US3256941A - Bag closure - Google Patents

Description

June 21, 1966 s J, RNMA BAG CLOSURE Filed Sept. 25, 1964 INVENTOR 5mm/sl. J. RIVM/,u1

BY m l eig/64,44

ATTORNEYS AUnited States Patent O 3,256,941 BAG CLOSURE Samuel J. Rvman, White Plains, N.Y., assignor to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 23, 1964, Ser. No. 398,666 1 Claim. (Cl. 229-62) The present invention relates to plastic containers; more particularly, this invention relates to sealed plastic bags which are easily opened and easily sealed shut again.

Plastic bags, particularly bags made of polyethylene, have come into great popularity for packaging various materials and articles. For example, clothing or similar articles often are packed in heat-sealed polyethylene bags. Often a prospective purchaser desires to open the bag to inspect its contents. Because the bag is heat-sealed, it must be cut or torn open to permit this inspection. the customer decides not to buy the article, it will be diflicultto sell because its protective bag has been destroyed. This is true even if the torn bag is laboriously sealed shut again by conventional methods.

' Often, several perishable articles such as fruits and vegetables are packed in one plastic bag. As pointed out above, once the bag is torn or cut open, it cannot be reclosed easily. Therefore, any articles remaining in the bag after it is opened are unprotected from contamination and -easily could fall out. If the bag were easily opened without cutting or tearing, and were easily resealable, it would be convenient for the user to take a few items out of the bag, and then reseal the bag, thus maintaining the protection of the remaining items.

Accordingly, one object of the present invention is to provide a plastic bag which is easily opened without cutting or tearing it, and which is easily closed and resealed without the use of special additional equipment or materials.

It is a further object of the present invention to provide simple, sturdy, long-lasting reclosable plastic bags which are inexpensive to manufacture.

The drawings and description that follow describe the invention and indicate some of the ways in which it can be used. In addition, some of the advantages provided by the invention will be pointed out.

In the drawings:

FIGURE 1 is a perspective view of the components of a plastic bag of the present invention prior to assembly of the bag;

FIGURE 2 is a perspective View of a plastic bag assembled from the components shown in FIGURE 1, the bag being open;

FIGURE 3 is a perspective View of the bag shown in FIGURE 1, the bag being lled and sealed shut;

FIGURE 4 is an enlarged cross-sectional view taken along line 4-4 of FIGURE 2;

FIGURE 5 is an enlarged cross-sectional view taken along `line 5-5 of FIGURE 3; and

FIGURE 6 is a perspective, broken-away view of another plastic bag of the present invention, the bag being open.

`A polyethylene plastic bag 10 is shown in FIGURE 1 of the drawings. The bag 10 is formed from a sheet 12 of thin polyethylene lm which is folded upon itself along a bottom fold line 14. The folded-together edges of the sheet 12 are heat-sealed together at 16 and 18.

A portion of sheet 12 extends beyond the other por- ICC it is to be understood that holes of any shape may be utilized in accordance with the present invention.

A strip 24 of polyethylene which has a pressure-sensitive adhesive coating 26 on one surface (see FIGURE 4) is applied to the rear surface of flap 20 as shown in FIG- URES 2 through 5. The adhesive coating 26 binds the strip 24 to the flap 20. It should be understood that the polyethylene 12 is very thin (e.g., 1 or 2 mils thick), and that the Vthickness of all the materials is exaggerated in the drawings for the sake of clarity. The strip 24 advantageously can be made of paper, aluminum foil, or other similar materials and can be made thicker than the bag iilm for added strength. It is especially advantageously made of polyethylene thicker lthan the material 12 so as to simplify theprocess of making the bags.

To close the open top of the bag 10, the flap 20 with the attached adhesive strip 24 is folded along line 28 (see FIGURES 3 and 5) and is pressed against the front wall of the bag 10. The thin film 12 thus is pressed into the holes 22 and against the adhesive surface 26 in the holes as is shown in FIGURE 5. The adhesive connection between theistrip 24 and the front bag wall is strong enough to hold the bag 10 closed despite considerable stress from the bulging contents of the bag.

To reopen the bag, the flap `20 and strip 24 are grasped with the fingers along the lower or outermost edge 30 of those members and are pulled loose from the front Wall of the bag. The holes 22 are located such that a small strip of plastic remains between each hole and the edge 30, thus providing a convenient finger-grip strip. Because strip 24 is pulled into holes 22 by the adhesive, the fingergrip strip tends to bend slightly outward'as shown in FIGURE 5, thus making it easy togrip.

Advantageously, the pressure-sensitive adhesive 26 is non-setting and tacky, and has good adhesive strength. However, it is preferably not aggressively adhesive `since too much adhesion may result in a tearing of the polyethylene when the ap is removed from contact with the wall 12. An adhesive which has been found to have the above desirable properties and is particularly suitable for use in bags of this invention is the pressure-sensitive adhesive designated #539-16-1 and fsold by F. P. Bartlett & Co. However, similar adhesives are readily available and are widely used, for example, in `sealing the ends of bread wrappers. Since such adhesives have a relatively long life, the bag 10 may be opened and closed many times.

The bag 32 shown in FIGURE 6 is like the bag shown in FIGURES 1 through 5 except thatino strip 24 is used. Instead, the flap 20 is made longer, the adhesive 26 is coated upon a portion of flap 20 located inwardly from holes 22, and the outer portion of ilap 20 is folded over along line 34 so that the portion of ap 20 with holes V22 in it overlies and adheres to adhesive 26. To close bag 32, .the ilap 20 is folded over upon and pressed against the front wall of the bag. The front bag Wall adheres to the adhesive 26 in holes 22 in the manner described above, :thus providing an easily opened and re-sealed plastic bag.

While only two-wall bags have been shown in the illustrated embodiments, it is to be understood that sidewalls may be added t-o the bag structures without departing from the teachings ofthe present invention. In addition, it should be understood that various different flexible plastic materials can be used in containers of the present invention, including cellophane, paper and other traditional bag materials, as well as polyethylene and other modern materials.

The above description of the invention is intended to be illustrative and not limiting. Various changes or mod-ilications in the embodiments described may occur to those skilled in the art and these can be made without departing from the spirit or scope of the invent-ion as set forth in the claim.

Patented-June 21, 1966 t i I claim:

A reclosable bag of exible plastic material, said bag having two opposing walls defining a bag opening, a projecting ap portion on one of said walls at said bag opening, said ap having at least one gap near its outermost edge and a strip of pressure-sensitive adhesive on said ap inwardly from said gap, said flap being folded over upon itself with said gap overlying'said adhesive strip and with the bag material adjacent said gap adherent to said strip, said folded-over ap being foldable over the other of said walls so that said other wall adheres tothe adhesive left uncovered by said gap and eects the closing of said bag opening.

References Cited by'the Examiner UNITED STATES PATENTS 3,079,066 2/1963 Roop i.-- 229-62 1/1937 swift s 229-80'

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