Technology Aluminium butts heads with steel in injection tooling
As materials technology continues to develop, aluminium is playing an even larger role in injection moulding. Alcoa, one of the world’s largest manufacturers of the lightweight metal, compares its performance with that of tool steel.
Aluminium as a mould material has proven itself in low temperature and low pressure applications, such as in the blow moulding and injection moulding of simple thermoplastics like polypropylene and polyethylene.
More Al moulds coming
Aluminium mould alloys are no longer limited to 5083 and 6061. There are now a myriad of high strength aluminium products in the market, including ones with improved through-thickness and property consistency. In addition to increased strength and wear resistance, aluminium alloys such as Alcoa’s Alumec series display a more consistent through-thickness strength and hardness, which further improves its machinability.
Moulders have started to capitalise on the benefits of aluminium, and it is now being used in full volume injection moulding practices for more complex thermoplastics and elastomers. As shown in the following table, development and prototyping is taking place with increasingly aggressive resins.
It is also possible to use aluminium for rubber moulding, and this is where it is important to discuss the application with the aluminium supplier, so that the right aluminium product can be selected for its purpose.