US3490507A - Carrying bag - Google Patents

Description

Jan. 20, 1970 l. GRAs'HoRN- CARRYING BAG Filed April 22, 1968 FIG. 2

FIG. 3

INVENTOR: INGO GRASHORN ATT'YS United States Patent O Int. Cl. A45c 3/00,3/02; B65d 33/02 U.S. Cl. 150-1 4 Claims ABSTRACT F THE VDISCLOSURE A carrying bag having side walls, a closed bottom and an open upper end and formed from a multilayered structure consisting of one or two sheets of a thermoplastic material enclosing on either side a wide-meshed planar reinforcing textile structure. The bag can be slotted at the upper end thereof without further reinforcement to provide a handle.

It is known that Ibags, sacks, lcarrying pouches and the like can be produced from sheet materials such as paper, plastic .films or foils, coated fabrics and similar materials. However, such articles often tear easily and are not durable, or else the production of the bag and especially the production of the sheet or base material is extremely time consuming and expensive.

One object of the present invention is to provide a very durable and strong carrying bag which can be easily manufactured or assembled. Another object of the invention is to provide a multilayered planar structure capable of being shaped and formed into a bag in which perforations or slots can be made without further reinforcement.

Thus, it has now been found in accordance with the invention that a durable carrying bag, sack, pouch or the like can be produced in a very simplified manner if the bag consists of a thermoplastic polymer sheet material reinforced by a wide-meshed planar textile structure whose threads intersect approximately perpendicularly to one another with the textile structure being enclosed on either side by the plastic sheet material and being coextensive therewith. This multilayered structure can be readily shaped and formed into an integral bag having side walls, a closed bottom and an open upper end and at least one slot can be punched or cut therefrom without any further reinforcement.

The carrying bag of the invention is described in greater detail in connection with the accompanying drawing in which:

FIG. 1 is a perspective view of the finished carrying bag constructed of a multilayered material in accordance with the invention;

FIG. 2 is a vertical side view of an enlarged portion of the multilayered material illustrating one embodiment of its `arrangement with reference to the main loading direction of the bag as indicated by the arrow;

FIG. 3 is a vertical side view of another embodiment of the multilayered material and its arrangement with reference to the main loading direction of the bag;

FIG. 4 is a partial vertical cross-sectional view taken through a particular three-layered structure in which a Wide-meshed textile material is sandwiched between two layers of a plastic sheet material; and

FIG. 5 is a partial vertical cross-sectional view taken through another particular multilayered structure in which a wide-meshed textile material is embedded in a single layer of a plastic sheet material.

Referring first to FIG. 1, the carrying bag 1 is essentially a tubular multilayered sheet structure which has 3,490,507l Patented Jan. 20, 1970 ICC been folded flat `with inwardly folded side walls 2 and front and back side walls 3, the bottom edge 4 of the bag being closed, for example by heat sealing or welding of the thermoplastic sheet portion of the multilayered structure. The upper end 5 of the bag remains open, for example by cutting a continuous tubular material just below the heat seal which forms the bottom of the next bag. The tubular multilayered sheet can itself be formed in a conventional manner from a single elongated flat multilayered sheet, e.g. by overlapping and sealing along one of the inwardly folded side edges 6. However, it is especially advantageous to prepare the bag with a seamless bottom by folding an elongated strip at the middle to form the bottorn fold 4 and then heat sealing or welding the side edges 6. In order to provide a carrying handle, one and preferably two slots are punched out of a side wall 3 adjacent the upper edge. In such cutting or punching operations, itis not necessary to further reinforce the bag along the resulting exposed edges.

In the completed bag 1, a wide-meshed planar textile structure 8 is inserted between two thermoplastic sheets 9 and 10 (as indicated in FIG. 4) or else the textile structure 8 may be embedded in single thicker layer 11 of a thermoplastic sheet material (FIG. 5), eg. by introducing the wide-meshed vstructure, into a softened or molten mass of the polymer before it is hardened or solidified into the sheet material.

