Such cartons are subject to a large amount of handling, and at some stages during their use they are subjected to very high compression forces. For bananas, the cycle begins with picking of unripe bananas in countries such as Guatemala or the Dominican Republic and loading the unripe bananas into the carton. To do this, the local depot receives corrugated fibreboard blanks and assembles the cartons on-site. Because a particular banana transportation company may frequently change depots and because of the large number of depots involved, it is generally not practical to install expensive and sophisticated carton assembling plants at these locations. Accordingly, an important objective for such cartons is that they are simple to assemble on-site at the picking locations.

However, a further requirement of such cartons is that they be capable of withstanding the very high pressures which are applied after they leave the packing location. For example, to optimise use of space in ship holds, the cartons are often stacked very high resulting in a very large compression strength being applied in the vertical direction to the lower cartons. When being loaded onto the ship and subsequently off-loaded and transported in vehicles, there can be side impact forces applied as the cartons are being handled.

Accordingly, fruit cartons of this type have the conflicting requirements of being very simple to assemble and also of providing a very high resistance to compression forces. A still further requirement of fruit cartons of this type is that they be suitable for use at the retail outlet in the destination country for displaying

the goods. This criterion is becoming increasingly important as retailers demand simpler methods for handling the goods and more effective display.

A still further requirement for such fruit cartons is that they provide a large degree of ventilation through the carton. This is particularly important for ripening of bananas and avoiding"hot spots"arising in certain cartons on a loaded pallet.

For example, if the temperature of bananas in a particular box rises by as little as 2°C relative to those around it during the ripening process, such a"hot spot"may cause premature ripening and loss of the bananas. When one considers the relatively low commercial margins which are involved in purchase and distribution of bananas, one will appreciate the importance of minimising the degree of damage caused by the physical handling of the produce and inconsistent ripening. If the fruit is bruised in handling heat is generated leading to inconsistent ripening. This in turn leads to problems at the point of sale as imperfections do not allow the full retailing potential to be realised.

Traditionally, the type of carton which has been used comprises two almost equal halves which are telescoped together to form the base and cover for a carton, both halves extending for the full height of the carton to provide a double wall thickness. The outer carton is removed at the point of sale leaving the bananas displayed in the inner carton part.

The invention is directed towards providing an improved carton which provides the necessary compression strength, is relatively simple to assemble, provides a large degree of ventilation, and is simple for the retailer to use for effective display of the produce.

Statements of Invention According to the invention there is provided a carton comprising:-

an inner carton part; and an outer carton part; the inner carton part having reinforcing corner struts at the junction between adjacent walls of the inner carton part; and the inner carton part having flaps which overlap the corner struts on erection of the inner carton part.

In one embodiment of the invention the inner carton flaps comprise side flaps and end flaps which are overlapped, on assembly. Preferably the flaps are adhesively bonded to one another, on assembly.

In another embodiment of the invention the inner carton part is erected from an inner carton blank which is formed from a unitary sheet of material such as corrugated fibre board.

Most preferably the inner carton blank comprises ;- a first side wall panel; a first end wall panel; a second side wall panel; a second end wall panel; and corner strut-forming panels between adjacent side and end panels.

Preferably the corner strut-forming panels comprise three strut panels between adjacent side and end panels. Desirably the inner carton blank includes corner strut-forming panel portions at the free ends of the inner carton blank, the corner strut-forming panel portions, on assembly, forming a fourth corner strut.

Preferably, the corner struts extend diagonally between adjacent side and end panels.

In a further embodiment of the invention the carton parts have ventilation holes which are in registry on assembly of the inner carton part to the outer carton part.

In another embodiment of the invention the carton parts have handle-forming cut- outs which are in registry on assembly of the inner carton part to the outer carton part.

In a preferred embodiment of the invention the inner carton part is telescopically engaged with the outer carton part, on assembly. Most preferably the inner carton part is removable from the outer carton part, for display.

