GB2410735A

GB2410735A - Cardboard pallets

Info

Publication number: GB2410735A
Application number: GB0402577A
Authority: GB
Inventors: Martyn Reader; Andrew Carter
Original assignee: SCA Packaging Ltd
Current assignee: SCA Packaging Ltd
Priority date: 2004-02-05
Filing date: 2004-02-05
Publication date: 2005-08-10
Also published as: GB0402577D0

Abstract

A cardboard pallet comprises a base sheet 4 and a plurality of side walls 8 hingedly connected to the base sheet 4. Opposed pairs of side walls 8 have openings 12 to receive the forks of a fork lift truck. The side walls 8 are further provided with flaps 16 which are secured to a top sheet 6. Spacers 10 are arranged between the base sheet 4 and the top sheet 6. Preferably the top sheet is secured by folding the flaps over it.

Description

24 1 0735 - 1 Pallets The present invention relates to pallets and in

particular to cardboard pallets. Cardboard pallets are becoming popular in view of their relatively light weight and their ability to be recycled after use. They also overcome the timber treatments required by timber pallets to meet regulation ISPM15 for export packaging.

The present invention seeks to provide a cardboard pallet which is easy to manufacture and is robust in use.

From a first aspect, the invention provides a cardboard pallet comprising: a base sheet; a plurality of side walls hingedly connected to said base sheet at least one opposed pair of side walls having openings to receive the forks of a fork lift truck; a top sheet spaced from said base sheet; and one or more spacers arranged between said base sheet and said top sheet; wherein at least one of said side walls is provided with a flap which is secured to said top sheet.

Thus in accordance with the invention, one or more flaps formed on side walls of the pallet are used to at least assist in securing the top sheet of the pallet in position by being folded over and secured to the top sheet.

Preferably each side wall is provided with a securing flap.

Preferably the side walls of the pallet are formed integrally with the base sheet of the pallet to facilitate manufacture. Most at least one opposed pair of side walls and more preferably all the side walls have openings in appropriate positions so as to receive - 2 - the forks of a fork lift truck.

Preferably the flaps overlie the top sheet. This considerably simplifies manufacture and provides protection for the edges of the top sheet.

The base sheet and top sheet of the pallet may be formed from any suitable board material. In a preferred embodiment, the base sheet is made from a solid board material. A preferred board material comprises a double kraft paper outer liner with a hard sized inner. This material has the advantage of a certain degree of inherent water resistance. Preferably, however, the base sheet is also provided with a waterproof outer coating, for example of polyethylene.

Solid board material is not, in general particularly rigid, so preferably the top sheet is of a relatively rigid material to give the pallet rigidity.

Preferably, therefore, the top sheet is of a corrugated board construction, most preferably a double wall corrugated material.

This is a novel arrangement in its own right, so from a further aspect, the invention provides a cardboard pallet comprising: a base sheet; a top sheet spaced from said base sheet; and a plurality of spacers arranged between said base sheet and said top sheet; wherein said base sheet is formed from a solid board material and said top sheet is formed from a corrugated board material.

The top sheet may also be provided with a waterproof coating, for example of polyethylene.

The top of the pallet may be of a laminated construction. For example, a further sheet may be laminated onto the top sheet to provide additional strength. This could, for example, comprise either a corrugated or a solid board material.

Where flaps overlie the top sheet, the further - 3 - sheet may be positioned within the boundary formed by the flaps so as to form a planar upper surface.

Means to attach or locate a container on the pallet may also be provided on the top of the pallet. For example wings may be attached to the top sheet such that they may be interleaved with bottom flaps of a container to be carried by the pallet. The wings may be formed as a unitary member attached to the top sheet at a hinge line. The member may therefore comprise a central strip to which the wings are hingedly attached and which is attached, preferably bonded to the top sheet.

Preferably the strip has lateral extensions which are secured under the flaps of the side walls.

The spacer(s) arranged between the base sheet and the top sheet are preferably also made from a board material. Most preferably they are formed from a spirally wound board material, most preferably a solid board material. This construction provides extremely good crush resistance, and is particularly simple.

In the simplest embodiment each spacer may be generally circular in section, although other shapes can be formed in this manner, for example elliptical or generally rectangular shapes.

Any suitable number of spacers may be provided, but in the preferred embodiment, rows of spacers, preferably equispaced, are provided across the width of the pallet. In one example, three rows of spacers are provided.

The base sheet may be provided with one or more openings which will accommodate the wheels of a pallet truck.

The pallet of the invention is very easy to assemble and manufacture. In a preferred method of manufacture, as a first step the base sheet and side walls are erected and glued into a tray shape. The spacers are then bonded into appropriate positions on the base sheet and, if appropriate, bonded also to the - 4 - side walls of the tray. The top sheet is then bonded to the tops of the spacers and the side wall flaps then folded over and bonded onto the top sheet.

