Principle of RIM resin injection moulding

A former having roughly the shape of the article to be moulded is immersed in a suitable liquid compound that forms a deposit onto the former, which is possibly heated to ease the increase in thickness of the deposit. The former can be first sheathed with a knitted fabric to reinforce the dipped polymer. This process is used in special cases  

The main advantages and drawbacks of dipping onto a former are  

A solution of the polymer is sprayed onto a former that has roughly the shape of the article to be moulded. After drying the polymer is demoulded. 

This process is used in very special cases to produce, for example, bellows made out of polyurethane. All precautions must be taken concerning health and safety according to local laws and regulations. 

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