When you’re commissioning a new injection mould tool, comparing tooling quotations seems straightforward enough.
You have a component that needs manufacturing, several suppliers quote to produce the mould tool, and naturally the price of that tooling becomes an important part of the decision.
But the lowest tooling price doesn’t necessarily result in the lowest manufacturing cost.
A mould tool might produce thousands, hundreds of thousands or even millions of components during its working life. What happens during all those production cycles can ultimately have a much greater impact on cost than the initial price paid for the tool.
The tool is only the beginning
The right tooling strategy depends heavily on what you’re actually trying to manufacture.
A tool designed for prototype parts or a relatively short production run has very different requirements from a mould expected to produce millions of components reliably over many years.
There is little benefit in over-engineering a tool for a genuinely low-volume requirement. Equally, saving money on the initial tooling can prove expensive if the mould is expected to cope with high-volume production and wasn’t designed with that requirement in mind.
This is why understanding anticipated production volumes, product life, material, component design and future requirements before the tool is commissioned is so important.
Cycle time can change the economics considerably
Once production begins, cycle time becomes an important part of component cost.
Imagine two mould tools producing exactly the same component. One consistently produces the part a few seconds faster than the other.
Across a few hundred components, the difference might be relatively insignificant. Across hundreds of thousands or millions of cycles, those seconds accumulate into a considerable amount of machine time.
Cooling design, material flow, ejection and the overall design of the mould can all influence how efficiently a component can be produced.
The objective isn’t simply to create the fastest possible cycle either. It needs to be a stable, repeatable cycle that doesn’t compromise component quality or unnecessarily stress the tooling.
Reliability matters too
A mould tool that requires frequent attention can quickly become expensive.
Unplanned maintenance, production interruptions, tool repairs and excessive setup time all have a cost attached to them, even if those costs aren’t obvious when the original tooling quotation is being considered.
Good tool design should therefore consider what happens throughout the production life of the mould, not simply whether it can successfully produce the first components.
Accessibility for maintenance, appropriate materials and components, cooling, venting and the way moving parts are designed can all influence long-term reliability.
Scrap can quickly outweigh an initial saving
Another consideration is process stability.
A well-designed mould running within a good processing window should be capable of producing consistent components repeatedly.
If tooling or process limitations result in an increased scrap rate, even a relatively small percentage can become significant at volume.
You’re not only losing the material in the rejected component. You’ve also used machine time, energy and potentially inspection and operator time producing something that cannot be supplied to the customer.
Again, this is why looking beyond the initial tooling price matters.
Maintenance and tool life
Every production mould requires looking after.
Components wear, vents require cleaning, ejector systems need maintaining and working surfaces need inspecting. Preventative maintenance is simply part of keeping a mould performing properly.
But how a tool has been designed and manufactured can have a considerable influence on its service requirements and working life.
For a high-volume product, investing appropriately in tooling at the beginning can help reduce downtime and maintain consistent production over a much longer period.
The cheapest tool can sometimes be exactly the right tool
None of this means that more expensive tooling is automatically better.
That’s equally misleading.
If you only require a relatively small number of components, there may be little commercial sense in investing in tooling designed for millions of cycles.
The real question isn’t:
“What is the cheapest mould tool we can buy?”
It is:
“What is the most appropriate mould tool for the number of components we need to manufacture?”
That’s a very different conversation.
Think about the component cost, not just the tooling cost
At Dudley Associates, this is one of the reasons we encourage customers to involve us while their products are still being developed.
Understanding the expected production volumes, component design, material requirements and longer-term plans allows tooling decisions to be made in the context of the whole manufacturing project.
Sometimes that means investing more in the mould tool.
Sometimes it means deliberately choosing a simpler, lower-cost tooling approach because that’s all the project requires.
Ultimately, the aim is the same: to manufacture the required component reliably, consistently and at the right overall cost.
Because the cheapest mould tool and the cheapest way of manufacturing a plastic component aren’t necessarily the same thing.
