Hydraulic or Toggle Clamp

Hydraulic mechanisms have proved the favoured means of press operation within the rubber industry for a number of reasons. Historically, before the advent of the injection process, rubber moulding was accomplished using compression or transfer techniques with hydraulically operated presses. These presses could be manufactured cheaply and run using water as the hydraulic fluid, with a simple accumulator system to develop the necessary pressure. The same water supply was used to raise the high steam pressure that was used to heat the platens. The operators required to set up these simple presses could be easily trained and needed no special engineering skills. The rubber industry was therefore conditioned to the use of hydraulic presses, well before the advent of injection moulding. In time the hydraulic systems were refined and changed to oil. 

In practice, many presses combine hydraulic and mechanical locking processes. High speed, low pressure, jack rams are used to effect a rapid movement to a point 

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In most cases, the compression movement is done by the clamping unit of the injection-molding machine. Modern machines with hydraulic or toggle clamping units are able control the position and the... 

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