EP1743841A1 - Transport container or pallet made of plastic - Google Patents

Abstract

The pallet crate has walls (3), a base (2) and a supporting frame (5) under the base. Some or all of these are made from plastic foam, the remainder being made from non-foamed plastic.

Description

The invention relates to a transport box or a pallet made of plastic, wherein the transport box consists of a bottom and four side walls, which are arranged at the bottom and wherein the pallet consists of a bottom construction with an approximately flat Auflastfläche.

Such boxes and pallets are produced by injection molding with suitable injection molds in large quantities. They are used in a variety of applications and must be very stable and torsionally rigid, especially when used with heavy loads in the area of the ground. This stability is usually achieved by suitable rib arrangements, by placing an underbody, and the like. reached.

From the DE 39 09 022 C2 for example, a one-piece made of plastic transport container has become known, under the bottom of which a ring surrounding the box bottom frame is arranged, which is connected by means of transverse ribs to form pockets with the ground. This transport container is characterized not only by its runnability and smooth running on roller and roller conveyors but also by the high stability and torsional rigidity of its soil. Also, the bottom slack at heavy central load is less than in boxes with only perpendicular to the bottom fin arrangements. This reduction in bottom sag is transmitted, albeit to a lesser extent, to the frame, which has led to increased noise when running on roller conveyors, which could be remedied by chamfering the frame on its inside.

In other cases, for example, in crates are arranged to load transfer elaborately constructed corner pillars on the bottle case inner walls to grant their stability and to allow high circulation rates of the box.

Stable constructions of boxes and pallets have hitherto been reinforced by the use of load and stress-removing elements, such as ribs, corner pillars, and the like. achieved with high material usage. As a result, the means of transport and storage become expensive and difficult to wash during production.

From the industry and the consumer but lightweight, material-saving transport boxes and storage means are required, which nevertheless have excellent stability and torsional rigidity and can be easily cleaned.

The invention avoids the disadvantages of the prior art. It is therefore the object of the invention to provide transport boxes and pallets which have excellent stability and high torsional rigidity even at high loads and yet have a low weight.

The invention is that the transport and storage box or pallet consists of both solid plastic and foamed plastic.

The hitherto known transport and storage boxes or pallets are completely molded from solid plastic. Material and weight savings due to a lower material usage while achieving an enormous rigidity is achieved according to the invention when the boxes and pallets are partially made of foamed plastic and otherwise made of solid plastic.

The foamed plastic has a void-rich three-dimensional cell structure. The cavities are formed by a multiplicity of cell walls arranged in different spatial directions, which are interlinked and which mutually support one another,

This cell structure requires the excellent stiffness of the foamed plastic while saving material and reducing weight.

In order to foam the plastic material, the procedure is such that either the plastic material in the injection mold is foamed by a physical blowing agent, or that the foaming process is already initiated in the injection molding machine by withdrawing the plastic mixed with blowing agent brings the piston in the injection molding machine under volume enlargement of the space for pre-foaming and presses by pre-pushing the piston, the prefoamed mass in the Hersteltungsform. The first injected plastic cools on the mold to a flat outer and inner surface, while the inside of the walls and / or the bottom of foamed material. The cavity size and number can be increased by mounting parts of the tool, so that one can achieve a greater wall thickness, wherein inside the wall foamed plastic is located.

To inject a ertndungsgemäßen box or pallet according to the invention one proceeds, for example, so that one injects the entire box or pallet with the same propellant mixed with plastic and indeed so that you first injects the massive parts of the box or pallet of plastic and let the solid plastic to Fomnstabilität cool, while the areas to be made of foamed plastic, are spared by the use of moldings. In a second step, these molded parts are withdrawn in a defined manner while simultaneously injecting plastic and filling these spaces with foamed plastic.

With this method, a molding is injected with a single plastic mixture, which consists of both foamed plastic, as well as solid plastic. However, the moldings sprayed with this method can have slight optical unevenness on the outer surfaces. Because the injected in the first step, added with blowing agent plastic reacts despite pressure and volume preservation within the injection mold to a small extent, which can lead to "streaks" on the surfaces of the molding.

If these optical unevenness of the outer surfaces are avoided, the box or pallet according to the invention made of two plastics can be injected within an injection molding process, on the one hand from a non-propellant plastic which is pressed into the mold with the recess to be foamed and a second with propellant plastic used to fill the foamed areas. In this way, moldings are obtained which have optically perfect surfaces.

To increase the stability, it is advantageous if the load-bearing structural elements of the means of transport or the pallet consist of foamed plastic. This can be, for example, corner posts of a bottle crate.

To avoid the tearing or twisting of handles of a box, it is expedient if the (hand) grip areas consist of foamed plastic.

The use of foamed plastic is also useful when strong wall thicknesses of the plastic product are required.

Particularly advantageous is the design of a transport box or a pallet when the floor is made entirely or partially of foamed plastic. The floor then has excellent torsional rigidity on and an undesirable bottom deflection at heavy load is avoided.

In the described in the introduction integrally made of plastic transport container, under the bottom of a circumferential frame is arranged, which is connected by means of transverse ribs to form pockets with the bottom, it is advantageous if the limited by the encircling frame interior of the underfloor of foamed Plastic exists. The foamed inner region may form a flat surface with the standing surface of the peripheral frame, or the foamed inner region may be concave (toward the bottom bottom side) with respect to the approximately flat base of the reinforcing frame.

