PALLET MADE OF MASSIVE CARDBOARD

The present invention concerns a pallet.

It is generally known that pallets are means that are frequently used for storing and transporting goods. The best known pallets are wooden pallets.

For specific hygienic reasons in certain sectors, such as the food sector, the feed sector, the pharmaceutical industry and the new international rules, imposed for example by the Food and Agriculture Organization and/or by legislations in certain countries regarding phytosanitary measures and import and export, wooden pallets must be subjected to a special thermal or other treatment which can prevent the spread of vermin such as insects, bacteria, rats, mice and the like.

A disadvantage thereof is that such a treatment is expensive and time-consuming.

Moreover, in order to prevent fumigation of loads on wooden pallets and in order to obtain pallets that can be cleaned better or that meet the very stringent hygienic standards and safety requirements, such as the absence of splinters and metal parts, pallets made of other materials such as plastic and aluminium have been developed.

However, because of their very high cost price, they are little successful in the industry and in the distribution sector.

It is also known that single-use pallets or multi-use pallets, which can be recycled in an economical and environmental-friendly way, are an interesting alternative of course.

The development of cardboard pallets which can be processed in a conventional pulp installation is obvious. Cardboard pallets have been described in a number of patents such as EP 1,588,952 and EP 1,695,915.

However, all these cardboard pallets are made of corrugated board parts which are compressible and sensitive to moisture when heavily loaded, which is extremely disadvantageous for high-load application fields.

The present invention aims to remedy one or several of the above-mentioned and other disadvantages.

To this end, the present invention concerns a pallet that is made of parallel longitudinal elements, perpendicular cross elements and vertical supporting elements placed at regular distances, whereby the supporting elements, the cross elements and the upper longitudinal elements are placed vertically to the lower longitudinal elements, whereby at least some of the above-mentioned elements of the pallet are made of massive cardboard, i.e. compressed or glued paper.

By massive cardboard is meant cardboard here which, as is known, is preferably made by processing old paper with

water into fibres, purifying it, spreading it in the form of leaves and dehydrating it in a cardboard machine, mechanically pressing it and drying it. Then, the cardboard is covered on either side and cut into sheets in a cutting machine. These sheets are used in cardboard manufacturing to produce among others shipping packages for various products such as flowers, fruit and vegetables, frozen fish and meat, records, nuts and bolts, etc., but also document files, covers and puzzles are made out of it.

As is clear from what precedes, massive cardboard should have certain qualities in order to be able to pack moist products in it, and at the same time it must be sufficiently rigid in order to be able to stack the boxes. Further, a possible print on the box should remain nice- looking, as the producer of the packed article definitely likes to make it clear what is held in the box.

Massive cardboard typically has a weight between 500 and 1000 gram per square meter, and after it has been covered with paper this may even increase up to 2000 g/m ² , sometimes even 10,000 g/m ² . Typically, the thickness of massive cardboard is situated between half a millimetre and three millimetres.

Massive cardboard is shipped worldwide, as opposed to corrugated cardboard which is usually delivered within a range of 400 km. Massive cardboard is carried along on fishing boats to pack the catch in, and it is often used in flower, fruit and vegetable auctions, but also emergency houses and chairs are made out of it. It is an all-round

product that can be entirely recycled.

A massive cardboard pallet according to the invention offers many advantages .

A first major advantage is that a massive cardboard pallet according to the invention is hygienic and can be immediately put to use in many industries without having to undergo any thermal or other processes to kill vermin for example.

An additional advantage is that a massive cardboard pallet can be recycled via the conventional paper recycling process, which is good for the environment.

Another advantage is that a massive cardboard pallet according to the invention can be entirely or partly decorated, which offers new possibilities for a better management of the flow of goods and possibly even advertising possibilities.

Another advantage is that a massive cardboard pallet according to the invention has a modular construction, as a result of which different lengths, widths and heights can be realised.

An additional advantage is that a massive cardboard pallet according to the invention is cheap compared to synthetic materials and wood, that it is light compared to wood and that, nevertheless, it has the same look and configuration as wooden pallets.

Another advantage is that a massive cardboard pallet according to the invention can be put directly into contact with food products, provided the legal hygienic standards are being followed during production.

