US2020300A - Bag and method of making same - Google Patents

Description

Nov. l2, 1935 R. N. CUNDALL I BAG AND METHOD MAKING SAME File Jan. 9, 1951l Patented Nov. 12, 1935 PATENT OFFICE BAG AND METHOD F MAKING SAME Robert N. Cundalh Hamburg, N. Y., assigner, by vmesne assignments, to Bagpak, Inc., a corporation of Delaware Application January 9, 1931, Serial No. 507,615

' 4 Claims.

This invention relates to a bag and method of sealing the same and more particularly to multiple walled bag adapted to contain powdered materials, such as flour, sugar, lime, plaster, gypsum, fertilizers and the like, in which it is not only necessary to close the bag in such manner that the fastenings at the mouth of the bag will not break or loosen but also to provide a seal which prevents the leakage or sifting `out ofthe contents when the bags` are handled eifher when the bags are' inverted or when they' are set down and the material tends to blow out through the impact of setting the bag down.

In the development of open mouth paper bags i l5 for use as larger sizedpackages of powdered materials it has been found desirable to make them with the walls of a number of thicknesses of pa-v per. As there is a limit to the strength which can be obtained from a single thickness of paper the most effective way to provide the necessary strength for large bags has been found to provide a bag having a number of walls or in ehect a single bag made of a number of bags set one within the other. This not only provides the requisite strength but also permits of employing a moisture resistant bagor wall as the outer wall'which can be thin and inexpensive and not only protects the contents of the bag but also protects the inner walls or bags which can be made of a non-moisture resistant paper. While this development has produced bags of suilicient strength, their use has been prevented from a more -general application, particularly in the handling of fine, dusty materials because of the difculty in making them sift-proof at the mouth when the closure was made, and in the case of the larger sizes of bags the need of extra strength at the mouth or place of closure.

This application is a companion to my application, Ser. No. 507,616, filed January 9, 1931; and l the application of myself and William B. Powell,

Ser. No 507,874, iiled January 10, 1931.

One of the principal' objects of this invention is to provide a bag fornely powdered or dusty materials in which the mouth of the bag is closed in such manner as to provide a strong, durable and permanent closure and seal which is also sift-proof andA entirely prevents the fine, dusty materials from sifting out through the closure. Another purpose is to provide a bag which when closed is as strong at the mouth or'place of sealing as any other portion of the bag.

Another aim is'to provide a bagV of this char-- acter in which there is no danger of the sealing material falling into the contents of the bag,

A further object is to provide such a bag and process which permits of the sealing of the bag to be providedby automatic processes and avoid all hand operations. f

A still further aim is to provide a bag which is 5 neat in appearance and can be provided with a sift-proof seal of the requisite `strength at very low cost. e

Another purpose is to provide a bag which is eifectively sealed against the possibility of con- 10 tamination and which is also pilier-proof thereby permitting its use for contaminable foodstuffs and alsofor relatively valuable materials subject to pilfering.

In the accompanying drawing: ,l

Fig. 1 is a fragmentary prospective view of a multiple walled bagr closed and sealed in accordance with-my invention.

Fig. 2 is a fragmentary vertical section therethrough. 20 Fig. 3 is al fragmentary horizontal section taken on line 3 3, Fig. 2.

Fig. 4 is a view similar to Fig. 1 showing a modied form of my invention.

Fig. 5 is a fragmentary vertical section there- 25 through. Fig. 6 is a. view similar to Figs. 1 and 4 showing a further modified form of my invention.

Fig. 7 is a fragmentary vertical section of the form shown in Fig. 6. 30 Fig. 8 is a fragmentary perspective view of a bag showing a stillv further modifled form of my invention.

Fig. 9 is a fragmentary vertical section through the form of bag shown in Fig. 8. 35 In the present. application the invention is shown as embodied in a bag which is already Aformed i. e. in closing and 'sealing the mouth of the bag, but it will also be apparent that the invention can be embodied in closing and sealing40 the bottoms of bags during their manufacture.

