US2536529A - Method of producing bags with opening means - Google Patents

Description

2 Sheets-Sheet l R mm lt SAMUEL BERG STEIN- a INVENTOR.

S. BERGSTEIN METHOD OF PRODUCING BAGS WITH OPENING MEANS Jan. 2, 1951 Filed Aug. 9, 1944 Jan. 2, 1951 s. BERGSTEIN METHOD OF PRODUCING BAGS WITH OPENING MEANS 2 Sheets-Sheet 2 Filed Aug. 9, 1944 iQE Patented Jan. 2, 1951 2,536,529:- METHOD or PRODUCING BAGSWI'TH OPENING MEAN Samuel Bergstein; Cincinnati, Ohio; assignor to Robert Morris Bergstein and Frank" David Bergstein, trustees Application August 9, 1944; seriaiNb. 548;652'

4 Claims. 1

The inventionrelates to th'e' problem of facili tating'the removal of the contents of: a bag or" liner." by the user.- lts'prin'cipal object has to do with the provision of means for the ready removal of the liner" closure or seal, in whole or in'part;

Another object o f the invention is the attainment of the" objective just'mentioned, while retaining the integral nature ofthe bag or liner, so that its protective characteristics are not sacrificed; Yet another object'is the provision of a; method whereby such liners" or bags may bema'de conveniently a'ndinexpensively; as hereinafter set forth,

My invention is particularly adapted for use in" connection with lined containers such as are shown in the Robert M. Bergstein Patents 2,099,257, of November 16, 1937, and2,250,24=9, of July 22, 19 11, madeby the methods disclosed in Reissue Patent No. 20,789, of'July12, 1938, and by mechanisms such as are shown in Patent 2,114,621, April 19', 1938; and Patent 2,166,388, of July 18, 1939. However, the invention is not limited to any particular types" of lined containers, but isequall suited for use'with other types or for use with separate bags as'such; as will become apparent as the description proceeds.

These and other'objects of my invention, which will'beset forth hereinaftero'r will be apparent to one skilled in the art upon reading" these specifications, I accomplish in that construction and arrangement of partsand in that procedure, ofwhich I shall novwdescribe exemplary embodimerits.-

Referring to the drawings:

Figure 1 is a diagrammatic plan view of a section of, one form of bagmach ne, showing the devices for performing m'y 'invention. incorporated therein;

Figure 2 shows asectioriofabag machine with an alternate form of my device incorporated therein.

Figure 3 is a partial sectional viewtaken along the line 3.--3 of Figured;

Figure 4C a partial sectional view" taken along tfie=line 4l--4 of Figure-"L Figure 5 isapartial sectional view taltenalong' theline 5-'-5 ofFigureZ.

Figure 6 shows a has prepared inaccordance with my invention imposed on a carton blank as taughtin Patent 2,259,249.

t Figure is the flat; prelinedlzcarton of 'the type shown in Batent 2 ,250;2-49 previcu'siy'mentieneo; hutembodyingmy invention.-

Figure: 83' showercontainenzsuchiasillustrated inFi'giire-l; after it-has been set up, filled, sealed, shipped and partially opened by the user, that is; the top flaps have been folded back intoopenposition; exposing the sealed liner, which now must be opened.

Figures 9, 10 and 11 illustrate steps in the operation of removing the sealed-end of the-liner in accordance" withthe present invention.

Figures 1213- and 14am a" similar series otviews sho'wing the operation of opening the liner when the linenhasbeen treated as l'iereinafter expained in connection with" Figure 2;

Briefly, in the practice of my invention; I have found that its objects may be attained by forming apredetermined line of weakening in the wane of a bag orliner sothat they will tear readily along" thepredetermined line, and then" coating said weakenedline including a contiguous" area" of the bag walls with a film-forming substance capableof bonding; tightly with the said walsand capable of filling or closing perfora-- tion'sin the-'weakenedline; or forming a tenacious membna'ne thereover, thus preserving the proofness of thebag walls inspiteo'f the line of weak ening. The line or lines of weakening may be configured as hereinafter set forth. They may be continuous so as completely to define a 1 line for severance; or, in materials hard to tear at a folded edge" but readily torn after initial severance; they may merely be located tostar't a linepi'tean The applied film will be such thatit' will severalong the weakened" lines in'the base w'eb'or bag'wall. The filmmay be colored. to call attention-to theline or lines of weakening;

In Figure l is shown a section of a bag machine into which section unit length tubes are beingdeliveredat the left'handend or the draw ing from a tubing deviceinot shown). As they enter the illustrated'ma'chine section, the" cut-tolengthtubesare-picked up by lugs 51 on the chains 56,and' so are carried in timed relation to positively driven frictionally surfaced: upper and lower belts 58- which continue to carry the tubesin-timed relationship. Duringtheir course" of" traveL-the tubes may be closed at one end! to iormbagsieithen by folding or sealing or otherwise,- as desctibedin-Patent-2.114;621 previously v mentioned.