From a further aspect, therefore, the invention provides a method of manufacturing a cardboard pallet comprising the steps of: providing a blank having a base panel, and a plurality of side wall panels hingedly attached thereto, at least one said side wall having a flap at it free edge; folding said side walls upwardly and securing them to form a tray; securing a plurality of spacers within the tray; positioning a top sheet over said spacers; and folding said flap over said top sheet and securing it thereto.

From another broad aspect the invention provides a cardboard pallet having a tray-like bottom part incorporating a bottom sheet and side walls, one or more spacers arranged within the tray, and a top sheet secured in the top of the tray to close the tray.

In broad terms the top sheet and side walls of the pallet may overlap and preferably the side walls comprise flaps which extend over the periphery of the top sheet.

In the preferred embodiment, the various components are glued together using a PVA adhesive. However, the side wall flaps may be bonded to the top sheet by this or another adhesive such as a hot melt adhesive.

Some preferred embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a pallet in accordance with the invention; Figure 2 shows an exploded view of the pallet of Figure 1; Figure 3 shows the blank from which the base sheet - 5 - of the pallet is constructed; Figure 4 shows, in a perspective plan view, an intermediate stage in the assembly of the pallet; Figure 5 shows a second embodiment of the invention; Figure 6 shows a third embodiment of the invention; and Figure 7 shows the embodiment of Figure 6 attaching to a container.

With reference to Figure 1, a rectangular pallet 2 comprises a base sheet 4, a top sheet 6 and four side walls 8. A plurality of spacers 10 are arranged between the base sheet 4 and the top sheet 6. The side walls 8 are each provided with openings 12 to receive the forks of a fork lift truck.

As can be seen from Figure 3, the base sheet 4 and side walls 8 are formed from a one-piece blank of board material. In this particular embodiment the sheet material is a solid board material comprising a double kraft paper outer liner with a hard sized inner. Such materials are widely available on the market. The board is also provided with a polyethylene or other waterproof coating. Typically the board is 3mm thick.

As can be seen from Figure 3 the base sheet 4 is also provided with four openings 14 which in use will accommodate the wheels of a pallet truck.

The side walls 8 are provided with flaps 16 along their upper edges for retaining the top sheet 6 as will be described further below. Opposed side walls 8 also comprise glue flaps 18 as will also be described further below.

The top sheet 6 is of a corrugated construction.

In this particular embodiment, it is preferred that the top sheet is a heavy duty double wall corrugated arrangement, i.e. one having facing sheets 20, 22 and two sheets of corrugation 24 separated by a further, intermediate sheet 26, as shown in the detail of Figure - 6 - 2. This provides a particularly rigid sheet construction.

The spacers 10 are each formed from a spirally wound sheet of solid board material. This may be of the same material type as the base sheet and is preferably waterproof to prevent ingress of water into the spacers.

In one embodiment, the spacers may be made from 3mm thick material. In another embodiment, the spacers may be made from 9mm thick material, in which case 9 or 12 spacers might only be required. This depends on the

specification required of the pallet.

As can be seen in Figure 4, there are eighteen spacers 10 arranged in three rows across the base sheet.

Assembly of the pallet will now be described.

Starting from the base sheet blank shown in Figure 3, the side walls 8 of the pallet are folded up and secured to each other by the glue flaps 18. This produces a tray 28 as shown in Figure 4. The spacers 10 are then bonded into position on the base sheet 4 and against the side walls 6 in the positions shown. At this stage, the tray 28 is still relatively flexible, but the final stage in assembly is the attachment of the top sheet 6 which, as discussed above is relatively rigid. This sheet 6 is glued onto the tops of the spacers 10 and the side wall flaps 16 then folded over and glued to the upper face of the top sheet 6. This laminated construction considerably stiffens the pallet assembly. A PVA adhesive is used to bond the various components of the tray together except for the side wall flaps which are bonded to the top sheet using a holt melt adhesive, for example.

Thus the pallet 2 is, in effect, constructed as a tray having a base 4 and side walls 8, one or more spacers 10 arranged within the tray and a top sheet 6 which closes the tray.

Turning now to Figure 5, a second embodiment of pallet 30 of the invention comprises a pallet 2 as described above, but with an additional reinforcement sheet 32 laminated, e.g. by bonding, to the top sheet 6 of the pallet 2. The reinforcement sheet 32 is typically of a solid board or corrugated material and is dimensioned to fit snugly within the space 34 defined inside the folded over side wall flaps 16 to present a substantially continuous pallet upper surface.

With reference to Figures 6 and 7, the pallet 2 of Figure 1 may be provided with a pair of wings 40 to locate a container 42 on the pallet 2. As can be seen from Figure 7, the wings 40 engage inside base flaps 44 of the container 42, thereby keying the container 42 onto the pallet 2.

The wings 40 are provided on a unitary member 46 made from a board material, typically a corrugated board, which has a central strip 48 attached, preferably bonded to the top sheet 6 of the pallet. The strip 48 has lateral extensions 50 which are secured under the side wall flaps 16.

