US2092858A

US2092858A - Bag and method of making same

Info

Publication number: US2092858A
Application number: US715236A
Authority: US
Inventors: Charles F Richard
Original assignee: JOHNSON AUTOMATIC SEALER CO LT
Current assignee: JOHNSON AUTOMATIC SEALER CO LT; JOHNSON AUTOMATIC SEALER CO Ltd
Priority date: 1934-03-12
Filing date: 1934-03-12
Publication date: 1937-09-14
Anticipated expiration: 1954-09-14

Description

Sept. 14, 1937.

C. F. RICHARD BAG AND METHOD OF MAKING SAME Filed March 12, 1934 NEAT SEAL I I .\a

m m. V my PRESSED \y B Y 0%,Mm2/Y-MZ TTORNEK Patented Sept. 14, 1937 UNITED STATES BAG AND METHOD OF MAKING SAME Charles F. Richard, Battle Creek, Mich, assignor to Johnson Automatic Sealer Co., Ltd., Battle Creek, Mich., a limited partnership association of Michigan Application March 12, 1934, Serial No. 715,236

13 Claims.

This invention relates to bags and to methods of making bags, and is more particularly concerned with bags of polygonal cross section that are formed from unitary blanks of paper or like material.

It has previously been proposed to make a bag of this general character by folding a blank about a suitable mandrel, overlapping the end edges of the blank to form a seem in one of the sides of the bag, tucking and folding one side edge of the blank to form a bottom for the bag, and then sealing the seam and bottom by the use of adhesive or, where the material of' the blank is self-sealing, by the application of heat. Bags have also been constructed by wrapping blanks about mandrels in such a manner as to form smooth continuous bottoms for the bags, all of l the seams lying in the side panels of the bags and being formed by overlapping and sealing the side edges of the blanks. However, in all of these bags provided with overlapping seams much difdculty has been experienced in attaining a sufficiently tight seal at the seams to render the bags moisture-, airand sift-proof, particularly when said bags are used for food products of various kinds and as liners for cartons. Where the efficiency of the seal at the seams of a bag depends entirely upon the degree of adhesion between overlapping portions of the blank, the smallest imperfection in said adhesion renders the seal practically ineffective, and far greater care must be exercised, resulting in greater expense, in making such a seam than if the emciency of the seal were obtained by some other 3 factor in addition to adhesion between portions of the blank.

It is therefore one of the objects of the present invention to provide a bag of novel construction formed from a unitary blank of material and having seams lying only in the sides thereof, said seams being efficiently sealed in an improved manner against the passage of air, moisture and the material with which the bag may be filled.

Another object is to provide a new and eflicient method of making a bag from a single blank of material which is characterized by a novel manner of forming and sealing the seams of said bag.

A further object is to provide a bag of improvedconstruction wherein a more efiicient sealing of the seams is attained as the result of both a novel form of fold of the edges of the blank and adhesion between the folded portions. Still another object is to provide a novel method of making a bag from a unitary blank of 55 material wherein the seams are closed and sealed by folding the edge portions of the blank over and over upon themselves and then causing the folded portions to adhere to one another, which method also comprises a new manner of disposing of the blank material in excess of that actually utilized in forming the bottom and sides of the bag.

A still further object is to provide both a bag and a method of making the same which are improvements over the bags and bag making methods of the prior art and which result in a container especially well adapted for use either as a liner for cartons or as an individual package for products such as foods because of the high moisture-, airand sift-proof qualities of its seams.

These and other objects will appear more fully from a consideration of the detailed description of the invention which follows. While only one embodiment of the bag and method constituting the present invention has been illustrated in the accompanying drawing, it is to be expressly understood that this drawing is for the purpose of illustration only and is not to be construed as defining the scope of the invention, reference being had for the latter purpose to the appended claims.

Referring now to the drawing, wherein like reference characters indicate like parts throughout the several views:

Figs. 1-7 are diagrammatic illustrations of the successive steps involved in the method of making a bag according to the present invention, Fig.7 also showing the bag in its completed form.