In a preferred embodiment of a pallet according to the invention, all the parts are massive cardboard sections which, in the case of the vertical supporting elements, can be glued together so as to form a cylinder and which are placed and assembled at regular distances.

This is advantageous in that a relatively light and cheap pallet is obtained which, irrespective of the thickness of the parts and their mutual distances, can support heavy loads .

The invention also concerns a massive cardboard section which can be used as a longitudinal element, a cross element or a supporting element for a pallet.

Preferably, all the longitudinal elements and cross elements have the same U-shaped massive cardboard sections, and all the supporting elements can moreover be composed or made of the above-mentioned U-section.

This is advantageous in that an even cheaper production process of a pallet according to the invention is obtained.

In a preferred embodiment, the massive cardboard is reinforced with a fibrous material as a reinforcing agent .

This offers the advantage that the pallet according to the invention is formed of a material which is . even stronger than massive cardboard as such, as a result of which the pallet will have an even larger bearing capacity.

The invention also concerns a method for manufacturing a pallet according to any one of the preceding claims, whereby the massive cardboard sections are pressed, cut and punched, the sections are assembled as the elements of the pallet (1) and the elements are fixed together by means of gluing and/or a mechanical connection.

In order to better explain the characteristics of the invention, the following embodiments of a pallet according to the invention are described as examples only without being limitative in any way, with reference to the accompanying drawings, in which:

figure 1 schematically shows a massive cardboard pallet in perspective; figure 2 is an enlargement of figure 1 according to

F2; figure 3 shows the vertical structure of the pallet; figures 4 to 9 included show a top view of different supporting elements; figure 10 shows a variant of the massive cardboard pallet 10 and; figure 11 shows a combination with exclusively longitudinal elements and supporting elements which can also be used for other applications;

figure 12 schematically shows a variant of a massive cardboard pallet according to the invention, seen in perspective; figure 13 is an enlarged section of figure 12 according to line XIII-XIII; figure 14 shows the vertical structure of the pallet according to figure 12; figure 15 shows a variant of figure 11.

Figure 1 shows an embodiment of a pallet 1, being a horizontal bearing surface. The pallet 1 is built from bottom to top by placing parallel lower longitudinal elements 2, supporting elements 3, perpendicular cross elements 4 and upper longitudinal elements 5 respectively at regular distances. On every lower longitudinal element 2 are hereby provided as many supporting elements 3 as there are cross elements 4. The number of upper longitudinal elements 5 may be equal to the number of lower longitudinal elements 2, but in figures 1 and 2 it is higher than the number of lower longitudinal elements 2, as a result of which also loads of small dimensions can be easily born by the pallet 1.

The invention also concerns a massive cardboard section which is used or can be applied as the longitudinal element 2 and/or 5, the cross element 4 and/or the supporting element 3.

Figure 3 illustrates the vertical structure of the pallet 1 and shows that the longitudinal elements 2 and 5 and the cross elements are massive cardboard U~sections, whereby

the cross elements 4 have cut-outs 6 which mesh with the legs of the upper longitudinal elements 5. So, there are twice as many cut-outs 6 as there are upper longitudinal elements 5.

Figure 3 also shows that the supporting elements 3 are optionally provided with cut-outs 7 at the top and at the bottom in order to place the supporting elements more firmly on the lower longitudinal elements 2.

The lower longitudinal elements 2 provide for a rigid foundation for the pallet 1, but, optionally, the lower longitudinal elements 2 can also be omitted.

Figures 4 and 5 show a top view of a supporting element 3 which is built of two U-sections 8 that are glued together.

Variants of a section 8 according to the invention are possible, as shown in figures 6 to 9 included.

In figure 6, two angular L-sections 9 are glued together.

In figure 7, the supporting element 3 is one large U- section 10 and in figure 8 it is a circular section 11.

Finally, figure 9 shows U-shaped sections 12 which are either or not glued together but whose dimensions and composition are identical to the sections out of which the elements 2, 4 and 5 are made.

Other shapes for the sections are possible as well.

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All sections 8-12 that are used as supporting elements 3 in a pallet 1 are applied in a vertical position and are restricted in height, whereby they are also made of paper webs that are glued together. In other words, the sections 8-12 can also be made of massive cardboard.

The shape of every section 8-12 is obtained during the production process by means of gluing or pressing and profiling the different paper webs.

