GB2342343A - Blanks for protective holders - Google Patents

Abstract

A package e.g. for chemicals such as pesticides comprises a flexible pouch of a water soluble material such as PVOH disposed within a flexible water protective bag, and an outer holder formed from a blank. The blank comprises a first side wall panel 12 and second side wall portions 14l, 14r, with intervening end wall panels 13l, 13r of generally elliptical form bounded by arcuate fold lines 15l, 15r, 16l, 16r. The portions 14l, 14r are overlapped and joined by cooperating tongues 18, 21 to hold the package closed.

Description

Blanks for containers This invention relates to blanks for containers, and concerns in particular a blank and a sleeve-like container made therefrom that is suitable for use as part of a containerisation system that may be of value in, for example, the packaging of fluids-especially gels and liquids-contained within a plastic bag, particularly such a bag in the form of a water-soluble envelope.

In the Specification of British Patent Application No: 97/14,079.2 (Publication No :.............. ; P1474Sub) there is described and claimed a blank and a sleeve-like container made therefrom and suitable for the packaging of fluids contained within a water-soluble plastic bag. The present invention relates to an alternative form of blank that is easier to erect into the required container form.

It has for some years been proposed that a very convenient way to market, transport and use possibly hazardous chemicals such as herbicides, pesticides and like agricultural substances that are to be dispersed in water prior to their use is in the form of a flexible package or pouch made of a material-the primary packaging material-which itself is water soluble. The pouch is then placed in a secondary package-a waterprotective bag-to prevent the pouch being damaged if the whole is wetted by accident (as it might be were it tc be exposed to rain or a high ambient humidity), and the bag is conveniently given a handle and a tear nick or strip so that it may easily be grasped and then opened by hand without using cutting tools.

For storage and/or transportation, one or more of such pouch/bag combinations are typically retained within an outer shipping carton, commonly of corrugated fibreboard or the like, that is either roughly the right size to hold the one (or more) pouch/bag combination or is partitioned (rather like a wine box) to keep each pouch/bag relatively secure, and to provide additional strength and some protection against puncturing or tearing.

Such a containerisation system-water-soluble pouch as the primary package, water-protective bag as the secondary package, and outer shipping carton-is well-known in the Art; various examples of it are described in Rhone-Poulenc (Gee) US Patent No: 5,405,013 and in Rhone-Poulenc (Knudsen) EP Published Patent Specification No: 0, 631, 947A A double-layer package like the pouch/bag combination is easy and safe to use. The Operator simply takes the combination out of the shipping carton, tears open the protective bag, and without opening-or even touching-the inner pouch simply tips it into an appropriate quantity of water, whereupon the watersoluble primary packaging material dissolves and the contents of the pouch disperse as required. The Operator is not exposed to the pouch's possibly hazardous contents, and the risk of accidental spillage is reduced Typical flexible water-soluble packaging materials useful as the primary packaging-the pouch-are the various films made from polyvinyl alcohol (PVOH), while typical protective materials useful as the secondary packaging-the bag-are nylon/polyethylene laminates.

Many other possible materials are described in the aforementioned US and European Patent Specifications.

PVOH (and other) films can if properly used make excellent water-soluble pouches for all sorts of fluids.

Unfortunately, though, the pouches can become susceptible to damage due to mechanical shock, despite their enclosing protective bag. It is too easy for a severe impact to take the water-soluble pouch material beyond its elastic limit, causing rupture typically around the seal area of the pouch. Moreover, such materials have flexibility and like characteristics which are, regrettably, deleteriously affected by temperature changes. Thus, at temperatures of around 0 C and below PVOH and similar films become increasingly brittle, to the point at which they can fail. The problem will be better understood from the following comments.

A PVOH primary packaging pouch containing a liquid or gel, whether in its protective secondary packaging bag or not, is somewhat shapeless, and left to itself will"flow"into the lowest mechanical energy shape it can. On a flat surface this is usually lying flat on the surface; if restrained within a larger container such as a shipping carton it may slump over, creasing as it goes.

If such a pouch is simply dropped from a metre (about 3ft) or more onto a hard surface it will almost inevitably burst; the impact subjects the pouch and its contents to considerable hydraulic pressure, and the forces involved can easily stretch the PVOH material beyond its elastic limit. This is particularly so at temperatures of 0 C or below, when the PVOH becomes less and less flexible. The situation is worsened if, as is most likely, the flexible PVOH film has wrinkled or creased (a typical occurrence when the pouch/bag combination is stored in a shipping carton).

