DE2718401A1 - Synthetic resin palette with carrier table - has soft and flexible cord-like anti-slip elements - Google Patents

Abstract

Palette has >=1 cold-like anti-slip elements made of relatively soft and flexible material on the upper surface and/or on the under surface of the carrier table. The palett pref. comprises a polyolefin resin, esp. a high density polyethylene (density 0.95-0.98). The anti-slip cords may consists of low density polyethylene (0.91-0.93) ethylene-vinyl acetate copolymers, ethylene-ethylacrylate copolymers are thermoplastic rubbers and mixtures of these materials. Used for handling relatively hard goods, e.g. boxes contg. bottles, etc., the anti-slip elements being easily deformed so as to obviate excessive slipping.

Description

Pallet with a synthetic resin tray

The invention relates to a pallet made of synthetic resin, on the supporting board Anti-slip elements are provided.

Resin pallets are widely used in various application areas, as their water absorption is small, they clean themselves quickly and hygienically read, and because they have a consistent quality due to mass production processes and have a fixed shape and dimensions, and because they are different from Wooden pallets do not contain nails. Synthetic resin pallets are not, however, in this respect advantageous as they are slippery, thereby not only causing damage or breakage -gungen with the pallets themselves, but also with those lying on them or attached Goods is caused.

Are synthetic resin pallets by a chain or roller conveyor or transported by a forklift truck, the pallets slide easily on such means of transport, whereby the stability of the stacked pallets is lost. Especially if Pallets longitudinally inclined conveyors used in department stores or the like are installed, are transported downwards, the downward speed decreases the pallet accelerates to. In such a case, it is difficult to control the speed of the pallets, with the result that the pallets collide with each other. Further, the goods or goods go into an unstable one due to the moment of inertia State over and often fall off when the pallets are stopped.

To avoid such sliding, it is common to see irregularities on the traction panel when casting or manufacturing a pallet, or Openings in the support panel after the casting process for inserting Qummian sets bring in. It has proven difficult with such anti-skid Elements sliding processes according to the type and shape of the goods and the type, To effectively prevent the design and operating procedure of the transport facilities.

Alternatively, a thin rubber layer with a large coefficient of friction was used attached to the pallet. If the pallet exists z. B. from a polyolefin resin, so the bonding properties are poor, so that the rubber layer is easy to come off. Avoiding sliding involves problems not only due to the coefficient of friction can be solved alone. In particular, when the coefficient of friction is too high, it falls stacked goods fall down as a column when the pallets are shocked are and cannot slide.

The object of the invention is therefore to provide an improved pallet made of synthetic resin indicate which has anti-slip properties over a long period of time and for Handling of relatively hard goods or goods, such as crates containing bottles, Mineral oil cans etc.

is suitable and can be funded by any funding.

The improved synthetic resin palette is also said to be particularly suitable be to be moved longitudinally inclined conveyors in the downward direction.

According to the invention, this object is achieved with a pallet made of synthetic resin solved in that several string-shaped anti-slip elements on the lower and the upper surface of the support panel are provided, the anti-slip Elements consist of relatively soft and flexible material.

The anti-skid elements deform easily to an excessive extent Avoid sliding when the goods are loaded onto the pallet or when the pallet is loaded onto a roller conveyor.

In the following exemplary embodiments of the invention are based on the Drawing explained in more detail. 1 shows a perspective view of an embodiment a pallet according to the invention with two-sided engagement possibility; Fig. 2 shows a plan view of the pallet shown in FIG. 1; Fig. 3 is a side view the pallet shown in Figure 1 and FIG. 4 is a plan view of the bottom of a further embodiment of the invention.

Any one of Use synthetic resin made from many known synthetic resins. Among these synthetic resins are mentions the polyolefin resins, e.g.

high density polyethylene (with a density of 0.95 to 0.98), polypropylene and ethylene-propylene copolymers, vinyl chloride resins such as polyvinyl chlorides and Polyvinylenedene chloride, styrene resins such as polystyrene, acrylonitrile-styrene copolymers and acrylonitride-butadiene-styrene terpolymers, polyamide resins and polyester resins. Polyolefin resins, particularly polyethylene, are based on these Kunatharzen their physical properties and the economy of the pallets.

