US3067923A - Carton - Google Patents

Description

C. W. THIETS Dec. 11, 1962 CARTON 2 Sheets-Sheet 1 /C/c.

Filed Nov. l5, 1960 Dec. 1l, 1962 c. w. THIETs 3,067,923

yCARTON Filed Nov. 15, 1960 2 Sheets-Sheet 2 hired States This invention relates to disposable cartons which may be used either to contain or exclude liquid, and to shipping containers which include such cartons. The invention is particularly directed to self-sealing reinforced parallelepipedal cartons which may be large enough to hold several gallons of liquid Without leakage during extended shipment or storage.

Various more or less liquid impervious cartons have been known for many years. One example is the cornmon cardboard milk carton, in which a formed container is immersed in molten paraffin or similar material to coat both inner and outer surfaces and thereafter filled with milk or similar dairy products. Milk cannot be stored for more than a few days, and such cartons are seldom shipped for very great distances.

Multi-ply cartons have previously been formed from cardboard laminated to an inner liner of metallic foil, waxed paper, plastic film, etc.; all such containers heretofore known to me are subject to leakage if constructed larger than conventional milk cartons, used to contain liquids, and subjected to extended shipment or storage. More recently there have been available multi-gallon parallelepipedal cartons in which a flexible plastic bag is mounted in a corrugated cardboard shipping container and sealed to one or more sides, at least at the portions of the side adjacent the corners. When such cartons are lled with liquid and shipped for very great distances, leaks invariably occur because of the repeated flexing of the plastic lm liner, especially at the top of the carton.

In accordance with my invention, I have devised a compact carton which is completely hermetically sealed and which can be fabricated in capacities as great as gallons or more at costs far below those for metal or glass containers. When filled with liquid my novel carton resists flexing for extended shipping periods. The usually vulnerable corners where the sides intersect the top are protected, and thus even 5-gallon or larger cartons embodying my invention are practically immune to flex-induced leakage in the course of normal commerce.

My invention comprises a parallelepipedal carton which is completely hermetically sealed, the carton being formed from relatively stiff moisture-impervious sheet material. Each end of ythe carton is sealed by a folded closure formed from integral extensions of the sides of the carton. I have overcome the problem of llex cracking lwhich has heretofore plagued the industry by firmly atlixing between the end of the carton and the folded closure a separate flex-inhibiting stitfening pad having slightly smaller dimensions than the inner cross-sectional dimensions of the carton. The stiftening effect imparted by this pad minimizes or prevents the vibrating or fluttering action which is otherwise characteristic of the top of such cartons when in transit, and thereby greatly inhibits the formation of leaks caused by flex cracking of the carton material at the corners formed by the intersection of the top and two adjacent sides.

My invention Will be better understood by reference to the attached drawing, in which like numbers refer to like parts in the several views and in which:

FIGURE 1 is a plan view of a carton blank prior to set-up;

FIGURE 2 is a view in perspective of a partly formed carton, showing one end open;

Patented Dec. 11, 1962 FIGURE 3 is a view in perspective of a partly formed carton, showing the upper end closed and a stiflenhig pad ready to be applied;

FIGURE 4 is a cross-section of one type of seal for the carton; and

FIGURE 5 is a partially cut away view in perspective of the completely formed carton surrounded by a corrugated sleeve and mounted in a corrugated box for shipping.

In FIGURE 1, the portion of the blank which will ultimately form the inside of the carton lies uppermost, the blank being divided vertically into 8 parts by fold lines I8, 19, 20, 2l, 22, 23, and 24. It is similarly divided horizontally by base fold lines 25 and 25a, and Second fold lines 26 and 26a. The portions of the blank lying above base line 25 are folded to form the top of the carton, lwhile the portions of the blank lying below base line 25a are folded to form the bottom of the carton. In the finished or semiinished carton the top closure is formed from half panels l2 and i3, which comprise one end, half panels I5 and 16, which comprise the other end, and panels 14 and 1'7, which represent opposite side panels. Half panels 12a, 13a, 15a and 16a., and side panels 14a and 17a are analogous panels used in forming the bottom closure.

