WO2010086883A1

WO2010086883A1 - Reinforced pallet made from recyclable material

Info

Publication number: WO2010086883A1
Application number: PCT/IS2010/000002
Authority: WO
Inventors: Olafur H. JΌNSSON; Friδrik R. JΌNSSON; Friδrik Ari FRIORIKSSON; Jόhann BJÖRGVINSSON; Valgeir GUÖMUNDSSON
Original assignee: Graenar Lausnir Ehf.
Priority date: 2009-02-02
Filing date: 2010-01-29
Publication date: 2010-08-05
Also published as: IS8789A; IS2687B

Abstract

The present invention relates to a pallet made from recycled paper or plastic material, rectangular in shape, with loading surface (9) provided with reinforcing indentations (7) which run in the same diagonal direction at opposite corners, but do not generally combine (2a, 2b, 2c, 2d). The indentations at adjacent corners have orthogonal direction with respect to each other and may combine (8). Additional indentations (5) may run along the sides of the rectangular loading surface (9) between the feet (1). The pallet is also provided with multiple tapering feet (1) having slightly elongated shape, with flat bottom, having fanfolded side walls (6a, 6b, 6c) for reinforcement, with indentation(s) (3, 4) at the end walls of the feet (1) for additional reinforcement and for facilitating stacking of empty pallets.

Description

Reinforced pallet made from recyclable material

Description

Field of the invention

The present invention relates to a pallet structure, made from recycled paper or plastic material. Furthermore the invention relates to methods for manufacturing the pallet.

Background art

Traditionally, pallets have been made from timber, cardboard or some plastic material. Timber is though rather expensive material and, besides, much work is involved in constructing pallets from that material and such pallets are also quite space demanding. Increased demand for cleanness in recent years and requirement for an environment as free from microorganisms as possible, has made their use less appealing. Although good experience has been obtained from using pallets made of cardboard and plastics, their raw materials are, however, expensive.

The aim of the present invention

The aim of the present invention is to construct robust pallets from waste paper. The advantages are that the raw material is inexpensive and easily available in large quantities in most places. The pallets are environmentally acceptable since no toxic materials are used in their production and they canthemself be recycled in same manner as their raw material. An additional aim is to provide pallets made from plastic materials, preferably from recycled plastic articles.

Summary of the invention

The intention of the present invention is achieved by providing reinforcing structures in the loading surface of the pallets and by folding the walls of the pallets feet in order to increase the load carrying ability. These features are in accordance with the characterizing part of claim 1. The other embodiments of the invention are according to the characterizing parts of the other claims.

Detailed description of the invention

The present invention will be described in detail with reference to the following figures.

Figure 1 is a perspective view of one embodiment of the invention.

Figure 2 shows the pallet from fig. 1 from above.

Figure 3 shows the structure of the feet in more detail, a) twin foot from the middle section of the pallet b) single foot from the end edge.

Figure 4 is a) side view and b) end view of a standard (euro) pallet of the type shown in the previous figures (measurements in mm).

Figure 5 shows stacked empty pallets.

The pallet of the embodiment shown in the figures is rectangular in shape. The loading surface (9) is provided with indentations (7). These have diagonal directions, where indentations at opposite corners have the same direction and do not combine. Indentations in adjacent corners have orthogonal direction, with respect to each other, and may optionally combine to form V-shaped structures (8). Thus these indentations can be regarded to belong to four groups (2a, 2b, 2c and 2b), of nine each in the case shown. The number and positions can be varied to serve the intended use of the pallet. Besides, there are similar indentations (5) along the edges of the rectangular loading surface (9) in between the feet. The function of all these indentations is to strengthen the loading surface (9) by forming rigid beam like structures. The feet (1) are elongated and have slightly tapering shape with flat bottom. The walls of the sides have multiple folds (6a, 6b and 6c) forming zig-zag folding on each side to prevent the foot from crumpling when load is applied to the pallet. The number of folds can be varied depending on intended use; three in the case shown. In the middle section of the pallet shown the feet are paired, two and two. Furthermore, the feet are provided with shallow indentations (3, 4) in the end parts, except where facing the end edges of the rectangle. These indentations (3) reach approximately one third to half of the length down the foot and combine the double feet in the middle of the pallet. The latter indentations are to further increase the strenght of the pallet and furthermore, the bottom of these indentations form a stop when the empty pallets are stacked on each other, thus preventing them sticking together.

To increase hydrophobicity of the product, Aquapel® D350 may be added to the paper pulp. Furthermore, to increase the strength of the product, Hercobond® 5250 may also be added. These have been added at the concentration of 5 L and 800 ml to 6 m³ of water, respectively. Both products are obtained from Ashland Hercules Water Technologies. These materials are considered environmentally safe to use. Similar products that er available commercially may be used instead. It is also possible to use other types of additives such as fibers to alter the properties of the pallet.

The method of production of the pallet is by known methods or modifications of them as described in the Icelandic patent application no IS 8688 (corresponding to WO 2009/057162), which is incorporated herein by reference. In that method, hot air at about 250⁰C is used in the drying process, which ensures at the same time sterilization of the pallets.

