IE42083B1 - Improvements relating to packages - Google Patents

Description

This invention relates to shipping packages.

Rectangular filled cartons are normally shipped in conventional closed fibreboard cases made up of corrugated material and having over-lapping flaps at both ends. In the case of food and other products, the cases must be strong enough to withstand usual handling and stacking forces and must be sealed to protect the contents from contamination, injury, and tampering.

Upon arrival at the retail outlet, the cases are cut open and discarded, and the individual cartons are price tagged and displayed on shelves. The cost of the case and the expense of its disposal add to the cost of the product in the carton. As the cases are cut open, several' of the cartons contained therein are sometimes cut and must be discarded.

The use of polymeric heat-shrinkable films for the shrink-wrap packaging of materials is well known and is described in the following United States Patent Specifications Nos. 3,219,183; 3,058,273; 2,711,346; 3,416,288; 3,338,406; 3,050,402; 3,198,327; 3,447,675 and 3,694,995. The prior art generally deals with heat-shrinkable materials disposed around a plurality of rigid or hard objects, suoh as steel - 3 cans, in order to hold the objects together as a unit package, either in a spaced or contiguous relationship.

One problem with such packages resides in the difficulty of applying printed information to the exterior polymeric surface. Also well known are corrugated material trays in combination with a shrinkable film to hold objects thereon in a stacked relationship. A problem with Such an arrangement is that the vertical strength of the package is limited to the strength of the stacked objects.

According to the present invention, there is provided a shipping package adapted to be stacked vertically upon and under other such packages and consisting of a rectangular sleeve of a single or multiple wall corrugated fibreboard,open at both ends, a plurality of rectangular cartons packed in said sleeve in a firm contiguous fashion therewith, with outwardly facing surfaces of said cartons being substantially flush with the open edges of the sleeve, and an overwrap comprising a sheet of heat-shrinkable polymeric material applied around and shrunk down onto the sleeve, said overwrap tightly overlying and engaging the outwardly facing surfaces of the cartons at the open ends of the sleeve and a pair of opposed walls and all eight corners of said sleeve, said overwrap at least partially overlying the other pair of opposed walls of said sleeve; in which the fibreboard of the sleeve is joined or is seamless so as to form a continuous sleeve and is disposed with the corrugations thereof running between the open ends and parallel to the corner edges of said sleeve, the cartons which are crushable cartons being contained in the sleeve under pressure so that the said cartons exert pressure outwardly against the sleeve and the sleeve exerts pressure inwardly against the cartons and wherein the cartons fill the entire volume of the said sleeve in said firm contiguous fashion therewith, with the outwardly facing surfaces of the said cartons being substantially flush with the open edges of the sleeve and retained therein by said overwrap, the corresponding - 4 walls of the cartons being aligned with one another and the vertical walls of the cartons in a position for packaging being parallel with the walls of said sleeve so that the strengths of said cartons and said sleeve are combined to impart stacking strength to the shipping package, when stacked with the walls of the sleeve vertical, the cartons, sleeve and overwrap together forming a unitary package.

The conventional case is replaced with a 10 rectangular sleeve or tube having open ends and no end flaps. The sleeve is sized such that the rectangular cartons, when compression packed in contiguous fashion in the sleeve, completely fill the volume of the sleeve with outwardly facing walls of the cartons presenting substantially flat surfaces at the open ends of the sleeve.

When the package is constructed properly, the vertical compressive or end strength is unexpectedly superior to that of conventional filled cases, thereby enabling, if desired, the use of lower weight packing materials with attendant cost savings. The improved end strength is due to the combined strength of the cartons and the sleeve. Compression packing of the cartons in the sleevo results in the best possible alignment of all load bearing members, particularly the individual cartons. The cartons thus contribute to end strength to a greater degree than do the cartons in a conventional case having flaps.

There is another possible reason for strength improvement in the package of the present invention. In the assembly of a conventional corrugated material case having end flaps, it is virtually impossible to maintain the case in a square configuration as the flaps are being glued closed. Any skewing of the rectangular base will also result in a concave configuration in the planes of the flaps. The result is that the highest portion of the concave configuration will pick up the stresses from an external load prematurely, and cause premature fatigue and failure, thereby detracting from the optimum theoretical strength levels. The package of the present invention does not employ flaps and is more flexible, thereby affording the ability to simultaneously pick up an external force across the maximum bearing area and minimizing fatigue or damage due to isolated force levels.