The blank shown in FIGURE l may be formed from a wide Variety of moistureor liquid-impervious materials; in certain instances conventional wax-treated cardboard may be suitable, while in others kraft paper which is extrusion-coated with polyethylene, nylon, or other liquid-impermeable film-forming plastic or polymeric material, will be preferred. Similarly polyvinyl chloride, polyvinyl alcohol and various other films are useful under various appropriate conditions for specific applications. I have found that an extremely suitable general purpose product may be formed from heavy kraft paper, 10 point white cupboard, potlatch paper, or the like, to which is laminated a membrane having an exposed polyethylene layer in conjunction with a tensilized polyester lilm layer. The polyethylene provides heat sealing properties; the polyester film prevents penetration of any liquid contents which might seep through the polyethylene and imparts high mechanical strength and dimensional stability. A two layer membrane having a 11/2 mil (0.0015 inch) film of polyethylene laminated to a 1/a-mill (0.0005 inch) film of polyethylene terephthalate film, such as Mylar polyester film, has been found highly effective, and will be referred to in describing the attached drawing. Other laminated membranes may be used to provide specific desired properties; e.g., aluminum vaporcoated 0.0005 inch polyester film sandwiched between a 0.001 inch and a 0.0005 inch polyethylene film may be used to retain the lavor or taste of the package contents or to provide an especially elfective barrier to oxygen or carbon dioxide.

The carton blank shown in FIGURE 1 is formed into an envelope, which can later be converted into a parallelepipedal carton, by being folded along line 21 in such a manner that iin panel 10 is placed in direct contact with fin panel 1l, fin panels 31 and 31a being folded at their midpoints to be placed similarly in contact with themselves throughout their coincident area. Fin panel 10 is then adhered or sealed to lin panel Il, and the two halves of tin panel 31a are sealed to each other, the upper end remaining open for convenience in filling. This envelope may be shipped in this condition to the ultimate consumer or, if desired, it may be adhered inside a corrugated cardboard shipping container and the entire assembly folded flat.

In converting the envelope described in the preceding paragraph to a carton, the user first folds it at along lines 19, 20, 22, and 23 to provide a rectangularly crosssectioned `body portion, fold lines 18 and 24, and 21 tending to flatten out and conform to the straight sides on which they then appear. Because fin panel 31a is sealed to itself throughout its coincident area, the -bottom side panels 14a and 17a are thereby simultaneously lbent inwardly along fold line 25a, end panels 12a- 13a and 15a- 16a being bent outwardly along fold line 25a. The outward folding of the end panels and the inward folding of the side panels causes half end panel 15a to be folded inwardly along diagonal line 29a and half panel 16a to be folded inwardly along diagonal line 30a; by exactly the same process panel 12a is folded along line 27a and panel 13a is folded along line 28a. The seal formed by adhering the two halves of fin panel 31a to itself is then folded flat against the bottom of the carton, i.e., against side panel 14n. At this point, the partially set up carton appears as in FIGURE 2, with the triangular ear formed by the folding of end panel 12a- 13a shown extending, the second ear, formed from end panel 15a-16a not being shown but extending behind the carton. The ears are then folded over the bottom and adhered thereto, preferably in the same manner as hereinafter described in conjunction with the top closure.

The carton as shown in FIGURE 2 is now filled with liquid or other contents, and the folded top closure effected in much the same way as the folded bottom closure. Side panels 14 and 17 are bent inwardly along base line 2S, while end panels 12-13 and 15-16 are bent out- Wardly, thus forming triangular ears by folding together the inner surfaces of end half- panels 12, 13, 15, and 16 along diagonal lines 27, 28, 29, and 30, respectively. The contacting inner surfaces of fin 31 are now sealed together typically by pressing them at 70 lbs. per square inch between two 400 F. metal bars, after which fin 31 is folded into contact with side panel 14, as shown in FIGURE 3. In order to form a flat top and an effective seal, the distance from base fold line 25 to fold line 26 should be 1/2 the breadth of the package, i.e., 1/2 the distance between fold lines 19 and 2-3. Rigidifying and stitfening pad 40, preferably constructed of an appreciably thicker and stiffer material than the carton, is now placed on the end of the carton, centered with respect to the cross-section of the carton and adhered to fin 31 and side panels 14 and 17. The triangular ears formed from end panels 12-13 and 15-16 are now adhered to the upper surface of pad 40, thereby greatly rigidifying the upper end of the carton; if desired, pad 40 may be provided with slots to accommodate the ears and thus afiix pad 40 in position. this manner is effectively freed from the problems of vibration, flutter, and flexing.