The amount of paper pulp/slurry is selected in the way that the dry weight of a standard (euro) pallet is from 0.5 to 10.0 Kg, preferably about 2.5 Kg. This results in typical thickness of about 3.2 to 8.1 mm (2.5 kg; the higher figure for the top of an indentation). The loading ability was tested according to EN ISO 8611 on paper pallet. When tested with 861 kg load the pallet fulfilled the requirement of the standard. However, it did not pass the test when the load was 1010 kg (deflections over limits). Maximum load in a compression test of one corner foot averaged 230 kg (n = 3). Tensile strenght, measured on samples (n = 3) from top of an indentation (thickness = 7,0 mm; density = 0.28 g/cm³) and bottom of an indentation (thickness = 3,3 mm; density = 0.37 g/cm³), was 1,06 MPa and 1,72 MPa, respectively. E-modulae measured on these samples were 65 MPa and 125 MPa, respectively.

Stacking of the pallets is possible if the load limit is not exceeded. When empty, it is contemplated that 60-70 pallets can be stacked in a 40 feet container. In that way space for 1300 - 1500 pallets per container is provided for.

The pallet can be produced in any size for different use. The standard pallet size (euro standard), 120 cm x 80 cm, will be loaded and used as any other standard pallet (rigid, interlocked or in columns). For other purposes, the pallets will be produced in different sizes, e.g. half the standard size (60 cm x 80 cm) and in any size there in between when desired and in even in smaller sizes, e.g. corresponding to one fourth of the standard euro size. Larger pallets are also conceivable, e.g. the size 120 cm x 100 cm. These will be provided with different number of feet, e.g. six for the half standard size, and optionally having modifications in the pattern of the strengthening structures, i.e. the folds of the feet and the indentations in the loading support. AU these alterations fall within the scope of the invention described above.

Although the pallet structure of the invention was developed for paper pallets, the form may also be suitable for pallets made from plastic material; material that can also be recycled.

Claims

1. Pallet made from recycled paper or plastic material, rectangular in shape, characterized by:

a) loading surface (9) provided with several reinforcing indentations (7) which run diagonally in the same direction at opposite corners (2a and 2c; 2b and 2d) but do not generally combine, where the indentations in adjacent corners have orthogonal direction with respect to each other (2a and 2b; 2b and 2c; 2c and 2d; 2d and 2a), where the indentations of adjacent corners may combine (8), where additional indentations (5) may run along the sides of the loading surface (9) between the feet (1);

b) multiple tapering feet (1) having slightly elongated shape, with flat bottom, provided with fanfolded walls (6a, 6b, 6c) for reinforcement, and optionally with an indentation(s) (3, 4) in an end wall.

2. The pallet according to claim 1, characterized in that the number of feet (1) is from 4 to 36.

3. The pallet according to claim 2, characterized in that the number of feet (1) is 12.

4. The pallet according to claim 2, characterized in that the number of feet (1) is 6.

5. The pallet according to claim 3, characterized in that the six feet (1) in the middle section are paired, two and two.

6. The pallet according to any one of the preceeding claims, characterized in that the dimensions of the rectangular loading surface (9) is about 80 cm x 120 cm.

7. The pallet according to claims 1-5, characterized in that the dimensions of the rectangular loading surface (9) is about 80 cm x 60 cm.

8. The pallet according to claim 7, characterized in that it is made by cutting the pallet of claims 5 and 6 into two parts in between the twin feet (1) or by dividing the molding unit used for making the pallet of claims 5 and 6 or by constructing dedicated molding unit.

9. The pallet according to any one of the preceeding claims, characterized in that the number of diagonal surface indentations (7) is from 4 x 1 to 4 x 40.

10. The pallet according to claim 9, characterized in that the the number of diagonal surface indentations (7) is 4 x 9.

11. The pallet according to any one of the preceeding claims, characterized in that the number of folds (6) in the walls of each foot (1) is from 2 x 2 to 2 x 16.

12. The pallet according to claim 11, characterized in that the number of folds (6) in the walls of each foot (1) is 2 x 3.

13. The pallet according to any one of the preceeding claims, characterized in that the pallet is made from paper pulp/slurry in which additives have been optionally added to increase the strength and/or hydrophobicity.

14. The pallet according to claims 1-12, characterized in that the pallet is made from plastic material.

15. Method for manufacturing a pallet according to claims 1 to 13, the method comprising the steps of:

placing a robotic arm or a mechanical device carrying a first male molding unit to a container - applying air suction to first male molding unit for obtaining sufficient fibrous slurry onto the molding face; forming the object; removing said first male molding unit from the container; draining excess water from the mold; pressing the object against airtight elastic material while applying air suction to the mold; - transferring the object from the first male molding unit to the first female molding unit by air activated means; transferring said first female molding unit to a drying unit; and applying hot pressurized air flow through the object for drying the object.

16. The method according to claim 15 characterized in that the manipulation and transfer of the molding units is performed by a robotic arm or a mechanical device with three-dimensional freedom of rotation.