The present invention seeks a solution to this, so as to reduce significantly the risks associated with stress cracking of the water-soluble film used to make the primary packaging pouch. In particular, the present invention proposes a way of mitigating, in part if not in whole, the issue of cold temperature transportation of water-soluble pouch packaging-especially that containing hazardous chemicals such as pesticides and herbicides, in both liquid and gel presentations.

Moreover, whilst the invention was conceived with the transport of hazardous chemicals in mind, other products susceptible to shock could equally utilise its principles. What the invention proposes is a containerisation system which allows for protection of the product against mechanical shock, puncture and cold climate temperature fluctuations. It also puts forward a stand-alone containerisation system which allows for protection of the product.

To achieve these aims the invention suggests the use of a novel construction of outer, storage-box, container, or holder, in which may be placed the pouch/bag combination, and that will provide the thusplaced pouch/bag combination with the required ability to withstand and be cushioned against the likely physical shocks associated with normal conditions of transport, storage and use. More specifically, the invention suggests the use, as this holder, of an openended sleeve-like receptacle made from a suitably-shaped and-cut blank that has been folded in such a way as to wrap around, and more securely to hold, a pouch/bag combination placed therein; this is accomplished by making the holder in a curvilinear shape like that of a pillow, which shape corresponds more or less to the natural"relaxed"shape of the pouch/bag combination to be disposed therewith. Such a pillow-shaped holder can be achieved by the use of a blank (from which the holder is to be constructed by folding and the like) wherein the fold lines defining the side and end walls of the portion are arcuate, such that as the blank is folded into its erect form it naturally takes on the required pillow shape.

As noted above, in the Specification of British Patent Application No: 97/14,079.2 (Publication No :.............. ; P1474Sub) there is described and claimed a blank and a sleeve-like container made therefrom. This blank is of the type just describedthat is, it has fold lines defining the side and end walls of the portion which are arcuate, such that as the blank is folded into its erect form it naturally takes on the required pillow shape. This earlier the blank also has double-depth edge strips that can be used to provide the holder with double-cuff-like strengthening and shock-absorbing members around the two end edges of the sleeve, and when erected and in use the holder formed from the blank is kept closed by a closure flap the corners of which are inserted into the space between the cuff members and part of the sleeve body.

It has been found that this double-edge-strip/ double-cuff structure, though excellent for the purpose of providing the required strength and shock-absorbing powers, is not so convenient from the point of view of erecting the holder from the blank, for bending and folding the edge strips into place as the cuffs is a task which, though relatively easy when done manually, is not at all simple if done by a machine. The present invention relates to an alternative form of blank that is easier to erect (especially by machine) into the required container form.

In one aspect, therefore, the invention provides a blank from which may be formed a protective holder, the blank being made of shape-retaining material and comprising a main section having five aligned panels defining a first side wall of the container, at either end of the first side wall, and defined thereat each by a first arcuate fold line, an end wall of the container, and at the end of each end wall, and defined thereat by second arcuate fold lines, a portion of the second side wall of the container, the second side wall being in use opposed to the first side wall, with its two portions dimensioned to overlap free end over free end, the two arcuate fold lines defining each end wall being curved towards each other such that the end wall is elliptical, and wherein at the free end of one second side wall portion there is a protruding tongue with its body extending into the portion and defined by slits therein, and at the free end of the other second side wall portion there is a matching but recessed tongue with its body extending into the portion and defined by slits therein, such that when the two portions are moved towards each other (as when erecting the container from the blank) the protruding tongue on one moves into engagement with but over the recessed tongue on the other, while the wall portion either side of the protruding tongue similarly moves into engagement with but under the wall portion either side of the recessed tongue.

The invention also provides, of course, a protective holder when made by erecting such a blank.

The invention provides a blank for a protective holder, the blank being made of shape-retaining material. This blank is generally a paper product, preferably corrugated fibre board. However, other materials, including multi-wall materials, may be usedtypically plasticsgsheets such as that known by the trade name"CORREX"Z. A preferred material, though, is a single-wall"B"flute corrugated fibre board material made from recycled materials, although it will be understood that the fluting media used may vary depending on the nature of the product to be packaged and the strength required in the holder. Indeed, whilst numerous other materials and combinations of fluting medium could be utilised, the material known by the trade name"TEST"is particularly preferable since it is made from recycled material and is therefore inherently weaker than a pure kraft (virgin), construction. This is a desirable feature, as a holder made therefrom, when assembled and subjected to mechanical shocks, affords much greater resilience (cushion factor) and energyabsorbing characteristics.

Where the material used for the blank of the invention is fluted board, the fluting is preferably aligned generally from end to end of the blank (and thus normal to the fold lines). This gives increased shockabsorbing and inherent strength properties to the holder made therefrom.

