An anodised aluminium injection mould in a two-year EU-funded thermoplastics moulding research programme performed close to the standard of the steel one - among other surprises.
Project ALAMO, a two-year European Union funded research programme coordinated by Rapra Technology, is drawing to a close with some spectacular results. The project was initiated to investigate innovative uses of anodised aluminium in the field of thermoplastics moulding, concentrating on injection and rotational moulding, with the ultimate aim of competing directly with steel tooling. Aluminium has several known advantages for tooling applications - easy machining, good thermal properties, light weight and excellent recyclability but it has suffered from a perceived lack of wear and chemical resistance.

The anodised coating perfected by the team from across Europe has given the wear and chemical resistance without compromising the inherent beneficial properties of aluminium.

The programme members combined expertise in various fields - anodising, materials testing, mould manufacture, moulding and 3D moulding simulation, using both injection moulding and rotational moulding techniques to produce test tools which compared traditional P20 steel, aluminium, and anodised aluminium mould tools (for rotational moulding and injection moulding) The results were promising to say the least.

The rotational moulding tool exhibited a 20% reduction in cycle time compared to a conventional aluminium tool due to the rapid heating and cooling made possible by the high emissivity of anodising combined with the excellent thermal conductivity of aluminium.

There was a corresponding reduction in energy usage and the resultant mouldings were thoroughly tested and showed no difference in material properties.

The injection mould was a four impression tool which compared wear rates over 10,000 mouldings of an abrasive glass filled nylon compound.

The results were conclusive: the anodised aluminium insert performed close to the standard of the steel one whereas the non-anodised aluminium insert showed marked wear in the gate area, visible to the naked eye.

The final phase of the ALAMO project has been to make some industrial demonstrators in order to expand on the positive results of the tests phase.

These results are expected around November 2006 when the project reaches the end of its current funding.

However the resulting technology will continue under the guidance of the SME partners in the project.