These raw material resins can be mixed with an antioxidant, an ultraviolet one Radiation absorbing agent, a foaming agent, a coloring agent, a pigment, an inorganic filler such as cellulose fiber and an inorganic one Fillers, such as glass fibers, contain calcium carbonate and talc. Under from the point of view of weight, physical properties and economy it is advantageous to make the pallet from foamed polyolefin resin.

The inventive synthetic resin pallets can be according to any Molding processes, e.g. injection molding, blow molding, centrifugal molding, vacuum molding or by casting.

It is also possible to design extruded sheets as pallets. The pallets can be in the manner of a two-sided or a four-sided Be designed engaging type.

The synthetic resin pallet is on the surface of the carrier board with several Longitudinal and transverse grooves provided to accommodate anti-slip elements, as is still the case is explained in more detail. The grooves can be made while the pallet is being formed or later be formed by cutting or milling.

The anti-slip member according to this invention has the shape a strand or a rope, such as a bar or a ribbon and can be made of any relatively soft and flexible material that deforms appropriately under a load or in engagement with conveyor rollers. Advantageous it is important that the material is weldable. Suitable materials consist e.g. made of low-density polyethylene with a density of 0.91 to 0.93, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers and thermoplastic rubber and mixtures of the substances mentioned. When an ethylene-vinyl acetate copolymer alone or an ethylene-thylacrylate copolymer is designed solely in a strand for use as a slide-preventing element, the former copolymer contains up to 30 percent by weight vinyl acetate, during the the latter copolymer contains up to 15 percent by weight of ethyl acrylate. If there is a Mixture with a polyethylene of low density, there is for the content of vinyl acetate or ethyl acrylate no limit. It is advantageous, however, to use those just mentioned To use copolymers. Furthermore, there is no limit to the ratio of the polyethylene low density and copolymers.

The thermoplastic rubber is not used alone as a strand, but usually with a low density polyethylene or the copolymers mentioned with a ratio of less than 30 percent by weight of the thermoplastic rubber based on the weight of the mixture used. The term thermoplastic rubber " includes a block copolymer of an amorphous polymer (thermoplastic) with a Glass transition point of more than room temperature, and an amorphous one Polymers (rubber) with a glass transition point less than room temperature. In general, it is polystyrene-polybutadiene-polystyrene (-S-B-S) and polystyrene-polyisoprene-polystyrene suitable for use as thermoplastic rubber. Among those available on the market thermoplastic rubbers are Cariflex (manufactured by Shell Kagaku Kabushiki Kaisha) and Tuftremen (manufactured by Asahi Chemical Industry Co., Ltd.) are mentioned.

The anti-skid member of the present invention is in the form of a Rope made of a relatively soft and flexible material. Such a strand can be made by extruding the soft and flexible material, or that an extruded web of material is cut into strips or ribbons. In general, the anti-slip elements have a length that is substantially equals the width or length of the pallet's support panel. It is also possible to attach shorter strand parts with a space between each other. The cross-sectional £ orm the anti-skid elements can be round, rectangular, or any have other shapes, and the dimensions will vary depending on the softness and flexibility of the anti-slip member, the weight of the load, and others Factors determined. In the case that an anti-slip element made of an ethylene-vinyl acetate copolymer containing 14 weight percent vinyl acetate and having a melt index (MI) of 1.4 and a rectangular cross-section creates a width from 10 to 15 mm and a thickness of 0.5 to 3 mm, preferably from 1 to 2 mm the desired anti-slip properties. When the surface of the support panel is provided with grooves and the anti-slip elements are incorporated therein, it is necessary to increase the thickness of the anti-skid elements by at least the depth to increase the grooves.

The resin pallet of the present invention is on the top surface and the lower surface of the support panel with the above-described strand form provided with anti-slip elements. The number of anti-skid Elements fluctuates 3e according to the shape and weight of the load where the anti-slip Elements are arranged on the upper surface of the support panel while the number of the anti-slip elements on the lower surface depending on the shape and the type of conveyor and the weight of the load and the pallet itself depends. The number of the anti-skid elements is therefore determined according to the type of use of the pallet.