In another preferred embodiment of the invention the outer carton part has display indicia on an outer surface thereof which are visible when the inner carton part is removed from the outer carton part for display of produce such as bananas retained in the outer carton part.

In a further embodiment of the invention the outer carton part is erected from an outer carton blank which is formed from a unitary sheet of material such as corrugated fibre board.

Most preferably the outer carton blank comprises :- a first side wall panel;

a first end wall panel; a second side wall panel; a second end wall panel; and flaps which overlap, on assembly.

Desirably the flaps comprise first closure flaps extending from the side panels and second closure flaps extending from the end panels, the first and second closure flaps being overlapped on assembly to substantially cover the corner struts.

In another aspect the invention provides a carton blank formed from a unitary sheet of material such as corrugated fibre board, the carton blank comprising:- a first side wall panel; a first end wall panel; a second side wall panel; a second end wall panel; and corner strut-forming panels between adjacent side and end panels.

Preferably the corner strut-forming panels may comprise three strut panels between adjacent side and end panels. Desirably the carton blank includes corner strut-forming panel portions at the free ends of the blank, the corner strut-forming panel portions, on assembly forming a fourth corner strut. Preferably the corner struts, on assembly, extend diagonally between adjacent side and end panels.

In one embodiment of the invention the carton blank includes flaps which overlap the corner struts, on assembly. Preferably the flaps comprise a side flap for each side panel and an end flap for each end panel.

In another embodiment of the invention the carton blank includes ventilation holes formed therein.

In a further embodiment of the invention the carton blank includes handle- forming holes formed therein.

A further aspect of the invention provides a method of packaging fresh produce such as bananas comprising the steps of erecting an inner carton part, loading the produce onto a floor of the inner carton part, inserting an outer carton part over the inner carton part and the produce, and turning the packaged carton so that the floor of the inner carton part is uppermost. Preferably the method includes the step of removing the inner carton part from the outer carton part for display at point of sale.

In a preferred embodiment of the invention the method of packaging fresh produce utilises a carton or a carton blank according to the invention.

Brief Description of the Drawings The invention will be more clearly understood from the following description thereof, given by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a plan view of a blank used to form an outer carton part; Fig. 2 is a plan view of a blank used to form an inner carton part;

Fig. 3 is a perspective view of the inner carton part in a folded configuration; Fig. 4 is a perspective view of the inner carton part being erected; Fig. 5 is a perspective view of an erected inner carton part in an in-use orientation; Fig. 6 is another perspective view of the erected inner carton part; Fig. 7 is a perspective view of the outer carton part in an erected configuration; Fig. 8 is a perspective view of the outer carton part in a bottom-up erected orientation; Fig. 9 is a perspective view of the assembled carton in an erected transport and display orientation; and Figs. 10 (a) to 10 (h) are perspective views illustrating the various stages of the erection and use of the carton.

Detailed Description Referring to the drawings there is shown a carton 1 which is assembled from two blanks, namely, an outer carton portion blank 2 and an inner carton portion blank 3.

Referring particularly to Fig. 1, the outer blank 2 is formed from a unitary sheet of corrugated fibre board. The various panels, flaps, tabs and openings are defined by cuts and lines of weakness or fold lines, as shown most clearly in Fig. 1. The

outer blank 2 comprises a pair of side wall panels 10 and a pair of end wall panels 11, each of which have ventilation slots 13. The end panels 11 also have hand openings 18, which also provide ventilation. The side wall panels 10 have closure flaps 14 and the end wall panels 11 have closure flaps 15 which are overlapped and glued together on assembly into the erected configuration 25 of Figs 7 and 8.

The outer blank 2 also has an end flap 21 extending from one free end of one side panel 10 and which is adhesively bonded to the face of one end panel 11 adjacent the free end thereof. In this configuration the blank 2 may be folded about a central fold line 20 for flatpack transportation to a point of packaging. At the point of packing, the flaps 14,15 are folded down, overlapped and adhesively bonded at the overlap for erection of the outer carton portion 25.

