Flexible bags – Bag having means to facilitate opening it by severing bag... – Including a separate tearing element which is gripped and...
Reexamination Certificate
1999-11-05
2001-11-13
Pascua, Jes F. (Department: 3727)
Flexible bags
Bag having means to facilitate opening it by severing bag...
Including a separate tearing element which is gripped and...
C383S086000, C383S085000, C383S109000, C383S203000, C383S210000
Reexamination Certificate
active
06315448
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to openings for bags, and particularly to multiwall bags having a pinched closeable end and an opposite closed or open end. The invention is directed to bags of this type having either a flat tube style or with gussets. This type of bag is known in the industry as a pinched bottom open mouth (PBOM) bag. The invention is more particularly directed to providing an easy opening and pour spout-forming manually openable feature at the pinched closed end of the bag. The invention relates to the PBOM type of bag for use in containing granulated or powdered products, such as chemicals, animal feed, dry milk, and other pourable types of products.
The invention is further related to providing an easy opening tab assembly at the pinched closure which allows multiwall bag making machines to incorporate the tab assembly during machine production of the bags, wherein the tab assembly is positioned to be retained by the pinched closure to lie flat against the bag when formed.
The present invention is especially directed to use with gusseted multiwall PBOM bags for providing an easy opening, peelable tab assembly permitting the consumer to (1) quickly open a filled and sealed bag and (2) contemporaneously form an easy pouring spout for dispensing the product therein. The invention overcomes deficiencies in the prior art in regard to the manufacturing of such bags, which typically require the unsanitary inclusion of a tear open tab located at least partially inside the bag and folded with the pinched closure between the walls of the bag. Therefore, a goal of the invention is to provide such a tear opening tab assembly that places any adhesive bonding of the tab assembly safely away from the inner contents of the bag, which is of particular concern when a comestible product is within the bag, such as dry milk powder and other flowable granulated type of food materials.
The invention is further aimed at providing a tab assembly that is peelable to open the bag and form a pour spout, which may optionally have a recloseable feature that can be manufactured in a manner whereby the peelable opening of the tab assembly remains flush on the face of the bag during the filling, shipping and handling of the bag so as not to be inadvertently caught on machine or handling equipment, which could otherwise rip it off and degrade the bag. This achievement also allows bags to be stacked flat, such as on a pallet, and then easily loaded and unloaded from a truck or the like.
It is also an objective of the invention to provide a tab assembly having a peelable opening tab member that can be manually lifted to tear open the plies of one wall of the bag, but allowing the bag plies of the other wall of the bag to remain intact. It is further a goal of the invention to provide such a tab assembly that may be located either adjacent a corner of the pinched closure or between the corners.
SUMMARY OF THE INVENTION
In general, the invention provides a peelable tab assembly for a bag that is formed with a pinched closeable end and an opposite closed or open end, which bag is filled by the packer with a flowable product, typically granulated or powdered materials, such as pet food, rice, chemical powders, powdered milk and other “dry” commodities. After the pinch closeable bag end is closed, and the bag is then filled, the remaining open end may be closed in the bag-filling line. In the case of flush-cut open ends, they may be sewn or adhesively sealed to closure in a known way. The opposite end may be manufactured in the closed condition, with the pinched closure end left open, leaving it to the packer to make the pinch closure after filling. The invention is also useful for block bottom and satchel bottom bags. Alternatively both ends of the bag may be pinch closeable. The tab assembly of the invention is used in cooperation with a standard multi-wall tubular bag usually having two or more plies of paper, and often also having an inwardmost plastic ply for sealing the product therein.
The tear open tab assembly incorporates a bag tube having front and back walls. The back wall extends lengthwise a greater distance than the front wall allowing for the folded over pinched closure to be made. The front and back walls may be single plies or multi-plies, typically made of paper, and stepped lengthwise. The pinched closure involves folding over the end portions of the plies of the front and back walls of the bag tube around a fold line space downwardly away from an upper edge of the first wall plies at the same end of the bag. The pinched closure portion of the bag thus is a flap constituted by end portions of the walls of the bag tube at a bag end, which flap is folded over on said fold line that is spaced from the end edge of the front wall at said end. Therefore, the flap comprises the end portions of the front wall ply or plies taken from the fold line to said end edge of the front wall ply or plies, plus a portion of the back wall ply or plies coextensive with said end portion of the front wall, and the extension of the back wall. The peelable tab assembly has a first section that is overlain by a portion of the back wall extension when the pinch closure is completed, but has a contiguous second section that is not overlain by the back wall. The peelable tab assembly first section is adhered between the overlying back wall and the front wall during the pinched closure. The peelable tab assembly first and second sections are commonly bonded to the outer face of the front wall, which bonding is made before making the pinched closure. The first and second sections have a mutually peelable first portion, or portions, that is peeled away from a second portion, or portions, that remains on the bag front wall face to open the bag by means of tearing open the back wall at the pinch closure. The front and back walls of the bag may have side gussets joining them along opposite lateral side edges of the bag or otherwise the bag may be non-gusseted.
The peelable tab assembly may be arranged adjacent a corner of the bag, where the front and back walls meet at the bag side edge, or otherwise may be provided along the pinch closure intermediate the lateral side edges of the bag. When positioned adjacent the corner of a gussetted bag, the peel tab assembly is arranged to tear a margin along side the gusset adjoining the front wall and form a pour spout. The peelable tab assembly first and second portions are releasably bonded together preferably by means of a pressure sensitive adherent. The peelable tab assembly is initially adhered to the front wall of the bag as one integral unit during bag manufacturing. The pressure sensitive adherent in one embodiment is a tackified adhesive allowing for the first portion of the peel tab assembly to be rebonded to the second portion after being peeled away to tear open the bag. Optionally, the second portion may have an adherent attaching it to the first portion which does not remain tacky. This latter option may be utilized when the nature of the product within the bag usually would require the bag contents to be dispensed in one pouring. Another option is to provide the adherent between the first and second portions to reside on the first portion rather than the second portion.
The first and second portions are laminae forming the peelable tab assembly. They may be single lamina, but either or both can be made of multiple laminae.
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patent: 4610651 (1986
Bemis Company Inc.
Lee Mann Smith McWilliams Sweeney & Ohlson
Pascua Jes F.
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