US2016851A - Fastening - Google Patents

Description

Oct. 8, 1935. C v. B A 2,016,851

FASTENING Filed April 3, 1950 AVAVAVAVOVAEAVQX'AXA Patented Oct. 8, 1935 'UNITED -STATES FASTENLNG Charles V. Brady, St. Louis, Mo., assignor to Bemis Bro. Bag Company, St. Louis, Mo., a Corporation of Missouri Application April 3, 1930, Serial No. 441,264

3 Claims.

This invention rela'tes to fastenings for fabric or paper and the like, and With regard to certain more specific features, to seams for fastening fabric, and adapted to be used more particularly 5 in connection with the manufacture of bags.

Among the several objects of the invention may be noted the provision of an improved seam for woven fabric and/or paper lined bags and the like, which is made without sewing in a binder strand,

10 such that a strong air-tight and moisture-proof fastening may be obtained; the provision of a fastening seam of the class described which has a higher efliciency with less thickness and bulk than was had in prior sewed Seams; and the provision 15 of a fastening of the class described which may be quickly and economically manufactured, particularly in connection with bags, said bags requiring no subsequent turning after manufacture. Other objects Will be in part obvious and in part 20 pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which Will be exemplified in the structure hereinafter.

vention thereto, With certain parts laid open for purposes of description; and,

Fig. 2 is a cross section taken on line 2-2 of 35 Fig. 1, said cross section being diagrammatic and having certain thickness exaggerated for purposes of clarity. A

Similar reference characters indicate corre- Sponding parts throughout the several views of 4 the drawing. i

As explained in my copending patent application for Fastening, filed February 8, 1930, Serial No. 426,795, now Patent No. 1,853,0l3, dated April 5, 1931, the conventional mode of fastening or 45 seaming edges of woven fabric comprises overlaying two or more layers of fabric and sewing therethrough a strand of some nature such as a thread, cord, twine or the like. This method of fastening or seaming has certain disadvantages 50 which arise from several causes. For example, a bag seam should be quite strong, but, with a prior type of bag having a double or greater thickness at each seam, and stitching therethrough, the efficiency of the connection is only of the order of 55 60 to 70 per cent; that is, the seam per se has but 60 to 70' per cent of the strength of the goods ln which the seam exists The efliciency depends in part upon the number of layers of cloth included in the seam, but, because of the increase in bulk, the number of layers of cloth cannot be increased indefinitely. Even the conventional four-thickness seam is bulky.

The reason for the low efficiency above referred to is found in the fact that stresses applied to the sewed seam are concentrated at the points through which the thread passes. Thus the Strain is greater in the regions around the threads and separation is likely to occur in such regions.

The described Separation also leads to leakage or sifting through the openings of finely 15 comminuted materials. Bags for holding such finely comminuted materials, calcium chloride for instance, have been lined With paper, an adhesive being used between the paper and the fabric in certain constructions. When such a bag is sewed at its seam, the stitching goes through the paper, as well as through the fabric, and the local concentration of the stresses not only Weakens the seam but stretches the openings through which the thread passes and causes sifting therethrough, thus preventing the procurement of the best Sealing eifect from the liner. The openings further permit passage of moisture to and from the interior of the bag. It will be understood that openings are present, not alone because of the stresses, but because the needle punctures themselves form openings, disregarding subsequent stretching.

The weakness of this prior sewed seam is also due to some extent to the fact that the threads beyond the sewed seam do not pull in the same line with thecontinuatibn of these threads running around the girth of the bag. The threads beyond the seam Stand out almost at right angles to the body of the bag and when stressed, these threads running around the girth of the bag tend to be broken ofi.

Another disadvantage of using thread or cord or the like for sewing Or binding is that it necessarily passes through the fabric and/or paper liner from inside to outside and Vice versa and functions as a capillary wick for moisture and the like which is transferred along the thread and into the bag, or vice versa. Furthermore, if the substance in the bag contains any substance injurious to the threads, the threads themselves may be attacked and weakened or destroyed.

It Will thus be seen that the present invention provides a. leak proof, lighter, stronger, more durable, and more flexible bag by eliminating 56 both the holding strands and the punctures in herent in the application of said strands.

The invention therefore provides on one hand a seam particularly adapted to bags which are to contain materials which readily' absorb or give up moisture, oil and the like and/or those materials which are wholiy or in part flnely comminuted and/or those of substantial density requiring strong bags, although the above is not to be taken as a limitation of the use of the bass.

The invention also provides means for improvedly closing what is known as an open-mesh bag, often composed of twisted paper strands and used for transporting fruits, vegetables and the like. This type of bag is not air or moisture proof.

Referring now more particularly to Fig. 1, there is illustrated at numeral l a bag comprising, for example, an outer layer 3 of woven fabric such as burlap. For use with flnely comminuted material, this outer layer 3 of woven fabric has fastened thereto an inner layer 5 comprising, for instance, papier mach or other paper which will yield without cracking when the bag is folded or otherwise strained. The inner layer 5 is held to the outer layer 3 by means of a waterproof adhesive Such as an asphaltic material [5.