If the sheet of heat-shrinkable material is transparent the cartons are visible and there is less likelihood that the cartons will be damaged or cut when the package is opened, as compared with conventional eases having overlapping flaps at the ends. The fibreboard sleeve presents an excellent printing surface and for this reason is superior to the packing. of a plurality of cartons solely by means of a shrink or other flexible or transparent wrapper.

The invention is further described, by way of example, with reference to the accompanying drawings, in which:FIG. 1 is a perspective view of the composite parts of a shipping package in accordance with the present invention; and FIGS. 2, 3 and 4 are perspective views of the completed shipping package, each illustrating an arrangement of cartons therein.

Figure 1 illustrates the three components which comprise a shipping package in accordance with the present invention, namely a rectangular corrugated fibreboard sleeve 10 having open ends 12, a plurality of rectangular fibreboard cartons or packets 14 to be packed snugly in the sleeve, and a heat-shrinkable band or tube 16 of sufficient size to slip over and cover the open ends and a pair of opposite sides of the sleeve. The band or tube 16 normally will comprise integrally extruded tubular film - 6 or flat film formed into a tube, or a flat film may simply be wrapped around the ends of the fibreboard sleeve.

The sleeve 10 may be constructed of suitable sheet stock having compressive strength in the direction from open end to open end thereof, such as conventional corrugated fibreboard wherein the corrugated or fluted sheet is bonded between a pair of spaced walls. Opposite ends of the fibreboard sheet are connected to form a tube, and the tube is shaped With four corner edges running parallel to the flutes. The sleeve 10 thus has four walls connected in rectangular fashion, and one or more walls may carry desired printed information, suoh as product identification or coding. Although singlewall corrugated board will normally provide sufficient strength, double and triplewall corrugated boards may also be employed.

The sleeve 10 ls of a size to receive a plurality of filled rectangular cartons 14 in a stacked relationship within the sleeve. The cartons, which would normally be made up from a flexible fibreboard material, are preferably egui-sized and have substantially flat side and conventional flapped end surfaces. The cartons are arranged in a contiguous array and when properly assembled, together define a rectangular solid having a volume which is substantially equal to the volume between the open ends of the sleeve. The solid thus defined by the carton' arrangement has six outwardly facing and substantially flat and planar surfaces, which are discontinuous only at the junctures between adjacent cartons. Four of the'exposed surfaces of the arrayed cartons are placed in full contact with the respective interior walls of the sleeve; the other two exposed surfaces of the array occupy the open ends of the sleeve and are substantially flush with the edges at the open ends. The other unexposed surfaces of each carton are each in full contact with a corresponding surface of an adjacent carton 43083 - 7 or an interior wall of the sleeve.

As shown in the figures, the sleeve and cartons therein define a structurally solid assembly, with two opposed end surfaces being made up of the outwardly facing carton surfaces. In order to hold the cartons in the sleeve and to increase the integrity of the assembly, the shrinkable band is wrapped or otherwise provided around the sleeve so as to overlie the open ends, and is then shrunk down onto the sleeve (in the direction of the corrugations) to retain the cartons in a contiguous relationship. Due to the compressive strength of the corrugations of the sleeve 10, the shrinking of the film down onto the cartons is controlled to provide a firm but not excessive holding force. The resultant combination of the sleeve 10, the cartons 14 and the band 16 thus provides a strong package having undistorted walls and a high degree of flexibility in comparison with conventional packages.

The band 16 is preferably in the form of a tubular section of transparent, heat shrinkable thermoplastic film, . which has a large enough diameter to fit over the open ends of the sleeve and is sufficiently long to completely cover the open ends with extra material at both sides.

As shown in Figures 2, 3 and 4, the material is heat shrunk over the four corners and end edges of the sleeve, such that the material completely overlies the open ends and a pair of opposed walls of the sleeve. The edges of the material lap over onto the other opposed pair of surfaces of the sleeve and terminate in the form of oval windows at 18. The band 16 may be conveniently made up from flat sheet material by joining and heat sealing opposite edges of an appropriate size flat sheet.

