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Publication numberUS3018943 A
Publication typeGrant
Publication dateJan 30, 1962
Filing dateJul 27, 1959
Priority dateJul 27, 1959
Publication numberUS 3018943 A, US 3018943A, US-A-3018943, US3018943 A, US3018943A
InventorsKeating Alexander F
Original AssigneeBemis Bro Bag Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Bag
US 3018943 A
Images(2)
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Description  (OCR text may contain errors)

Jan. 30, 1.9 62 A, F, KEATING 3,018,943

BAG

Filed July 27, 1959 FIGS.

2 Sheets-Sheet 2 United States lemis Bro. Bag Company, St. Louis, Mo., a corporation of Missouri Filed July 27, 1959, Ser. No. 829,571 8 Claims. (Cl. 229-625) This invention relates to bags, and more particularly to valve bags made of plastic-lined cloth.

The invention is particularly concerned with sewn valve bags made of plastic-lined cloth, such as a bag made of material having an outer layer of burlap and an mner layer of polyethylene and having a valve provided with a paper valve sleeve at one corner of the bag. In particular, the invention has been applied to a bag made of material consisting of an outer layer of burlap, an intermediate layer of creped kraft paper and an lnner layer of sheet polyethylene, with asphalt between the layers. In the manufacture of such bags, the sleeve is inserted by hand in the end of the bag at the valve corner prior to closing the end of the bag and provision must be made for holding it in place during subsequent operations. The hand operation does not lend itself to adhesive securement of the sleeve directly to the polyethylene lining, and it.has heretofore been the practice to staple the sleeve to the bag body to hold 1t in position, the staples being removed after they have served their-purpose. 'Ibis procedure is time-consuming.

Accordingly, among the several objects of the invention may -be noted the provision of a new construction for bags of the class above described which enables the sleeve to be adhered in position at the valve corner, in such `manner as to hold it in proper position during the rformation of the valve and the sewing of the end of the bag, and also to provide a complete adhesive seam between the valve ap and an end of the sleeve overlapping the valve ap.

Another object `of the invention is the provision of a construction such as described wherein the sleeve is a sleeve of the so-called tuck-in type, having a reversely folded portion extending out of the bag through the valve opening, this portion being adapted after the bag has been filled by means of a lling spout extending through the sleeve and into the bag, to be folded up and tuckedinrgto Iclose the sleeve. A further object of the invention is the provision of a construction such as described which facilitates the sewing of the end of the bag, especially in the area of the valve.

Otherf objects and features will be in par-t apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated:

FIG. l is a plan view of a composite multiply web from which bags of this invention are made, certain plies and laminants of the web being shown broken away in part;

FIG. 2 is an enlarged section taken on line 2 2 of FIG. l, thicknesses being exaggerated; t Y

FIG. 3 is a view in elevation of a bag bvody made from a blank segmented from the FIG; 1 web in an intermediate condition thereof;

FIG. 4 is a view in elevation of the bag body turned inside out from its FIG. 3 condition -to bring it into its t final condition, and showing a valve sleeve inserted at the valve corner;

FIG. 5 is a plan view of the valve sleeve per se;

3,918,943 Patented Jan. 30, 1962 FIG. 6 is a perspective view showing how the sleeve is inserted in the bag body;

FIGS. 7 and 8 are views illustrating steps in the forma tion of the valve;

FIG. 9 is a View in elevation of a completed bag; and,

FIG. l0 is a longitudinal vertical section through the valve. p

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

FIGS. 1 and 2, of the `drawings show a Iweb 1 of composite bag material from which are segmented rectangular blanks to be formed into bags of this invention. This web is essentially a three-ply web, comprising a layer or ply 3 of cloth, more particularly burlap, a layer or ply 4 of paper, more particularly creped kraft paper, and a layer or ply S of exible sheet plastic material, more particularly polyethylene. The plies are laminated by means of laminant 7, more particularly asphalt. It will be understood that web 1 may be formed by applying molten asphalt between the plies and combining the plies, the asphalt on cooling acting to hold the plies together. The paper 4 and asphalt 7 terminate short of one of the longitudinal edges of the web, leaving unadhered marginal portions 3a and 5a of the burlap and polyethylene plies along this edge of the lweb (its upper edge as viewed in FIGS. 1 and 2). Also, in the course of the formation of the web, a relatively narrow paper strip 9 is combined with the web extending along the stated one longitudinal edge thereof on the polyethylene ply S, this strip being secured to the polyethylene ply by a layer 11 of asphalt therebetween. The outer edge of the strip 9 is generally coincident with fthe edges of the plies 3 and 5. Asphalt 11 extends throughout the width of strip 9. The paper of which strip 9 is composed is preferably of such nature that there is no substantial bleeding of asphalt therethrough.

