DK3188974T3

DK3188974T3 - Plastic load carrier

Info

Publication number: DK3188974T3
Application number: DK15759767.5T
Authority: DK
Inventors: Dominik Lemken; Thomas Walther
Original assignee: Hofer Kg
Priority date: 2014-09-03
Filing date: 2015-09-03
Publication date: 2019-04-08
Also published as: DE102014217575A1; EP3188974A1; PL3188974T3; WO2016034682A1; SI3188974T1; EP3188973A1; HUE044031T2; EP3188975A1; EP3188973B8; DE202014105564U1; DK3188973T3; ES2729242T3; PL3188973T3; PT3188974T; WO2016034513A1; SI3188975T1; EP3188975B1; DE102014217575B4; SI3188973T1; PT3188973T

Description

DESCRIPTION

[0001] The invention relates to a method for producing a plastic load carrier which consists at least partially of one or more recycled plastics, each recycled plastic being provided as a homogeneous new-product substitute free from foreign materials.

[0002] Load carriers or plastic load carriers exist in a wide range of different designs. For example, transport and/or storage pallets, as are described in the prior art according to DE 92 06 959 U1. That case relates to a transport and storage pallet made of thermoplastic and substantially recycled plastic. Reference is made here generally to recycled polycarbonate. The costs thus can be reduced, and the recycling process simplified. In practice, however, polypropylene and polyethylene and recyclates thereof are used as plastics.

[0003] Besides transport and storage pallets of this kind, there also exist transport containers and reusable transport containers made of plastic which likewise fall under the umbrella term "plastic load carrier". Transport containers of this kind, and in particular reusable transport containers, can typically be collapsed for transport, as is described by way of example in EP 2 256 049 B1. In the collapsed state of the known transport and/or storage containers the side walls hinged to the base are arranged parallel to the base. In the upright state the side walls by contrast are oriented vertically relative to the base, wherein each two side walls are locked to one another releasably.

[0004] In addition, what are known as flatbed trolleys, which have a support area and castors arranged on the base, are also plastic load carriers. Such flatbed trolleys, also referred to as dollies, are used and employed in order to transport a number of goods stacked one above the other. To this end, the carrier surface is typically made of plastic and may have a profiling (see DE 102 01 282 Al).

[0005] Plastic pallets which use new plastics are known in many embodiments. Reference is made merely by way of example to publications EP 1 076 Oil B1 and EP 2 216 255 B1. In the latter case the obligatory skids are made of a more rigid material than the rest of the pallet. In fact, the same polymer as is used for the base material of the pallet is used, but with recourse to a glass-fibre-reinforced plastic. Any possibility for recycling is thus hindered.

[0006] In the generic prior art according to DE 195 46 940 Al, a transportable material system is described, with the aid of which storage and/or transport means also can be produced. These can be produced, inter alia, from homogeneous recyclate. Polymers which are constructed from the same macromolecules are described as homogeneous.

[0007] DE 44 14 956 Al relates to recyclable refillable reusable containers. These can also be fed to a recovery process within the scope of homogeneous recycling. Here, all thermoplastics from which corresponding basic elements can be produced by means of suitable and known production methods, for example blow moulding or injection moulding, can be considered.

[0008] The teaching according to utility model DE 2 97 16 383 U1 relates to a bottle crate which can be shredded, and the resultant homogeneous plastic granular material can be used again immediately for the production of bottle crates. This results in a cost saving.

[0009] Lastly, DE 198 30 913 Al relates to a plastic processing and recycling method for producing plastic materials. Here, different physical parameters between a recyclate and the corresponding pure plastics are also compared, inter alia.

[0010] The prior art cannot provide satisfaction in all aspects. If we consider the known plastic load carrier according to DE 92 06 959.2 Ul, different plastics are used, the mechanical properties of which are indefinite. This can be attributed inter alia to the fact that unaltered foreign materials are contained in the plastic to a greater or lesser extent depending on the recycling method. In addition, multi-component plastics are typically processed, the properties of which in respect of the mechanical stability and also flow behaviour are indifferent and are retained. The invention seeks to remedy this .

[0011] The technical problem addressed by the invention is that of developing a method of this kind for producing a plastic load carrier such that reproducible properties are observed and the recyclability is facilitated.

[0012] In order to solve this technical problem, the invention relates to a method according to claim 1.

[0013] Within the scope of the invention the plastic load carrier is thus, in the first instance, produced predominantly from plastic, for example apart from add-on parts such as castors in the case of the flatbed trolleys already discussed. This plastic is one that is produced wholly or partially from one or more recycled plastics. In principle, one or more new plastics and one or more recycled plastics can be mixed with one another. The recycled plastics in accordance with the invention are homogeneous new-product substitutes free from foreign materials .

