| 摘要 |
908,544. Moulding thermoplastic package covers. HESSER, MASCHINENFABRIK A.G., FR. Jan. 30, 1961 [Feb. 23, 1960], No. 3506/61. Class 87(2). Package covers 10 which have a folded margin 11 are moulded from thermoplastic sheet material by conveying the material between a punch 2 and die 3 to form cover blanks connected together by webs, to a radiant heater 4 to be plasticised, then to a forming tool comprising a female mould 15 and a twopart male punch 16, 17. The blank is clamped between the plunger 16 and mould 15 then the sleeve 17 moves downward to form the margin 11, simultaneously the blank is sucked against the mould 15 by applying a vacuum. The finished package covers connected together can be rolled up or separated with or without webs 13. Several package covers can be made simultaneously by using multiple stamping and forming tools. |
