Conformal cooling for injection moulding tools and inserts
Firstly, what do we mean by ‘conformal cooling’?
In essence, conformal cooling is the production of cooling channels within injection mould tools that follow the shape of the cavity and core. This ensures that every critical part of the mould tool is cooled in a controlled and consistent manner. The results include better part quality and faster cycle time.
Until recently, however, it has been difficult to engineer effective conformal cooled injection mould tools, as channels need to be drilled directly into each mould tool; running straight cooling channels close enough to the mould cavity for efficient heat transfer can therefore be challenging, especially when parts have complex geometries. Similarly, cooling channels also have to compete for space with other features, such as ejector pins or moving inserts, further reducing the efficiency of the cooling process.
Although injection mould toolmakers have developed solutions to this problem they inevitably add to the time, complexity and cost of producing each mould tool or mould tool insert.
A new approach to Conformal Cooling
The development of additive manufacturing technologies offers a new method of manufacturing conformal cooling channels. Direct metal laser sintering (DMLS) allows complex shapes to be easily constructed, layer by layer, allowing channels of almost any shape to be incorporated into a design. Conventional laser sintering systems, however, are relatively slow as they build each part and leave a surface finish that requires subsequent machining; this adds to cost and lead-time.
To address these issues, we have invested in an innovative new technology: hybrid metal additive manufacturing to produce a range of standard and customised conformal cooled inserts, under the name ConformaL Cool.
Our CNC hybrid additive metal manufacturing system allows tool inserts, complete with custom-design conformal cooling channels, to be produced quickly and with extremely high levels of accuracy in a range of metals. Each insert is automatically finished to fine tolerances as it is built by an integrated machining head.
To improve lead-times still further, we can also build the customised injection mould tool inserts on standard tool parts, such as bolsters and injection plates, in our Rapid Production Mould Tools service. As a result, we are able to reduce typical lead-times from more than 12 weeks to less than 6 weeks – often faster.