GB2288783A

GB2288783A - Pallets

Info

Publication number: GB2288783A
Application number: GB9404651A
Authority: GB
Inventors: Robert George Bindley; Douglas John Sparkes
Original assignee: Rigid Containers Ltd
Current assignee: VPK Packaging Ltd
Priority date: 1994-03-10
Filing date: 1994-03-10
Publication date: 1995-11-01
Also published as: GB9404651D0

Abstract

A pallet (10) for use in relation to the storage and/or transport of food industry products is constructed of kiln-dried wood and has a surface treatment providing a permeable coating especially a water-based emulsion primer applied by dipping the pallet into a bath of primer. <IMAGE>

Description

P A L L E T S This invention relates to pallets, for example pallets of the kind suitable for use with a fork-lift truck. More particularly, the invention relates to pallets for use in relation to the storage and transport of food industry products.

Pallets for use in relation to the food industry are subject to a variety of requirements specific to that industry, which apply to varying degrees according to the particular application of a particular pallet.

Examples of these requirements are the following.

Firstly, there is a need for a high standard of performance in relation to avoidance of contamination of food products carried on the pallet. This requirement means that the pallet should minimise the absorption of materials spilled on the pallet and should have an ability to be cleansed of contaminant materials in a readily-effected manner.

A further factor relates to the weight of the pallet.

While in the loaded condition pal lets are handled by fork-lift trucks and the like, in the unloaded condition there is a requirement for an upper limit on the weight of the pallet which is related to manual handling thereof, and this limitation has quite severe consequences in relation to the use of certain materials for the construction of pallets. Thus, for example, the use of conventional pine timbers is in many cases ruled out simply on grounds of weight.

A further factor concerns generation of toxic gas or vapour phase materials in the event of combustion. There is a requirement for the generation of such materials to be minimised.

Thus, the requirements of a food industry pallet are many and varied and in view of the obvious volume requirements for such a product there is a need for an improved compromise to be provided between cost and the meeting of various ones of these requirements, and an object of the present invention is to provide improvements in one or more of these respects or generally.

According to the invention there is provided a pallet for use in relation to the storage and/or transport of food industry products. In accordance with a first aspect of the invention the pallet comprises timber or wood which has been kiln-dried. Applied to the surface of the kiln-dried wood or timber there is a surface treatment material of the kind defined in the definition below.

Surface treatment materials suitable for use in accordance with the invention include surface treatments producing a permeable coating. Examples of such permeable coatings are water-based emulsion primers.

In an embodiment a pallet constructed mainly or entirely from kiln-dried wood treated with a surface treatment material in accordance with the above definition exhibited very significant improvements in relation to previously known pallets. Thus, the pallet was not only able to meet the weight requirements, but also exhibited very remarkably improved properties in relation to minimising contamination transfer, ability to be washed and endurance of the effects of washing and other aspects of the arduous operating conditions of the pallet without significant damage to the surface treatment or surface finish of the pallet. Indeed, in one series of tests it was found that the wooden structure of the pallet was itself significantly damaged by the steam-cleaning and other cleansing operations before the surface finish of the pallet was significantly removed.

In the embodiment, it was found that the pallet exhibited an ability to be effectively cleansed by a water-based washing operation without unacceptable absorption of the water (and thus likewise of soluble contaminants) whereby the contamination and cleansing requirements were met and simultaneously the expected weight penalty arising from water absorption was avoided. The extent to which this performance characteristic was achieved with kiln-dried wood increased the extent to which the performance was a matter of surprise to the man skilled in the art.It had been expected that such kiln-dried wood would exhibit a high tendency to absorb significant amounts of water thereby by increasing the effective density of the wood It is believed that there is an operative inter relationship between the defined class of surface treatment materials and the kiln-dried wood which produces this heterodox performance in a manner which is not directly attributable to the known characteristics either of the wood or the surface treatment material.

In accordance with a preferred mode of use of a pallet according to the invention, the colour coding and/or finish applied to the pallet are such that the pallet is used only for storage and/or delivery of food industry products and thus is not contaminated with chemicals, fertilizers etc. Such is achieved by means of pallet colour coding and/or finish regulations applicable to pallet use. In this way a so-called "closed loop" for the use of such food industry pallets is achieved, whereby exposure to contaminants is avoided.

In an embodiment, it is found that the kiln-dried wood is not only subject to the advantage of freedom from preservatives, but it is also found to be more free from staining and/or mould. These are additional factors which prove beneficial in the use of the pallet in the above-mentioned closed loop.

In the course of treatment of a pallet under construction in accordance with the principles of the invention, it is found that there is a high absorption rate by the kiln-dried wood of the surface treatment material. This produces a waterproof coating. Moreover, the thus-coated product is capable of being cleaned without water retention.

