US3243099A

US3243099A - Tape closure for gusseted bags

Info

Publication number: US3243099A
Application number: US433762A
Authority: US
Inventors: Howard J Winegard
Original assignee: Union Bag and Paper Corp
Current assignee: Union Bag and Paper Corp
Priority date: 1965-02-18
Filing date: 1965-02-18
Publication date: 1966-03-29
Anticipated expiration: 1983-03-29

Description

March 29, 1966 H. J. WINEGARD TAPE CLOSURE FOR GUSSETED BAGS Filed Feb. 18, 1965 INVENTOR HOWARD J. WINEGARD BY (M K @IMW ATTORNEY United States Patent Office I Patented Mar. 29, 1966 3,243,099 TAPE CLGSURE FOR GUSSETED BAGS Howard J. Winegard, Trenton, N .11, assignor to Union Bag-Camp Paper Corporation, New York, N.Y., a corporation of Virginia Filed Feb. 18, 1965, Ser. No. 433,762 4 Claims. (Cl. 229-62) The present application is a continuation-in-part of copending application Serial No. 397,749 filed September 27, 1964, now abandoned.

This invention relates to new and useful improvements in end closures for gusseted tubes or tubular bags having a pasted tape over the end of the tube or bag. More particularly it pertains to cut out portions on each side of either the front or back walls or both of such walls of the tube to permit the adhesive of the tape to bond to the gussets in the side walls of the bag.

Heretofore, it has been conventional practice in the case of gusseted tubes or bags having a flush-cut end to sew such end. In some cases a pasted tape is applied over or under the sewing line. It has not been possible to close and seal the end of such tubes or bags with only a pasted tape because the rough handling of such filled tubes or bags would dislocate the gussets at the end and cause leakage. In some instances where only a pasted tape is used it has been necessary before applying the pasted tape to either seal the inner faces of the tube or bag at the end or to fold over and paste Such end. It is an object of the resent invention to provide an improved method of closing and sealing the end of such blanks with a pasted tape so that the walls in the gussets are adequately secured. Such method eliminates the necessity of using sewing lines, inner sealing or folding over of the end. Since the sewing line has always caused a weakening of the paper at the sewing line, the present method provides a distinct advantage in this respect. Furthermore, the present method permits utilization of the full length of the tube, which is not possible with sewing or folding over of the end, and has less material in the tube or bag construction than any pasted or sewn closure presently on the market.

A further object of the invention is to provide a novel method of closing and sealing an open end, whereby the sealed end will be cut out in both the front and back walls or one of such walls next to the gusset area so that the sealed bag or tube will be substantially flat and rectangular in configuration have a very neat appearance.

A further object is to provide a novel method of. closing bag ends which is particularly applicable to bags of the intucked type, wherein the bag end walls are pressed into flatwise relation with the edge walls intucked between the front and back walls, both the front and back walls or one of such walls are cut out next to the gussets, and a strip of tape is then folded over the end edges of the flattened bag end walls and adhered thereto.

A further object of the invention is to supply to a customer a bag which has the tape aflixed thereto so thatthe customer can fill and seal the .bag with a siftproof closure Without needing or employing sewing machines or any other closing materials.

Another object of the invention is to provide a tape closure which lends itself to the use of a tear strip for quick opening of the closureaud the end of the bag.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the article possessing the features, properties, and the relation of elements, which are exemplified in the following detailed disclosure,

and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective elevational view having the cutout areas of the front and back walls and the partly applied tape closure at an end of a tubular bag of multiply construction;

FIGURE 2 is a view of the embodiment of FIGURE 1 with the tape completely sealed;

FIGURE 3 illustrates a sectional view taken through line 3-3 of FIGURE 2;

FIGURE 4 illustrates an embodiment in perspective of the closure system of the invention applied to an automatic bottom bag;

FIGURE 5 illustrates an embodiment in perspective of the closure of the invention applied to a square or folded bottom bag; and

FIGURE 6 is a perspective elevational view of the upper portion of a bag having the cutout areas of the front wall and the partly applied tape closure at the upper end of the bag.

