NO20093338A1 - New boxes for transporting food - Google Patents

Abstract

Box (1) made by EPS for the manufacture and / or storage of foodstuffs. The box has sides and bottom, and a plastic film (5) is glued to an upper edge surface on the sides of the box, the plastic film constituting a lid on the box. The invention also encompasses a method of making such a box.

Description

The present invention relates to a new type of EPS boxes, in accordance with the introductory part of patent claim 1.

Background

Today, foodstuffs, and especially fresh fish, are often transported in boxes made of EPS (Expanded PolyStyrene). Transport in EPS boxes is the cheapest and most efficient way to transport fish. Such a box is light, functional, hygienic, solid and can be adapted to the Europallet. The fish is placed in the box together with ice, possibly an absorbent, after which a lid of EPS is placed on the box, and packing straps attach the lid to the box. Such boxes with lids and packing straps are well known in the art, e.g. from Bewi

AS.

During transport, most of the ice will melt, and to avoid the food being left in water, which reduces quality, most EPS boxes are designed with drainage holes in the bottom so that excess water can drain out. During long transport, water will therefore flow out of the boxes, and from the means of transport, such as a truck. This water is mixed with fluids from the fish, and is therefore an unfavorable discharge. The alternative is to use sufficient amounts of absorbents, and this is done, among other things, for air transport.

Filling the crates with ice instead of food is very disadvantageous and makes transport expensive. You can also use dry ice instead of regular wet ice, but dry ice is much more expensive and it cannot be in direct contact with the food itself. The alternative to using EPS boxes with ice is to use other boxes and provide cooling during the entire transport in other ways. The boxes must also have an intrinsic strength so that they can be stacked, moved and handled without the risk of them breaking.

Purpose

It is a purpose that the EPS boxes, in accordance with the present patent application, should be lighter and have a smaller external volume than known EPS boxes with the same internal volume. It is also a purpose that the boxes should be air and liquid tight, so that the atmosphere inside the boxes can be controlled. It is also a purpose that the boxes should provide better opportunities for branding.

The invention

The objectives are achieved with an EPS box in accordance with the characterizing part of patent claims 1 and 7. Further advantageous features are provided in the associated independent claims.

The invention relates to a box made of EPS, where a lid made of EPS is usually used to prevent loss of cold, as well as to protect the contents, as the lid is attached to the box with packing straps. In the present invention, this lid is replaced with a plastic film which is glued directly to the EPS box. With this film, a significant reduction in volume and weight is achieved, and it is undesirable, but possible to achieve a box that is liquid and/or gas-tight. By using a transparent plastic film, the contents are also easier to inspect for the end user, who no longer needs to open the box to check the contents. The film also offers good opportunities for branding, because it can be printed directly on the plastic film. Direct printing on EPS is possible, but the result is often poor and causes a lot of wreckage. The alternative is the use of stickers, but this results in additional costs and extra work.

An adhesive is used to attach the plastic film to the EPS box. Although this adhesive should not be in direct contact with the contents of the box, it is an advantage that an adhesive is used that is FDA-approved for indirect contact with food. The glue must adhere well to EPS, and preferably have a lower melting point than EPS so that EPS does not deform or melt when the glue is applied. When EPS melts, styrene gas is developed, which is possibly carcinogenic to humans.

In this context, "to glue" means the use of an adhesive/glue to attach two parts to each other, either releasably or firmly. By "glue" is meant any type of adhesive that is suitable for attaching two parts to each other, either releasably or firmly. Different types of glue can be used, preferably glue that is applied in one step and reactivated in another, e.g. glue that is activated by temperature, pressure, ultrasound or ultraviolet light. It is also conceivable to use glue which is applied in one step and which hardens in another. It is also conceivable that the glue used is a type of plastic that is first attached to the EPS box, and that when the plastic film is applied it is welded to the plastic that has already been applied to the EPS box. It is of course a prerequisite that the plastic applied to the EPS box adheres to it, and does not come loose during welding. The terms "glue" and "to glue" as used in this text shall be interpreted to include all of the above examples. A preferred example of a heat reactivated adhesive is ethylene vinyl acetate (CAS# 24937-78-8, also known as EVA). It is a copolymer of ethylene and vinyl acetate. The proportion by weight of vinyl acetate usually varies from 10 to 40%.

In a particularly advantageous embodiment, the glue is applied immediately after the box is produced, so that

the adhesive is applied under dry, controllable conditions. The glue can also be applied to the box after the contents have been put in, but then there is a risk that water, ice or other elements prevent optimal adhesion between the glue and the EPS. After the contents have been placed in the box, the glue must be reactivated and the plastic film applied. If the properties of the glue allow it, it can also be molded into the EPS box, when it is produced.

In an advantageous embodiment, the upper edge surface on the side walls of the EPS box is made with a horizontal, circumferential groove where the glue is laid, so that the contact surface between EPS and glue is as large as possible, without the wall thickness of the box changing.

The plastic film that is placed as a lid on the EPS box must also be approved for foodstuffs in the same way as the glue. The plastic film is preferably gas-tight, and has high tensile strength, e.g. about 13 MPa. It is also preferred that it can be printed directly on the plastic film, and that it is made in a quality that does not fog. It is also a prerequisite that the film adheres well to the adhesive, and that it is not changed by the reactivation or curing of the adhesive, for example it must have a melting temperature that is higher than the reactivation temperature of the adhesive, in those cases the adhesive is to be heat-activated. In order to obtain a film with satisfactory properties, it can be advantageous to use a plastic film with several layers.

