Plastics
Most Thermoplastics can be processed by injection moulding. Below you will find the most common ones:
Acrylonitrile-Butadiene-Styrene
Nylon
Polycarbonate
Polypropylene
Polystyrene
There are two basic types of plastic, thermoset which cannot be resoftened once moulded and thermoplastic which can be repeatedly softened and reshaped .
There are literally thousands of types of plastic each suited to a
peraticular purpose. if you are unsure what your requirements are, let
us advise you.
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The Process
The
injection moulding machine consists of a heated barrel equipped with a
screw (usually driven by a hydraulic motor), which feeds the molten
plastic into a temperature controlled split mould via a series of
channels. The screw melts (plasticises) the plastc granules, 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.
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On
most machines the mould is held closed by a combination of clamping and
hydraulic pressure. This is known as the locking force. 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 |
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Modern
injection moulding machines, such as those that we use, are controlled
by a built-in computer. This gives the superior consistancy and quality
that discerning customers demand.
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