Referring especially to Fig. 2 the inner blank 3 is also formed from a unitary sheet of corrugated fibre board which may be of double thickness. The various panels, flaps and openings are defined by cuts and lines of weakness or fold lines. The blank 3 comprises a pair of side wall panels 30 and a pair of end wall panels 31, each of which have ventilation slots 32. The end wall panels 31 also have hand openings 33 which also provide ventilation. On assembly, the ventilation slots, 13,32 and hand holes 18,33 of the inner and outer blanks 2,3 are in registry.

It will be appreciated that the ventilation and other apertures 13,18,32, and 33 in the inner and outer carton parts 25,50 may be oversize with respect to one another.

The inner blank 3 also includes four corner struts, three of which are defined by diagonal wall panels 37 between adjacent side and end panels 30,31. The blank 3 also includes sidewardly projecting panel portions 38,39 which are overlapped and adhesively bonded, on assembly to form a fourth corner strut 36 as illustrated particularly in Fig. 3.

The inner blank 3 has closure flaps 40,41,42,43 which are folded down, overlapped and adhesively bonded, on assembly as illustrated particularly in Figs. 4 and 5 to form an inner carton part 50. The blank 3 may be folded as illustrated in Fig. 3 for flatpack transportation to the point of packaging. It will be noted that the flaps 40,41,42,43 overlap at the corner reinforcing struts 37,36 on assembly.

This is particularly important for load distribution. In addition, the flaps 40,41, 42,43 are particularly important in ensuring that the carton maintains its shape, in use. The flaps 40,41,42,43 further ensure that the load is evenly applied when a number of cartons are stacked one upon another.

In use, and referring in particular to Figs. 10 (a) to 10 (h) the inner carton portion 50 is first erected by opening up the blank 3 from the folded flatpack configuration of Fig. 3 with the flaps 40,41,42,43 uppermost. The flaps 40,42 are then folded down as illustrated in Fig. 10 (a). The flaps 41,43 are then folded down and adhesively bonded to the flaps 40,42 to form an erected inner carton portion 50 as illustrated in Fig. 10 (b). After erection, the inner carton portion 50 is inverted into the orientation of Fig. 10 (c) in which the overlapped flaps 40,41,42,43 form a support floor for bunches of bananas.

Referring to Fig. 10 (d) the outer carton portion 25 is similarly erected by opening up the blank 2 from the folded flatpack configuration with the flaps 14,15 uppermost. The flaps 15 are folded down as illustrated in Fig. 10 (d). The flaps 14 are then folded down and adhesively bonded to the flaps 15 to form an erected outer carton portion 25.

The overlapped flaps 14,15 also form on inversion of the outer carton portion 25 a support floor for bunches of bananas as will be explained in more detail below.

Referring now to Fig. 10 (e) the inner carton part 50 is first arranged into a packaging orientation with the flaps 40,41,42,43 lowermost. Bunches of bananas are then loaded into the inner carton part 50. When loaded, the outer

carton part 25 is telescopically engaged over the packaged inner carton part 50 as illustrated in Fig. 10 (e). After packaging, the assembled carton 1 is inverted into the storage and transportation orientation of Fig. 10 (f). The carton is transported in this orientation to the point of sale. At the point of sale the inner carton part 50 is readily telescopically removed as illustrated in Fig. 10 (g). This operation leaves an open-topped tabled outer carton part 25 for effective retailing as illustrated in Fig. 10 (h).

The invention provides a carton which is very simple to erect, pack, transport, and use for retail display. When the closure flaps are in the closed position, they provide a significant extent of coverage for the goods within the carton and thus a good deal of protection. In addition, the closed flaps are important in providing a degree of strength of the walls so that the carton can withstand the forces which are applied, in use, especially in association with the reinforced corner struts.

The invention is not limited to the embodiments hereinbefore described which may be varied in detail. For example, the closure flaps may be of any size, depending on the nature of the end use of the carton. Any suitable ventilation opening arrangement may be used, depending on end use requirements.