The strength and the bearing capacity of the pallet 1 is determined by the number of supporting elements 3 on the one hand, and the inherent strength of each supporting element 3 on the other hand. This inherent strength is determined to a large extent by the number of paper layers inside the sections 8-12, the quality of the gluing, the shape and dimensions of the section 8-12, the vertical positioning of the sections 8-12 in the pallet construction 1 and the height of the supporting element 3.

Typically, the height of every supporting element 3 is situated between 10 and 20 cm, and the thickness of every section 8-12 is typically in the order of magnitude of 5 mm, more generally between 2 and 7 mm.

The glues that are used to manufacture the sections 8-12 are water-soluble or water-dispersible glues such as silicates, polyvinyl acetate (PVA) , starch, dextrins, hot melts, etc.

As the different paper layers in the elementary sections 8- 12 are fully glued, little or no dust at all is produced during the production process of the pallets 1 or pallet parts 2-11, in other words during the cutting, punching and gluing of the individual sections 8-12 into elements 2, 4 and 5 or supporting elements 3. Little or no dust at all is formed as a result of the mechanical damage during use either, i.e. during the loading and unloading of the pallets 1. Thanks to the intensive gluing of the different paper layers in the sections 8-12, the inherent strength of these elementary structure elements 2-5 is much larger than with structure elements 2-5 made of corrugated cardboard.

In order to further improve the water-resistance and any possible linting behaviour (a technical term for dust formation) of the sections 8-12, these sections 8-12 may contain a coating, for example in the form of a coated paper layer, an aluminium coating or a synthetic outer layer.

These more water-resistant outer layers are provided during the production of the sections 8-12.

This outer layer may also be formed of a coloured or decorated paper web or synthetic foil. This easy way of colouring and decorating the sections 8-12 which form the supporting or bearing elements 2-5 makes it possible to produce pallets with a personal touch in a flexible and economically sound manner, which simplifies the sorting, classification and identification of goods in warehouses, during transport, etc.

When used in the transport and distribution sector, the massive cardboard pallet 1 preferably has dimensions of 80 by 120 cm, which is the size of what is called a euro pallet. Naturally, also other dimensions are possible for the pallet 1, such as common sizes such as 100 by 120 cm or 40 by 60 cm. Different degrees are possible for euro pallets, depending on the bearing capacity, for example a static bearing capacity according to ASTM D1185 of at least 1300 kg and preferably 1500 kg, and even better 1800 kg. For cardboard pallets in general, the dynamic bearing capacity depends on the construction, but for a massive cardboard pallet 1 according to the invention, a high load is very well possible.

In a preferred embodiment of a section 8-12 and/or the pallet 1 according to the invention, a fibrous material has been additionally incorporated in the massive cardboard.

The fibrous material may be flax (Linum usitatissimum) , cotton (Gossypium hirsutum, inter alia) , hemp (Cannabis sativa) , sisal (Agave sisalana) , henequen (Agave fourcroydes) , abaca or what is called Manila hemp (Musa textilis) , jute (Corchorus capsularis or Corchorus olitorius) or another natural fibrous material, such as for example cellulose, i.e. a polysaccharide of the family (C ₆ H ₁₀ Os) _n .

This is advantageous in that a pallet 1 is obtained with even more bearing capacity without any considerable increase in weight of the pallet 1.

The fibrous material may also be synthetic, for example acryl or nylon. Also steel or another reinforcement agent may be incorporated in the massive cardboard.

The fibrous material is preferably incorporated in a section 8-12, but it may also be incorporated directly in the supporting element 3 for example, provided the latter is not made in the shape of one or two sections 8-12.

The horizontal bearing elements and the vertical supporting elements 2-5 can be connected to form a pallet 1 in several ways, such as by means of gluing, stapling, screwing, clamping, etc.

When using said massive cardboard pallets 1 in the food industry, gluing is the most indicated method. The glues used thereby may have different compositions, such as silicates, PVA, dextrins, acrylates, hot melts or other components. Under normal conditions of use, these glues are sufficiently water-proof, but they can nevertheless be solved in a conventional paper pulp installation.