In FIGURE 1 there is shown a 3-ply tubular bag 11 having front and back opposite walls 1-2 and 16, respectively, and two gusseted side walls 14 with median fold lines 14a. Four indented cutout portions, two in front wall 12 and two in back wall 13, are represented by the numeral 15 and are located at the upper edge of the wall. Such cutouts 15 are positioned in this illustration between the median fold lines 14a and the outer edges of the

walls

12 and 13. The tape closure 16 is adhesively coated on its inner surface 17 which contacts the outs de of the top portions of the front and back walls of the bag to provide a sealed closure. The critically located indented cutout portions in the front and back walls are so dimensioned as to permit the adhesive inner surface of the tape to preciseiy contact the inner surface of each side of the infolded gusset and to thereby hold the gusset in positively sealed relation to the front and back walls, and to thereby prevent any dislocation of the gusset when the bag is filled. The adhesion in this precise location prevents leakage of the bag contents at the side wall-top edge seal which invariably occurs when the tape of the conventionally'tape sealed bag is fitted over the gusset. The gussets are not usually sealed and the walls fold outwardly under the pressure of the contents of the bag thus limiting its utility. In this illustration the bottom end of the bag has the same closure as the top.

In FIGURE 2 the top is shown with the tape sealed in place. The broken lines show the cutouts in relation to the median gusset fold line 14a and how the gusset portions are exposethby means of the indented cutout portions of the front and back walls, to the adhesive surface I of the closure tape.

FIGURE 3 shows a sectional view of the tape sealed end taken through lines 3-3 of FIGURE 2, and illustrates the 12 plies of a three-ply tubular bag being held in effective sealed relation by means which do not require the installation of additional expensive machinery or any complex steps of ply separation or partial removal.

FIGURES 4 and 5 show how the top closure of the only made in the front wall 12. In this case the bottom end of the bag may have the same closure as the top or may have the bottom closure illustrated in FIGURES l, 4 or 5.

In the manufacture of the bag with the top closure of FIGURE 1 it is necessary to apply the tape 16 to the top edge of the back wall 13 in such manner that the adhesive within the cutout areas in such wall will not adhere to the adjacent side walls of the gussets. If such gusset side walls are adhered to the tape through the cutouts, the mouth opening of the bag is reduced so that in some cases it may be difiicult to fit the bag onto a filling spout of a bagging machine. Furthermore, after the bag with the top closure of FIGURE 1 is filled by the packer it will be necessary to react the adhesive on the tape so that the side walls of the gussets are adhered to the tape through all four cutouts. If heat sealing is used it necessitates the application of heat and pressure to both the front and back walls along the folded over tape. With the proper equipment and methods the manufacture and closure of the bag with this construction may pose no problems.

If the problems described in the preceding paragraph do arise, it has been found by tests that the top closure shown in FIGURE 6 will sufiice in most cases. The cutouts 15 are made in the wall opposite the tape. This simplifies the application of the coated tape since there is no danger of bonding the adjacent side walls of the gussets to the tape and restricting the size of the bag mouth. After the bag is filled and the tape folded over the opposite wall having the cutouts, the tape is adhered to such wall and to the adjacent side walls of the gussets through the cutouts. It has been found that, although only one side wall of each gusset is in efiect secured to the adjacent front or back wall, the gussets are sufiiciently held in place so that in most instances they will not pull away and expand when the bag has been filled and closed.

In some cases the packer may wish to apply the tape after the filling of the bag as part of his closing operation. In these instances the manufacturer of the bag can supply the bags with the cutouts in both front and back walls as shown in FIGURE 1 or only in one Wall as in FIGURE 6. The packer then fills the bag, applies the tape over the ends of the front and back walls, and adheres it to such Walls and the side walls of the gussets, thus completing a closure as heretofore described.