For purposes of illustration, the drawing shows the various steps in the formation of a quadrilateral bag of rectangular cross section from a blank of self-sealing wax impregnated paper, although it is to be distinctly understood that the invention is not limited to bags of this particular shape or to blanks of waxed paper. Also, while the embodiment of the method illustrated involves the use of a mandrel of suitable construction to assist in the folding of the blank, it is obvious that the inventive concept of the method is not limited to the use of any specific apparatus. As shown in Fig. 1, the first formative step in the method of the present invention'involves the folding of a blank of suitable material, such as provides a smooth continuous bottom and two opposite smooth continuous sides l2 am. It for the bag. The blank 8 is preferably of such width that this first folding step leaves the side edge portions l4 and'l5 thereof projecting beyond the ,edges of the mandrel by amounts exceeding onehalf the width of the other two opposite sides It and ll of the mandrel.

After the blank 8 has thus been folded to a substantially U shape, the next step in the method, indicated in Fig. 2, comprises engaging the blank at substantially the centers of the edges of those parts of projecting edge portions l4 and I5 forming the bight of the U, as at points i8 and I9, and exerting at said points a-downward force tending to narrow the distance between the adjacent vertical portions of each side edge of the blank. At the same time, and while maintaining the downward pressure at points I 8 and IS, the opposite portions of each of projecting edge portions II and I5 of the blank are brought together and creases are made in the blank against mandrel sides l6 and I! along parallel lines 20, 2|, 22, 23, 24, 25 26 and 21, as shown in Fig. 3. This second creasing or folding operation forms the other two

opposite sides

28 and 29 of the bag and leaves each of said sides with a double thickness of paper, indicated at 30 and 3|, extending outwardly at right angles to the plane of said side, and with a

triangular flap

32, 33 coplanar with said side and extending downwardly below the bottom of the mandrel.

At this phase of the method, it will be noted that the bottom and each of the four side faces of mandrel II are covered by a single thickness only of the blank material, and that each of the side edges of the blank is doubled with the doubled portions of each edge lying together and parallel to the lines 20-21 along which the blank is creased.

The next-step in the method according to the present invention is to close the seams of the bag thus provided in sides 28'and 2! by folding the outwardly projecting double thicknesses 30 and 3| over and over upon themselves and then flattening the over-and-over folded portions into the planes of the associated sides of the bag. These folding and flattening operations are indicated in Figs. 4, 5, and 6.-

In Fig. 4, the outer halves of projecting edge portions 30 and 3| of double thickness are shown folded through an angle of while in Fig. 5 the folding has been continued through an angle of so that the side edges of the blank lie closely adjacent the blank:

material forming sides

28 and 29 of the bag, leaving a quadruple thickness of blank material extending perpendicularly to each of said sides. Fig. 6 shows the thus folded seam portions folded through another angle of 90 and flattened substantially into the planes of

sides

28 and 29. -It will be noted that the side edges of the'blank now lie covered by the folded seam portions. It is to be understood that projecting edge portions III and 3| may be made proportionately longer than those shown in the drawing, andlor the first folds therein may be 'made nearer to the edges, if it should be desiredthat more than three 90 folds be made in the folded seam portions.

The formatiosrof the bag may becompleted by folding

triangular flaps

32 and 33, and the overlying portions of folded and" flattened edge portions 30 and 3|, baekwardly through 180 into the planes of their associated

sides

28 and 29. Pressure may now be applied to the folded seam portions and backwardly turned flaps to tightly compress the overlying thicknesses of the ball material and sharply crease all of the folded edges thereof.

Due to the novel manner of forming the folded seams just described, wherein the doubled portions of the side edges of the blank lie together and covered by the folded portions of the blank, the seams of the bag are rendered practically sift-proof, and even moisture-proof and air-proof to a substantial extent. However, in order to increase the latter two qualities to a maximum, the method of the present invention also includes the formation of an adhesive seal between the various overlying thicknesses of the blank material in the folded seam portions and backwardly turned flaps. Q

Where the blank 8 is of waxed paper, as in the embodiment disclosed, the adhesive sealing may be readily attained by applying pressure and heat to the desired portions for a sufficient time to cause adhesion of the overlying thicknesses one to the other through the medium of the sealing material with which the blank is impregnated, as indicated by the legend in Fig. 'I. When the heat sealed portions have cooled sufficiently to vset, the completed bag may be removed from mandrel l l ready for use either as the inner liner for a carton or as the sole container for any desired material.