One of the most effective ways of closing a multiple walled bag containing dusty materials 1s by stitching the sides of the mouth of the bag together with cotton thread. Stitching through 45 the sides of themouth of the bag, however, has

'the eect of weakening the bag and dusty materials will leak through the top of the bag between the stitches. Also in the stitching of the bag the stitching needle is, of course, larger than 50 The most effective Way that has been found to make a. bag tight or sealed at the opening is by some form of gluing. Inasmuch, however, as the principal object of employing a multiple Walled bag is to obtain the required strength it is obviousthat in cases where great `strength is needed unless some method of reinforcing 'this seal is obtained, it will not be as strong as the walls of the bag. The present invention therefore proposes to combine stitching and gluing in such manner that the' stitching provides a closure of the necessary strength and the gluing not only seals the bag at the closure but also strengthens the stitching. While the invention proposes the use of stitching and gluing it will be apparent that in place of the stitching another form of fastening which extends through the walls of the bag could be employed, such as staples, and that while glue is preferable -any adhesive or hardening plastic material can be employed, preferably one that is quite liquid at the time of application and will harden to a stiff gummy condition, such a condition being preferable to a glue which becomes brittle.

, The invention is shown as embodied in a multiple walled bag having an inner wall I0 and an outer wall II although the invention can be embodied in any bag which is fabricated'in any suitable manner to provide a mouth I2 at its upper end. The bag when furnished to the packer is at and before filling the packer opens up the mouth of the bag and deposits the dusty or powdered materials into the bag so that it is contained within the inner wall or bag I Il. In the form of the invention shown in Figs. 1 to 3 a layer of glue or other adhesive material I3 is applied to the inside of the inner wall III adjacent the mouth I2, this layer of glue extending from one end of the mouth of the bag to the other. After this layer of glue has been applied the mouth of the bag is closed by bringing the sides of the bag together and rolling or pressing themso that the layer of glue I3 forms a seal for the mouth of the inner wall` or bag I0. At

the same time that the mouth of the bag is being rolled together a row of stitching I4 is provided across the mouth of the bag below the layer of glue I3. This row of stitching I4 is provided by passing the closed mouth of the bag through a sewing machine which stitches through the opposite walls of both the inner and outer bags I0 and II and extends from one end of the mouth of the bag to the other so that a strong and reliable closure is effected for the bag. The needle of the sewing machine, is however, larger than the thread employed and therefore during the sewing operation the needle punches holes I5 through the walls of the bag at its mouth which are necessarily larger than the thread I4 received in these holes. Therefore in the absence of provision to prevent it the dusty materials which the bag contains would sift out through the holes I 5 and be lost. To prevent this a layer of glue I6 is applied to each side of the bag at its mouth and covers the stitching I4. These layers of glue can be applied in any suitable manner, such as by suitable rollers, brushes or the like and when so applied the liquid glue enters the hole:` I5 and seals the same, as indicated in Fig. 2. By this means it is apparent that the escape of any dusty materials through the mouth of the bag or through the holes I5 is prevented since the glue acts as a complete seal. At the same time the glue strengthens the stitching I4 since each stitch is cemented to the bag and in order that the stitches cut or tear through the holes I5 it is necessary that the stitching first be broken free of the glue I6.

It is therefore apparent that the bag is provided with a strong closure inthe stitching I4 5 and that at the same time this closure is sealed and strengthened by the glue.

In the form of the invention shown in Figs. 4 and 5 only one layer Il of glue is provided for sealing purposes. 'I'his layer of glue is applied 10 to the inside of the inner Wall of bag I0 and extends from one end of the mouth of the bag to the other. In stitching the bag the row of stitches I4 is passed horizontally from one end of the mouth of the bag to the other and is ar- 15 ranged to stitch directly through opposite walls of both the inner and outer bags and through the layer of glue Il. In so stitching the bag the layer of glue I'I is rolled or pressed between the opposite walls or sides of the mouth of the bag 23 and a part of this layer of glue I'I forces out through the holes I5 formed by the needle of the stitching machine and which are necessarily larger than the thread I4. It is therefore apparent that the dusty materials which the bag g5 contains cannot pass directly out through the mouth of the bag since the layer of glue I'I prevents this, nor can they pass out through the holes I5 formed by the sewing machine needle since these holes are also sealed by the layer of 31) glue I'I.

