Background Art A method and apparatus for forming structural articles from weak substrates such as polystyrene and cardboard (known as the ARMACEL process), and articles so formed, are disclosed in the applicant's International PCT Patent Application No.

PCT/AU95/00100 entitled"A method and apparatus for forming structural articles" (WO 95/23682), International PCT Patent Application No. PCT/AU96/00541 entitled 'Layered Structural Article" (WO 97/09166) and International PCT Patent Application No. PCT/AU00/00250 (WO 00/59709) -the contents of all three of which are hereby incorporated into the present specification by cross reference. A further, presently unpublished specification is that of International Patent Application No.

PCT/AU2004/000826 which discloses the encapsulation of an interior member which is not at least partially fluid permeable or is perforated to become so. The disclosure of that specification is also hereby incorporated by cross-reference.

These specifications disclose forming structural articles from a shape defining interior member of inherently weak material such as expanded polystyrene or cardboard and at least one external skin. The basic steps of the method comprise: 1. heating a thermoformable sheet intended to form the external skin, 2. bringing the heated sheet alongside the interior member, 3. applying a fluid pressure differential between opposite surfaces of the interior member and the sheet to conform the sheet to the shape of the interior member and mutually engage same, and 4. maintaining the fluid pressure differential until the sheet has cooled.

In particular, the ARMACEL process has been used in the past to make structurally strong articles from inherently weak materials, for example, fabricating a load bearing box from polystyrene, or fabricating a load bearing pallet from cardboard. In

addition, it is known to bind together structurally two or more articles by encapsulating the articles utilising the ARMACEL process.

The present invention extends the use of the ARMACEL process in an unexpected fashion and finds particular application in existing warehouse environments. As will be explained hereafter in more detail in relation to the drawings, many existing warehouses in order to keep initial capital costs to a minimum have used the most inexpensive possible material for the shelves which are required to support the goods stored within the warehouse. As a consequence, such shelving has traditionally been made from particleboard, or similar timber like products often fabricated from sawdust and glues of various descriptions. Because of increasing standards both in terms of operation and functionality and in terms of occupational health and safety, there are various commercial pressures being applied to the operators of such warehouses to increase the functional capability of their shelving. For example, it would be highly desirable if such shelving were able to be washed in order to clean same, and it would also be desirable if such shelving did not continually shed small fibres of timber derived cellulose which hitherto have contributed greatly to dust loads within the warehouse.

Object of the Invention Such pressures have resulted in some warehouse operators replacing shelves made from particleboard with shelves made from metal, even to the extent of stainless steel shelves. Naturally this represents a very substantial capital expenditure. The object of the present invention is to enable the functional capabilities of existing structural components to be expanded without having to incur the capital cost of replacing the actual components.

Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a method of expanding the functional capability of existing components fabricated to bear a structural load, said method comprising the steps of : (i) removing each said component from its existing position,

(ii) substantially permanently encapsulating said component with a thermoformable sheet plastics covering utilizing a process known per se to thereby increase the load bearing capability of said component, and (iii) after said encapsulation process returning said encapsulated component to said existing position or an equivalent position.

In accordance with a second aspect of the present invention there is disclosed a component having expanded functional capabilities after having been subjected to the abovementioned method.

Brief Description of the Drawings Embodiments of the present invention will now be described with reference to the drawings in which: Fig. 1 is a perspective view of existing prior art shelving arrangements within a warehouse, Fig. 2 is a perspective view similar to Fig. 1 but showing the same shelving after being encapsulated utilizing the ARMACEL process, Fig. 3 represents a front to rear cross-sectional view through one of the shelves of Fig. 2, Fig. 4 is a similar cross-sectional view through a shelf of a second embodiment incorporating stiffening ribs, and Fig. 5 is a similar cross-sectional view through a shelf of a third embodiment illustrating encapsulation of a metal mesh.

Detailed Description As seen in Fig. 1, warehouse shelving 1 takes the form of metal uprights 2 which support horizontal shelves 3. The shelves 3 can support a significant mechanical load and transfer it to the uprights 2. The uprights 2 are made from steel in order to provide sufficient load bearing capability to accept the load transferred to each upright 2 by all the shelves 3 which the upright supports.

However, in order to keep initial capital costs to a minimum, the shelves 3 have typically hitherto been made from particleboard or similar timber substitutes which

are normally fabricated from sawdust or similar timber particles held together in a matrix of glue or a glue substitute.

The main advantages of the material from which the shelves 3 are made is its low initial cost and low weight. The shelves 3 suffer from numerous disadvantages. For example, the particleboard is permeable to moisture and actually absorbs moisture from humidity in the air. In addition, the material is not very rigid and therefore tends to bow or sag into a curve when loaded and the moisture absorbent material can adopt a permanent set as indicated in Fig. 1 due to this combination of moisture absorption and lack of rigidity.

Furthermore, the shelves 3 are not able to withstand exposure to liquids. Thus if one of the pails 6 located on the lower shelf 3 were to leak, this would almost certainly result in the shelf absorbing the leaked liquid and expanding, generally to the point where the shelf was rendered inoperable and needed to be replaced. As a consequence of this disadvantage, there is an incentive for warehouse operators to ensure that containers for liquid are stored on the lowermost one or two shelves so that in the event of a breakage of a container, or other leakage of the liquid contents of the container, only one or two shelves are destroyed by the escaping liquid.

