EP0075573B1

EP0075573B1 - A method of producing a pallet

Info

Publication number: EP0075573B1
Application number: EP82901023A
Authority: EP
Inventors: Olav M. Haugan
Original assignee: Norpapp Industri AS
Current assignee: Norpapp Industri AS
Priority date: 1981-04-07
Filing date: 1982-04-01
Publication date: 1985-08-07
Also published as: FI68581B; WO1982003371A1; DK147731B; FI823980A0; FI823980L; DE3265169D1; DK147731C; NO149203C; NO811197L; EP0075573A1; NO149203B; FI68581C; DK538882A

Abstract

A pallet container which comprises a pallet and a container secured to the top side thereof, especially intended for transporting and storing bulk materials. The pallet (1) has an upturning circular neck or collar (8), and a shell (5) of several plies of sheet material, especially paper, is secured to the exterior of the neck or collar. The shell (5) may consist of wound, one-sided corrugated cardboard (10, 19, 20) with the corrugated side facing inwardly. Inside the container, which thus consists of the shell (5) and pallet (1), a watertight bag or sacks (13), preferably of plastic, may be glued. The pallet container is produced in that a finished, produced pallet having a circular neck on the top surface thereof is secured with its top side to the end of a winding mandrel having a diameter corresponding to the diameter of the neck. One-sided corrugated cardboard to which glue has been applied is wound in several plies onto the mandrel and the neck of the pallet, so that the plies become glued to each other and to the neck. A watertight sack (13), for example of plastic, may be drawn down over the mandrel (14) before the pallet (1) is secured to the end of the mandrel. The wound shell will then become glued to the sack.

Description

The present invention relates to a transport container assembly, a so-called pallet container, comprising a pallet and an associated container secured to the top side thereof, especially intended for the transportation and storage of bulk material, such as plastic pellets and the like.
Containers of the above-defined type are utilized as disposable containers, i.e., they are not returned and reused. It is therefore obvious that such containers should be as inexpensive as possible to manufacture, yet should be rugged enough not to become damaged under the stresses to which they are subjected during use. It should be noted that the stresses are relatively great, since such containers often are utilized to contain 1000 kg real weight.
The pallet utilized in such pallet containers is normally a four-way pallet, i.e., the pallet has openings on four sides for convenient access from all sides for the fork of a fork truck. Hitherto, so-called Eruopallets have most often been utilized, i.e., pallets composed of two wooden platforms with intermediate spacer blocks. The container or drum part of the pallet container has usually been made of double-sided corrugated cardboard. This is a relatively inexpensive and strong material, but has definite limitations in regard to the shape of container possible. Double-sided corrugated cardboard cannot be shaped along a curved line, but must be bent and broken along straight lines. The containers which have been used up to now have therefore been many- sided, e.g., in the form of octahedrons, so-called "octabins". Such polygonal containers, however, are not the most desirable either from the point of view of production or use. Double-sided corrugated cardboard must be stored as flat, rigid sheets, then cut to the correct format, and thereafter bent and fastened together by stapling to form a polygonal container. There are also difficulties in making a bottom and lid for such containers, as well as in securing such containers to the pallet. In addition, when such large containers are filled, for instance with plastic pellets, radial forces of not inconsiderable magnitude are produced which will tend to press against and straighten out the walls of the polygonal container.
Also there is known from French Patent 2,128,054 a pallet container which comprises a pallet and a tubular container secured to the top side of the pallet. Both the container and the pallet are rectangular, and the container has to be made separately and thereafter secured to the pallet.
The object of the present invention is to provide an inexpensive method of producing a pallet container wherein the above drawbacks are avoided and which is efficient and practical in use, which has a desirable shape from the point of view of force distribution, which is more moisture-resistant than the previously used pallet containers of this type, and has a great thermic insulation capacity.
According to the present invention a method of producing a pallet container, comprising a pallet and a tubular container secured to the top side of the pallet, especially intended for the transportation and storage of bulk materials such as plastic pellets or the like is characterized in that a pallet having a circular neck on the top surface thereof is secured with its top side to the end of a cylindrical winding mandrel having a diameter corresponding to the diameter of the neck, and that one-sided corrugated cardboard to which glue has been applied is wound in several plies on the mandrel and the neck of the pallet, so that the plies become glued to each other and to the neck.
A further development of the method of the invention is characterized in that a watertight sack of a suitable material, e.g., plastic, is drawn over the mandrel before the pallet is attached to the end of the mandrel and that the wound shell is glued to the sack.
The invention will be explained in greater detail with reference to the accompanying drawings, wherein

Figure 1 shows an embodiment of a pallet container in accordance with the invention,
Figure 2 is a cross section along the line 11-11 in Figure 1,
Figure 3 is a cross section along the line III-III in Figure 2, and
Figure 4 is a schematic drawing showing the production sequence for a pallet container in accordance with the invention.

