NL1002605C2 - Pallet and method for manufacturing such a pallet. - Google Patents

Description

Short indication: Pallet and method for manufacturing such a pallet.

The present invention relates to a pallet mainly made of thermoplastic plastic material, comprising an upper deck for carrying goods to be placed on the upper deck, feet extending downwards from the bottom of the upper deck, which feet define insertion channels for lifting means, and optionally, parallel to the top deck, a bottom deck at the bottom of the feet. The present invention also relates to a method for manufacturing such a plastic pallet.

Plastic pallets of this type, in particular made of polyethylene or polypropylene, are generally known, in particular in an embodiment which is designated by the term "four-way pallet". In the case of a "four-way pallet", all four side surfaces, which extend between the upper deck and the lower deck of the pallet, each have two insertion openings and subsequent insertion channels for the forks of a lifting means, for instance a forklift truck or a pallet truck. pallets usually have a standard size, such as 800 x 1200 mm for a so-called "Euro-pallet" or 1000 x 1200 mm for an "industrial-pallet".

In a generally known application, pallets loaded with goods are stored in pallet racks. Here, a pallet rests exclusively on two horizontal and parallel beams of a pallet rack, which beams have a mutual distance which is only slightly smaller than the corresponding dimension of the pallet.

With the plastic pallets known to date, the problem arises in the above-mentioned application that a pallet will sag after a longer period of time with the risk that the pallet will fall down between the supporting beams. This is caused by the creeping behavior of the plastic material of the pallet under the influence of the continuous and in principle unfavorable load on the pallet. The sagging problem occurs especially with plastic pallets where the top deck, or both decks in the case of a double-deck pallet, is mainly composed of narrow ribs with openings therebetween.

The present invention aims to solve the above problem. Furthermore, the present invention aims to provide a solution to the problem that goods placed on the known plastic pallets can easily shift and thus fall off the pallet.

The present invention provides a plastic pallet according to the preamble of claim 1, characterized in that a plurality of elongated profiles of fiber-reinforced plastic material distributed over the relevant deck are embedded in at least one of the decks of the pallet.

Preferably, the fiber-reinforced profiles extend substantially from one side of the relevant deck to the opposite side of the relevant deck. In the case of the placement of the pallet according to the invention in the previously described pallet rack, the pallet is then preferably placed in the rack such that the pallet with its fiber-reinforced profiles lies transversely over both supporting beams of the rack.

Further advantageous embodiments, as well as a method for manufacturing the pallet according to the invention are described in the claims and the following description with reference to the drawing. In the drawing: fig. 1 shows in perspective an exemplary embodiment of a pallet according to the invention, fig. 2 shows a section along the line II-II in fig. 1, fig. 3 on a larger scale detail A in fig. 2, and Fig. 4 shows in cross-section the fiber-reinforced profile with anti-slip strip embedded in the rib of Fig. 3 and produced by co-extrusion.

35

Figure 1 is a perspective view from above of an embodiment of a substantially block-shaped plastic 1002605 -3-four-way pallet 1 according to the invention with a rectangular top deck 2, which is delimited by two pairs of two opposite and parallel side surfaces resp. 3.3 'and 4.4'.

The side surfaces 4, 4 'are defined by the outer peripheral edge of the upper deck 2 and three feet 5a, 5b and 5c, each one at one corner of the pallet and one in the middle, and an elongated bottom beam 6, which aligns the feet 5a, 5b, 5c connected to each other at the bottom side. In the middle between the side surfaces 4,4 'there is the same construction of three feet and a lower beam. Due to this arrangement of feet and beams, two parallel insertion channels 7,7 'extend between the side surfaces 4,4', which are intended for receiving the forks of, for example, a forklift truck or a pallet truck. Two parallel insertion channels 8,8 'also extend between the side surfaces 3,3', which can also be used for inserting the forks of a lifting means.

The upper deck 2 of the pallet 1 is essentially built up of intersecting ribs running parallel to the side surfaces 3,3 'and 4,4' of the pallet 1. At the location of the openings of the insertion channels 7,7 'and 8,8', additional reinforcing ribs 11 running from a crossing of two ribs of the upper deck 2 to the center of the corresponding part of the outer peripheral edge of the upper deck 2 are provided.