For additional strength it is sometimes desirable to fold over the mouth I2 of the bag. In doing this the mouth I2 of the bag is reversely folded as indicated at I8. In the form of the 35 invention shown in Figs. 6 and 'I the mouth` of the bag is so folded and the row of stitching I4 is passed through this folded portion so that the stitching extends through four times the number of walls of which the bag as a whole is com- 3 posed. As in the other forms this stitching extends from one end of the mouth of the bag to the other. As in the other forms the holes I5 which the sewing machine needle makes in stitching and which are necessarily larger than 45 the thread I4 must be sealed to prevent the escape of the dusty materials through these holes. To prevent this escape the layer of glue I6 is applied to opposite sides of the bag at its mouth and in being applied is rolled or pressed so that 50 a part of this glue is forced into the holes I5 and around the thread so as to seal the holes I5 and completely prevent the escape of the dusty materials through these holes. As in the other forms of the invention this sealing glue or adhesive 55 notonly prevents the escape of the 'dusty mate- I rials but also strengthens the stitching I4.

or turned as indicated at I 8 in the same man- 6() l ner as in the form of the invention shown in Figs. 6 and l. Before so folding over the mouth of the bag or during this folding operation a. layer of glue I9 is applied to the outer side of the outer wall II from one end of the mouth of the bag to 65 the other end in such manner that when the mouth of the bag is folded over as at I8 this layer of glue is disposed between the folded-over portion I8 and the body of the bag against which it is folded. The bagis then run through the 70 stitching machine and the row of stitches I4 is provided for the full length of the mouth of the bag, the stitching extending through the four thicknesses of the bag. During the stitching operation theholes I5 formed by the stitching 75 `needle are'` necessarily larger than the thread Il and a part of 'the glue from the layer I9 squeezes out through the holes I5 and provides a seal which prevents the dusty materials from leaking out through these holes and escaping.

It will be noted that the invention has been shown and described as embodied in the sealing of the mouth of a bag already fabricated.- It is obvious. however, that the invention can be embodied in closing the bottom of the bag as Well and that the bagcan be closed and sealed at both ends in accordance with the invention and the-invention is therefore to be construed as equally applicable to this use.

It is apparent that in all of the forms of the V invention a strong and reliable closure is provided. by stitching the mouth of the bag from one end of the mouth to the other and that at the same time glue or other adhesive is so applied as to seal both the mouth of the bagy and also to seal the holes made by the stitching needle so that the mouth of the bag is completely sealed and the escape of any of the dusty materials which the bag is designedV to contain is prevented. At the same time in each form the glue or other adhesive strengthens the stitching so that therev is less liability for the mouth of the bag to accidentally be torn open. Each ofthe forms of the invention also provides a bag in which the clasure is strong and durable and ,equal to any other portion of the bag; there is no danger of Y bits of glue breakingland `falling into the contents of the bag so as to contaminate the contents; and'the seal is neat in appearance and the closing can be readily effected by automatic means. Each of the forms of the invention seals the bag so as to prevent contamination thereby permittingits use for foodstuis and also pro' vides a seal which is pilferproof thereby permitting its use for shipping valuable materials which are particularly subject to pilfering.

While the bag hasbeen shown and described with particular reference to a multiple walled bag it is apparent that some features of the invention can be embodied in a single walled bag and the invention therefore also comprehends this application'.r

folded-over part.

I claim as my invention:

1. A bag of the character described, comprising a tubular body made of flexible material and having a mouth at at least one end, a reverse fold provided at said mouth of the bag and forming 5 a closure, fastening means extending through said reverse fold for holding said mouth reversely folded and a hardening plastic material forming a seal for said closure.

2. A bag of the character described, compris- 1o ing a tubular body made of flexible materialvand having a mouth at at least one end, a reverse fold provided at said mouth of the bag to provide a closure for said bag, said fold comprising both walls of the bag folded in the same direction one over the other, a hardening plastic material in said fold and fastening means extending through said reverse fold and penetrating said hardening plastic material, said hardening plastic material forming a seal preventing the escape of the contents from said bag through the openings resulting from the penetration of said bag by said fastening means. V

3. The method of closing and sealing a multiwalled bagcomprising a tubular body made of flexible material and having a mouth at at least one end, which consists in applying a hardening plastic material to an outer wall of said bodyv near` the mouth and folding said plastic-coated material upon itself to cause adhesion at the region between two contacting faces of said wall of the bag and passing fastenings through the sides of said bag and through said hardening plastic material whereby the hardening plastic material seals the holes formed by the penetration of said fastenings.

4. The method of closing and sealing abag comprising a tubular body made of flexible material and` having a mouth at at least one end, which consists in applying a hardening plastic material Vto 'an outer wall of said bag near sa'id mouth and folding over said mouth of the bag to provide a closure for said bag, and passing fastenings through the body of said bag and said 45 ROBERT N. CUNDALL.

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