For example are the anti-skid elements on the top surface attached to the support panel, several elements are near both ends of the Carrying panel is provided, or 1 to 8 elements are evenly spaced across distributed over the entire surface of the support panel. It is also possible to use the anti-slip To design elements in the form of a grid (i.e. transversely and longitudinally). On the The lower surface of the support panel will have 2 to 8 evenly spaced sliding edges Elements placed near the opposite ends of the support panel, though their arrangement can also be the same as that on the upper surface, If a plurality of uniformly spaced anti-slip elements near four sides the support panel, it is not necessary to change the direction of the fastening or the alignment of the pallet on a roller conveyor or the like to pull.

Even if there is a single anti-skid element along the center line the pallet is provided, sliding can be effectively prevented.

The height of the anti-skid element above the surface of the support panel should be 0.5 to 3 mm, preferably 1 to 2 mm, although deviations depending on the weight of the load and the physical properties of the anti-skid elements possible are.

When the number of the anti-skid elements is small, or when their height is too high, they will be due to the load or the Rollers of the conveyor is excessively de40rm, making it difficult to place the load on the To let the pallet slide along. This not only increases the ease of use, but the resistance against the rollers also increases. If the deformation is too big, it can Do not sound the pallet along an inclined conveyor for long. For this The reason is where the anti-skid elements are on the lower surface of the Pallet are attached, it is desirable that they be continuous through the conveyor rollers are deformed, so that the best results can be achieved when the anti-slip Items along the entire length of the pallet in a direction perpendicular to the axes of the rollers are arranged. Even if the anti-slip elements are discontinuous or are arranged non-uniformly, sufficient slip restraint can be effected will. If the elements are too hard and too high, the pallet and the load strive after that to vibrate.

The anti-slip elements can be welded to the support panel or an adhesive may be attached, but the procedure given above will be followed preferred for its resistance to peeling.

Although the anti-skid elements directly onto the surface of the Support panel can be welded on, it is advantageous to have parallel grooves in the Form the surface of the support panel with a depth of about 1 to 2 mm and the To weld anti-slip elements onto the bottom surfaces of the grooves. The width the grooves should preferably be larger than the width of the sliding elements, so that the latter is given the opportunity to deform.

In the following, embodiments of the invention are based on the Drawing explained in more detail.

The synthetic resin pallet 1 shown in Figures 1, 2 and 3 is designed so that they can be pushed through the forks of a forklift (not shown) That can be carried into the pallet of a string of two opposite sides are introduced. The palette shown has a hollow rectangular shaped body. Because the structure of the pallet itself is not essential to this invention, description becomes unnecessary However, the pallet is solid and light in weight should be. In the example shown, the top surface 2 and the under.

Surface 3 of the support panel grooves 5; string-shaped anti-skid Elements 4 are welded to the bottom surfaces of the corresponding grooves 5. the anti-slip members 4 on the upper surface and the lower surface run under right WimeSn.

As already explained, each anti-slip element must extend over the extend out top or bottom surface of the support panel.

In a further embodiment, there are several parallel anti-skid Elements welded directly to the lower surface of the support panel.

Because the anti-slip elements made of relatively soft and flexible F2terial, with a predetermined thickness, on the upper and / or the lower surface are welded onto the carrying panel, they deform when they are loaded with goods or over the conveyor rollers, which allows sliding movements to prevent the load on the pallet or the pallet on the conveyor rollers. if the pallet is to run downwards on inclined conveyors, it is possible to control the downward speed of the pallet.

For this reason, the pallet according to the invention is particularly suitable for Carrying relatively hard goods such as boxes containing bottles, mineral oil cans and synthetic resin fiber canisters are particularly suitable.

Examples are given below, but it should be noted that that the invention is not limited to these special examples.