The blank has panels defining first and second opposed side walls of the holder, between which, and defined by first and second fold lines, are the two end walls of the holder. Each of these fold lines is arcuate, the sense of the arc-bowed in or bowed outbeing such that the end walls are generally correspondingly elliptical. It is this which causes the holder erected from the blank to take on the desired pillow shape that more or less matches the natural shape of the liquid-containing bag to be disposed therein.

There is little else that can be said about the fold lines and their arcuate nature, save to observe firstly that it may be convenient, depending on the material from which the blank is made, to perforate the fold lines (both to render easier the folding of the blank, and to make the resulting holder crumple, and so absorb shock, more readily), and secondly that in general the degree of arc will be small, else it may be difficult to fold the blank properly. Thus, the arcuate nature of the fold lines defining the elliptical end walls is preferably such that the centre point heights of the fold lines are generally in a ratio of centre point height: outer limit of the walls of 100: 1 or less, so that the residual inflatability of a bag held therebetween is set at optimum performance to dissipate maximum"hydraulic shock". A preferred range is from 4: 1 down to 1. 5 : 1, and in one example the ratio is 2: 1. It might also be worth observing that the greater the degree of arc the more the erected holder will be "waisted"as well as"rounded".

At the end of each end wall the blank of the invention has, defined thereat by second arcuate fold lines, a portion of the second side wall of the container. The two portions are conveniently much the same size-though one could be smaller than the other and are dimensioned to overlap, free end over free end, when the holder is erected from the blank; an overlap of around a fifth to a quarter of the end-to-end wall dimension (around 2inches, or 5 cm, for a standard-sized holder) is suitable.

To keep the erected holder shut and its pouch/bag contents secure therein the blank is provided with a protruding tongue on one second wall portion that matches, and interacts with, a recessed tongue on the other second wall portion. In either case-protruding or recessed-the body of the tongue is defined by slits extending into the portion, conveniently normal to the free end thereof. In relative terms the protruding tongue is slightly less than half the depth of its portion, the recessed tongue closer to a fifth, the actual amount depending on the degree of overlap of the portions; for a standard-sized holder this is around 2 inches (5 cm) for the former, 1 inch (2.5 cm) for the latter.

To improve the ease with which the blank can be folded to bring the free ends of the second wall's two portions together, and then slide them into the required over/under-lapping engagement with each other, it is convenient to make the free end of the portion carrying the protruding tongue slightly convex, so that, when the blank is folded in the appropriate way, bring the two free ends together, and the natural curve of the end walls causes the two second wall portions themselves to be curved (towards the first wall, in the required pillow shape), the two corners of the convex free end portion are almost automatically aligned underneath the two corners of the other portion's free end.

The holder of the invention-that is, the holder made from the blank of the invention-is, as explained previously, primarily intended to be an outer, protective holder for a bag-specifically, a pouch/bag combination-of some liquid or gel substance. The invention therefore naturally extends to the conglomerate of a holder of the invention when including interposed between the first and second side walls a bag -specifically, a pouch/bag-containing such a liquid or gel. This bag may conveniently have at one end a longitudinally-extending flap defining a handle which projects outwardly of the erected holder when the bag is disposed therein. It will also very preferably incorporate a tear nick or strip, whereby it may be opened (by the User) without the need for there to be employed any cutting tool. Moreover, the bag advantageously has a shape matching that of the outer holder-thus, a waisted shape which is congruent to the preferred waisted shape of the second side wall-defining panel (such a shape is normally natural to a bag made from what is in effect a pair of flexible oblong sheets joined face to face all round their periphery and containing a liquid or gel).

Perhaps slightly surprisingly, a number of pouch/bag-filled blank-derived holders of the invention can be quite conveniently stacked side to side in a relatively stable and safe manner, without significant risk of the pouches rupturing. It would seem that in the stack the adjacent conglomerates lie major face to major face but the contact between them is not full face but rather along a line where each curved pillow surface touches the next. This allows the stack to absorb applied mechanical shock energy both by the individual conglomerates rocking back and forth, and by them flattening out and distorting slightly.

A stack of this kind can then be contained within a larger, conventional shipping carton (made from corrugated fibreboard, say), again for storage or transport, with a reduced or even zero risk of any of the individual component's contents being damaged if the larger carton is dropped. In this connection it is noted that a number of conglomerates of pouches, bags and holders of the invention, both in and out of larger shipping cartons (these latter held eight filled holders), were tested for Drop Strength according to the standard UN Drop Tests (see Martin Castle's The Transport of Dangerous Goods, Revised Addition published by PIRA International in 1995). The filled cartons were dropped from various heights (up to about 1.2m, at which height the UN Drop Tests are effected) at various temperatures (down to-23 C) and in several orientations (flat on, edge on, corner on, etc) onto a hard surface.