The pallet container produced by the invention consists of a pallet 1 which preferably is molded of expanded polystyrene. The pallet consists of a solid plate 2 with legs extending downwardly from the bottom surface thereof, in the illustrated example three legs 3, arranged so that two openings 4 are provided for inserting the fork of a conventional fork truck. To avoid unnecessary amounts of force, the corners of the pallet are bevelled off. Secured to the top side of the pallet is a circular shell 5 made of windings of sheet- formed material. The top opening of the container is closed by a lid 6. In the cutaway portion of Figure 1, it may be seen that the container is filled with bulk goods 7, e.g., 1000 kg of plastic granules.
A practical embodiment of the pallet container may be seen more clearly in Figures 2 and 3. On the top side of the plate-formed part 2 of the pallet, an upturning circular neck 8 is provided, to which the shell 5 is secured. The shell consists of several plies of one-sided corrugated cardboard (seen best in Figure 3). The neck 8 has a corrugated periphery 9 corresponding to the corrugations 10 on the inner corrugated ply 11 of the shell. Optimum joining of the shell 5 to the neck 8 is thereby obtained. To allow water to run off so that the lower end of the shell 5 will not become wet, the top surface of the pallet may have a sloping edge 12. Inside the container, a bag or sack 13 of plastic may be glued.
Figure 4 shows how the pallet container of the invention is produced. The sack 13 is drawn over the winding mandrel 14 on a winding machine 15. The outer end of the mandrel is provided with a pin 16 which fits snugly inside a hole 17 in the top surface of the pallet 1. The mandrel 14 has the same diameter as the neck 8 of the pallet 1. When the pallet has been secured in this manner to the mandrel, a roll 18 of winding material, e.g., in the form of one-sided corrugated cardboard, is wound off the roll and placed on the mandrel, which is then made to rotate. Disposed between the winding mandrel 14 and the roll 18 is a glue applicator 19 for applying glue to the sheet material 20 on the inner surface of the material facing toward the mandrel. The one-sided corrugated cardboard is wound with the corrugated side facing inwardly toward the mandrel. In this manner one obtains a smooth and strong exterior surface on the finish shell 5, and as mentioned above, one also obtains a very good bond between the shell 5 and neck 8 since the periphery of the neck is given a ridged configuration in accordance with the corrugations of the winding material. If the sack 13 of plastic is inserted onto the mandrel prior to commencement of the winding operation, glue may be applied to all of the winding material on the side facing toward the mandrel, and the first ply of corrugated cardboard will then become glued to the sack. If for some reason one does not wish to include the sack, the first ply of the shell 5 must be without glue on the initial portion thereof which will be in contact with the mandrel, being provided with glue only on the portion thereof which lies around the neck 8.
To facilitate removal of the shell 5 from the mandrel 14, the mandrel can either be made to be collapsible, or one can introduce air into the mandrel which penetrates through small jet openings in the mandrel to pass out between the mandrel and the wound shell.
By placing a plastic sack inside the container already at the production stage, one obtains more efficient production in comparison with previous production procedures, since the insertion of a large sack of this kind in a finished container is a time-consuming job.

Claims

1. A method of producing a pallet container comprising a pallet and a tubular container secured to the top side thereof, especially intended for the transportation or storage of bulk materials such as plastic pellets or the like, characterized in that a pallet (1) having circular neck (8) on the top surface thereof is secured with its top side to the end of a cylindrical winding mandrel (14) having a diameter corresponding to the diameter of the neck, and that one-sided corrugated cardboard (18) to which glue has been applied is wound in several plies on the mandrel (14) and the neck (18) of the pallet, so that the plies become glued to each other and to the neck (8).

2. A method according to Claim 1, characterized in that a watertight sack (13) of suitable, preferably plastic, material is drawn over the. mandrel (14) before the pallet (1) is secured to the end of the mandrel, and that the wound shell is glued to the sack.