Example 1 An ethylene vinyl acetate copolymer (MI: 1.4 which is 14 weight percent Contains vinyl acetate and manufactured by Mitsui Polychemicals Co., Ltd. under the trade name EWalfex is sold) was extruded in the form of a sheet with a thickness of 2 mm, the web being slit into strips 20 minutes wide.

The strips were cut to include the anti-slip elements formed.

Four anti-slip elements were applied to the floor surface using hot air of the grooves each having a depth of 1 ima and welded on the upper surface the carrier board of a synthetic resin pallet were molded (under the trade name UPalletec "from Mitsubishi Kasei Kogyo Kabushiki Kaisha, which is also under the name Mitsubishi Chemical Industries Ltd. is known) to a pallet copy to be obtained according to FIG.

For comparison, a synthetic resin pallet without anti-slip elements was used and made a wooden pallet. The erfindungsge: wet pallet copy and the Comparative pallets were tested as follows.

A box filled with filled beer bottles. (26 kg) was on a pallet was put on that took a horizontal position, and it became the angle (Slip angle) at which the box begins to slide, measured, where the in the result shown in Table 1 resulted.

Table 1 tested pallet sliding angle pallet according to the invention 27 - 280 plastic plate without 14-15 ° anti-slide elements 1 - 15 wooden pallet 24 - 250 As this table shows, is the sliding angle of the pallet according to the invention larger than that of the comparison palettes.

Example 2 An extruded sheet of ethylene vinyl acetate copolymer was prepared in the same manner as Example 1 and in strips with a Width of 10 mm cut. Several anti-skid elements from these strips were welded to the bottom surfaces of the grooves, those on the bottom surface were attached to the pallet, which was identical to Example 1, in which the anti-skid elements were attached to the top surface of the pallet. The grooves had a depth of 1 mm and a uniform spacing of 20 mm. Anti-slip elements with a number as listed in the following table 2 were welded to areas 20 mm from both ends.

An incline of 21 (height): 1000 (horizontal) was measured on a roller conveyor and there were 24 crates filled with beer bottles (total weight 630 Kg) was placed on the pallet, and the pallet was placed on the conveyor put on, with the anti-slip elements possible at right angles to the axes the conveyor rollers have been aligned. That time was measured, the one Pallet required to move downward a distance of 4150 am to determine the anti-slip effect.

For comparison, the same measurements were made with a synthetic resin pallet without sliding-preventing elements (measuring object A), a wooden pallet from indoors getrocknatem Holz (test object B) and a wooden pallet made outdoors was stored and absorbed moisture (test object C).

The following table 2 shows the result of the measurements. Table 2 w - - number of the same chin- Ilauer of the ab- remark derenden Elew + nte warisbawbewegung ? 16.5 GlcSthsnderrrY 1 16s5 gripping obstacle Element was located ho in the Mittc kd 11> 4 in the 11.4 s :: S n 4 10.1 6 10.0 9, arc m <A 7o B 8.2 boo k9 15.0 The time it took for the wooden pallet to descend varied considerably depending on the conditions in which the wood was stored. In contrast, the duration of the downward movement of the comparison measuring object A, which does not contain any sliding-preventing elements, is short, so that when the pallet was stopped, the box was very strongly displaced due to a shock. This table also shows that according to the invention it is possible to control the duration of the downward movement by means of the number of anti-slip elements.

Example 3 The following synthetic resins were produced: A polyethylene low density (MI., 0.5; density 0.925, is available from Mitsubishi Chemical Industries Co. sold under the trade name "Nevatec-L").

B ethylene-ethylene arylate copolymer (MI. 6, from Nippon Unicar CQ.> Ltd. offered under the trade name "NUC ethylene copolymer EEAt).

C A mixture of 70 facial parts of said polyethylene low density, from 30 parts by weight of an ethylene vinyl acetate copolymer (MI, 2, Vinyl acetate content: 25% m from Mitsui Polychamicals Co., Ltd. under the Trade name "Evaflex" offered).