The gluing method, used during the pallet assembly, avoids any introduction of metal staples or screws which might come loose during use and which disrupt the HACCP processes in food factories. HACCP is a systematic approach aimed to identify, evaluate and control any possible hazards for the food safety. HACCP is based on seven examination phases. These phases are: 1 describing any possible hazards for every process step (Hazards) ; 2 determining the Critical

Control Points; 3 setting (internal) standards related to all Critical Control Points; 4 developing a control system to control the Critical Control Points; 5 developing a correction system for all possible deviations; 6 drawing up verification procedures; 7 developing a registration and documentation system.

Other assembly techniques, such as stapling, screwing, using taps, etc. will be chiefly used for pallets 1 which can be mechanically dismounted after use or whereby the bearing elements and/or supporting elements 2-5 of the pallet 1 itself can be further used in the further development and/or construction of goods that are stored on such a pallet 1.

In the preceding description have been provided cut-outs 6 in the cross elements 4, but it is not excluded that instead thereof, or additionally, cut-outs are provided in the upper and/or lower longitudinal elements 2.

Figure 10 shows a variant of a massive cardboard pallet according to the invention whereby the supporting elements 3, the upper longitudinal elements 5 and the cross elements 4 respectively are placed on the lower longitudinal elements 2.

In figure 10, the lower longitudinal elements 2 and the upper longitudinal elements 5 are made as U-sections whose legs are directed towards each other, but it is clear that legs of the lower longitudinal elements 2 can also be directed towards the bottom, as is the case in figure 1.

This may be advantageous in that the pallet 1 according to the invention is more hygienic and in that the accumulation of dust, moist or dirt on the lower longitudinal elements 2 is avoided.

This offers the advantage that the combination of the lower longitudinal elements and supporting elements 2, 4 and 5, as shown in figure 11, can also be easily used for other applications. Thus, two of these combination elements can be used for example to put a full plate on.

Figure 12 shows a variant of a massive cardboard pallet 1 according to the invention whereby the upper longitudinal elements 5 are glued directly on the cross elements 4 without any cut-outs 6 having been provided in the cross elements 4. The supporting elements 3 are hereby designed as tubular sections 8.

The enlargement in figure 13 moreover shows that the lower longitudinal elements 2, the cross elements 4 and the upper longitudinal elements 5 are formed of two U-sections whereby one of both U-sections is held with its legs in the other U-section.

Such an element 2, 4 or 5 can be made by pressing a first U-section 10 in another U-section 10. Hereafter, this configuration is referred to as "compressed" U-sections 10.

An advantage of compressed sections is that this connection method offers additional strength.

However, it is not excluded for two U-sections 10 to be laterally pressed and/or glued together, whereby the legs of the upper U-section 10 are for example situated to the right of the legs of the lower U-section 10, as seen in a cross section.

As represented in figure 14, round cut-outs 13 have been provided in the upper U-sections 10 of the lower longitudinal elements 2 and in the lower U-sections 10 of the cross elements 4, in which the cylindrical supporting elements 3 fit.

Round cut-outs 13 may possibly also be provided in the upper U-sections 10 of the cross elements 4 and in the sections of the upper longitudinal elements 5, as a result of which the supporting elements 3 mesh with the upper longitudinal elements 5.

An advantage of compressed U-sections 10 is that the sections can be connected more firmly than in a glued assembly, as shown for the U-sections 8 of the supporting elements in figure 1. The compressed sections may possibly be formed of sections of different dimensions.

Optionally, the compressed U-sections 10 may also be wrapped in a paper layer or foil in view of a further reinforcement or for aesthetical reasons.

It is clear that also the sides of the U-sections 10 may be covered with a foil or the like, for example as a

protection against bacteria or vermin.

As mentioned above, the invention aims a massive cardboard pallet 1 whose elements 2-5 can mesh by applying all sorts of techniques such as gluing, stapling and/or pressing and by either or not providing cut-outs, slots, collars and the like in/on one or several of the elements.

It is clear that the cut-outs may have all sorts of shapes, including among others the straight cut-outs 6 as represented in figure 3 and the round cut-outs 13 as represented in figure 14.

A variant of figure 11 whereby the U-sections 12 are compressed is represented in figure 15.

All the elements 2-5 are preferably made of massive cardboard, but it is not excluded that for example the supporting elements are made of another material, for example of wood.

The present invention is by no means restricted to the embodiments described as an example and represented in the accompanying drawings; on the contrary, such a massive cardboard pallet according to the invention can be made in many different ways while still remaining within the scope of the invention.