... polystyrene granule. In the extruding process, Foam agent (such as Butane gas or LPG ) is injected at high pressure.After extruding , foaming ... , cooling, shaping and hauling off, it is winding to finished ps foam sheet rolls ... plate,supermarket tray ,cake tray , KT board ,instant noodle bowl ,foam tray etc. It is widely used in the packing of ...