WO2003006341A1

WO2003006341A1 - Transportation set for chilled products

Info

Publication number: WO2003006341A1
Application number: PCT/NO2002/000262
Authority: WO
Inventors: Trygve B. Marstrand
Original assignee: Coolsafe System As
Priority date: 2001-07-13
Filing date: 2002-07-12
Publication date: 2003-01-23
Also published as: NO20013475L; NO20013475D0

Abstract

The invention relates to a set for transport of reefer goods in a cooled means of transport, comprising: one or more cases (2) for containing the reefer goods and arranged for stacking, a pallet (1) for supporting a stack of one or more cases (2), stiffening elements or corner protectors (6) for placing on the corners of the pallet with the object of stiffening the stack of cases and creating a free space round the stack of cases. The invention is characterised in that the cases (2) are made substantially of a heat-conducting material.

Description

Transportation set for chilled products

The present invention relates to a set for transport of reefer goods or cargo, mainly fish in a cooled means of transport, comprising one or more cases for containing the reefer goods and arranged for stacking, a pallet for supporting a stack of one or more cases, and stiffening elements or corner protectors for placing on the corners of the pallet with the object of stiffening the stack of cases and creating a free space round the stack of cases. The invention is characterised in that the cases are essentially made of a heat-conducting material. The most common, if not the universal method of transporting reefer goods such as fish over long distances and in large quantities is by means of cases in a heat-insulating material, e.g. expanded polystyrene, which cases are cooled internally by wet ice or dry ice and stacked in trucks or planes for transport. An example of such a method and device is disclosed in WO 94/15841, which illustrates a system comprising one or more cases for holding reefer goods and arranged for stacking, a pallet for supporting a stack of one or more cases, and stiffening elements or corner protectors for placing on the corners of the pallet with the object of stiffening the stack of cases. The cases according to this system are equipped with holes in order to be able to receive the cold from the dry ice, and the stack of cases is enveloped by a gasbag ventilated in the bottom. As stated, the publication deals with transport and storage of fresh fish in substantially heat- insulated polystyrene cases. The stack of cases described in the publication is heat-insulated during the entire duration of transport.

This is the standard, known method of procedure for transport of reefer goods. The goods are cooled at the time and place of packing, and the low temperature is maintained due to the heat insulation in the packaging. The packed cases are not cooled from the outside, and therefore in the prior art it is essential that the goods arrive at their destination at a specific time, i.e. before the temperature inside the cases reaches unadmissible levels. As mentioned, the prior art employs heat-insulated cases, which are large and have the inherent characteristic of being practically impermeable to cold and heat. For the sake of clarity we shall hereby define the term "environment" as the space located outside a stack of cases when it has not been covered by an external hood, and as the space that is located outside the stack including a hood when it is in place. In this connection it can be said that the stack of cases described in WO 94/15841 is not adapted for receiving cold from "the environment" during storage and transport, since the cases are made of a heat-insulating material and in addition the stack is covered by a heat- insulating hood.

In known solutions wet ice will be usually employed for cooling. The cases are filled with the wet ice together with the reefer goods in quantities of 2.5 - 5 kg per case depending on the duration of the transport. The ice in the cases will gradually melt, and the cooling effect will decrease. The length of the cooling time also depends on the temperature of the environment.

In the case of airfreight this creates problems if delays occur as the ice, and thereby the cooling effect, can disappear before the cargo arrives at its destination. In order to keep the melt water in the cases, which is a requirement in airfreight, the cases also have to be supplied with an absorbent that sucks up the water.

In the case of road freight, at the moment there is no requirement for the water to be kept in the cases. The melt water from the ice, however, is also an environmental problem. 90% of all transport of salmon from Norway to Europe is carried out by truck. On this run, 3-5000 litres of melt water run out of one truck loaded with polystyrene cases with salmon and ice. This results in pollution of both the environment and the vehicle. Trucks that transport fish in this manner usually cannot subsequently be used for transport of general cargo, since it is impossible to remove the smell of fish from the vehicle.

Since polystyrene is an insulating material, it will not be possible to cool the contents of the polystyrene cases by cooling attempts from without. The polystyrene cases will insulate against cold from refrigeration plants in trucks and cold storage plants, thus preventing them from being used effectively together with polystyrene cases. In this case the temperature of the environment will have little or no effect on the temperature of the cargo. If the cargo in the cases approaches a critical temperature during transport, it will be necessary to repack it in order to be able to cool it quickly.

Furthermore, polystyrene cases are large and take up a great deal of space even when they are empty. Polystyrene, moreover, is a material that can easily break and both full and empty cases have to be handled with care.

Finally, the material polystyrene represents an environmental problem. Polystyrene products already represent a threat to the environment during the manufacture of the products. After use the products are regarded as special waste, which has to be deposited at special sites, for which a fee must be paid. The use of polystyrene is therefore far from desirable with regard to the environment.

As already mentioned, these methods of transporting reefer goods are encumbered with a number of disadvantages.

Thus it is desirable to provide a system for transport of reefer goods, which differs from the present day cooling system with polystyrene cases and wet ice and which is not encumbered with the disadvantages involved in the solutions according to the prior art.

This and other objects are achieved with a set according to the invention for transport of reefer goods in a cooled means of transport, comprising: - one or more cases for containing the reefer goods and adapted for stacking,

- a pallet for supporting a stack of one or more cases,

- stiffening elements or corner protectors for placing on the pallet's corners with the object of stiffening the stack of cases in such a manner that it stands steady during transport, and creating a free space round the stack of cases. The invention is characterised in that the cases are substantially made of a heat-conducting material.

