Guidelines for the rotational moulding of liquid polymers

To date, powdered resins, particularly polyethylenes, have been the main form of raw material used in the rotational moulding industry. Cycle times are long compared with those of injection and blow moulding and the range of suitable resins is limited due to the high potential for degradation in this process. Reactive liquid systems such as polyurethanes present an attractive alternative to the use of powders since there is potential for greatly reduced cycle times and a wide range of engineering grade materials are available. This paper presents some guidelines for the processing of such materials by rotational moulding.