Web 1 is cut on lines such as indicated at 13 in FIG. l to segment it into rectangular bag blanks 15 each having a width correspondingV to twice the desired bag width and Y a height (the width of web 1) corresponding to the desired bag height. Each such blank is folded in half on a heightwise fold line 17 with the burlap 3 on the inside and the polyethylene 5 and paper strip 9 on the outside, and a seam 19 is sewn along the edge (the lower edge) of the folded blank opposite the edge where the paper strip is situated and aseam 21 is sewn along the edge opposite the fold line 17 (see FIG. 3). Seam 19 constitutes a bottom seam; seam 21 constitutes a side seam. Fold 17 constitutes the other side of the bag from side seam 21. In the sewing of these seams, the needle of the sewing machine tends to become heated due to friction, thereby tending to melt the asphalt at the holes made by the needle, the melted asphalt tending to run into and plugging the holes. Then the sewn blank of FIG. 3 is turned inside out to provide a bag body B such as shown in FIG. 4 in which the burlap 3 is on the outside, and the polyethylene 5 and paper strip 9 on the inside, the latter being located at the open upper end of the bag body. The polyethylene 5 then constitutes a liner.

FIG. 5 illustrates a valve sleeve 23 per se, in its initial state, prior to application to the bag body B. As shown, this sleeve comprises a generally'rectangular blank of paper, such as creped kraft paper. It has a plastic coating 25, such as a polyethylene coating, on one face thereof (which is its face away from the viewer as illustrated in FIG. 5). This blank is folded in half on a longitudinal center line 27, with its polyethyene-coated face on the inside, and has a stripe 29 of adhesive (any suitable paste vor glue) applied to its plain uncoated face (which is then on the outside of the folded blank) at one end. The sleeve 23, so folded, is then inserted with its adhesive-carrying end first i-n the corner at the open end of the bag body at the upper end of side fold 17 to dispose the stripe of adhesive 29 against the paper strip 9 and to cause the sleeve Vto become adhered to the paper strip 9 (see FIGS. 5 and 6). v

The `sleeve 23, together with a triangular portion 31 of the bag body which forms a valve ap, is folded into the open end ofthe bag as illustrated in FIG. 7. A portion 23a of the sleeve is folded back on a transverse fold line 33 lying inward from the inner end edge 35 of the valve ilap 31 to extend back outward over the valve ap (see FIG. 8). This leaves a relatively short portion 23h of the sleeve extending inward from the inner end edge 35 of the valve ap, this portion 23b being adhered to the inside of the inner margin of the valve ap by reason of adhesive 29 securing it to the paper strip 9. As the valve formation is completed, the portion 23b of the sleeve becomes reversly folded on center line 27 as regards the initial folded condition so that the coated face of portion 23b is on the outside of the reverse-folded portion 23b. Portion 23a becomes folded on center line 27 in such manner that the coated face thereof is on the inside. Corners 37 of the sleeve fold over between the sides of the valve flap 31 and the bag walls. These are of no consequence, and could be eliminated, if desired, by trimming off the corners of the sleeve when it is originally made.

Finally, the open end of the bag is closed by running 'a line of stitching 39 across the top of the bag through the unadhered marginal portions 3a and 5a of the burlap and polyethylene plies 3 and 5. This line of stitching constitutes the top seam of the bag. It extends through and Secures together the upper margins of the folded sides of the sleeve so that the sleeve is formed into a tube adapted to receive a filling spout. The stitching is run olf the side of the bag and throughout the length of the outwardly extending tuck-in portion 23a of the sleeve. jIn sewing the line of stitching 39, the needle of the sewing machine tends to become heated `due to friction, tending to melt the asphalt 11 between the paper strip 9 and the polyethylene 5, the melted asphalt tending to run into and plugging the needle holes. Omission of paper layer 4 and asphalt between the margins 3a and 5a of the burlap and polyethylene makes it easier to sew the top seam 39, particularly at the right-hand end of the upper margin of the bag where there is of necessity a considerable thickness of paper, 'polyethylene and burlap.

Thus, the bag B 'as completed (see FIGS. 9 'and 10) has 'a valve at the right-hand corner at its upper end,

the valve being constituted by the intucked valve flap 31 at this corner and by the paper sleeve Y23 extending from the valve flap. The sleeve includes the reversely folded tuck-in portion 23a extending out of the bag adapted after the baghas been filled by means of a lilling spout extending through the sleeve and into the bag to be folded up and tucked in to close the sleeve. The inside of this tuckin portion 23a bears the polyethylene coating 25. 'Ihe Sleeve is adhesively secured to valve ap 31 throughout `the width of the sleeve. This adhesive securement is present during the manufacture of the bag to hold the sleeve 'in proper position during the formation of the valve and the sewing of the end of the bag.

In view of the above, it will be seen that the several Objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the inventi'on, Vit `is intended that all matter contained in the above `description or shown in the accompanying drawings 'shall be Vinterpreted as illustrative and not in a limiting sense.