- It will be appreciated that when the fabric 3 has been rendered leak proof by application of the liner 5, it is desirable to have the seam which cooperates therewith as tight as the remainder of the bag, or the leak proof effect will be lost.

The material 3, 5 is folded over at lateral edges 1, one side 9 of the bag being continuous and the other side thereof comprising two webs or panels II, l3.

The improved seam of the invention is of lap construction (Fig. 2) comprising the edge of web H and the edge of web I3. The inner liner 5 is not carried to the edge of the web Il (see numeral 11), leaving a selvage area [9 down the edge of web l l which is neither covered by liner 5 nor by adhesive [5. Thus, the under edge of the fabric Web l l is uncovered prior to cementing.

The juxtaposed edge of the web |3 has the adhesive |5 and liner 5 carried up to the edge thereof (See numeral 2l).

As the bag is formed into its tubular shape shown in Fig. 1, the edge strips of the webs H, |3 are overlapped and juxtaposed, and as they come together an adhesive material or cement 23 is applied between the portions contiguous to said edges. The cement or adhesive material comprises preferably processed rubber, gum, latex, asphalt or a like Waterproof material. It is further desirable that this material be impervious to attack by that which is to be contained 23 which lies against the fabric of web H (see numeral IS) lying also against the fabric of web 13, efl'ects a strong joint. This is because the width of the area at numeral IS may be made as much as is desirable to obtain a proper strength. The joint may be made stronger than the remainder of the bag by using an ample wide area,

although this is not necessary and the area may be limited to provide substantially equal Strengths.

'I'he adhesion is particularly effective, because the cement surrounds and imbeds the upstanding fibers of the woven material 3 and passes into the interstices thereof. Thus, there is effected a substantially homogeneous material at 5 the juncture between fabric and cement. The part of the joint which effects best sealing is the fabric-to-liner region wherein the cement 23 lies between the liner 5 of the web H and the fabric 3 of web |3 (see numeral 25); However, the ce- 10 menting material in the fabric-to-fabric region also effects a Seal.. It will be understood that the mass of cement may be carried merely up to the edge 21 of the liner 5 and good results obtained. It will also be understood that a com- 15 pressing operation is used in juxtaposing the edges of the webs Il, I3, so that in actuality the seam is only slighty thicker than the cloth composing it and thus being thinner than diagrammatically shown in Fig. 2.

It will be seen that the joint comprises juxtaposed fabric faces between which the cement is positioned, the liner 5 having its edge away from the edge of fabric 3 so as to permit this. The reason for this construction is that the seam 25 holds with the proper strength between fabric faces, whereas it would not so hold between a paper and a fabric such as would be had ii the liner 5 went to the edge of web ii.

It will be understood that a suitable bottom 30 seam 29 is used on the bag.

It is to be understood that the various terms "binder", "cement", "adhesive", and the like, are used herein as distinguishing regions or locations, and not particular compositions of mat- 35 ter. That is, speaking from the standpoint of composition, the binder, cement, and adhesive may all be the same material, as asphalt. or they may be different materials, as asphalt and latex. The different words are used to aid in distin- 40 guishing the particular regions of application, from the Structural standpoint.

In view of the above, it will be seen that the several objects of the invention are achieved and other ad'vantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the Scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing 50 shall be interpreted as illustrative and not in a limiting sense.

I Claim:

1. A seam comprising two webs of fabric, a liner secured to each of said webs of fabric by 55 adhesive material, said liners being impermeable to said adhesive material, one of said liners extending to the edge of its respective web, while the other liner leaves a selvage portion of its web unlined, said selvage portion being juxtaposed 60 to the lined edge portion of the other web to form a region of fabric-to-fabric contact, with the liners of both webs positioned on the same side of their respective webs, and cement positioned between the fabric webs in said fabricto-fabric region, said liners also being impermeable to said cement.

2. A seam' comprising two webs of fabric, a liner secured to each of Said webs of fabric by adhesive material, said liners being impermeable 70 to said adhesive material, one of said liners extending to the edge of its respective web, while the other liner leaves a selvage portion of its web unlined, said webs being overlapped in such manner that said unlined web selvage juxtaposes the other web to :form a fabric-to-fabric region of contact, as well as a liner-to-Iabric region of contact, the liners of both webs being positioned on the same side oi' their respective webs, and cement positionedbetween the fabric webs in said fabric-to-fabric region, said liners also being impermeable to said cement.

3. A seam comprising two webs of fabric, a iiner secured to each of said webs of fabric by adhesive material, said liners being impermeable to said adhesive material, one of said liners extending to the edge of its respective web. while the other liner leaves a selvage portion of its web region, said liners also being im'permeable to said 10 cement.

CHARLES V. BRADY.

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