During moulding under pressure the synthetic pellets is melted, it is moulded in the desired shape by means of pressure and cast away by the machine. The pressure mould machine consists of two main units. They are called moulding and closing. The moulding unit consists of a heated cylinder and an auger. The synthetic material, usually processed in the form of granules, is accelerated through the auger. During acceleration the granule is melted by the developed heat. In this moment the auger moves backwards and by the acceleration on its top side builds up a massive pad. After the end of the acceleration process the auger is pushed forwards and the melted material is injected under pressure of 600-1500 bar. The closing unit consists of two bending plates: a closing plate that is movable, and a nozzle, that is fixed. The closing plate moves towards the nozzle. The injection pressure can reach in the big machines up to 4000 ton. After the cooling phase the mould is opened and the moulded shape is cast away automatically.