Improvements in and relating to the manufacture of sheets, tubes and other articles from polystyrene

摘要

Articles are formed from oriented polystyrene foil by welding together superposed laminations by means of heat and pressure applied by a mould, the pressure being maintained continuously during the whole of the heating and at least the start of the subsequent cooling period. Maintenance of the pressure prevents de-orientation and embrittling of the polystyrene.