US2539799A - Bag closure - Google Patents

Description

Jan. 30, 1951 W. O. STRELLER BAG CLOSURE Filed April 14, 1948 INVEN TOR. WOLFGANG O. TRELLER.

Mmm/EVS.

Patented Jan. 30, 1951 UNITED PATENT (JFICE BAGA CLOSURE wolfgang, New York, rN. Y., assignory to St. Regis k laper Company, New York, N. Y., a corporation of New York ppiieto Apri-1 1'4, 1948;sria1N'. 21,059

. 2 claims. (c1. 229-62) This' invention pertains' tol improvements inv and closures for paper bags;Y and the like, and

more especially to bag end closures of the sewn seam type. y

A common form of end closure for relatively large bags, i. e., those adapted' to packaging goods in bulk, such, for example; as cereals, flour,v ce* ment, etc., is' one wherein` the oppostely disposed will' portions of the bag end are overlappedy with a separate sealing tape of heavy paper or the like,

and secured together bymeans of a seam, which may' comprise anseries of staples, but more preferablly comprises a continuous sewn' seam of cotton thread or cord, or otherl suitable organic material. A serious objection to this' type of end closure resides in'l the fact that the needle holes resultingfro'rn'the sewing operation permit the packagedog'oods, especially if of finely ground o'r pulverulent material, to sift'l out, and' these holes further` provide points of ingress for insects and the like',v particularly as applied to'packaged coingv estibles ,y such as flour, cereals, etc. Likewise,` these'lnet-dle holes permit the bag contents to beA easily penetrated by moisture,` molds, fungi; etc., from theV outer atmosphere', and also prevent the packaging therein of goods of a viscous or easily owable character. n

Many attempts have heretofore been made to overcome this' difliculty, as for example, superimposing on the sealing tape, on one or both sides thereof, and along the line of stitching, such stitching-perforation-filling materials asv lter cord, paper strips or the like; or by attempting to accomplish the same result by folding the seal-V ing tape along the stitching` line' inonefor more folds. All such expediente are objectionable, however, either by reason of the additional e'xv pense of fabrication thereby entailed, or due to the fact that such expedients are either ineffective or weaken the' bag end closure.

In accordancev with the present invention, it is proposed to overcome these objections to prior constructions in ano-extremely simple, yet effective, manner. Thus, in accordance with the in-v vention` herein, the sealing tape, which overlaps the bag end,` is foldedback upon itself along 'an intermediateportion thereof; on; one or both' sigles of the bag, to fornr a pleat or' pleats substantially paralleling the bag end, and the closure completed by means of stapling, or more preferably, by means of a sewn seam passing through the pleated portion or portions of the tape and the bag walls interposed therebetween. In conjunction therewith, the extremities of the sealing tape are adhesively bonded to the opposite side walls, respectively, of the bag.

By virtue of this construction, the folded-'over or pleatedr portions of the sealing' tape effectively ll the stitching perforations, while the adhesive bonding ofv the sealing tape extremities to the opposite bag walls, respectively,` not only increases the rupture or breakage strength of the bagv end when packed with the packaged goods; in handling or throwing about, etc., but inv addition; seals off exposure of the stitching perforations,` whichY would otherwise occur between the bag walls and the edges of the sealing tape.

The invention is, of course, applicable'V to end closures for all typesrof bags, and is especially effective as applied to multiwall or multi-ply bags such as are employed inthe industry in treinen-` dous quantities for the packaging of goods in bulk as aforesaid.

In the drawings v Figure l is a" plan view of the upper end of a valve type of m'ultiwall bag, illustrating an en d closure `in accordance with one modification of the invention, Figure 2Y being a sectional view thereof, taken at 2--2 of Figure 1. Figure?, is a sectional view, similar to Figure 2, illustrating a" furtherrmodication of the invention. v

o Figure 4 is a plan view, similar to Figure 1,- sh'o-wing a.k further modication of the invention, appliedV as an end closure of an initially openended type Vofbagor asan end closure at the lower end of either ua valve type or open-ended type of bag. Figure 5 is a sectional view of the Figure 4 modication, taken at 5--'5 of Figure 4; while Figure 6 is a sectional view similar to Figure 5, but illustrating a further modification thereof. l y

Referring to Figures l and 2,` there is shown generally at Iii, the upper end v of a multiwall bag comprising a number of bag plies as indicatedat I I, this bagl being of the valve type, i. e., provided with ya valve sleeve corner as indicated at l2, to provide an aperture as indicated at I 3, for purposes of filling the bag with the goods to be pack# aged therein, for example, flour, cereals, cement or the like. `The bag is gusseted along the lateral edges as indicated at I4, I5, to provide a flat construction prior to filling. y Vlr accordance with the modification of the inven ...on illustrated in Figures land 2', the upper endsk i6 of the bag plies I I are overlapped with a strip of sealing tapev Il, composed, in the niodi cation illustrated, of creped paper as indicated at I8. The sealing tape il overlaps the ends I6 of the bag plies I I to the distance I9, 20 along the opposite, outer side walls 2l, 22, respectively, of the bag. An intermediate portion of the sealing tape is folded back on itself, on one side of the bag, in the manner shown at 23 in Figure 2, thereby to provide a pleat substantially paralleling the bag end, as illustrated more clearly in Figure 1. The closure is completed by means of a seam 24, which may be a series of staples, but more preferably comprises a sewn seam, which passes through `the opposite sides of the sealing tape, including the pleated portion thereof, and through the interposed bag plies in the manner clearly illustrated in Figure 2.