[0014] In fact, plastics from the group of polypropylene (PP) , polyethylene (PE) also polystyrene (PS) can be used particularly preferably as recycled plastics. Since the recycled plastics in question are free from foreign materials, mechanical and rheological properties that are practically identical to those of new products can be provided. This contributes in particular to the fact that the recycled plastic according to the invention is free from foreign materials. This shall be understood within the scope of the invention to mean that any foreign materials in the recycled plastic in question are reduced to a proportion of (much) less than 1 % by weight, typically even to less than 0.5 % by weight, and very particularly preferably to 0.1 % by weight and below. The proportion of foreign materials relates to the total granular material or weight of the recycled plastic.

[0015] In addition, residual moistures in the ppm range, typically in the range of up to 500 ppm, preferably up to 200 ppm, are observed in this context. In conjunction with the homogeneous nature of the recycled plastic in question, properties that qualify the recycled plastic in question as a new-product substitute are consequently observed. In other words, the recycled plastic according to the invention is used in a ratio of 1:1 as a replacement for new-product plastic of the same kind.

[0016] Resources are preserved in this way because recycled plastics are used. In fact, this preservation of resources is reflected in particular in the fact that the use of primary energy for the production of recycled plastic according to the invention is significantly reduced as compared to the corresponding new-product plastic. Typically, an energy saving of at least 30% can be observed if the recycled plastic according to the invention is used instead of the new-product plastic of the same kind. In addition, a plastic load carrier produced in this way can be particularly easily recycled because it is formed on the whole from homogeneous plastics.

[0017] In fact, the invention is based on the production utilising particularly advantageously merely homogeneous recycled plastic and new-product plastic of the same kind. The recycled plastic in question is a thermoplastic. The same is true typically also for the new-product plastic.

[0018] For example, the plastic load carrier may be produced as a new-product plastic from polyethylene (PE). In addition, plastics in which the new-product plastic is mixed with the recycled plastic in question preferably lie within the scope of the invention, and both plastics are preferably polyethylene (PE) . Polypropylene (PP) new-product plastic can very particularly preferably be used together with polypropylene (PP) recycled plastic for the production. In any case, the homogeneous nature of the plastic load carrier according to the invention ensures on the whole that any preparation and recycling is achieved particularly easily and favourably in terms of energy consumption .

[0019] The recycled plastic according to the invention generally has mechanical property values which deviate from the corresponding property values of the new-product plastic of the same kind merely by + /- 10 %. The mechanical property values in question are typically the breaking strength, the elongation at the yield point, the strain at the yield point, the modulus of elasticity, the notch impact strength, and also the temperature resistance.

[0020] In addition, the recycled plastic according to the invention advantageously and alternatively or additionally hereto has rheological property values which deviate from the corresponding property values of the associated new-product plastic of the same kind merely by approximately + /- 10 %. The rheological property values are constituted for example by the melt flow index, which in accordance with the invention is set for the recycled plastic similarly to that for the new-product plastic of the same kind.

[0021] The plastic load carrier according to the invention is typically produced by thermoforming and/or injection moulding. In addition, the plastic load carrier in question may advantageously be equipped with a security element in its interior or on its surface. The security element in question may be preferably, for example, an RFID chip or generally a transponder, i.e. an electronic chip, which can be read or written to wirelessly. Data of the plastic load carrier or also the goods transported hereby can be stored in the security element and read out therefrom or monitored.

[0022] For the production of the recycled plastic, conventional recycling methods can be used, for example such as those described in detail in US patent 4 830 188.

Here, plastic starting material is firstly shredded and then processed into shavings. These shavings or "flakes" for example have a maximum size of up to 8 mm. The shavings or flakes are then washed and classified, for example in order to separate out smaller particles of dust and dirt. Electrostatic or magnetic treatment is also conceivable in order to remove magnetisable metal particles.

[0023] The particles or shavings are then often subjected to a flotation, for example in water. Here, use is made of the different densities of individual plastics. In fact, polyolefins such as HDPE, LDPE and also polypropylene have densities in the range of from 0.85 to 0.95 cm3, i.e. below the density of water. Accordingly, such shavings tend to float on the water, whereas for example polyethylene terephthalate (PET) or also metals have a much greater density of 1.4 g/cm3 and more and therefore sink to the bottom. Consequently, the individual density fractions can be separated from one another as a result of the flotation.

[0024] In addition, a further separation can be performed via the setting of the surface tension, such that homogeneous recycled plastics on the whole are provided on the output side following a routine drying process and in addition are free from foreign materials. Of course, what are known as dry methods can also be used in principle instead of the described wet method.