According to the present invention it is provided that 2 fiber-reinforced profiles are embedded in several ribs of the upper deck. In this example these are the ribs indicated by the reference numeral 10, which extend rectilinearly over the length of the pallet 1 between the side surfaces 3 and 3 ', therefore transverse to the insertion channels 7 and 7' of the pallet 1. Between two of ribs 10 provided with a fiber-reinforced profile lie one or more ribs 12 not provided with such a profile.

Furthermore, in the surface of the upper deck 2 of the pallet 1, strips 13 of an anti-slip material are present, which project slightly above the surface of the upper deck 2 defined by the ribs. The strips 13 are provided on the ribs 10 provided with a fiber-reinforced profile, as will be explained below with reference to Figures 2,3 and 4.

In figure 2 it can be recognized that the ribs 10 of the upper deck 2 are substantially rectangular in cross section with a largest dimension perpendicular to the surface of the deck 2 and that in each rib 10 a fiber-reinforced profile 15 is embedded with a substantially rectangular cross section with a largest dimension at right angles to the surface of the deck 2. It will be clear that both the ribs 10 and the fiber-reinforced profile 15 embedded therein can also have a completely different shape.

It can furthermore be recognized in figure 2 that above the plastic material of the rib 10, in which the fiber-reinforced profile 15 is embedded, protrudes a strip of anti-slip material 13 over substantially the length of the rib 10 concerned, for instance over a height of approximately 1 millimeter. . In figure 3 it can be recognized that a strip 13 has a cross section such that it connects with its underside to the side of a fiber-reinforced profile 15 facing the surface of the deck 2 and from there, seen in cross section, tapering wider towards runs at the top and has a further outwardly projecting edge portion near the top on each longitudinal side of the strip 13.

According to the present invention, the production of the pallet 1 shown in figure 1 preferably takes place as follows.

First, the elongated profile 16 shown in cross section in Figure 4 is produced in a co-extrusion process. For this purpose, a fiber-reinforced profile part 15 of extruded thermoplastic plastic material is extruded and at the same time a profile part 13 of extruded thermoplastic anti-slip material is extruded, which profile parts 13 and 15 fuse directly together in that co-extrusion process into one whole. Preferably, the fiber-reinforced profile part 15 is manufactured from a thermoplastic plastic material with 1002605 -5- therein chemically coupled glass fibers, for example polypropylene with 30% chemically coupled glass fibers, known under the trade name "Vestoleen PV 7010".

For the anti-slip profile part 13, a rubber-like material is preferably used, in particular a thermoplastic vulcanizate, for instance as known under the trade name "Sarlink 3170".

Because the anti-slip profile part 13 is connected to the profile part 15 by co-extrusion, two advantages are achieved. Firstly, a very strong adhesion of the anti-slip profile part 13 to the underlying profile part 15 is obtained, so that the anti-slip profile part 13 does not come loose from the pallet 1 even after a long period of use. This adhesion is considerably stronger than when the anti-slip profile part 13 would be disposed in the mold cavity without profile part 15 and would then adhere to the plastic material to be introduced into the mold cavity. Secondly, precisely because it is fixedly connected to the profile part 15, the anti-slip profile part 13 can easily be brought into the mold cavity in the intended place and held firmly there, even when the molten plastic material flows with force into the mold cavity when injection molding the pallet.

If the sagging of the pallet is not considered problematic, or has been solved in any other way than with fiber-reinforced profiles in a deck of the pallet, the above-mentioned advantages of providing an anti-slip profile part co-extruded with another profile part already clearly indicate that the other profile part does not necessarily have to be of fiber-reinforced plastic material in order to apply anti-slip strips in this advantageous manner. Therefore, a pallet can also be provided, in which at least one of the decks of the pallet is embedded profile parts distributed over the relevant deck, which are manufactured by co-extruding a profile part from thermoplastic plastic material and a profile part from thermoplastic plastic material with anti-slip 100? 05 -6 properties.

The profile parts 16 obtained by coextrusion are arranged in a deck part of the mold cavity of a suitable mold during the manufacture of the pallet. This deck section 5 of the mold cavity is advantageously provided with grooves, into which the profiles 16 fit with a part of their anti-slip profile parts 13. By subsequently introducing a suitable thermoplastic plastic material into the mold cavity, the profiles 16 are embedded in the plastic material of the pallet 1 in the manner shown in the figures. The plastic material can for instance be polyethylene or polypropylene, in particular plastic material used previously.

