Process for sealing glass container openings
AssigneeHosokawa Yoko Co., Ltd.
InventorsSusumu Niwa, Masao Koike
Life of this patent
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Abstract
In the sealing of a glass container containing a product such as a food product by means of a cover comprising a metal foil having on one surface thereof a sealant layer of a thermoplastic resin, the opening end of the container is preheated, and the cover is placed on the opening end, after which the cover is pressed against the opening end successively by a heating plate and a separate pressing plate. By this process, a positive seal and a high sealing process efficiency are obtained even when the container content is a product such as a heated liquid food product and even when the rim surface of the opening end of the container has some projecting irregularities.
Claims10
Process for affixing covers onto glass containers which comprises the steps of:
- (a) providing a glass container having an opening end;
- (b) providing a cover comprising a piece of metal foil having a shape suitable for covering said opening end and a sealant layer of a thermoplastic resin laminately secured to one surface of the metal foil;
- (c) preheating the opening end of said glass container;
- (d) placing the cover on the opening end so that the sealant layer contacts the opening end;
- (e) pressing the cover, as it is heated, against the opening end by means of a heating plate having a cushioning layer provided on the part of the heating plate which contacts the cover thereby to cause the cover to adhere to the opening end of the glass container through the heating of the sealing thermoplastic resin so that said sealant is in an adhesive state;
- and
- (f) pressing the cover against the opening end of the glass while said sealant is in an adhesive state by means of a pressing plate at a temperature lower than that of the heating plate in step (e) so as to cool said sealant thereby assuring positive sealing of the opening end by the cover;
- said heating plate means of step (e) and pressing plate means of step (f) being entirely separate means.
Dependencies are inferred from the claim text.