D A mixture of 60 parts by weight of said polyethylene low density and 40 parts by weight of the named ethylene-ethyl acrylate copolymer, E is a mixture of 70 parts by weight of said low density polyethylene and 30 parts by weight of a thermoplastic rubber of the type S-B-S (from the company Asahi Chemical Industry Co., Ltd. sold under the trade name tITufpreneu).

All resins were extruded into a strand with an elliptical Cross-section (thickness 3 am, width 10 µm), and there were four anti-slip elements from this strand welded into the grooves, all 1 mm deep and one Width of 10 mm and provided on the lower surface of the resin pallet were (identical to the pallet used in Example 1, in which the anti-slip Items were arranged on the top surface of the pallet). The anti-skid El. -Ninth were on the face at a distance of 20 am (with the exception of each 20 mn at both end areas of the support panel). The duration of the downward movement of the pallets with the anti-slip elements made of the synthetic resins concerned was seen in the manner shown in Example 2, wherein the result is shown in Table 3.

Table 3 Measurement object Duration of downward movement sec.

A 9.0 B 10.8 C 9.7 D 10.2 E 9.5 Each test object has a comparison with plastic pallets without anti-slip elements improved duration of the downward movement.

Claims (18)

Claims 1. Pallet with a support panel made of synthetic resin, d a it is indicated that at least one string-shaped anti-slip Element (4) made of relatively soft and flexible material on the upper surface (2) and / or the lower surface (3) of the support panel (1) is provided. 2. Pallet according to claim 1, characterized in that the anti-slip Elements (4) on the upper surface and the lower surface of the support panel (1) are provided. 3. Pallet according to claim 1, characterized in that the anti-slip Elements (4) on the upper surface (2) of the support panel (1) near the itself opposite ends of the support panel (1) are provided. 4. Pallet according to claim 1 to 3, characterized in that the anti-slip element (4) or the anti-slip elements on the support panel (1) are welded on. 5. Pallet according to claim 1, characterized in that the pallet made of polyolefin resin. 6. Pallet according to claim 5, characterized in that the polyolefin resin contains a high density polyethylene. 7. Pallet according to claims 1 to 6, d a d u r c h g e k e n n z e i c h n e t that the anti-slip element (4) is made of relatively soft and flexible Material is aufgenut, d @@ in essentially a polymer or copolymer of ethylene consists. 8. Pallet according to claim 7, characterized in that the main component of the anti-slip element (4) contains a low density polyethylene. 9. Pallet according to claim 7, characterized in that the main component of the anti-slip element (4) contains an ethyl vinyl acetate copolymer. 10. Pallet according to claim 9, d a d u r c h g e k e n n z e i c h n e t that the vinyl acetate content of said ethylene vinyl acetate copolymer is less than 20 percent by weight. 11. Pallet according to claim 7, d a d u r c h g e k e n n z e i c h n e t that the anti-slip element (4) consists of a material that is essentially consists of an ethylene-ethyl acrylate copolymer. 12. Pallet according to claim 11, characterized in that the content of ethyl acrylate of the ethylene-ethyl acrylate copolymer is less than 15 percent by weight amounts to. 13. Pallet according to claims 7 to 12, d a d u r c h g e k e n Note that the material is mixed with a thermoplastic rubber is. 14. Pallet according to claims 1 to 4, d a d u r c h g e k e n n notices that at least one of the upper and lower surfaces of the Carrying board (1) with a groove (5) to accommodate a slide-preventing element (4) is provided, and that the anti-skid element (4) sits a height bo that is greater than the depth of the groove (5) so that the anti-slip element (4) over the surface the support panel (1) protrudes. 15. Pallet according to claim 14, characterized in that the width the groove (5) is larger than the width of the anti-slip element (4). 16. Pallet according to claim 14, d a d u r c h g e k e n n z e i c h n e t that the anti-slip element (4) is between about 0.5 to 3 µm above the surface the support panel protrudes. 17. Pallet according to claims 1 to 4, characterized in that the anti-slip element (4) has a rectangular cross-section with rounded Has edges. 18. Pallet according to claim 14, d a d u r c h g e k e n n z e i c h n e t that the anti-slip element (4) is welded to the bottom surface of the groove (5) is.