A common type of stitch which may be employed for the seam 24, where a sewn seam is employed, is known as the double chain stitch, in which, on the rear side of the same, the loops of the needle thread 25, Figure 2, are chained into loops of a looper thread 23. It has been found that the looper side of the seam is ordinarily strong enough, and lls the needle perforations on the loop of thread on the 26 side Suniciently, that it suiiices in many instances to omit a pleat in the sealing tape on the looper side, as shown in Figure 2, and merely to provide the pleat on the opposite side of the sealing tape, the latter as shown at 23.

A much stronger construction and more eiective closing of the needle perforations is, however, obtained in accordance With the modification of the invention illustrated in Figure 3, wherein the sealing tape is folded back on itself on both sides of the bag to provide oppositeiy disposed, pleated portions 23 and 21, throug which the seam is sewn as at 24.

It will be observed in both the Figures 2 and 3 modifications, that the lower extremities i9 and 2li of the sealing tape extend well below the pleated portions 23, 24 thereof, to provide sealing tape portions 28 and 29, disposed below the pleats, which portions are rmly bonded or cemented to the outer surfaces of the outer bag plies 2|, 22, thereby to increase the strength of the closure in handling or throwing about of the bag when packed, and also to seal the lower extremities i9 and 20 of the sealing tape to the bag walls 2|, 22 against exposure of the stitching perfcrations which might otherwise occur therebetween in the absence of such bonding of portions 28 and 29 of the sealing tape to the opposite bag walls 2 I, 22.

it will be noted that in the Figures 2 and 3 modifications the sealing tape is pleated in such fashion that the pleats point downwardly, i. c toward the median line of the bag. In the Figures 4 6 inc. modifications, the pleating is in the opposite direction, i. e., the pleats point toward the bag end. Thus, referring more particularly to Figures 4 and 5, there is illustrated generally at 30, an end of a multiwall or multi-ply bag, the plies of which are indicated at 3|. The extremities 32 of the bag plies are overlapped with a strip 33 of sealing tape composed, as in the previous modiiications, of creped paper as indicated at 34, this sealing tape extending downwardly along the opposite sidewalls 34, 35 of the bag to the distances 3E, 3l respectively. An intermediate portion of the sealing tape on one side of the bag is folded back on itself to form a pleat substantially paralleling the bag end as shown at 33, and the bag end closure is completed by a stapled or stitched seam 39, passing through the opposite sides 40, 4| of the sealing tape in the pleated portion 38 thereof, and also through the interposed bag plies 3|, as shown. It will be noted that in this modification the pleat 38 is so formed in the sealing tape as to point toward the bag end, i. e., toward the upper extremities 32 thereof.

As in the Figure 2 modification, if the .seam 39 comprises a sewn seam of the double chain stitch type, a pleat such as 39 may also be required, for many applications, only on the side opposite to the looper side 42 of the stitching. As above stated, however, a stronger construction is secured, and one in which the stitching perforations are more effectively closed, if pleats are provided on both sides of the sealing tape as illustrated in Figure 6 at 38 and 43, respectively. In the Figure 6 modification, as in Figure 5, both of the pleats 38 and 43 are so formed as to point to the bag end 32 as shown. Also, as in the Figures 2 and 3 modifications, the lower extremities 44, 4| of the sealing tape are rmly bonded or cemented to the opposite sidewalls 34, 35, respectively, of the bag, being interposed adhesively, and for purposes above stated. The modifications of Figures 2 and 3 are preferred to those of Figures 5 and 6, as the former have been found by tests to give a somewhat stronger construction'. I

What I claim is:

1. A bag having oppositely disposed walls terminating in a bag end, and a sift-proof closure therefor comprising a separate sealing tape folded over astride said bag end, an intermediate portion of said tape being folded back upon 1tself on at least one side of said bag, forming a pleat substantially paralleling said end, and a seam passing through the bag walls and the op- Y positely disposed portions of said sealing tape,

including the pleated portion thereof, the oppositely disposed edge portions of said sealing tape extending below said pleat and being adhesively bonded to the contiguous bag walls, respectively.

2. A bag having oppositely disposed walls terminating in a bag end, and a sift-proof closure therefor comprising a separate sealing tape folded over astride said bag end, an intermediate portion of said tape being folded back upon itselfv REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,140,104 Cheatham Dec. 13, 1938 2,345,434 Sterling i Mar. 28, 1944 Hartman I -Q Mar. 16, 1.948

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