The closure herein described is particularly well suited for the inclusion of a tear strip in the tape so that the end of the bag can be easily opened to remove the contents of the bag. Such strip, which may be of cord, plastic tape or like material, is illustrated in FIGURE 1 and designated 18. To facilitate grasping such strip a pair of slits 19 have been made in the tape adjacent such strip. It will be apparent that the pulling of such strip completely opens the bag, which is not possible with other forms of taped closures.

From the foregoing description of the figures it will be seen that the various embodiments of the invention each provides a novel, economical, and most satisfactory system of tape closure for a tubular bag body or blank which is adapted for use with every difierent type of gusseted multiply bag.

The prior art has, of course, recognized that the tape closure of multiply bags presents a problem if the requirernent of siftproof sealing in all areas, including gusset areas, is to be achieved in the commercially manufactured bags. The gussets of multiply bags infold the edges to multiply the number of thicknesses of material. A fourply gusseted bag has sixteen thicknesses of material at each infolded edge, and the present invention illustrates a three-ply gusseted bag in which no stitching step is followed in order to close the bag and in which only the precut tape is adhesively secured in overlapping relation to the aligned straight top edges of the front and back walls.

Heretofore, this problem of sealing multiply, gussetedtype bags without resorting to stitching of the gusseted areas has been solved by stepping the wall structures either completely across the bag or only in the infolded gusset areas. In any case such stepping operation requires the cutting and removal of pre-selected areas of the plies. The US. patent to Allen, No. 2,757,855, illustrates an approach to the problem which requires the manufactured bag to be modified by cutting only certain plies in pre-selected areas. This approach requires special bag making machinery and makes high speed production difficult. Furthermore, it is still necessary to fold over the end of the bag before applying the tape which increases the paper cost for the bag because of the extra tube length.

Although reference has been made in the figures and description to multiply bags Where extra thicknesses result from the number of plies of paper, it should be understood that the cutouts of the present invention can also be used for bags with a single wall. The problem with a single wall bag may not be as great as with a multiply bag but there is still the danger that the gussets will pull out of a filled bag. Consequently the gussets in either a single wall or multiply bag are retained in proper position by the cutouts herein described.

The present invention solves the problem of closure of gusseted-type bags without stitching and eliminates the tendency of the inner walls of the gussets to pull away and to expand when the bag is filled. On the conventional bag manufacturing machine there need only be added a simple cutting attachment to remove a segment, a major portion of such segment being located between the edge fold line and the medial inner fold line of the gusset, ie the cutout can extend partially beyond the median fold line of the gusset into the central area of the tube. The tape is so dimensioned in width that it will reach beyond the maximum depth of cut in the cutout portion. It will, of course, be understood that such segment can be square, rectangular or other shape, although the arcuate form is simple to make on a conventional tuber or bag machine.

Any suitable adhesive may be used; it may be of the well-known pressure-sensitive type for small bags and small loads, or it may be the same adhesive which is used to make the multiply tube. An example of a pressure-sensitive adhesive is a rubber latex type. A sodium silicate adhesive used to make grocery bags is an example of a conventional water-base type of evaporating or air drying adhesive. Thermoplastic adhesives may be used to provide a heat-sealing type, thus permitting precoated tape to be provided.

Since certain changes in carrying out the above process, and certain modifications in the .article which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to. fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a tubular bag structure having opposite front and back walls joined along edge fold lines to side walls which are infolded along inner medial fold lines extending the length of the bag to form gussets at each side of the bag, that improvement comprising cutouts at an end of the bag in each corner of both said front and back walls, said cutouts having a major portion positioned between the edge fold lines and the medial fold lines, and a closure tape at the said end of the bag in adhesive overlapping relation about said front and back walls, portions of said tape adhesively engaging the inner walls of the gussets on each side of the bag through the cutouts at front and back walls, said tape having a tear strip secured to it to provide an opening means for the bag.

