Lost core moulding

This technique is where components are placed in an injection mould and are then moulded over with another material. The term over-moulding covers both insert moulding and lost core moulding. This technique is not confined to plastics and over-moulding of metal inserts, such as to produce scissor handles and plastics on ceramics is commonplace. 

In this process, a component termed a preform is placed into the tool of an injection moulding machine. A second material is then moulded onto or around the preform. Two methods fall imder this category insert moulding and lost core moulding. 

Table 10.6 Process attributes of lost core moulding ...

Dust and particles releases are a general issue in all stages of the foundry process, and for all processes used. Dust is generated in the production and processing of sand moulds and cores, as well as in the finishing of the castings (both from lost moulds and permanent moulds). 

On the moulding side, a basic distinction is made between permanent and lost moulds. Foundries casting in permanent moulds, buy these metal moulds (dies) externally, but typically operate an in-house mould repair and maintenance shop. Foundries casting in lost moulds, often buy wooden, metal or plastic patterns (for their mould design) and operate an in-house pattern maintenance and repair shop. Moulds, cores and lost models are generally produced as part of the foundry process. 

Alternative moulding/core-making methods Lost Foam casting... 

A S Wotherspoon, Automated injection moulding with lost metal core technology (1988). 

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