The plastic mouldings are transformed into metal using the Lost Wax Method. Normally tooling would be made to produce the wax patterns. These are the starting point of the process. In this technique, the plastic mouldings replace the wax patterns.

The Lost Wax Method requires one pattern for every casting to be made. The customer supplies the mouldings and these are set up on the trees around which the block moulds are formed. When these moulds are fired, the plastic is burned out or ‘Lost’.  Finally the metal is poured into the mould and fills the cavities that the plastic patterns had occupied.

In this example, Alpha Moisture Systems Ltd required a metal version of their Dewpoint Hygrometer. Micro Metalsmiths used the existing plastic mouldings as patterns in their process. The only change needed was to replace the threaded inserts with tapped holes. Otherwise the metal covers were used as a direct repacement. As no additional tooling was required, project cost and lead-times were therefore dramatically reduced.

Metal parts are stronger and more rigid. They can also give enhanced resistance to extremes of temperature, resistance to solvent attack and improved EMC screening. This production route can therefore be used where a product needs to be ruggedised for use in the field.

The use of metal parts can also add to the perceived quality of products. This technique could therefore find a use where an enhanced version is required for the high end of a model range.

Micro Metalsmiths is an ISO9001 accredited company with a heritage of more than 40 years of innovation in the Precision Casting field.