The mechanism forperforming the present ingamma 1ower anvil roll 6t mounted r at 1!! in Figure 1. The film-forming substance is preferably one will be driven from the machine drive in such a way that the peripheral speed of the rolls will match the speed of travel of the bag tubes as moved by the conveyor means 58.

ticularly in view of the nature of the material from which the bag tubes are made. and heavy mat rals. it is sometimes possible to weaken them by cutting them part way through their thickness. The type of weak ning which I prefer is provid d by making slits of short length or tinv perforations, clos l spaced in the mat rial. These sli s are largely self-closing, so that when the subseouent coating material is applied, it will not strike through the slits to such an ext nt as eith r to adhere the walls of the bag together stron ly or to become disru ted and. therefore. no longer gas or liquid tight when the bag is forcibly openedv as in filling.

Having been provid d with a line or lin s of In thick maining on the rolls.

are thus coated with sealing substance, as in- V weakening as afor said, the bag tubes are next carried by means of the conveyor 58 to a device which applies over the lines of weak ning a stripe of film-forming substance. An annlioation roll, 63, is shown mount d on a shaft 64 iournal d on the side fra es of the machine. A lower roll 65 on a shaft 66 is shown as turning in a pan or reservoir 5 of the film-formine s bstance. A doctor or blade 68 controls the thickness of the layer of film-forming substance on the roll 65. In the ap aratus shown in Fi ure 1 and detailed in Figure 4, it will be evid nt that the roll 53 picks up a la er of the coating sub tance from the lower roll 65 in the intervals betwe n the passage of the bag tubes 69 so that as a bag tube pa'ss s between the rollers. a film of the sealing substance'is applied to'it on both sides in an area including the lin s of weakening. Such a stripe of film-forming substance is shown 50% parafiin wax (132 M. P.) V 50% micro-crystallin wax (Petrosene B-Socony Vacuum) V 1 2% ester gum, (melting point 154) lit will be und rstood that in Figure 4 a separate application of the film-forming substance may be made directly to the roll 63 from a separate pan of the substance and a transfer roll.

In Figure 2 I have shown an a paratus applied to the same type of machine for forming lines of weakening which extend diagonally across corner portions of the bag tube. This apparatus comprises. a roll H mounted on a shaft .12

jpurnaled on the side frames of the machine.

on the roll there is a perforating device 13 extending at an angle to the axis of the shaft. as shown. Dependinlg'upon the timing of the shaft in relation to the travel of thebag tubes, there may be one or more of these perforating devices.

- They operate against a lower roll 14 on a shaft similarly journaled and wide enough to serve as an anvil throughout the length of the diagonally arranged perforating device or devices. The bag tubes 69 are carried from this mechanism by the conveyor 58 to a coating or sealing mechanism comprising in this instance upper and lower rollsl and 15 on shafts H and i8 journaled in the side frames of the machine. Each such roll, as more clearly shown in Figure 5, has one or more raised, diagonally arranged printing surfaces, '59 or 80. These surfaces are arranged to be supplied with the sealing substance from rollers 81 and 32, turning in pans 83 and 8% of the sealing substance, through transfer rolls Siand 86. Doctors or blades,'8l and 83, control the thickness of the line of sealing substance re- The lines of perforation dicated at 89 in Figure 2.

r The lines of perforation formed in the bag tubes may be made before or after or concurrently with the formation ofeither of the end closure seams of the bag, and may be made at either or both ends of the bagtube. While I have illustrated in the drawings hereof right angle machines for treating unit length bag tubes, the skilled worker in the art in thelight of these teachings will be readily able to adapt the mechanisms shown to the treatment of an endless length of bag tube as it is being delivered from a tubing device, as in Patents 2,099,257 and Re. 20,789. or diagonally of rolls may be employed for-this purpose as well as spot printing devices appropriately shaped to apply the stripes of sealin adhesive. It is also possible to treat a strip of bag forming web so as. to provide appropriatelyrspaced lines of weakening therein and so as to seal these lines by an application. of filmforming sealing substance prior to the tubing of the strip. In such an operation, it is possible, if desired, to cause the stripe of sealing adhesive to be located inside the bag tube, as will be clear.