[0025] The plastic load carriers within the scope of the invention typically have the form of a transport and/or storage pallet and/or a reusable transport container. Generally, both the transport and/or storage pallet and the reusable transport container can be produced from one or more recycled plastics according to the invention. Of course, it is also within the scope of the invention if for example only the transport and/or storage pallet are/is produced using one or more recycled plastics, whereas the reusable transport container is produced using new-product plastic .

[0026] The transport and/or storage pallet is typically equipped with interchangeable skids. Interchangeable skids of this kind are advantageous particularly against the background that transport and/or storage pallets of this kind are generally moved with the aid of industrial trucks and are often exposed to damage caused by prongs of the industrial trucks in question or by falling objects. Within the scope of the invention, damage to the skids now does not necessarily require replacement of the entire transport and/or storage pallet. Rather, it is sufficient to exchange just the damaged skid(s).

[0027] For this purpose, the skids in question are detachably connected to the underside of a load carrier with a regular spacing. The load-supporting surface is used on the one hand to receive the load to be transported. The underside of the load-supporting surface usually has receptacles into which the skids can be received, clipped into place.

[0028] In accordance with a particularly advantageous embodiment the transport and/or storage pallet is equipped on the upper side of its load-supporting surface with contours. These contours on the one hand may promote antislip transport and may help the load be received appropriately on the load-supporting surface. On the other hand, the contours may also cooperate with counter contours on the underside of the base of the reusable transport container, in such a way that the reusable transport container is held in a securely positioned manner on the reusable transport container.

[0029] So that the reusable transport container can be held in a securely positioned manner on the load-supporting surface, the load-supporting surface has the contours already described. The contours in question on the loadsupporting surface correspond to the counter contours on the underside of the base of the reusable transport container, such that the reusable transport container placed on the load-supporting surface is held on the load supporting surface in a manner secured against slipping. In addition, the design may be such that the skids of the transport and/or storage pallet may also be equipped with counter contours which correspond to contours on the side walls of the reusable transport container in the upright state. In fact, the side walls themselves could also function as contours.

[0030] In addition, an interaction of the counter contours at the skids of a transport and/or storage pallet with the contours on the load-supporting surface of a transport and/or storage pallet located therebeneath is conceivable. This results in perfect stacking of a number of these transport and/or storage pallets.

[0031] In this way, any number of stacks of transport and/or storage pallets on the one hand and one or more layers of one or more reusable transport containers on the other hand can be provided optionally. This simplifies the logistics and prevents the stacks from tipping over, and also prevents associated accidents.

[0032] The invention will be explained in greater detail hereinafter with reference to a drawing illustrating merely an exemplary embodiment, in which:

Fig. 1 shows a plastic load carrier in an embodiment as a transport and/or storage pallet;

Fig. 2 shows a plastic load carrier in an embodiment as a reusable transport container; and Fig. 3 shows a combination of the transport and/or storage pallet according to Fig. 1 with the reusable transport container according to Fig. 2.

[0033] A plastic load carrier is shown generally in the figures and is produced at least partially from one or more recycled plastics. The recycled plastic for example may be polypropylene with the following properties:

On the basis of the above table, it can be seen that the recycled plastic used in accordance with the invention, in the exemplary embodiment of polypropylene (PP), is formed as a homogeneous new-product substitute free from foreign materials. This means that the previously defined polypropylene recycled plastic according to the invention may replace new polypropylene plastic wholly or partially.

[0034] In fact, a mixture of the polypropylene recycled plastic in question in conjunction with new polypropylene plastic is used within the scope of the invention. This is possible because the used recycled plastic has mechanical and also rheological property values which deviate from the corresponding property values of the new product of the same kind merely by at most approximately + /- 10 %.

[0035] The presented plastic load carriers are produced on the whole by thermoforming and/or injection moulding. In addition, any security elements may be provided in the interior and/or on the surface. These security elements are constituted by one or more transponders, although these are not shown in the present case.

[0036] In the exemplary embodiment according to Fig. 1, the load carrier is formed as a transport and/or storage pallet 1. The transport and/or storage pallet 1 has skids 2 arranged on the underside for guiding and receiving for example prongs of an industrial truck. The skids 2 in question are exchangeable in the exemplary embodiment. In fact, the skids 2 are connected detachably to an underside

of a load-supporting surface 3. The load-supporting surface 3 is used to receive a load (not shown in greater detail).

[0037] In an alternative according to Fig. 2, the load carrier is a reusable transport container 4. The reusable transport container 4 is equipped with side walls 5 and a base. The side walls 5 are connected via hinges to the base .

[0038] In the collapsed state the side walls 5 are arranged one above the other, parallel to the base. Fig. 2 shows the upright state of the side walls 5. In the upright state the side walls 5 are typically locked releasably to one another in the region of their corners.

