An introduction to rubber moulding

Rubber moulding is a versatile manufacturing process, in which uncured rubber material is transformed into products such as seals, insulators, bumpers, or washers. It is used for items found across a wide variety of industries and sectors, from medical equipment to automotive parts.
Perhaps it should come as no surprise, then, that rubber moulding has become a major market in itself, as described here:

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Different rubber types

Whilst rubber is most commonly associated with the product of the Hevea or rubber tree, not all rubber used for moulding will have a natural origin. Today, there are many high-quality synthetic rubbers available which will also respond well to the moulding process.

Synthetic or manmade rubbers typically take the form of synthetic elastomers, which can offer benefits or properties that surpass those of natural rubber. If you want to determine which type of rubber could be right for your chosen application, it makes sense to consult a rubber moulding specialist such as

The process

The process itself can take one of three main approaches: compression moulding, injection moulding, or transfer moulding.

Compression moulding sees the uncured rubber being prepared into shapes which are then placed into the cavities of a preheated mould. The mould is then closed with hydraulic pressure, which is continued for the time required to mould the rubber into the chosen form.

Injection moulding is a slightly different approach which can also be used for moulding other materials such as metal and glass. In this technique, the uncured rubber is injected into the mould, where it will be held until it completes the vulcanisation (a chemical process) that will enable it to hold the desired shape.

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Finally, the transfer moulding approach involves the uncured rubber being placed into a transfer pot or “ram”. From here, it will be pushed through a runner and gate system before reaching a heated cavity. The rubber will then be kept in the heated cavity area until it completes the curing process which will give the item its final shape.

Joseph Brown

Joseph Brown