The manner of manufacture described above can advantageously provide a pallet which is reinforced against sagging and secured against slipping of goods.

It will be understood that the above-described plastic four-way pallet 1 is a one-piece pallet, ie the body of the pallet 1 is manufactured in a single manufacturing step from molten plastic material, unlike most known plastic four-way pallets, which are made up of two pallet halves fastened together.

1002605

Claims (14)

Pallet (1) mainly of thermoplastic plastic material, comprising an upper deck (2) for carrying goods to be placed on the upper deck, feet 5 (5a, 5b, 5c) extending downwards from the bottom of the upper deck, which feet to define insertion channels (7,7 #, 8,8 ') for lifting equipment, and possibly, parallel to the top deck, a bottom deck at the bottom of the feet, characterized in that at least one of the decks (2) of several elongated profiles (15) of fiber-reinforced plastic material are embedded over the relevant deck. Pallet according to claim 1, wherein the fiber-reinforced profiles (15) extend substantially from one side (3) of the relevant deck to the opposite side (3 #) of the relevant deck. Pallet according to claim 1 or 2, wherein the relevant deck (2) is substantially composed of ribs (10,11,12) and the fiber-reinforced profiles (15) are embedded in a number of the ribs 20 (10). Pallet according to claim 3, wherein the ribs (10) with fiber-reinforced profiles of the relevant deck (2) embedded therein are substantially rectangular in cross section with a largest dimension at right angles to the surface of the deck and in each of those ribs ( 10) a fiber-reinforced profile (15) is embedded with a substantially rectangular cross-section with a largest dimension perpendicular to the surface of the deck. Pallet according to one or more of the preceding claims, wherein at least one deck (2) of the pallet is provided on the surface with strips of anti-slip material (13) protruding above the surface of the relevant deck. Pallet according to claim 4, wherein a strip of anti-slip material (13) adheres on its underside to the side of a fiber-reinforced profile (15) facing the surface of the relevant deck (2). Pallet according to claim 5 or 6, wherein the anti-slip material is a thermoplastic rubber. 8. Pallet according to one or more of the preceding claims, wherein the fiber-reinforced profiles are manufactured from a thermoplastic plastic material with glass fibers chemically coupled thereto. 9. Pallet according to claim 5, wherein the anti-slip material is a thermoplastic material and the fiber-reinforced profiles are made of a fiber-reinforced thermoplastic plastic material and the strips of anti-slip material and the fiber-reinforced profiles are manufactured as one unit. 10. Method for manufacturing a plastic pallet, which pallet (1) has an upper deck (2) for carrying goods to be placed on the upper deck, feet extending downwards from the bottom of the upper deck, and optionally parallel to the upper deck, a lower deck on the underside of the feet, the method comprising introducing molten thermoplastic plastic material into a mold with a suitable mold cavity, a deck portion of the mold cavity defining a deck of the pallet, characterized in that, before molten plastic material is introduced into the mold cavity, a plurality of elongated profiles (15) of fiber-reinforced plastic material are arranged in a covering part of the mold cavity, which are embedded therein by the subsequent introduction of the molten plastic material into the mold cavity. 35 A method according to claim 10, wherein before the molten plastic material is introduced into the mold cavity 1002605 -9- in a cover part of the mold cavity, several elongated profiles (16) are arranged, which are composed of an elongated profile part of fiber-reinforced plastic material (15) and a longitudinally connected elongated profile part of anti-slip material (13), the cover part of the mold cavity forming elongated grooves in which the elongated profiles (16) are arranged with their profile part of anti-slip material (13), so that the profile parts of anti-slip material (13) protrude slightly above the surface of the respective deck (2) of the pallet. Method according to claim 11, wherein the elongated profile parts (16) to be arranged in the mold cavity are manufactured by co-extruding a profile part (15) of fiber-reinforced thermoplastic plastic material and a profile part (13) of thermoplastic plastic anti-slip material. Method according to one or more of claims 10-12, 20, wherein the fiber-reinforced profiles (15) are manufactured from polypropylene with chemically coupled glass fibers. 14. Method according to one or more of claims 10-13, wherein the profile parts of anti-slip material (13) are manufactured from a thermoplastic trap. 1002605