I claim:

l. A bag comprising a rectangular blank of material -consisting of an outer layer of burlap, an intermediate layer of paper and an outer 'layer of flexible sheet polyethylene laminated by means of asphalt, said blank being folded in half on a fold line which constitutes one side of the bag with the polyethylene layer on the inside and having sewn seams at the bottom, the top and the other side, said blank having a strip of paper laminated to the polyethylene by means of asphalt extending completely around the upper margin of the bag on the inside thereof, said bag having a valve constituted by an intucked valve ap at the corner thereof situated at the upper end of the folded side of the bag and a paper sleeve extending from the valve flap, said valve flap having a central fold spaced from the upper end of the bag, said sleeve being folded in half on a generally central fold in line with the central fold of the valve ap, an end poition of the sleeve lapping said paper strip and being secured thereto by adhesive, the upper margins of the sleeve being stitched together by the bag top seam.

2. A bag as set forth in claim l wherein the adhesive which secures the sleeve to the valve flap is on one face of the sleeve and the other face of the sleeve is coated over its entire area with polyethylene.

3. A bag as set forth in claim 1 wherein the sleeve is folded back on a transverse fold line located inward of the inner end edge of the valve ap to have a tuck-in portion extending out through the valve ap, the upper margins of said tuck-in portion being stitched together by a continuation of the bag top seam.

4. A bag as set forth in claim 3 wherein the adhesive which secures the sleeve to the paper strip is on one face of the sleeve and the other face of the sleeve is coated over its entire area with polyethylene so that the inside of the tuck-in portion of the sleeve is polyethylenecoated.

5. A bag as set forth in claim l wherein the paper layer and the asphalt laminant terminates short of the upper edges of the burlap and polyethylene layers, leaving unlaminated upper marginal portions of the burlap and polyethylene layers, the stitching for the bag top seam extending through said unlaminated upper marginal portions.

6. A bag as set forth in claim 5 wherein the upper edge of the paper strip is generally coincident with the upper edges of the burlap and polyethylene layers and the asphalt laminant for the paper strip and polyethylene layer extends throughout the width of the paper strip.

7. A bag comprising a rectangular blank of material consisting of an outer layer of cloth, an intermediate layer of paper and an outer layer of flexible sheet plastic laminated by means of a laminant, said blank being folded in half on a fold line which constitutes one side of the bag with the plastic layer on the inside and having sewn seams at the bottom, the top and the other side, said blank having a strip of paper laminated to the plastic by means of a laminant extending completely around the upper margin of the bag on the inside thereof, said bag having a valve constituted by an intucked valve ap at the corner thereof situated at the upper end of the folded side of the bag and a paper sleeve extending from the valve flap, said valve flap having a central fold spaced from the upper end of the bag, said sleeve being folded in half on a generally central fold in line with the centrol fold of the valve flap, an end portion of the sleeve lapping said paper strip and being secured thereto by adhesive, the upper margins of the sleeve being stitched together by the bag top seam.

8. A bag comprising a rectangular blank of multi-ply material including an outer ply of flexible sheet plastic laminated by means of a laminant to the next adjacent ply, said blank being folded in half on a fold line which constitutes one side of the bag with the plastic ply on the inside and having sewn seams at the bottom, the top and the other side, said blank having a strip of paper laminated to the plastic by means of a laminant extending completely around the upper margin of the bag on the inside thereof, said bag having a valve constituted 6 by an intucked valve flap at the corner thereof situated References Cited in the file of this patent at the upper end of the folded `side of the bag and a UNTTED STATES PATENTS paper sleeve extending from the valve flap, said valve flap having a central fold spaced from the upper end 21511068 Weeks Aug' l 1950 of the bag, said sleeve being folded in half on a gen- 5 2595446 Brady c May 6 1952 orally central fold in line with the central fold of the 2635803 Hartman Apr' 21 1953 valve flap, `an end portion of the sleeve lapping said paper FOREGN PATENTS strip and being secured thereto by adhesive, the upper 448,011 Canada APL 20, 1948 margins of the sleeve being stitched together by the bag top seam. 1()

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2517068 *Sep 8, 1947Aug 1, 1950Bemis Bro Bag CoFolded-in bag valve with sleeve insert
US2595446 *Sep 4, 1948May 6, 1952Bemis Bro Bag CoValved bag and its manufacture
US2635803 *May 2, 1950Apr 21, 1953St Regis Paper CoValve bag
CA448011A *Apr 20, 1948St Regis Paper CoHeat sealing
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4344558 *Jul 7, 1980Aug 17, 1982St. Regis Paper CompanyPinch bottom valve bag
US4382538 *Sep 26, 1980May 10, 1983St. Regis Paper CompanyValved lined container
Classifications
U.S. Classification383/50, 383/116, 383/56
International ClassificationB65D30/24
Cooperative ClassificationB65D31/142
European ClassificationB65D31/14A