners. The screw melts (plasticises) the polymer, and also acts as a ram during the injection phase. The screw action also provides additional heating by virtue of the shearing action on the polymer. The pressure of injection is high, dependant on the material being processed; it can be up to one thousand atmospheres.

It should be noted that, whilst in the diagram the flute pitch of the screw is shown as constant along its length, in practice it varies considerably dependent upon the polymer being processed. In particular the root diameter increases from hopper to nozzle to provide compression to the melt.

Size of Machine

On most machines the mould is held closed by a combination of toggle clamping and hydraulic pressure. This is known as the locking force. In a large machine this can be up to thousands of tons and is spread over the area of the mould. To counteract the injection pressure, a moulding with a large surface area will therefore need a machine with a higher locking force than a moulding with smaller surface area.

Computer controlled
Modern day injection moulding machines are controlled by a built-in computer. Acting on sensor fed information, it controls all the actions of the machine and ensures consistent output and shot to shot quality.

Microsystem 50

To view a flash animation of this process please click below.

Automated Injection Moulding Machine

for a list of leading UK based Injection Moulders

About The Battenfeld Group

Battenfeld has been established for almost 50 years and is one of the world's largest manufacturers of injection moulding machines. The product range includes machines for standard injection moulding, structural foam, airmould, co-injection and multiple-shot moulding. Battenfeld's commitment is to consistently be at the forefront of technological change and to support their customers in implementing their product ideas, developing injection moulding solutions for a vast range of applications. the machine range includes toggle, hydraulic and electronic and electrically powered machines, from stand-alone models to production cells and complete computer-monitored production lines.

Click Here for an idea of Processing Costs

This process page is kindly sponsored by the Battenfeld Group. For more info. Email sales@vuk.battenfeld.com