2. In a tubular bag structure having opposite front and back walls joined along edge fold lines to side walls which are infolded along inner medial fold lines extending the length of the bag to form gussets .at each side of the bag, that improvement comprising cutouts at an end of the bag in each side of the bag, each cutout being positioned in one of said front and back walls and having a major portion positioned between the edge fold lines and the medial fold lines, a closure tape adhesively secured at said end of the bag to either the front or back Wall and adapted to be folded over said end and adhesively secured to the opposite wall whereby portions of the tape will adhesively engage the inner walls of the gussets on each side of the bag through the said cutouts and a tear strip embodied in the tape and positioned to coincide with the tape fold line when the tape is folded over the end of the bag, whereby said strip will permit easy opening of the end of the bag.

3. In a tubular flexible bag structure having a front wall, a back wall and adjoining side walls, edge fold lines connecting said front, back and side walls, said side walls each being infolded along an inner median fold line to form a gusset which extends the length of the bag, cutouts at an open end of the bag in the front wall edge adjacent the edge fold lines of the bag, each cutout having a portion between the edge fold line and the median fold line, and an elongated closure tape adhered along its inner surface to the said open end of the bag, said tape embracing said front and back Walls in overlapping relation with portions of said inner surface of said tape adhesively engaging the areas of the gussets on each side of the bag underlying the cutouts.

4. In a tubular flexible bag structure having a front wall, a back wall and adjoining side walls, edge f-o'ld lines connecting said front, back and side walls, said side walls each being infolded along an inner median fold line to form a gusset which extends the length of the bag, cutouts at an open end of the bag in the front Wall edge adjacent the edge fold lines of the bag, each cutout having a portion between the edge fold line and the median fold line, and an elongated closure tape adhered along a portion of its inner surface to the back wall and adapted to be folded over the said open end of the bag and adhered to the said front wall with portions of said inner surface of said tape adhesivly engaging the areas of the gussets on each side of the bag underlying the cutouts.

References Cited by the Examiner UNITED STATES PATENTS 2,146,831 2/1939 Maxfield 53-28 2,272,530 2/ 1942 Patterson 53-28 2,527,073 10/1950 Port 22966 2,923,457 2/1960 Gerard 229-66 3,047,206 7/ 1962 Monahan et al. 2296 6 3,079,066 2/ 1963 Roop 22962 3,128,936 4/ 1964 Sprosty 229--62 JOSEPH R. LECLAIR, Primary Examiner.

DAVID M. BOCKENEK, Assistant Examiners.

Claims

1. IN A TUBULAR BAG STRUCTURE HAVING OPPOSITE FRONT AND BACK WALLS JOINED ALONG EDGE FOLD LINES TO SIDE WALLS WHICH ARE FOLDED ALONG INNER MEDIAL FOLD LINES EXTENDING THE LENGTH OF THE BAG TO FORM GUSSETS AT EACH SIDE OF THE BAG, THAT IMPROVEMENT COMPRISING CUTOUTS AT AN END OF THE BAG IN EACH CORNER OF BOTH SAID FRONT AND BACK WALLS, SAID CUTOUTS HAVING A MAJOR PORTION POSITIONED BETWEEN THE EDGE FOLD LINES AND THE MEDIAL FOLD LINES, AND A CLOSURE TAPE AT THE SAID END OF THE BAG IN ADHESIVE OVERLAPPING RELATION ABOUT SAID FRONT AND BACK WALLS, PORTIONS OF SAID TAPE ADHESIVELY ENGAGING THE INNER WALLS OF THE GUSSETS ON EACH SIDE OF THE BAG THROUGH THE CUTOUTS AT FRONT AND BACK WALLS, SAID TAPE HAVING A TEAR STRIP SECURED TO IT TO PROVIDE AN OPENING MEANS FOR THE BAG.