Conversely, if the liquid containers were stored on the uppermost shelf, there is a danger that escaping liquid might destroy all the shelves located below the shelf on which the liquid escaped. As a consequence, boxes 7 of dry goods are obliged to be stored above the pails 6. This does not necessarily lead to efficient warehouse operation.

Turning now to Figs. 2 and 3, in the first embodiment of the present invention the abovementioned disadvantages are substantially overcome by removing each of the shelves 3 and individually subjecting each shelf 3 to the ARMACEL process so as to create an encapsulated shelf 13. As schematically illustrated in Fig. 3, the encapsulated shelf 13 has a first layer 14 which extends over the underside of the shelf 13 and up the side edges of the shelf 13. Preferably the first layer 14 also covers a microchip 18 or bar code 19 (in the latter case the encapsulating layer 14 being transparent). In addition, the encapsulated shelf is provided with a second layer 15

which extends over the upper surface of the shelf 13 and again over the sides so as to overlap with the first layer 14. In the drawings a small gap is illustrated between the layers 14 and 15 and the shelf 13, however, this is only for the purposes of illustration and such a gap does not exist in practice. Instead the layers 14 and 15 are securely adhered to the surface of the shelf 13. There are no holes or openings in the layers 14, 15.

In addition, the layers 14,15 are in practical terms permanently applied to the timber of the shelf 13. The plastic encapsulation can only be removed with considerable effort and particles of the shelf 13 come away with the removed sheets 14,15 thereby destroying the shelf 13 for all practical purposes.

The microchip 18 and/or bar code 19 assist in the introduction of automation into warehouse activities.

It will be appreciated by those skilled in the ARMACEL process that the process utilizes a differential pressure applied to each of the layers 14 and 15 as they are being applied. This difference in pressure can be utilized to reverse the bow or curve which has formed in the shelf 3 so that the encapsulation naturally straightens and holds straight the curved shelf 3 so as to produce a flat shelf 13. This is the position illustrated in Fig. 2. In addition to flattening the shelves 3, the encapsulation process also produces a very much more rigid shelf 13 and thus not only is the unsightly bow removed from the shelves 3 but the encapsulated shelves 13 are able to carry increased loads without bowing.

Turning now to Fig. 4, a second embodiment of the shelf 23 is illustrated, the shelf 23 being provided with four stiffening ribs 26 which can be fabricated from inexpensive materials such as timber or even cardboard. This is because the encapsulating layers 24, or 25 together with the new shape of the encapsulated shelf 23 provides for an increased bending moment and thus greater rigidity. The material from which the ribs 23 are fabricated does not contribute substantially to the rigidity, instead the major contribution comes from the encapsulating layers applied by the ARMACEL process.

Finally, in relation to Fig. 5, a still further embodiment is illustrated in which a perforated steel plate 36 is encapsulated with layers 34 and 35 to create a refurbished shelf 33 of great rigidity and durability but still of low weight compared with conventional metal shelves.

The abovementioned PCT specifications provide an extensive list of plastics material which can be used in the layers 14,15 ; 24,25 and 34,35. The plastics can be either transparent or coloured as desired and, in particular, plastics having properties which are acceptable for food grade applications can also be used.

The above described arrangements provide a number of various substantial advantages. First of all an article of greater strength and longer operational life is created. In addition, the ARMACEL process itself is relatively inexpensive and therefore the cost of encapsulating an existing shelf 3 so as to provide an improved shelf 13,23, 33 is substantially less than buying an entirely new shelf, especially if the new shelf is fabricated from stainless steel or similar such high quality materials. In addition, because the particleboard is fully encapsulated, it no longer sheds small cellulose fibres and thus the creation of dust within the warehouse is substantially reduced. Also, the layers 14,15 ; 24,25 and 34,35, being entirely impervious to water and other liquids, means that the shelves 13,23, 33 can be washed down if necessary, are not harmed by spilt corrosive liquids such as acids, and are not damaged by leakage of liquids from containers. Furthermore, if such a leakage does occur, it is not generally necessary to purchase a new shelf as is the case with the shelf 3.

In addition, the encapsulated shelves can obtain HACCP and/or FDA approval and so are able to be used with food and/or pharmaceuticals.

In many warehouse situations, the warehouse includes many hectares of shelving and thus the cost of entirely replacing each shelf 3, with, for example, metal shelves is prohibitive. However, the cost of expanding the functional capability of the existing shelves is quite modest compared with the substantial improvement in performance able to be achieved.

Prior art searches conducted after the priority date have disclosed WO 92/09490 (to which US Patent No. 5,123, 359 corresponds). This specification discloses covering a timber pallet with a removable plastics coating so that the timber components thereof can be disassembled and re-configured if desired. The coating requires application of a top layer, then a bottom layer, and then subsequent formation of a seam between the two layers. Such a removable coating teaches away from the present invention where the plastics encapsulation is permanent. In particular, a removable covering does not bind with the existing component so as to increase its structural strength.

Furthermore, the removable coating not being bonded to the timber components, is liable to split. Such splits harbour moisture, bacteria, fungus, etc and prevent such an arrangement receiving HACCP or FDA approval. A similar situation arises in respect of the continuous seam formed between the two layers. The prior art specification discloses welding which implies that the two plastic layers to be welded cannot be under tension. Without overlapping as disclosed above it is virtually impossible to guarantee an impervious join at the seam.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention. For example, the present invention is also applicable to domestic shelving and cupboard doors.

The term"comprising" (and its grammatical variations) as used herein is used in the inclusive sense of"having"or"including"and not in the exclusive sense of "consisting only of.