There were no failures.

The invention is now described, though by way of illustration only, with reference to the accompanying Drawings, in which: Figure 1 shows a blank according to the present invention and capable of being used to form a single"wrap-around"outer "storage-box"container, or holder, unit of the invention; Figure 2 shows an end view of the blank, partially folded (nearly into the form of a"wrap around"holder unit of the invention); Figure 3 shows a sectional view (on the line III-III in Figure 1) of a fully formed and erected holder according to the invention in its locked-together configuration; and Figure 4 shows a perspective view of the fully formed and erected holder according to the invention.

The blank shown in Figure 1 has a main section (generally 11) having five aligned panels (12,131, r, and 141, r) defining a first side wall 12 of the container at either end of which is an end wall 131, r the junction with which is defined by a first arcuate fold line (151, r). At the end of each end wall, and defined thereat by second arcuate fold lines (161, r) is a portion 141, r of the second side wall of the container, the second side wall being in use opposed to the first side wall, with its two portions dimensioned to overlap free end over free end (see Figures 2-4). All the arcuate fold lines 15,16 are curved, the two for each end wall 13 being curved towards each other, such that the end walls are elliptical.

At the free end (171) of one second side wall portion 141 there is a protruding tongue (18) with its body (19) extending into the portion and defined by slits (20t, b) therein, and at the free end (17r) of the other second side wall portion 14r there is a matching but recessed tongue (21) with its body (22) extending into the portion and defined by slits (23t, b) therein.

As cab be seen from Figures 2 and 3, when the two portions 14 are moved towards each other (as when erecting the container from the blank) the protruding tongue 18 on one moves into engagement with but over the recessed tongue 21 on the other, while the wall portion (18w) either side of the protruding tongue 18 similarly moves into engagement with but under the wall portion (21w) either side of the recessed tongue 21.

It will be seen that the free edge of the free end 171 from which the protruding tongue 18 projects is convex in shape, while the free edge of the free end 17r carrying the recessed tongue 21 is straight. As can just be seen from Figure 2, this makes easier the fitting of the two portions 14 together. The way, once so fitted, the surfaces overlap is shown in Figure 3.

Claims (9)

1. Claims 1. A blank from which may be formed a protective holder, the blank being made of shape-retaining material and comprising a main section having five aligned panels defining a first side wall of the container, at either end of the first side wall, and defined thereat each by a first arcuate fold line, an end wall of the container, and at the end of each end wall, and defined thereat by second arcuate fold lines, a portion of the second side wall of the container, the second side wall being in use opposed to the first side wall, with its two portions dimensioned to overlap free end over free end, the two arcuate fold lines defining each end wall being curved towards each other such that the end wall is elliptical, and wherein at the free end of one second side wall portion there is a protruding tongue with its body extending into the portion and defined by slits therein, and at the free end of the other second side wall portion there is a matching but recessed tongue with its body extending into the portion and defined by slits therein, such that when the two portions are moved towards each other (as when erecting the container from the blank) the protruding tongue on one moves into engagement with but over the recessed tongue on the other, while the wall portion either side of the protruding tongue similarly moves into engagement with but under the wall portion either side of the recessed tongue.
2. 2. A blank as claimed in Claim 1 which is made of a single-wall"B"flute corrugated fibre board material.
3. 3. A blank as claimed in either of the preceding Claims, wherein, where the material used for the blank is fluted board, the fluting is aligned generally from end to end of the blank, and thus normal to the fold lines.
4. 4. A blank as claimed in any of the preceding Claims, wherein the arcuate fold lines are perforate, and the degree of arc is such that the centre point heights of the fold lines are generally in a ratio of centre point height: outer limit of the walls of from 4: 1 down to 1.5: 1.
5. 5. A blank as claimed in any of the preceding Claims, wherein the portions, at the end of each end wall, of the second side wall of the container are much the same size, and are dimensioned to overlap, free end over free end, when the holder is erected from the blank.
6. 6. A blank as claimed in any of the preceding Claims, wherein, to improve the ease with which the blank can be folded to bring the free ends of the second wall's two portions together, and then slide them into the required over/under-lapping engagement with each other, the free end of the portion carrying the protruding tongue is made slightly convex.
7. 7. A blank as claimed in any of the preceding Claims and substantially as described hereinbefore.
8. 8. A protective holder when made by erecting a blank as claimed in any of the preceding Claims.
9. 9. The conglomerate of a holder as claimed in Claim 8 when including interposed between the first and second side walls a bag containing a liquid or gel.