Containers for such products are usually made in sizes of several feet on each dimension, and when holding materials of the nature described can weigh hundreds of pounds. Typically, such containers may be made from 600 lb. test double wall corrugated material or 1100 lb. test triple wall corrugated material. Even such heavy duty containers when filled with the flowable materials and stacked two to four containers high for shipment are not immune from bulging of the container walls in the bottom units, with the attendant potential of container rupture or column failure which causes the upper boxes to topple over. Consequently, it has been necessary in the past to either compartmentalize such containers as load distributing structures, or to enclose such containers in wooden frames to provide wall support therefor.
The novel containers according to the invention not only eliminate the necessity for using wooden frames or compartmentalizing the containers, but also permit reduction in the necessary strength of the container wall structures from the previously mentioned types to container walls made of approximately 350 lb. test double wall corrugated material. These changes effect a substantial cost reduction in the containers used for these applications.
Briefly, as will be subsequently described in connection with the drawings appended hereto, the corrugated cartons may be on the order of 35 to 50 inches in height and somewhat greater in length and width, and are provided with an inside tubular rectangular liner and a two ply bottom pad fitted down inside the liner and adhesively secured to the inside bottom flaps of the carton. In one form of the invention there is disposed entirely peripherally around the outside of the carton sidewalls and extending upward for a distance from substantially the bottom thereof a belt of non-woven backing material with yarns laminated thereon and extending peripherally laterally completely around the carton. The belt yarns may be of any material which exhibits minimal elongation under tension. In another form of the invention the belt is disposed around the tubular liner which as a unit fits within the carton.
The belt backing material may typically be of non-woven polyester and approximately 20" or so in width extending upward from substantially the bottom of the carton or liner, and the yarns may typically each be 1800 denier formed of approximately 250 fiberglass filaments and arranged with a side by side density of 20 to the inch at the bottom reducing to 5 to the inch at the top and graded in between. The belt is wrapped around the carton or liner with the backing material against the carton or liner and held thereto with several glue spots, with the ends of the belt brought into abutment on the surface of the carton. A patch of the same material is then glued firmly over the butt joint with the filaments of the patch facing and adhered to the filaments of the belt.
It is a primary object of the invention to provide a novel reinforced corrugated container for safely holding flowable granulated materials and flowable gelatinous substances of relatively high density utilizing thinner than normal container walls and eliminating compartmentalization within the carton or wooden external structural framing as supplementary carton support structures.
Another object of the invention is to provide a novel reinforced container as aforesaid in which the corrugated carton or interior tubular liner is provided with a retaining belt extending entirely peripherally thereabout and upward for a distance from the bottom of the carton or liner.
Yet another object of the invention is to provide a novel reinforced container as aforesaid wherein the reinforcing belt structure is made of a non-woven backing material with parallel disposed yarns laminated thereon and extending lengthwise of the belt structure, the belt being secured to the carton or interior tubular liner to thereby dimensionally stabilize the carton.
A further object of the invention is to provide a method of making the aforedescribed reinforced containers.
The foregoing and other objects of the invention will become clear from a reading of the following specification in conjunction with an examination of the appended drawings, wherein:
FIG. 1 is an isometric view of a reinforced container according to the invention with the top flaps open and with a portion of a lower corner structure being sectioned away to disclose underlying details;
FIG. 2 is an enlarged fragmentary section taken through the carton of FIG. 1 as would be seen along the line 2--2 on FIG. 1;
FIG. 3 is a horizontal sectional view through the novel carton according to the invention as would be seen when viewed along the line 3--3 on FIG. 2, and also disclosing a partially removed section of the bottom structure to disclose the underlying configuration;
FIG. 4 is a fragmentary enlarged section through the wall of the reinforced container according to the invention as would be seen when viewed along the line 4--4 on FIG. 3;
FIG. 5 is an enlarged fragmentary corner detail of an alternate way of applying the locking patch to the reinforcing belt at the corner instead of on the face of a carton panel;
FIG. 6 is an isometric exploded view of another form of reinforced container according to the invention in which the container liner is reinforced instead of the outer carton;
FIG. 7 is an enlarged fragmentary view through the container structure of FIG. 6 as would be seen when viewed along lines 7--7 on FIG. 6; and
FIG. 8 is a fragmentary enlarged section through the container wall as would be seen when viewed along lines 8--8 on FIG. 7.
In the several figures, like elements are denoted by like reference characters.
Referring now to the drawings and first to FIGS. 1 to 4, there is seen a carton referred to generally as 10 having the usual top flaps 11, sidewalls 12, interior bottom flaps 13 and exterior bottom flaps 14, the carton being formed in the normal and usual structural fashion for such corrugated cartons. Disposed vertically within the carton is a rectangular liner tube 15 having its ends lapped at one corner by the flap 16. Disposed within the confines of the liner tube 15 and placed flatwise downward upon the interior bottom flaps 13 is a bottom pad 17 adhered to the upper surfaces of the interior bottom flaps 13 by adhesive 18.
Wrapped peripherally about the walls of the carton 10 for a distance extending upward from the bottom edge of the carton is a reinforcing belt 19 made of a non-woven backing material 20 which typically could be polyester, to which is adhered a plurality of side by side yarns 21 extending longitudinally of the length of the reinforcing belt and spaced laterally in a varying density arrangement as shown by the lines 22, the yarns being closely spaced at the bottom edge of the belt and gradually becoming wider in spacing towards the top of the belt. The yarns and their spacings typically could be 1800 denier yarns formed of 250 fiberglass filaments each at a density of 20 to the inch at the bottom edge of the belt reducing to 5 to the inch at the upper edge of the belt and graded therebetween.
As best seen in FIGS. 1 and 3, the ends of the reinforcing belts are abutted on one face of the carton as shown at 23, and a locking patch 24 is adhesively secured across the abutment line 23 to fixedly secure the ends of the reinforcing belt together and prevent their being separated under stress from the load within the carton. The path 24 is shown with gradation lines in FIG. 1, but it is to be understood that these gradation lines represent yarns on the inner face of the patch and not on the outer face. This is more clearly shown in FIG. 4 where the patch is shown to be of the same structure as the belt and includes a non-woven backing portion 25 and an array of yarns 26. As also shown in FIG. 4, the yarns and backing of the patch 24 are adhered to the yarns and backing of the reinforcing belt 19 by adhesive 27, with the yarns 21 and 26 facing one another. As shown in FIG. 4, the yarns do not appear to be in contact with each other, and this could occur in the relatively widely spaced upper regions of the belt, but toward the lower regions of the belt where the density is much higher, the yarns 21 and 26 will e in close proximity or substantial engagement with one another at their points of adherence.
An alternative locking patch configuration, and a preferred one, is shown in the detail of FIG. 5 which differs only from the structure shown in the other figures in that the ends of the reinforcing belt 19 are abutted at a corner of the carton instead of on a face of the carton, and the patch 24 is applied around the corner of the carton, all as shown in FIG. 5.
Considering now FIGS. 6 to 8 there is seen a carton 10' having sidewalls 12' and a tubular liner 15' as in FIGS. 1 through 5, but wherein the reinforcing belt 19' with its locking path 24' is disposed about and adhesively tacked to the periphery of the liner 15' instead of about the outer lower periphery of the carton 10'. This to some degree protects the reinforcing belt.
Having now described the invention in connection with particularly illustrated embodiments thereof, modifications and variations of the invention may naturally occur from time to time to those persons normally skilled in the art without departing from the essential scope or spirit of the invention, and accordingly it is intended to claim the same broadly as well as specifically as indicated by the appended claims.