[0039] Fig. 3 shows the combination of a plurality of transport and/or storage pallets 1 according to Fig. 1 with one layer or a number of layers of reusable transport containers 4 corresponding to the depiction according to Fig. 2. So that the individual load carriers or the transport and storage pallets 1 on the one hand and the reusable transport containers 4 on the other hand can be stacked perfectly, contours 6, 9 and counter contours 7, 8 are provided.

[0040] It can be seen with reference to Fig. 1 that the load-supporting surface 3 is equipped on its upper side with contours 6, which in the exemplary embodiment divide the load-supporting surface 3 into two sub-areas 3a, 3b. Counter contours 7 on the underside of the base of the reusable transport container 4 correspond to the contours 6 on the upper side of the load-supporting surface 3. The cooperation of the contours 6 with the counter contours 7 is such that the reusable transport container 4 is held in a securely positioned manner on the load-supporting surface 3 of the transport and/or storage pallet 1 in accordance with Fig. 2.

[0041] In fact, a total of two reusable transport containers 4 in the embodiment according to Fig. 2 can be placed transversely on one of the sub-areas 3a, 3b, more specifically in a manner secure against slipping. For this purpose, the contours 6 are recesses, whereas the counter contours 7 are formed as protrusions corresponding to the recesses. As a result, the load-supporting surface 3 of the transport and/or storage pallet can receive a total of four reusable transport containers 4 per layer, in accordance with the embodiment according to Fig. 2. This of course is merely exemplary and non-limiting.

[0042] The transport and/or storage pallet 1 corresponding to the depiction in Fig. 1 additionally has counter contours 8 on its skids 2, which counter contours interact with contours 9 on the associated reusable transport container 4. An interaction of the counter contours 8 of the transport and/or storage pallet 1 in question with the contours 6 of a further transport and/or storage pallet 1 arranged therebeneath (not shown) is possible. The contours 9 of the reusable transport container 4 are the upper-side edges of the upright side walls 5.

[0043] In fact, the edges in question of the side walls 5 engage by means of the contours 9 formed in this way with the counter contours 8, formed as protrusions, on the underside of the corresponding skids 2, in such a way that a transport and/or storage pallet 1 in accordance with the design according to Fig. 1 can be placed on a layer of reusable transport containers 4 in a securely positioned manner, as is shown in Fig. 3. The individual plastic load carriers 1, 4 according to the invention thus can be perfectly stacked.

Claims

A process for producing a plastic carrier (1,4) consisting at least in part of one or more recycled plastic materials, and said recycled plastic is designed as a homogeneous new product substitute, wherein plastic starting material is first shredded and processed into strips, and the load carrier (1,4) subsequently produced by deep drawing and / or injection molding, characterized in that the strips after the shredding of the plastic starting material are washed and classified, where the respective recycled plastic is designed as a new product substitute free of foreign substances, with any foreign substances in the the recycled plastic is reduced to less than 1% by weight.

Process according to claim 1, characterized in that only homogeneous recycled plastic and new product plastic of the same kind are used.

Method according to claim 1 or 2, characterized in that the recycled plastic is a thermoplastic plastic.

Process according to one of claims 1 to 3, characterized in that the recycled plastic is a polypropylene (PP), polyethylene (PE) or polystyrene (PS) plastic.

Method according to one of claims 1 to 4, characterized in that the recycled plastic has rheological properties which differ only by max. +/- 10% from the corresponding properties values for the new product plastic of the same kind.

Method according to one of claims 1 to 5, characterized in that at least one securing element, for example designed as an RFID chip or transponder, is incorporated into the interior and / or provided on the surface.

Method according to one of claims 1 to 6, characterized in that the load carrier is in the form of a transport and / or storage pallet (1) and / or a recycled transport container (4).

Method according to claim 7, characterized in that the transport and / or storage pallet (1) is equipped with interchangeable racks (2).

Cargo carrier according to claim 8, characterized in that the rods (2) are connected releasably, preferably clamped, on the underside of the cargo surface (3).

Method according to one of Claims 7 to 9, characterized in that the transport and / or storage pallet (1) is provided with contours (6) corresponding to counter contours (7) on the underside of a load surface (3) on the underside of its loading surface (3). bottom of the reusable transport container (4) in such a way that the reusable transport container (4) can be positioned securely on the loading surface (3).

Method according to one of claims 8 to 10, characterized in that the recycled transport container (4) is provided with contours (9) corresponding to counter contours (8) on the underside of the means (2) of the transport and / or storage pallet (1). such that the transport and storage pallet (1) can be positioned securely on the recycled transport container (4).