In FIGURE 4 a preferred Vertical side seal 10-11 is shown in greatly enlarged cross-section. The blank of which side fin panels 10 and 11 are part comprise kraft paper '32 coated with a laminated film of polyester 33 and polyethylene 34. The fin seal itself is folded back against the side panel of the carton along fold line 18, as is indicated in FIGURES 2, 3, and 5.

Although this reinforced carton has substantial utility, especially in half-gallon or smaller sizes, without further modification, the rigidity and leak proofness of both small and large cartons is still further enhanced by being mounted inside a corrugated cardboard box to form a composite package. A particularly effective manner of accomplishing this is shown in FIGURE in which the folded carton complete with stiffening pad 49, is mounted inside corrugated sleeve 50 and corrugated box 60. The inner top tiaps 6l and 62 of box 60 are folded down over the top of the carton while outer box iiaps 63 and 64 are in turn folded over and sealed to fiaps 61 and 62.

In a specific preferred example, the polyester surface of a preformed composite film membrane consisting of 0.0005-inch tensilized polyethylene terephthalate polymer (Mylar) film bonded to 0.0015-inch polyethylene film The top of a carton reinforced in was adhered to a strip of kraft paper having a thickness of 0.018 inch and a basis Weight of 58 lbs. per ream, and thereafter dried by passing it, film side in, around a 160 F. hot can. The laminating adhesive, conventionally used for adhering polyester films to paper, was the H, B. Fuller Companys 8020, a 39% solids aqueous emulsion of a synthetic rubber-resin blend, applied in the amount of about 5 wet grains per Z4 square inches. The strip was cut into 39" x 26 rectangular blanks, creased as shown in FIGURE l. Each blank was then folded to form a square cross-sectioned carton about 9 inches on each side and the bottom closure formed by folding as hereinbefore described, some of the cartons having an 8% x 8%" x 1A" 200 lb. burst strength A-fiute corrugated stiffening pad interposed between the bottom of the carton and the folded closure and being sealed thereto, and the other cartons being formed in the same way but including no stiffening pad. Each carton was placed in a snug 3/16 thick 275 lb. burst strength C-flute corrugated cardboard sleeve and placed in a corrugated cardboard box (also 275 lb. C-flute) in the manner of FIGURE 5. Each carton was then filled with 5 gallons of water containing a fluorescent dye, after which the top was folded, closed, and sealed; stiffening padswere omitted or inserted, as appropriate, to make the top and bottom closures substantially identical. The cardboard boxes were then sealed and the packages thereafter subjected to the procedure for the vibration testing of packaged products weighing less than lbs. specified by the National Safe Transit Committee, 1145 Nineteenth St. N.W., Washington 6, D.C. In this test, the package is placed on the table of a Gaynes vibrator and the vibration frequency adjusted so that the package leaves the table for at least 1/16 inch at some interval during the vibration cycle. A satisfactory package must not develop leaks within one hour. Packages without stiffening pads all developed leaks at one or more upper corners within 20 minutes, while packages having stiffening pads showed no trace of leakage after more than 3 hours. Identical containers were filled with water, reinforced with stiftening pads, packed in corrugated cardboard boxes, and shipped for over 700 miles by rail freight without the slightest indication of leakage.

The carton of my invention has, as I have indicated, particular utility in containing liquid, but it is also highly useful in the shipping of moisture-sensitive products, eg., ammonium nitrate, calcium chloride, isocyanate resin, etc. In such instances the resistance to cracking of this carton prevents moisture from penetrating and deleteriously affecting the contents of the package.

My invention also contemplates various mechanical modifications of the carton shown. For example, the triangularly folded end panel 15-16 shown in FIGURE 3 may be cut off `at some point intermediate fold line 25 and the apex of the triangle to form a pouring spout, the remaining open portion being temporarily sealed by a crimped steel band or similar device. Likewise, pouring spouts or similar fitments can be mounted in side panels 14 or 17 so that the contents of the package may be dispensed directly therefrom. In instances where the carton may be filled through the spout from which the contents will be dispensed, it may be desirable to form a closed envelope, sealed not only along fins 10-11 and 31a, but also along fin 31, thus eliminating the step of forming a top seal after filling the carton. Similarly, although the vertical fin seal facilitates carton fabrication and is therefore preferably located as shown, it may be placed at a corner or at the middle of one side. Lap seals may be suitable where the edge of the carton exposed to liquid or moisture is provided `with a suitable barrier, e.g., by extending the film liner around the edge.

