Often adding more cavities / impressions to a mould tool will result in lower unit costs as you are maximising the yield from each tool cycle. An exception to this rule is when the design of the part being moulded does not lend itself to a quick release.
An efficient moulding cycle requires parts to be moulded and removed quickly, once unloaded we need to re-dress and re-load the tool quickly so not to lose too much heat.
The time taken to load and unload the tool is called the “change over time”, this is targeted at 2 or 3 minutes, depending on the complexity of the tool.
Cure times are how long the material takes to vulcanise.
If the tool takes too long to changeover, then heat loss occurs and will result in cure times needing to be extended. This will result in fewer parts per hour being moulded and in turn increases the costs.
So, sometimes although we could fit many more cavities into a tool we will quote fewer cavities in order to keep change over times lower, stop the tool from losing heat and in turn reduce scrap and allow for more efficient production.
To discuss your moulding needs, please engage by chat, phone, email or our contact form, we look forward to speaking to you.