Talking Technical 1
Part 1: Quick Release Mould Connectors
In the first part of BP&R's exclusive series, Craig Forrester reviews some of the techniques that can bring significant improvements to productivity in an injection moulding shop. In this instalment, the focus is quick release mould connections.
Most injection moulds need to be connected to circuits providing water, hydraulics and, often, also gas. Minimising the time taken to make and break these connections can dramatically improve productivity by decreasing machine down time and also eliminating risks caused by cross-connection.
With the relentless drive for more and more flexible manufacturing and the necessity to produce smaller batch runs cost effectively, the requirement to rapidly change your mould tool becomes a real focus for both mould tool manufacturers and injection moulding facilities alike. Quick release connectors become a necessary, practical, reliable and cost effective solution.
The use of quick release connectors in place of fixed connections often brings the single most significant reduction in mould change times.
A vast range of quick release connectors is available, including full flow, double shut-off and flat faced, clean-break designs, all answering application specific process needs.
Where the application demands absolute spillage free connection/disconnection, such as hydraulic or water glycol connection, clean-break, flat face connectors can be specified. This eliminates not only the spillage of the medium, but also prevents any ingress that could inhibit the performance of the process, resulting in efficiency losses or, in the worst cases, damage to the expensive tooling and machinery.
The implication of medium spillage is often under-estimated. There are the obvious costs of the medium itself but, more importantly, the potential health and safety issues. The danger to operators resulting from the unsafe environment created by relatively low levels of hydraulic oil or water glycol on the shop floor should not be overlooked. Last, but not least, the not insignificant clean-up costs resulting from spillage have a negative impact on profitability in an ever-demanding industry.
Critical to the efficiency of the mould change is the accurate and rapid identification of the thermal regulating circuits. Cross-connection will result in additional down time and can cause costly damage to the tooling. When there are a limited number of circuits, colour coding of the hoses and connector plugs and sockets often provide the best solution. For larger or more complex temperature control circuits, the solution to cross-connection is better provided by a multi-coupling system; guaranteeing consistent circuit integrity. Once installed, the multi-coupling can only be connected in one orientation, making it impossible to confuse circuits.
Those experienced in the mould change process will fully appreciate the potential and often real time losses in simple circuit identification.
The ever-increasing demand resulting from technical advancement in plastic injection moulding provides auxiliary suppliers with continuous challenges in new product development; very real examples being the ability to handle higher temperature mediums and the market demand for greater safety and improved ergonomics.
The use of quick release connectors should often be the first consideration in speeding up mould changes to improve productivity. Once this step has been taken, then other techniques, such as mould clamping and transfer, should be evaluated. These are all topics that I will return to in future articles in this series.