The heat shrinkable material described herein may comprise any of the uniaxially or biaxially oriented polymeric films which upon application of heat are shrunk to a decreased surface area. Suitable films include oriented polyolefinic films such as polyethylene, polypropylene, - 8 polyisopropylethylene and polyisobutylethylene. Other exemplary films are polyvinyl chloride polyethylene terephthalate, polyethylene - 2,6 - naphthalate,polyhexamethylene adipamide, and the like, as well as polymers of alpha mono-olefinically unsaturated hydrocarbons having polymer producing unsaturation such as is present in butene, vinyl acetate, methyl acrylate, 2 -ethyl hexyl acrylate, isoprene, butadiene acrylamide, ethyl acrylate N - methyl - n - vinyl acetamide and the like. This list is illustrative Of the types of polymeric films known in the art and is not intended to be exhaustive of all heat shrinkable films, since many- others are known which may be successfully employed.

The film of the preferred embodiment is a polyolefin and preferably biaxially oriented polyethylene.

The thickness is not critical and may vary between at least 1.0 and 20 mils. The material is preferably transparent to reveal the markings on the sleeve and the labels or printing on the cartons facing the open ends. The film also reduces penetration of moisture or vapour into the package and allows for the insertion of information panels under the film.

Various possible arrangements of the cartons within the sleeve are shown in Figures 2, 3 and 4. It will be noted that the completed package is intended to be shipped and stored with the flutes disposed vertically, in order to withstand forces imposed on the package when several packages are stacked. It is also important that the largest and hence weakest panels of the cartons be arranged or oriented to receive the maximum degree of protection from the sleeve and film, especially since the package may be subjected to lateral gripping forces as well as compressive stacking forces during loading and storage. The arrangements shown in Figures 2, 3 and 4 are designed to provide such protection, as will now be described. 0 83 - 9 As shown in Figures 1 and 2, the cartons may be arranged in the sleeve with their largest panels facing the open ends of the sleeve or perpendicular to the sleeve corners. In this manner, the larger panels are protected against deflection by the relatively rigid flutes of the sleeve. This arrangement is particularly beneficial to allow display of the cartons in the retail outlet after the transparent overwrap has been partially or entirely removed.

Another suitable arrangement is shown in Figure 3, in which four rows of cartons are provided with the ends facing outward, and the larger carton panels face and are protected by the sleeve and film together, and the smaller side surfaces face the other opposed walls of the sleeve, which are not protected entirely by the transparent overwrap. This arrangement is desirable to facilitate the application of price markings to the tops of the cartons after the transparent wrap has been removed from either one or both ends of the package.

In the arrangement shown in Figure 4, the side surfaces of the cartons are arranged to face outwardly from the open ends of the sleeve and the larger carton panels and ends are oriented parallel to respective pairs of opposed walls of the sleeve. In order to protect the larger panels, the polymeric band is applied in such a manner that, it completely overlies the sleeve walls in contact with the larger panels, in order to impart additional support and protection thereto.

It has been found that the package of the present invention when properly packed and compared with a conventional package of the same size having the conventional flaps, may have a top to bottom compressive strength improvement of the order of 25% and the package has excellent handling characteristics. Moreover, elimination of the flaps and the folding and pasting operation provides for about a 50% reduction in cost. Compression packing of a sleeve improves the strength ί . 'iff contribution of the cartons and provides for better squareness that improves stability for storage and handling.

The following example is given in further illustration of the present invention.

The strength of one shipping package in accordance with the present invention was compared with the strength of a conventional singlewall corrugated material package, the case of which had flaps. The respective packages were of the same size, and equal numbers of identical cartons containing ready-to-eat cereal were packed in each case in an array similar to that shown in Figure 3. The package of the present invention was made up from a sleeve of single ply corrugated board of the same specifications as the board in the conventional package, and the wrap was made up from a 3 mil. tube of biaxially oriented polyethylene. The open ends of the carton filled sleeve were covered with the wrap as shown in Figure 1 and the wrap was shrunk to the maximum extent possible, within the control provided by the sleeve, by application of heat. Ten packages of each type were prepared and subjected to compression tests on all three axes. The following table illustrates the test results.

