Composite vessel excellent in preservability and process for preparation thereof
AssigneeToyo Seikan Kaisha, Ltd.
InventorsYoshitsugu Maruhashi, Sadao Hirata
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Abstract
Disclosed is a function-separated composite vessel excellent in the easy openability, preservability and resistance to the deformation due to reduction of the pressure, which comprises a cup-shaped outer member composed of a paper substrate and a flexible seamless cup-shaped inner member composed of a gas-barrier plastic material, wherein the peripheral wall face of the inner member is substantially exactly fitted in the inner side of the outer member but is not bonded to the wall face of the outer member and an opening of the inner member is bonded to a curl portion or flange portion formed on an opening of the outer member.
Claims17
A function-separated composite vessel excellent in the easy openability, preservability and resistance to the deformation due to reduction of the pressure, which comprises (1) a cup-shaped outer member composed of a paper substrate and having a barrel portion, a bottom portion bonded to the lower end of the barrel portion and a curl or flange portion formed on an upper end opening of the barrel portion, said bottom portion being formed of a paper sheet having an air permeability, and (2) a flexible seamless cup-shaped inner member composed of a gas-barrier plastic material, said inner member being formed by plug-assist-forming a film of the gas-barrier plastic material within the outer member as a female mold until the film is substantially exactly fitted in the inner side of the outer member and an opening of the inner member is bonded only to the curl portion or flange portion of the outer member, whereby when the vessel is hot-filled, the opening of the vessel sealed and the filled contents allowed to cool, deformation of the configuration of the cup-shaped outer member caused by reduction of the inner pressure in the sealed vessel due to decrease of the volume of the content and condensation of vapors is substantially avoided.
A composite vessel excellent in the preservability, which comprises a cup-shaped outer member having a curl or flange portion at the open end thereof and composed of a paper substrate having a gas permeability and a flexible seamless cup-shaped inner member having a layer of a blend comprising an ethylene-vinyl alcohol copolymer and a polyamide at a weight ratio of from 95/5 to 5/95, wherein the cup-shaped inner member has such a size that the inner member is substantially exactly fitted in the inner side of the outer member and an opening of the inner member is bonded only to the curl or flange portion of the outer member, the inner member is draw-formed so that the draw ratio H/D defined as the ratio of the height H of the inner member to the size D of the opening of the inner member is at least 0.5, and the cup wall of the inner member is molecularly oriented.
A process for the preparation of composite vessels excellent in the preservability, which comprises supplying a flexible film or sheet having a layer of a blend comprising an ethylene-vinyl alcohol copolymer and a polyamide at a weight ratio of from 95/5 to 5/95 to the vicinity of an opening of a cup-shaped outer member composed of a paper substrate having a gas permeability and plug-assist-forming the film or sheet with said outer member being as a female mold until the film or sheet is substantially exactly fitted in the inner side of the outer member and bonding said shaped film or sheet to said outer member only in the vicinity of the opening thereof.
Dependencies are inferred from the claim text.