The lines of perforation and sealing films may be made across a preformed closure without impairing the closure. They may be made in bag walls prior to closure, and when so made will not interfere with the formation of the closure or the seal thereat. perforated or weakened prior to the formation of bagtubes and is then provided with the sealing films, the nature of the tubin operation becomes unimportant, and bellows-fold or intucked bag tubes may readily be made. Wherebags or bag tubes are first made andthen perforated, it is necessary to take precautions to insure that the sealing films cover the lines of perforation through their length. Hence it is most con sealed at that end prior to'the formation of lines of weakening and the covering thereof, as described, or whether the bag tubes shall be perforated and thereafter closed and sealed.

r The machine sections shown in Figures 1 and 2 ma be caused to deliver the ba tubes to apparatus for imposing them upon carton blanks and adhering them thereto, followed by the tubing of the carton blanks, as set forth in the patents to which reference has been made.

A bag tube 69 sealed at one end, as at 98, an having the sealed lines of weakening It, is shown Perforating devices located axially 7 Where bag material is" Figure 6 as imposed upon ai c'arton blank 's I.

This particular blank is one shown Patent 2,250,249 and istubed by bending it along score lines: intermediate the end walls: of the carton. The bag tubes, however, maybe applied to other types of carton and maybe sealed at one end or open at both ends'priorto such imposition. Fi ure 6' shows the application of adhesive, as at 92, so as to cause the bag or bag tube to adhere to the enclosing body walls of the carton, so that when'theca-rton is squared up or erected, the bag or b'ag tube will likewise be squared up and opened at least on one end preparatory to filling, The lined carton 9.! is shown in knocked down form inrFigure 7. It will be erected, filled, the-bag sealed, and the carton closed, asinthe patents set forth above.

Figure 8 shows such a filled. carton after it reaches the-hands of the ult mate consumer and after he has opened the flaps 93 so as to disclose the filled bag 69. The nextstep, asindicated in Figure 9, is to pull upwardly upon the end closure seam 90 of the bag. A further upward pulling operation, accompanied by a twisting operation, as illustrated in Figure 10, will serve to cause the upper portion of the bag to sever from the lower portion along the weakened line formed therein which, in this case, is a continuous peripheral line substantially. coinciding with the upper edges of the enclosing walls of the carton. The upper portion of the bag may be entirely removed,.as shown in F gure 11,v and after the removalofa portion of the contents 3d oi the package, it may be reclosed by folding over the closure flaps 83;.

Where the lines of weakening have been made as described in connection with. Figure 2, the carton may first be opened, as shown in Figure 12, then the top of the bag raised or unfolded, shown in Figure 13. The bag may then be torn along the lines of weaken ng 89 so as to remove a corner thereof, 95. This provides an opening in the bag through which a portion of the contents may be removed by pouring; and if the removed corner 95 of the bag is properly proportioned, suflicient of the upper parts of the bag Walls will remain to p rmit a folding over of these bag wall portions and reclosure of the bag, as well as reclosure of the carton, as explained above.

It will be apparent that according to my invention, the nature of the material to be applied to seal up the perforations or line of severance can be adapted to the particular product to be packed within the liner or bag. In the case of lard, for example, it would be desirable to use some greaseresistant medium so there would be no leakage or seepage of the fat and so that the liner would retain its integrit and provide protection until the top is finally removed by the user, as illustrated. In the case of other products such as powders, the compound or sealing medium over the line of perforation should serve the primary purpos of retaining siftproofness, and in such an event, might be a material such as paraffin wax (or a resin modified paraffin, to overcome brittleness). In certain other cases, as for example, a flaky or granular content within the liner or bag, the use of any sealing medium at all may be unnecessary, in which case the perforating alone could be used, by-passing the unit which applied the sealing medium, although I prefer to use the sealing medium to provide the maximum possible protection of the contents. A sealing medium, such as described herein, properly applied and bonded toi walls' ofthe bagwill, however, provide protec= tion again'st infiltration or loss of moisture, vapor and gases, where special gases are employed As indicated, I. may also color the sealing medium some distinctive" shade, such'as bright red, for example, so that the: lineof. tear is plainly and clearly marked, and this'is another feature of my invention.

1' have indicated that my invention is adapted to use on" separatelbags as well as bags or'liners within carton bodies, and this will now be readily apparent from. the previous description... My opening means'is particularly desirable and par ticularly advantageous for bags formed of'ma'terials which are difiicult to tear and which are tightly sealed, such, for example, as a bag made ofrubber hydrochloride sheeting, such as Pliofilm laminated to "paper; In such alaminated bag, the

fused mouth is very difficult to open due to the bonding quality of the Pliofilm; and the rubbery nature of the Pliofilm. liner also makes it ex tremelydifficultto tearsuch a bag open. By'niy invention, these problems are entirely eliminated, and: at the same time through the use" of the proper'sealing medium to cover over the perforation or line ofseverance, the essential protective characteristics of such Pliofilm lined bags can be fully retained, providing a protective bag or liner which can be readily and simplyopened when desired.

