THE EFFECTS OF WATER DROPLET SIZE AND VELOCITY ON SPRAY COOLING OF POLYMERS DURING ROTATIONAL MOULDING

摘要

The cooling process in conventional rotational moulding has a relatively long cycle time. It is normally accomplished by external forced air convection and external water spray cooling. In some instances, an evaporative cooler is employed to create atomised fog external to the mould during the cooling cycle. Internal water spray cooling is an attractive approach to reduce the cycle time and enhance the product properties in rotational moulding. It is shown that water spray cooling of polymers is affected by water droplet size and water droplet velocity. This paper outlines an introduction to the characterisation of water droplets. The effects of these parameters on water spray cooling of polymers are also presented, using a purpose built experimental test rig.