METHOD FOR MANUFACTURE OF POLYSTYRENE FILM Russian patent published in 2003 - IPC

FIELD: procedure of production of polystyrene films designed for packing of food products. SUBSTANCE: initially prepared is the starting mix of milled shock-proof polystyrene and milled thermoplastic at the following relation of components, percent by weight: shock-proof polystyrene - 85-96, thermoplast - 4-15, after that the mix is subjected to extrusion with formation of a sheet. Before extrusion the mix of polystyrene and thermoplastic is melted by heating and mixed in the molten state. After extrusion the formed sheet is cooled down, cut in width and rolled, and the cut, formed as a result of the above sheet cutting, is milled and added to the starting mix at the following relation of the components, percent by mass: shock-proof polystyrene - 42-96, thermoplastic - 4-15, the mentioned cut - the rest. EFFECT: enhanced effect of modification of shock-proof polystyrene by thermoplastic and reduced amount of waste. 1 dwg, 1 ex