A Comparison Between Forced Air Convection Heating and Direct Electrical Heating of Moulds in Rotational Moulding

摘要

The rotational moulding process is unique in that the mould and the plastic must be heated from room temperature to over 200 °C(400℉). This stage in the process is slow using conventional convection heating because the polymer is a poor conductor. This is particularly evident when a large mass of polymer has to be heated. In recent times other methods of heating have been proposed to improve the heat transfer and give the moulder better control over what is going on inside the mould. This paper compares an electrical heating method with forced air convection heating to identify any advantages that may accrue from direct electrical heating of the mould.