Itwill. be apparent thataccording to the ad'- ,iustment of the machine, the line of severance canbe placed in any predetermined, desired location, or at anydesired angle to the bag or tube itself. In Figure 9, the line of severance is placed substantially flush with the top of the outer carton but, if desired, this could be raised to the point where it was slightly under. the sealed or. folded closure of the bag, so that after the sealed port on is torn there st ll remains sufficient extending material to be refolded over the surface of the contents. As ShOWn in Figure 12, the line of severance, if preferred, may be placed at an angle or on the bias, so that only a corner or a portion of the seal is removed by the user to provide a simple and effective means of pouring, rather than removing the entire sealed area; and this is a matter of choice, depending on the nature of the product packed.

It will also be apparent from the foregoing that my invention may be carried out at various stages in the manufacture of bags or tubes. Several of them have been illustrated in the drawings; but it will be readily apparent to those skilled in the art that, if desired, my invention might be practiced by the incorporation of suitable devices after the formation of the web into a continuous tube but prior to severing it into bag lengths.

Variations are within the sco e of my invention, and it is not intended to limit the invention to the particular forms described, except as covered by the claims herein. By my invention, I have provided means whereby flexible bags or tubes, even if made of extremely durable material, can be readily and easily opened by the user when desired, and I have further provided means whereby this can be achieved without sacrificing the inherent protective characteristics of the bag or liner itself, and. have accomplished all this with no separate manufacturing operation or labor cost. The invention is not limited to single-ply bags; and it may be applied also to coated bags, where the sealing substance may be the same as the coating, or a substance capable of. bonding firmly with it. Having thus described my inven- 3i tlon in certain exemplary embodiments, what! claim as new and desire to secure by Letters Patent is:

a 1. A process of forming a sealable and openable composite package which comprises forming a bag tube from web materials, closing and-sealing one. end of said bag tube, forming in said bag tube transverse lines for severance. adjacent but spaced from the closed end of said tube, coating said lines for'severance with a thermoplastic sealing subsbtance, formin a carton blank having a' series of body walls in articulation and capable of forming a closed tube, said body walls having ends in alignment in said blank, otheroparts of said blank articulated to said body walls for forming end closures thereof, and depositing said preformed bag tube on said blank in such a way as to align said lines for severance with the aligned ends of the body walls of said blank, and tubing said blank about said bag tube with the interposition of adhesive between the body walls of said blank and said bag tube whereby to adhere said bag tube to said body. walls.

' 2. A process of forming bags or liners which includes the steps of providing a fiat bag tube having open ends, sealing one end of said tube transversely by adhering the walls thereof together across said end, forming lines of perforation in opposite wall portions of said tube, said lines starting at an edge of the bag at a point adjacent but spaced from said transversely sealed end and extending through said sealed end, and thereafter covering said lines for severance with a thermoplastic sealing substance.

' 3. A process of forming bags or liners which comprises the steps of providing a flat bag tube having open ends and lines of perforation in op- 'posite wall portions of the tube, said lines starting at an edge'of the bag at a point adjacent but spaced from an open end thereof and extending 8 slantwise to the longitudinal axis of the bag and intersecting the said open end intermediate its ends, sealing the said end of said tube transversely by adhering the wallsthereof together across said end, and thereafter applying to said lines of perrelation and adjacent portions of the tube walls a thermoplastic sealing substance.

4.-A process'of making bags or liners which includes the steps of conveying unit lengths of flexible flat bag tubes having open ends in a path of travel, sealing one end of said tubes transversely by adhering the walls thereof together across said ends, forming lines of perforation in opposite wall portions of said tubes, saidlines starting at an edge of the bag tubes at a point adjacent but spaced from said transversely sealed ends and extending through said transversely sealed end intermediate the ends thereof, and thereafter applying to said lines of perforations and adjacent portions of the tube Walls a thermoplastic sealing substance.

SAMUEL BERGSTEIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,198,278 Rosenzweig Sept. 12, 1916 1,517,96 Drysdale Dec. 2, 1924 1,943,796 Hartmann Jan. 16, 1934 2,035,766 Potdevin et al July 6, 1937 2,129,989 Alfred Sept. 13, 1938 2,132,144 Blum Oct. 4, 1938 2,183,2 1? Poppe Dec. 12, 1939 2,216,527 Weiss et a1. Oct; 1, 1940 2,225,288 Woehlert Dec. 1'7, 1940 r 2,293,182 Vogt Aug. 18, 1942 2,382,175 1945

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