Mold-making technology could speed up product development

Engineerblogger
June 23, 2012

3D solid model for a vacuum form tool created in Mechanical Desktop. Credit porenstein.com

 A new way of rapidly producing prototype molds for vacuum-forming processes could help make product development quicker and cheaper.

The system uses a grid of adjustable pins to quickly create different shapes that function as molds for plastic vacuum forming, rather than the now-conventional method of rapid prototyping that involves building molds layer by layer (additive manufacturing).

The inventor of the prototype technology, Brunel University student Patrick Bion, said the system would enable product developers to make changes to prototypes much more quickly than with additive manufacturing.

‘Many companies now use additive manufacturing for making molds, but rather than having four hours of making a mould to then vacuum form onto and then needing to change something and repeat that process we’re looking for instantaneous molding,’ he said.

‘You can update the CAD data and have the pins reconfigured in a matter of 18 minutes. We’re trying to redefine “rapid” in rapid prototyping while making the technology attainable to industry.’

Once commercialized, the system should be much cheaper than existing technology that functions in a similar way but positions the pins hydraulically rather than electrically, Bion added.

‘That system weighs about 20 tonnes and costs millions of pounds. The whole objective was to develop a system architecture that would bridge the gap between reconfigurable tooling technology and commerce.

‘So we’re trying to develop a low-cost, compact system that can compete financially with additive manufacturing systems.’

The 2mm pins are adjusted using a linear actuator running CAD data and held in place using polyethylene foam, then clamped into place for the vacuum forming before being covered by neoprene or silicon interpolation material to smooth the surface of the mold.

Bion hopes to develop the scalable system to produce larger and more detailed molds using smaller pins.

‘The next step is finding a more technically advanced foam that will enable us to position those pins with higher accuracy,’ he said. ‘At the moment, it can position them within 0.5mm.’

Source: The Engineer