LAMINATED MATERIAL AND METHOD FOR PRODUCING LAMINATED MATERIAL Russian patent published in 1995 - IPC

FIELD: food-processing industry. SUBSTANCE: laminated material is made from steel or aluminum sheet, whose both sides are covered with composite polyester films glued simultaneously by thermal lamination. Polyester films contain inner layer of amorphous copolymer on ethylene glycol base, tere- and isophtalic acids mixture with molar ratio of 80:20, with softening temperature of 140 C and melting temperature of 210 C, and thicker outer layer of balanced film from crystalline polyethylene terephthalate or its mixture with 5% of weight of inner layer copolyester mixture. with melting temperature above 250 C and crystallinity degree of 45-50% Method involves heating metal sheet to temperature of T₁, which exceeds melting temperature of inner layer copolyester of T₁ 150-260 C, preferably 200-250 C, but below melting temperature of outer layer crystalline polyester; repeating heating of obtained material by induction heater to temperature of T₂ sufficient for adherence between outer layer film, inner layer surface and metal sheet, but below melting temperature of T₂ of outer layer film; holding material at this temperature for time interval not exceeding 2 sec; quickly cooling material by dipping into reservoir with water or by linear water cooling. EFFECT: increased efficiency and high quality of material. 11 cl, 1 dwg, 3 tbl