In order to avoid bottom deflections, it is advantageous if the pockets forming transverse ribs of the above-described transport are wholly or partially washed with foamed plastic, so that at least a few pockets are completely or partially filled with foamed plastic. It is advantageous if at least the central pockets of a longitudinal and / or transverse side are completely or partially filled with foamed plastic.

The box described above is very well run on roller tracks when the reinforcing frame has an obliquely upwardly extending portion at the rim facing the center of the box.

It is useful if the peripheral frame is made of foamed plastic on the bottom bottom or if the frame and the entire floor construction made of foamed plastic.

The with respect to the above-described embodiments of the transport means with circumferential, arranged on the bottom of the box frame, but may alternatively be implemented cumulatively on a box. Likewise, under the floor arranged reinforcing / running frame does not have to be a peripheral frame, but it may also be two parallel arranged on opposite sides of the transport and paving means runners. These transport and storage means are used both for transport and storage, for example, in a high-bay, where the runners serve as bases of the transport and storage means.

In particular, the bottom formations of the above-described transport and bearing means with a bottom side arranged frame is also applied to the bottom training of pallets and trays.

The transport / storage means and pallets are made in one piece. But they can also be made in several pieces in suitable methods.

Fig.1

einen Querschnitt durch einen Transportkasten mit umlaufendem Bodenrahmen,

Fig.2

einen Querschnitt durch einen weiteren Transportkasten mit umlaufendem Bodenrahmen,

Fig.3

einen Querschnitt durch einen weiteren Transportkasten mit umlaufendem Bodenrahmen.

The essence of the invention is explained in more detail with reference to Ausführungsbeispieten schematically illustrated in the drawings. It show the:

Fig.1

a cross section through a transport box with revolving floor frame,

Fig.2

a cross section through another transport box with a revolving floor frame,

Figure 3

a cross section through another transport box with rotating floor frame.

FIG. 1 shows a transport box (1) produced in one piece from plastic, which consists of a flat bottom (2) and side walls (3) which are arranged on the bottom (2). Under the bottom (2) a surrounding around the box frame (4) is arranged, which is connected by means of transverse ribs (5) to form pockets (6) with the bottom (2). The interior of the frame (7) is made of foamed plastic [shown in phantom], while the rest of the box is made of solid plastic. The foamed plastic inside the frame is lower than the surrounding frame (4). The bottom (2) is made of solid plastic, while the foamed plastic is arranged below the bottom (2).

Figure 2 shows the box of Figure 1, but the peripheral frame (4), the bottom (2) and the frame interior (7) made of foamed plastic, while the rest of the box is made of solid plastic. Again, the plastic inside the frame is lower than the surrounding frame (4).

In Figure 3, a transport and storage means is shown with a circumferential frame, wherein the side walls, and the bottom lying within the frame are made of solid plastic. The frame is bounded by longitudinally downwardly facing longitudinal ribs and filled with foamed plastic. In frame frame ribs (9) of the subsoil are arranged.

LIST OF REFERENCE SIGNS

1

shipping boxes

2

ground

3

Side wall

4

Circumferential frame

5

transverse rib

6

bag

7

Frame interior

8th

longitudinal rib

9

ribbing

Claims (13)

Transport box or pallet made of plastic,
wherein the transport box consists of a bottom and four side walls, which are arranged on the floor and
the pallet consists of a floor construction with a flat load surface,
characterized,
that the transport box or the pallet consists of both solid plastic and foamed plastic. Plastic transport box or pallet according to claim 1,
characterized,
that the load-bearing construction elements consist of foamed plastic. Plastic transport box or pallet according to claim 1,
characterized,
that the floor is entirely or partially made of foamed plastic. Plastic transport box or pallet according to claim 1,
characterized,
that the (hand) grip areas are made of foamed plastic. Plastic transport box or pallet according to claim 1,
characterized,
that those elements are made of foamed plastic, which require a strong wall thickness. Plastic transport box or pallet according to claim 1,
characterized,
that the transport box or the pallet are made in one piece. A plastic transport box or pallet according to claim 3, comprising a peripheral reinforcing frame or runners connected to the lower surface of the floor by transverse and longitudinal ribs to form laterally open pockets,
characterized,
that the interior of the subfloor, which is delimited by the encircling reinforcing frame, consists of foamed plastic. Plastic transport box or pallet according to claim 7,
characterized,
that the foamed inner region forms a flat surface with the stand area of the surrounding frame. Plastic transport box or pallet according to claim 7,
characterized,
in that the foamed inner area is concave with respect to the approximately planar base surface of the reinforcing frame. Plastic transport box or pallet according to claim 3, with a circumferential reinforcing frame or runners connected to the lower surface of the floor by transverse and longitudinal ribs, forming laterally open pockets,
characterized,
that the longitudinal and transverse ribs forming the pockets are wholly or partly covered with foamed plastic, so that the pockets are completely or partially filled with foamed plastic. Plastic transport box or pallet according to claim 7-10,
characterized,
in that the reinforcing frame has an obliquely upwardly extending section at the edge facing the center of the box. Plastic transport box or pallet according to claim 3,
characterized,
that a peripheral frame at the bottom bottom made of foamed plastic is made. Plastic transport box or pallet according to claim 3,
characterized,
that the box bottom and the surrounding frame are made of foamed plastic.

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