Polyethylene - process
PE undergoes a rotational moulding process, in which the solid-coloured raw material (PE powder) is measured and poured into a steel- or aluminium mould. The mould is heated to around 270 degrees and rotates around its axis for typically 20-40 minutes, after which it cools for around 40-60 minutes. After another 10 minutes the mould is opened and the finished object can be removed. As it cools it is kept under pressure order to achieve the ideal shape. Mould lines are trimmed to get the object ready for wrapping. The entire process takes roughly one hour per object.