There is thus provided by the present invention both a bag of novel construction and a simple and eflicient method of making such a bag from a single blank of material, both of which are characterized by the high quality of the seals at the portions of the bag where the edges of the blank are joined and folded. The bag provided by the present invention has a smooth continuous bottom and all but two smooth continuous sides, the two discontinuous sides containing all of the seams necessary for the formation of the bag. These seams are formed by a novel method of creasing and folding the side edge portions of the carton blank, and the high degree of tightness of the seams is attributable both to said folding and to an adhesive sealing of the folded and overlying portions of the blank. .By thus rendering the efficiency of the seal dependent upon both folding and adhesion, rather than upon adhesion alone, the bag and bag forming method of the present invention constitute marked improvements over the bags and methods previously known to the art, and provide a container which, because of its high moisture-, airand sift-proof qualities, is especially well adapted for use either as a liner for cartons or as an individual package for products such as foods.

It will be obvious that the invention is not limited either to the exact form of bag shown in the drawing or to the specific steps of the method disclosed, but is capable of a variety of embodiments. For example, the bag may be of any desired polygonal cross section, other than rectangular, and may be made from any suitable material in addition to wax impregnated paper. Likewise, the steps of the method may be carried out independently of apparatus of any specific character, such as the mandrel shown, and may be employed in the formation of bags of shapes and materials in addition to those specifically disclosed. Various other changes, which will now appear to those skilled in the art, may be made both in the form and details of construction of the bag and in the various steps of the method of making the same, without departing from the spirit of the invention. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. A bag of polygonal cross section made from an integral blank of material comprising an open top, a smooth continuous bottom and at least two opposite smooth continuous sides, each of two other sides having therein an over-and-over folded, sealed seam wherein the edges of the blank lie together and covered by the folded portion thereof, each of said folded seam portions lying in substantially the same plane as the associated side of the bag. s

2. A bag of polygonal cross section made from an integral blank of material comprising an open top, a smooth continuous bottom and at least two opposite smooth continuous sides, each of 'two other sides having therein an over-and-over folded, sealed seam lying in substantially the same plane therewith and a triangular flap folded back from the bottom edge into the plane of said side, the edges of the blank lying together and covered by the folded portions thereof.

3. A bag of polygonal cross section made from an integral blank of waxed paper comprising an open top, a smooth continuous bottom and at least two opposite smooth continuous sides, each of two other sides having therein a seam consist'ing of a double thickness of the blank material folded over upon itself, flattened into substantially the same plane as the associated side of the bag, and sealed through the medium of the wax with which the paper is impregnated, and wherein the edges of the portions of the blank forming said seams lie together.

4. A quadrilateral bag made of self-sealing material comprising a unitary blank folded on two transverse lines to form a smooth continuous bottom and two smooth continuous sides, the parallel side edges of the thus folded blank being brought together and folded over to form seams in the other two sides wherein the side edges of the blank lie together, said seams lying in substantially the same planes as the associated sides of the bag and being substantially hermetically sealed.

5. A quadrilateral bag comprising a unitary blank of material folded on two transverse lines to form a smooth continuous bottom and two smooth continuous sides, the parallel side edges of the thus folded blank being brought together and folded over and over to form seams in the other two sides, and a triangular flap folded back from the bottom edge into the plane of each of said seamed sides and overlying a portion of the seam formed therein, said over-and-over folded seams being substantially hermetically sealed and said flaps being sealed to said seamed sides.

6. A bag made from an integral blank of material comprising an open top, a smooth con tinuous bottom and sides which are smooth and continuous except for a pair of opposite, overand-over folded, sealed seams wherein the edges of the blank lie together and covered by the folded portion thereof, each of said folded seam portions lying in substantially the same plane as the associated side of the bag.