What I claim is:

l. A completely hermetically sealed parallelepipedal container comprising a rectangularly cross-sectioned carton yformed from relatively stiff moisture-impervious sheet material subject to failure by flex cracking, each end of said carton being sealed by a folded closure formed from integral extensionsof the sides of said carton, and including a separate flex-inhibiting stiffening pad of slightly smaller dimensions than the internal cross-section of said carton positioned parallel to said ends firmly aixed between said end 4and said folded closure and lying within the rectangle formed by imaginary extensions of the sides of said cartons.

2. A hermetically sealed rectangularly cross-sectioned carton formed from relatively stiff moisture-impervious sheet material subject to dex-cracking, at least the top of said carton being structurally stiened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular Hex-inhibiting stilfening pad similar in dimensions to the internal horizontal cross-section of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to one.

half the breadth of said closure, each end panel having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said side panels being folded toward each other at 90 angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines t0 form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a tin, contacting surfaces of said iin being hermetically sealed together, said fin being folded against one of said side panels; said flex-inhibiting stilfening pad being of slightly smaller dimensions than the inner dimensions of said body and positioned over said fin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and adhered to said pad.

3. A hermetically sealed package of liquid contents, highly resistant to leakage induced by vibration and comprising a rectangularly cross-sectioned carton formed from sheet material impervious to said liquid, at least the top of said carton being structurally stiifened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular flex-inhibiting stii'fening pad similar in dimensions to the internal horizontal cross-section of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to onehalf the breadth of said closure, each end panel having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second lfold line; said side panels being folded toward each other at 90 angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a n, contacting surfaces of said iin being hermetically sealed together, said iin being folded against one of said side panels; said flex-inhibiting stiifening pad being of slightly smaller dimensions than the inner dimensions of said body and positioned over said fin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and adhered to said pad; said carton being snugly surrounded on at least four sides by a stiff t3 sleeve, the thus-surrounded carton being in turn snugly positioned in a strong cardboard box.

4. A hermetically sealed parallelepipedal package of liquid contents, highly resistant to leakage induced by vibration and Which can be shipped for great distances without loss of the contents, and comprising a rectan gularly cross-sectioned carton formed from sheet material impervious to said liquid, the top and bottom of said carton being structurally stiffened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular flex-inhibiting stitfening pad similar in dimensions to the internal horizontal cross-section of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to one-half the breadth of said closure, cach end panel having third and fourth -fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said side panels being folded toward each other at angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a iin, contacting surfaces of said fin being hermetically sealed together, said iin being folded against one of said side panels; said dex-inhibiting stiffening pad being of slightly smaller dimensions than the inner dimensions of said body and positioned over said fin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and aiiixed to said pad.

5. A hermetically sealed parallelepipedal package of liquid contents, highly resistant to leakage induced by vibration and which can be shipped for great distances Without loss of the contents, and comprising a rectangularly cross-sectioned carton, the top and bottom of said carton being structurally stiifened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular flex-inhibiting stiifening pad similar in dimensions to the internal crosssection of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner yfold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a Second fold line parallel to the base fold line and spaced therefrom a distance equal to one-half the breadth of said closure, each of said end panels having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said Side panels being folded toward each other at 90 angles along their respective 'base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a iin, contacting surfaces of said fin being hermetically sealed to gether, said tin being folded against one of said side panels; said dex-inhibiting stiifening pad being of slightly smaller dimensions than the inner horizontal dimensions of said body and positioned over said tin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and adhered to said pad; said carton being snugly contacted on at least four sides by a corrugated cardboard sleeve which is in turn iirmly positioned in a corrugated cardboard box; and a heat-andpressure-sealing, fluid-impervious, flexible, strong, selfd supporting, preformed plastic film membrane covering the entire interior surface of said interconnected panels and effectively sealed thereagainst at least along all fold line areas and against the areas extending from said second fold lines to the free edge of said panels.

