A Step-by-Step Guide to Compression Moulding Rubber Machinery

Compression moulding is the most common moulding technique you will notice in the rubber industry. The other two are transfer moulding and injection moulding.Get more news about compression moulding machine,you can vist our website!

Compression moulding is a closed mould process and you apply high pressure on the job. It is best used when you have low to medium production volumes for larger parts where tightest tolerances and flawless finishes are not required. Examples may include diaphragms, valves and gaskets, Dampers, O-rings, seals, rubber wear parts, etc depending upon their areas of application.As shown in the figure above, in compression moulding, you place an uncured rubber profile in a heated mould. Then you soften the uncured rubber by the heat and press them forcing the rubber compound to fill the mould cavity. The rubber is thus made to conform to the shape of the mould and then you cure it to produce your finished article.

Compression moulding presses are mostly hydraulically driven, where a hydraulic pump powers a hydraulic cylinder (or cylinders) that drive the ram or slide. (Caution: there are pneumatically powered presses too).

Stroke: The amount of possible ram travel. Stroke is the total distance that the ram can travel, from full extension to full retraction.
Shut Height: The distance between the bed bolster and the ram bolster when the ram is fully extended. This is also commonly known as the Closed Height. As standard, this dimension is usually within “0.25” due to assembly processes.
Daylight: The distance between the bed bolster and the ram bolster when the ram is fully retracted. This is also commonly known as the Open Height.
Bolster: The removable plate that serves as the working surface for the bed and ram. The plate is usually bolted to the bed and rams substructures. The bolsters can be machined with a variety of work holding features such as; T-Slots, Drilled and Tapped Holes, Lift Rails for Quick Die Change, etc…
Bed Height: Bed Height is the distance from the bottom of the hydraulic press structure to the working height or top of the bed bolster.
Remote Power Skid: Some press applications may require that the hydraulics be located remotely from the press itself. Other applications may preclude the power system from being able to be installed at the top around the crown structure of the press. In these cases, the power system and even the controls may be designed into a separate unit capable of being placed adjacent to the press or away from the press.
Heated Platens: These are plates that have heating capabilities.