The reduced weight and the reduced volume provide major savings in transport costs. When you can also achieve a completely airtight box, you can pack the fish with a controlled atmosphere, and this opens up new methods for packing and transporting fresh fish. A reduction in the amount of ice, for example, will contribute significantly to lowering transport costs.

By replacing the lids with a plastic foil, the underside of the base and the upper part of the side walls and/or the upper edge surface can be made with corresponding designs, so that the bottom of an adjacent box that is stacked on top will act as an insulating lid. This results in a further reduction in volume, so that more boxes can be stacked in height, without increasing the outer dimensions of the pallet. This results in large savings in transport costs.

Example

In the following, an example of a box will be described where the EPS lid has been replaced with a plastic film, and where a number of boxes are placed on a pallet. The example is shown in the attached figures, where figure 1 shows a box with a circumferential groove,

figure 2 shows the box in figure 1, with a glued plastic foil, and

figure 3 shows a pallet with new boxes with plastic foil in comparison with a pallet with traditional boxes.

Figure 1 shows a fish box 1 in EPS (in this case an EPS with a melting temperature of 103°C has been used) which has been modified to receive a plastic film as a lid instead of a traditional EPS lid. The case is designed with a circumferential groove 2 in the upper edge surface on the sides of the case, and in the embodiment shown, the groove has the shape of a semicircle, and is about 0.5 cm wide, and about 0.5 cm deep. In addition, the upper edge surfaces of the box are designed with a discontinuously raised outer edge 3, which corresponds to recesses/tracks 4 in the underside of the box, so that boxes can be stacked stably in height.

An EVA glue, for example Krystal Lim FDA 105, is placed in slot 2, at a temperature of approx. 70°C. After the glue has been applied, the box 1 is cooled and transported to the place of use, where fish and ice are placed in the box. The glue is then reactivated with heat, e.g. by using a frame with a temperature of 80°C which is lowered onto the glue and heats it up. The frame has the same shape as slot 2 and has a width of 0.3 mm, to avoid direct contact between the hot frame and the EPS box itself.

Next, a plastic film 5, in the case shown a 40 µm thick two-layer plastic film of PE and EVA, with the EVA layer facing the glue, is placed over the box 1 and guided down until the film 5 adheres to the glue, and preferably until the film is in contact with the upper edge surfaces of the box, so that it is glued to the EPS box. A box with fish and ice, provided with such a plastic film, is shown in figure 2.

The savings by using plastic film 5 instead of traditional EPS lids 6 are large. A traditional lid weighs 200 grams, and a plastic film with glue, in accordance with the above example, weighs approximately 15 g. The weight saving per case will thus be approximately 185 g, and per pallet (24 cases) this will amount to 24<*> 185 g, i.e. 4,440 kg. However, to ensure that there are no holes in the top boxes, as well as to prevent cold loss, it would be an advantage if the top layer also had traditional lids, and the savings per pallet would thus be (24-3)<*> 185 g = 3,840 g. Weight savings on the boxes themselves due to a new design with elevations and grooves, comes in addition.

A lid builds approximately 2 cm, and the volume saving per pallet (8 boxes in height) will thus be 7<*>2cm; 14 cm. However, when the boxes are additionally designed with elevations on the upper edge surface and corresponding grooves on the underside of the bottom, the boxes can be stacked closer than before, and the total saving in volume, with boxes in accordance with the present invention, is as shown in figure 3 , 23.9 cm, or about 230 litres.

In the above, a preferred embodiment of the present invention is shown and described. The figures and the example are only given to illustrate an embodiment of the invention, and should not under any circumstances be interpreted as limiting the invention as it is defined in the attached patent claims.

Claims (9)

1. Box (1) made of EPS for the production and/or storage of foodstuffs, the box having sides and a bottom, characterized in that a plastic film (5) is glued to an upper edge surface on the sides of the box, and that the plastic film forms a lid on the box . 2. Box (1) in accordance with claim 1, characterized in that the upper edge surfaces on the sides of the box are designed with a circumferential groove (2), preferably a horizontal groove, and that the glue is placed in this groove after the box is manufactured. 3. Box (1) in accordance with claim 1 or 2, characterized in that the adhesive is of a type that can be reactivated with heat at a temperature that is lower than a temperature at which the EPS deforms and/or melts. 4. Box (1) in accordance with one of the above requirements, characterized in that the box with the plastic film (5) is gas-tight. 5. Box (1) in accordance with one of the above requirements, characterized in that the underside of the bottom and the upper part and/or the edge surfaces of the side walls are made with corresponding designs (3, 4), so that the upper part of the side walls can be inserted in the bottom of an above box. 6. Box (1) in accordance with claim 5, characterized in that the side walls have an outer, circumferential, raised edge (3) on the upper edge surface, and that the underside of the bottom has corresponding depressions (4). 7. Method for producing an EPS box (1) in accordance with claim 1, characterized by a) casting a box (1) of EPS with side walls and bottom in the usual way, b) applying an adhesive to an upper edge surface of the side walls, c) place a plastic film (5) over the box, and bring it down at least until contact adhesive is achieved. 8. Method in accordance with claim 7, characterized by further comprising a step to reactivate the adhesive between steps b) and c) in claim 7. 9. Method in accordance with claim 7 or 8, characterized in that the plastic film (5) in step c) is brought down until contact with the adhesive is achieved, and further until contact with the upper edge surface of the box (1) is achieved.