'7. A bag made from an integral blank of selfsealing material comprising an open top, a smooth continuous bottom and sides having therein a pair of diametrically opposite seams, each of said seams consisting of a double thickness of the blank material folded over and over upon itself, flattened into substantially the same plane as the associated side of the bag, and sealed with the side edges of the blank lying together in said seam.

8. The method of making a bag from a unitary blank of material which comprises folding said blank into substantially U shape to form a smooth continuous bottom for the bag, bringing the adjacent edge portions of the blank together and folding them along parallel lines to form the sides of the bag and to provide the bag with a pair of opposite seam portionseach consisting of a. double thickness of blank material extending outwardly from the bag, folding each of said double thicknesses over upon itself to close the seams, flattening each of the thus folded seam portions into the plane of the associated side portion of the bag, and adhesively scaling to one another the overlying thicknesses of said folded and flattened seam portions.

9. The method of making a bag of polygonal cross section from a unitary blank of material which comprises folding said blank along two parallel transverse lines into substantially U shape to form the bottom and two sides of the bag, bringing the adjacent edge portions of the blank together and folding them along parallel lines to form the other sides of the bag and to provide each of two of said sides with a double thickness of material extending laterally outwardly from the center line thereof, folding each of said laterally extending, double thicknesses over' upon itself to close the seams of the bag, and flattening the thus folded portions into the planes of the associated sides.

10. The method of making a bag of polygonal cross section from a unitary blank of material which comprises folding said blank along two parallel transverse lines into substantially U shape, engaging the material at the middle of the edges of the bight of the U and exerting a downward force thereon while bringing the adjacent edge portions of the blank together and folding them along parallel lines to form the other sides of the bag and to provide each of two of said sides with a double thickness of material extending laterally outwardly from the center line thereof andwithatriangular flapextending downwardly from the bottom edge thereof and lying in the same plane therewith, folding each of said laterally extending double thicknessesover upon itself to close the seams of the bag, and flattening thethusfolded portions and turningthetriangular flaps back through 180 into the planes of their associated sides.

11.- The method of making a bag of polygonal cross section from a unitary blank of material which comprises folding said blank along two parallelv transverse lines into substantially U shape, engaging the material at the middle of the edges of the bight of the U and exerting a downward force thereon while bringing the adjacent edge portions of the blank together and folding them along parallel lines to form the other sides of the bag and to provide each of two of said sides with a double thickness of material extending laterally outwardly from the center line thereof and with a triangular flap extending downwardly from the bottom edge thereof and lying in the same plane therewith, folding each of said laterally extending double thicknesses over upon itself to close the seams of the bag, flattening the thus folded portions and turning the triangular flaps back through 180 into the planes of their associated sides, and adhesively sealing the seams and folded flaps.

12.Themethodofmakingabegfromaunitary blank of self-sealing material which comprises folding the blank about three of the faces of a mandrel of quadrilateral cross section to form the bottom andtwo of the opposite sidu of the bag, the side edges of the blank projecting beyond the edges of said three faces of the mandrel, folding said projecting side portions of the blank against the other two opposite faces of the mandrellmtilthelatterareeoveredbyasinglethickness only of the blankmaterial to form the other two sides of the bag, the material in excess of that necessary to cover said faces extending at right angles thereto with the edges of the blank outeredge portions of the blank projecting beyond the edges of the mandrel by amounts exceeding onehalf the width of the other two opposite sides thereof, engaging the projecting edges of the portion of the blank forming the bottom of the bag and exerting thereon a downward force while bringing the parallel projecting edge portions of the blank together and creasing them against the mandrel to form the other two opposite sides of the bag, said creasing operation leaving each of said last named sides with a double thickness of paper extending outwardly atrlght angles thereto and with a triangular flap coplanar therewith extending downwardly below the bottom of the mandrel, folding each of said outwardly extending double thicknesses of paper over upon itself through 180 to close the seams of the bag, flattening said folded seam portions into the planes of the associated sides, turning the triangular flaps back through 180 into the planes of said sides, and sealing the overlying thicknesses of paper in said folded seam portions and backwardly turned flaps to one another and to said bag sides by the application of heat thereto.

CHARLES F. RICHARD.