The individual sets of threads 12 and 13 are preferably laid or interwoven at approximately right angles to each other, and the wide-meshed textile material is then arranged in the finished bag structure such that one of the two thread directions coincides with the direction in which the bag is normally loaded, i.e. its main loading axis as indicated by the arrow in FIG. 2. On the other hand, the wide-meshed textile material can also be arranged in the finished bag structure such that each of the two sets or groups of threads running approximately at right angles to each other forms the same angle with the vertical direction in which the bag is normally loaded. Thus, with the main loading direction of the bag as a symmetrical axis as indicated -by the arrow in FIG. 3, each set of threads forms a 45 angle on either side of this axis.

The type of thread, its strength and thickness as well as the type and -s'trength of the thermoplastic sheet material enclosing or enveloping the textile structure should of course conform to the desired size and loading capacity of the carrying bag. The individual threads may be monofilaments having a circular, oval or flattened cross-section or they may be multifilament strands. The thread thickness can be the same in both directions, but in a particularly preferred embodiment of the invention, the group of threads running in the main loading direction of the finished bag have a greater thickness than the group of threads running transversely thereto. The interval between parallel threads should be in a range of about 3 to 16 mm., preferably between 5 and 12 mm.

Oriented polypropylene, polyamide or polyester fibers, e.g. nylon or polyethylene terephthalate, are especially useful as the threads in the wide-meshed planar textile structure. As the thermoplastic sheet material which encloses the planar textile structure, there may be used for example films or foils of polyethylene, polypropylene, plasticized polyvinyl chloride, cellulose, and the like.

The term threads and textile structure are employed herein especially so as to include a preferred 4open mesh sheet structure formed by overlapping or superimposing one group of threads at an angle to another group of threads, particularly where the threads are `in the form of small flat bands (as illustrated in FIGS. 3 and 5). In this case, the width of the bands is about 2 to 6 mm., and the interval between adjacent bands can be about 3 to 30 mm.

When the carrying bag or the like constructed in accordance with the invention is filled or loaded, then the thermoplastic sheet material is so completely relieved of stress by the reinforcing threads of the planar textile structure that there is practically no distortion of the sheet material and the load placed thereon falls well within its limits of strength. Surprisingly, even with the relatively wide intervals between the threads as recommended for purposes of the invention, one achieves a very high degree of strength so that the thermoplastic sheet material can be relatively thin and pliable. At the same time, the bag can be quickly and easily formed as though it consisted solely of a thermoplastic film without the thread reinforcement.

The particular multilayer structure of the invention provides a bag or sack having an integral relationship between the essential layers and sufficient strength so that additional welded or glued supports or reinforced borders or the like are superfluous. Thus, it is unnecessary to add a handle in the form of a strap, cord or similar means which must be separately fabricated and attached to the bag. Instead, it is sufficient to provide a slot near the upper end of the multilayered bag by punching, stamping or otherwise cutting out a portion of the bag wall, with the resulting carrying bag still retaining its strength without further reinforcing the cut or exposed edges.

The invention is hereby claimed as follows:

1. A carrying bag consisting of two separate outer layers of a thermoplastic polymer sheet material enclosing a separate inner reinforcing wide-meshed planar structure composed of small flat bands of an oriented fibrous material selected from the class consisting of polypropylene, polyamide and polyester, two groups of said bands being laid at an angle to one another in superimposed relationship with the individual bands in each group running parallel to one another, the bands having an individual width of from about 2 to 6 mm. and an interval between adjacent parallel bands of about 3 to 30 mm., said inner wide-meshed planar structure being coextensive with said outer layers of sheet material and the resulting multilayered structure being shaped and formed into an integral bag having side walls, a closed bottom and an open top.

2. A carrying bag as claimed in claim 1 wherein said outer layers are composed of a thermoplastic polymer selected from the class consisting of polyethylene, polypropylene and polyvinyl chloride.

3. A carrying bag as claimed in claim 1 wherein one group of said bands is arranged at right angles to the other group of bands and is positioned in the finished bag structure to coincide with the direction in which the bag is normally loaded.

4. A carrying bag as claimed in claim 1 wherein at least one slot is stamped out of the multilayered structure near the upper open end of the bag without further reinforcement.

References Cited UNITED STATES PATENTS 2,109,558 3/1938 Waters 229--3.5 X 2,167,634 8/1939 Calvert 229-3.5 3,248,041 4/ 1966 Burke 229-55 3,255,951 6/1966 Kay 229-54 DAVID M. BOCKENEK, Primary Examiner U.S. Cl. X.R.

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