Such an arrangement can be used with or without an additional reinforcement as used in the embodiment of Figure 5.

It will be appreciated that various modifications may be made to the embodiments described above without departing from the scope of the invention. For example, materials of those described above may be used for the various components. Also, the number and position of spacers may also be changed. All that is important is that the spacers are not placed in a position where they will interfere with the insertion of fork lift forks.

They may be placed in rows or in some other pattern across the pallet. Also other forms of spacer may be used.

Also, the side wall flaps 16 may lie under the top sheet 6 although that is not preferred. In other arrangements the top sheet may have flaps which overlie the side walls. l r - 8 -

Claims

Claims 1. A cardboard pallet comprising: a base sheet; a plurality of side

walls hingedly connected to said base sheet at least one opposed pair of side walls having openings to receive the forks of a fork lift truck; a top sheet spaced from said base sheet; and at least one spacer arranged between said base sheet and said top sheet; wherein at least one of said side walls is provided with a flap which is secured to said top sheet.
2. A pallet as claimed in claim 1 wherein a plurality of and preferably each side wall is provided with a securing flap.
3. A pallet as claimed in claim 1 or 2 wherein the side walls of the pallet are formed integrally with the base sheet of the pallet to facilitate manufacture.
4. A pallet as claimed in claim 1, 2 or 3 wherein all the side walls have openings to receive the forks of a fork lift truck.
5. A pallet as claimed in any preceding claim wherein the side wall flaps overlie the top sheet.
6. A pallet as claimed in any preceding claim wherein the base sheet is made from a solid board material.
7. A pallet as claimed in claim 6 wherein the base sheet is made from a board material which comprises a kraft paper outer liner with a hard sized inner.
8. A pallet as claimed in any preceding claim wherein t - 9 - the base sheet is provided with a waterproof outer coating.
9. A pallet as claimed in any preceding claim wherein the top sheet is of a relatively rigid material.
10. A pallet as claimed in claim 9 wherein the top sheet is of a corrugated board construction.
11. A pallet as claimed in claim 10 wherein the top sheet is of a double wall corrugated material.
12. A cardboard pallet comprising: a base sheet; a top sheet spaced from said base sheet; and at least one spacer arranged between said base sheet and said top sheet; wherein said base sheet is formed from a solid board material and said top sheet is formed from a corrugated board material.
13. A pallet as claimed in any preceding claim wherein the top sheet is provided with a waterproof coating.
14. A pallet as claimed in any preceding claim wherein the top of the pallet is a laminated construction.
15. A pallet as claimed in any preceding claim wherein a reinforcement sheet is laminated onto the top sheet.
16. A pallet as claimed in any preceding claim wherein the reinforcement sheet is a corrugated or a solid board material.
17. A pallet as claimed in any preceding claim wherein the reinforcement sheet lies within the boundary formed by the side wall flaps. l -
18. A pallet as claimed in any preceding claim further comprising means to attach or locate a container on the pallet.
19. A pallet as claimed in claim 18 wherein said location means comprises wings attached to the top of the pallet for interleaving with bottom flaps of a container to be carried by the pallet.
20. A pallet as claimed in claim 19 wherein the wings are formed as a unitary member attached to the top sheet at a hinge line.
21. A pallet as claimed in claim 20 wherein the unitary member comprises a central strip to which the wings are hingedly attached.
22. A pallet as claimed in claim 21 wherein the strip has lateral extensions which are secured under the flaps of the side walls.
23. A pallet as claimed in any preceding claim wherein the spacer(s) are made from a board material.
24. A pallet as claimed in claim 23 wherein the spacers are formed from a spirally wound board material, most preferably a solid board material.
25. A pallet as claimed in claim 24 wherein each spacer is generally circular in section.
26. A pallet as claimed in any preceding claim wherein rows of spacers are provided across the width of the pallet.
27. A pallet as claimed in any preceding claim wherein the base sheet is provided with one or more openings - 11 which will accommodate the wheels of a pallet truck.
28. A method of manufacturing a cardboard pallet comprising the steps of: providing a blank having a base panel, and a plurality of side wall panels hingedly attached thereto, at least one said side wall having a flap at it free edge; folding said side walls upwardly and securing them to form a tray; securing a plurality of spacers within the tray; positioning a top sheet over said spacers; and folding said flap over said top sheet and securing it thereto.
29. A method as claimed in claim 28 wherein selected components are bonded together using a PVA adhesive.
30. A cardboard pallet having a tray-like bottom part incorporating a bottom sheet and side walls, one or more spacers arranged within the tray, and a top sheet secured in the top of the tray to close the tray.
31. A pallet as claimed in claim 30 wherein the top sheet and side walls overlap.
32. A pallet as claimed in claim 31 wherein the side walls comprise flaps which extend over the periphery of the top sheet.