Industrial Rubber utilises various Moulding Techniques for the manufacture of Rubber Components. The moulding process selected will depend on many things – for example the number, size and shape of the parts and the dimensional tolerances required of the finished part.
Below is a very brief summary of the type of moulding process Industrial Rubber can offer.
RUBBER MOULDING – FROM COMPOUND TO FINISHED PRODUCT
Most rubber compounds are a mixture of a base polymer to which has been added various ingredients that modify its properties and allow it to be made into the material we recognise as rubber.
The rubber compound needs to be prepared for the moulding process and preparation varies depending on the moulding method to be used.
This method uses a heated hydraulic press into which the mould is fitted. The rubber compound is prepared by extruding and cutting or cutting from sheet into a pre-determined weight and shape. These pre-forms are referred to as blanks. The blank is placed directly into the cavity. The mould is then closed and heat and pressure applied to vulcanise (cure) the rubber.
Transfer Injection Moulding:
This method uses similar equipment to compression moulding except the blank is placed in a transfer chamber usually located above or below the mould cavity. A piston is used to transfer the rubber via a feed gate into the cavity when the mould is closed in the hydraulic press. The part is then cured as the compression moulding process
This requires specialist injection equipment with the uncured rubber compound usually prepared as a strip which is fed directly into an injection unit that plasticises and prepares a predetermined “shot weight”. The rubber is then injected directly into the cavity where it is cured