Compression Strength (lbs.) TB SS EE Sleeve with shrink wrap 1492 482 246 Standard corrugated case 1166 475 473 The terms TB, SS and EE designate top to bottom, side to side (i.e., from upper right to lower left in Fig. 3) and end to end (from upper left to lower right in Fig. 3) respectively. The end to end strength measurement was taken in the direction normal to the larger carton panels, and the side to side strength measurements correspond to compression in the direction normal to the carton side panels, while TB designates compression parallel to the flutes or corrugations of the sleeve.

The top-to-bottom strength is the most critical, since this value determines the extent of permissible vertical stacking. It. may be seen that the top to bottom strength of the shipping package of the present invention was 28% greater than that of a conventional package. The side to side strengths were substantially the same. The conventional package exhibited superior end to end strength, which was due, primarily, to the presence of the flaps. The loss in end to end compression strength, however, is not usually important.

In actual field tests, where the packages were subjected to conventional handling, including side clamping, the package of the present invention was found to have more than adequate strength both side to side and end to end. The significant increase in top to bottom strength was a substantial and unexpected plus, permitting a 25% increase in stacking height without any offsetting disadvantages. And at the same time, costs of packaging were reducted by 50%.

Claims (12)

1. A shipping package adapted to be stacked vertically upon and under other such packages and consisting of a rectangular sleeve of a single or 5 multiple wall corrugated fibreboard, open at both ends, a plurality of rectangular cartons packed in said sleeve in a firm contiguous fashion therewith, with outwardly facing surfaces of said cartons being substantially flush with the open edges of the sleeve, and an overwrap comprising 10 a sheet of heat-shrinkable polymeric material applied around and shrunk down onto the sleeve, said overwrap tightly overlying and engaging the outwardly facing surfaces of the cartons at the open ends of the sleeve and a pair of opposed walls and all eight corners of 15 said sleeve, said overwrap at least partially overlying the other pair of opposed walls of said sleeve; in which the fibreboard of the sleeve is joined or is seamless so as to form a continuous sleeve and is disposed with the corrugations thereof running between the open ends 20 and parallel to the corner edges of said sleeve, the cartons which are crushable cartons being contained in the sleeve under pressure so that the said cartons exert pressure outwardly against the sleeve and the sleeve exerts pressure inwardly against the cartons and wherein the 25 cartons fill the entire volume of the said sleeve in said firm contiguous fashion therewith, with the outwardly facing surfaces of the said cartons being substantially flush with the open edges of the sleeve and retained therein by said overwrap, the corresponding walls of the cartons 30 being aligned with one another and the vertical walls of the cartons in a position for packaging being parallel with the walls of said sleeve so that the strengths of said cartons and said sleeve are combined to impart stacking strength to the shipping package, when stacked with the 35 walls of the sleeve vertical, the cartons, sleeve and overwrap together forming a unitary package. 43083

2. A shipping package as claimed in claim 1, wherein said sleeve is comprised of multiple wall corrugated fibreboard.

3. A shipping package as claimed in claims 1 or 2 wherein the sheet of heat-shrinkable polymeric material is in the form of a continuous band covering the open ends and a pair of opposed walls of the sleeve, the edges of said sleeve being shrunk over and terminating in openings on the other pair of opposed walls of the sleeve.

4. A shipping package as claimed in any of claims 1 to 3 wherein each of said rectangular cartons has a pair of opposed surfaces which are larger than the other surfaces thereof and wherin said larger surfaces face the open ends of said sleeve.

5. A shipping package as claimed in any of claims 1 to 3 wherein each of said rectangular cartons has a pair of opposed surfaces which are larger than the other surfaces thereof and wherein said larger surfaces face the opposed walls of said sleeve which are covered by said sheet.

6. A shipping package as claimed ln claim 5 wherein the top and bottom of each carton each faces an open end of the sleeve.

7. A shipping package as claimed in claim 5 wherein side surfaces of each container face the open ends of said sleeve.

8. A shipping package as claimed in any preceding claim in which the sheet of heat-shrinkable material comprises tubular film.

9. A shipping package as claimed in any preceding claim in which the sheet of heat-shrinkable material is transparent.

10. A shipping package substantially as herein described with reference to and as illustrated in Fig. 2 of the accompanying drawings.

11. A shipping package substantially as herein 5 described with reference to and as illustrated in Fig. 3 of the accompanying drawings.

12. A shipping package substantially as herein described with reference to and as illustrated in Fig. 4 of the accompanying drawings.