In an embodiment, the top timbers of the pallet are not square cut but are formed with chamfered edges. This finish, in association with the surface treatment defined above results in a pallet which is largely splinter-free.

The pallet has the character of promoting surface water run-off without water absorption.

An aspect of the use of a pallet in accordance with the principles of the invention relates to the service or repair of the pallet after a period of use. During such service or repair, pallets according to the invention are subjected to a further surface-treatment process in which the entire pallet, rather than a repaired wooden component thereof, is retreated and thus recoated.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: FIGURE 1 shows a plan view of a pallet for use in the food industry; FIGURE 2 shows a side elevation view of the pallet of Figure 1, the direction of viewing being indicated by arrow II in Figure 1; FIGURE 3 shows an end elevation view of the pallet of Figures 1 and 2, the direction of viewing being indicated in Figure 1 by the arrow III; and FIGURE 4 shows a portion of Figure 2 on a larger scale and in more detail.

As shown in the drawings, a pallet 10 comprises an assembly of kiln-dried wood comprising four corner blocks 12 and four centre blocks 14.

Mounted on top of the corner and centre blocks is a top deck assembly comprising three stringers or lengthwise panels 16 disposed parallel to each other and interconnecting the centre and corner blocks. Mounted on top of the stringers are transverse stringers or panels 18 mounted at spaced apart positions in parallel orientation at right angles to the lengthwise stringers.

Mounted below the corner and centre blocks 12 and 14 is an assembly of bottom transverse end stringers 20 disposed generally parallel to the top stringers 18 and aligned therewith, and bottom lengthwise stringers 22.

Pallet 10 is assembled from the blocks and stringers by means of nails in the conventional manner. Bottom lengthwise stringers 22 are disposed parallel to the top lengthwise stringers 16 and extend between the two end transverse stringers 20.

Chamfered edges 24 are provided on the bottom stringers 22 and 20 to reduce the damage produced by insertion of the forks of fork-lift trucks.

As shown in Figure 4, the transversely extending edges of tranverse stringers 18 are rounded or chamfered as shown at 26. This greatly reduces the production of splinters in normal handling of the pallet.

Pallet 10 comprises composite wood material for the blocks 12 and 14, but otherwise is constructed of kiln-dried pine wood.

After assembly, the pallet is dipped in a surface treatment material as described below. This surface treatment step results in a rapid absorption of the surface treatment material. The result is the production of a waterproof coating which can be cleaned by steam or water pressure treatment method without significant water retention in the body of the pallet. Likewise, it is found that the pallet can meet the manual handling weight criteria and possess the non-contamination advantages which have already been discussed above.

The surface treatment material which is applied to pallet 10 comprises a water-based emulsion primer. In one embodiment the surface treatment material comprises Sikkens Rubbol WP170 obtainable from Akzo Coatings Plc at 135 Milton Park, Abingdon, Oxfords hire. It is believed that other permeable coatings for surface treatment of wood may be capable of achieving the technical effects described above in relation to the invention.

More than one surface treatment stage, for example, by dipping, is preferably applied to the wood of the pallet construction. The surface of the pallet should be allowed to remain permeable and no subsequent top coating should be applied which would prevent this.

Claims

1. A pallet for use in relation to the storage and/or transport of food industry products, the pallet being constructed mainly or entirely of kiln-dried wood and having a surface treatment providing a permeable coating.

2. A pallet according to claim 1, wherein the surface treatment comprises a coating of a water-based emulsion primer.

3. A pallet according to claim 1 or claim 2, wherein the coating is substantially waterproof.

4. A pallet according to any one of the preceding claims, wherein the surface treatment is applied by dipping the untreated pallet in a bath of the coating material.

5. A pallet according to any one of the preceding claims, wherein the surface treatment is applied in more than one stage.

6. A pallet according to any one of the preceding claims, wherein at least a top deck of the pallet comprises timbers having chamfered edges.

7. A pallet according to any one of the preceding claims, the pallet comprising top and bottom decks of kiln-dried wood and blocks of composite material.

8. A pallet according to any one of the preceding claims, the pallet being colour coded and/or having a distinctive finish to indicate that it is intended for use in relation to the storage and/or transport of food industry products.

9. A pallet according to any one of the preceding claims, the pallet being substantially free of preservatives.

10. A pallet for use in relation to the storage and/or transport of food industry products, the pallet being substantially as described herein with reference to, and as illustrated by, the accompanying drawings.

11. A method of using a pallet as defined in any one of the preceding claims, wherein the pallet is used solely in relation to the storage and/or transport of food industry products.

12. A method according to claim 11, the method including the step of servicing and/or repairing the pallet, said servicing/repairing step including the step of re-treating the entire pallet with the coating material.