6. A hermctically sealed parallelepipedal package of liquid contents, highly resistant to leakage induced by vibration and which can be shipped for great distances Without loss of the contents, and comprising a rectangularly cross-sectioned carton, the top and bottom of said carton being structurally stiifened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular Hex-inhibiting stiffening pad similar in dimensions to the internal cross-section of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to one-half the breadth of said closure, each of said end panels having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said side panels being folded toward each other at 90 angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines Contact throughout the length lying between said midpoints and form a iin, contacting surfaces of said iin being hermctically sealed together, said iin being folded against one of said side panels; said flexinhibiting stifening -pad being of slightly smaller dimensions than the inner horizontal dimensions of said body and positioned over said iin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and axed to said pad; said carton being snugly contacted on at least four sides by a corrugated cardboard sleeve which is in turn rmly positioned in a corrugated cardboard box; and a heat-and-pressure-sealing, fluidimpervious, flexible, strong, thin, plastic layer covering the entire interior surface of said interconnected panels and effectively sealed thereagainst at least along all fold line areas and against the areas extending from said second fold lines to the free edge of said panels.

7. A hermctically sealed rectangularly cross-sectioned carton formed from relatively stiff moisture-impervious sheet material subject to hex-cracking, at least the top of said carton being structurally stiffened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular Hexinhibiting stiffening pad similar in dimensions to the internal cross-section of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming and edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to one-half the breadth of said closure, each of said end panels having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said side panels being folded toward each other at 90 angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so

that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a fin, contacting surfaces of said n being hermctically sealed together, said iin being folded against one of said side panels; said flex-inhibiting stiffening pad being of slightly smaller dimensions than the inner horizontal dimensions of said body and positioned over said iin and said side panels in contact therewith and within the rectangle forrned by imaginary extensions of said body, said ears being folded over and aflixed to said pad; said carton being snugly contacted on at least four sides by a strong, stiff sleeve which is in turn firmly positioned in a strong, stiff box; and a heat-and-prcssure-sealing, fluidimpervious, flexible, strong, thin, plastic layer covering the entire interior surface of said interconnected panels and effectively sealed thereagainst at least along all `fold line areas and against the areas extending from said second fold lines to the free edge of said panels.

8, A hermctically sealed parallelepipedal package of liquid contents, highly resistant to leakage induced by vibration and which can be shipped for great distances without loss of the contents, and comprising a rectangularly cross-sectioned carton, the top and bottom of said carton being structurally stiffened and sealed by a closure including folded panels which are integral extensions of the body of said carton, and a rectangular flex-inhibiting stiffening pad similar in `dimensions to the internal crosssection of said body; said panels comprising two opposing end panels and two opposing side panels connected at corner fold lines, each panel being connected to the corresponding major panel of the carton at a base fold line forming an edge of said closure, each panel having a second fold line parallel to the base fold line and spaced therefrom a distance equal to one-half the breadth of said closure, each of said end panels having third and fourth fold lines connecting the ends of its base fold line with the midpoint of its second fold line; said side panels being folded toward each other at angles along their respective base lines, and the inner surface of each end panel being folded together along said third and fourth fold lines to form substantially triangular ears, so that corresponding inner surfaces of the portions of the panels lying beyond the second fold lines contact throughout the length lying between said midpoints and form a 1in, contacting surfaces of said fin being hermctically sealed together, said n being folded against one of said side panels; said flex-inhibiting stifening pad being of slightly smaller dimensions than the inner horizontal dimensions of said body and positioned over said fin and said side panels in contact therewith and within the rectangle formed by imaginary extensions of said body, said ears being folded over and aft'ixed to said pad; and a heat-and-pressuresealing, fluid-impervious, flexible, strong, self-supporting, preformed plastic lm membrane covering the entire interior surface of said interconnected panels and effectively sealed thereagainst at least along all fold line areas and against the areas extending from said second `fold lines to the free edge of said panels.

References Cited in the file of this patent UNITED STATES PATENTS 2,326,649 Howard Aug. 10, 1943 2,331,010 Waters Oct. 5, 1943 2,337,730 Berch Dec. 28, 1943 2,372,452 Rohdin Mar. 27, 1945 2,944,715 Vergobbi July 12, 1960

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