The term "heat-conducting material" in this context will mean a material that is not heat insulating (an example of a heat-insulating material is polystyrene). An object of the heat-conducting material is to allow the contents of the cases to be influenced by the temperature of the environment, thus enabling the contents of the cases to be cooled relatively quickly by placing the cases in a cooled environment. A second important property of the material is low weight, thus reducing fuel consumption during transport.

The material must also be water resistant since during some parts of the process the cases will have to contain ice slurry without losing their rigid characteristics. The rigidity of the material must be sufficient to avoid deformation when the cargo is in place inside the cases.

Another important point is that the material is environmentally friendly both with regard to manufacture, use and as waste.

As already mentioned, the heat-conducting material does not need to be a material that is particularly suitable for conducting heat, the criterion being rather that it should not be an insulating material. An example of a suitable material is plastic materials in the form of foamed plastic, which is a "porous" plastic material. Another example is corrugated plastic, the use of which is illustrated in an embodiment of the invention. The corrugated plastic material comprises two outer, flat layers together with an inner, curved layer of plastic material.

In a second embodiment of the invention, the corner protectors, and/or the pallet are made substantially of corrugated plastic. In a special embodiment the set according to the invention is adapted for transport in a non-cooled means of transport, comprising cooling elements for placing on top of the stack of cases, as well as a thermally insulating hood for pulling over the stack with the object of heat insulating the stack against the environment. The cooling elements may advantageously contain air holes on the bottom.

In order to facilitate the transport of empty cases, in a preferred embodiment these are collapsible. The cases can then be stacked together after having been used. This is done, for example, by the edges of the cases being heat- welded, thus enabling them to be opened after use by the application of heat. Another possibility is to assemble the case by means of folding alone, and to unfold the case for stacking after use. The cases have thinner walls, lid and bottom than the traditional polystyrene cases, but have the same internal volume as the polystyrene cases.

The set according to the invention therefore has two variants or embodiments: one adapted for transport and storage of goods in a cooled environment, i.e. where cooling is provided on the outside of the packed cases, and one adapted for transport and storage in a non-cooled environment, where the set is equipped with cooling elements and a thermally insulating hood. The advantages of the non-insulated set are obvious: flexibility with regard to transport time is obtained, since the goods can be kept chilled for as long as necessary. For land transport the stack of non-insulated cases will be loaded into cooled trucks and on arrival at the destination the stack will be able to be stored directly in a cooled storage room. It is not necessary to repack the goods in any way.

For air transport, cooling elements will simply be added to the stack of pallets, and the heat-insulating cover or the heat-insulating hood will be pulled over the outside of the stack. Once again, it will not be necessary to repack the goods in order to adapt the transport packaging to suit air transport. This will naturally result in considerable savings in time, as well as ensuring the quality of the goods and the packaging, since the goods are not exposed to the external environment between their place of origin and their destination.

The term "hood" or "cover" in this context means a device for thermal insulation of the stack of cases from the environment. The hood may be in the form of a bag for pulling over the stack of cases, or as a light container with a lid that encloses the stack of cases.

The invention is described in greater detail below with reference to the attached figures, in which: Figures la- lb illustrate an embodiment of the set according to the invention, figures 2a-d illustrate an open case element and a lid, figure 3 illustrates a section of plastic corrugated material, figures 4a-b illustrate embodiments of the hood, figures 5a-b illustrate embodiments of the cooling element. Figs, l a- lb illustrate an embodiment of the set according to the invention.

The set according to the invention consists of one or more cases 2, a pallet 1 for supporting a stack of one or more cases 2, and stiffening elements or corner protectors 6 for placing on the corners of the pallet with the object of stiffening the stack of cases and creating a free space round the stack of cases. As stated, the cases 2 consist substantially of a non-insulating material.

The pallet 1, which in the case of road freight is usually a conventional wooden pallet, but for airfreight is preferably a watertight, lightweight pallet, is placed at the bottom of the stack of cases.

In a preferred embodiment of the invention the reefer goods cases 2 consist of a lightweight corrugated plastic material with good stacking strength.

Figures 2a and 2b illustrate an element 3 which can be assembled to form a case by means of folding and welding/gluing, and figures 2c and 2d illustrate a lid 5 for use together with the element. In this embodiment of the invention the cases 2 may be collapsible, the corner parts 4 being welded together by means of heat and may also be provided in such a manner that they are separated after use again by means of heat.

The cases 2 and their lids 5 are delivered in a flat package. A truck contains 12,000 units (cases + lids) against 1,200 units for empty polystyrene cases.

For loading in the truck, the cases are assembled mechanically, for example with a jig. Approximately 200 g of ice slurry is placed in each case together with the chilled item (the fish) in order to achieve sufficient moisture. An absorbent may also be included in the cases, but on account of the small amount of ice slurry and the fact that the cases are made of watertight material, this is not normally necessary. The lid is placed on the case, for example with a jig, and the cases are strapped. The cases 2 are stacked on the pallets 1 and 4, corner protectors 6 are attached with stretch film for secure transport and to ensure that the pallets stand steady in the truck. The corner protectors 6 cause a layer of air to be formed round the entire pallet load between the sides of the stacks facing out towards the stretch film and the actual stretch film. The extent of the layer of air is determined by the thickness of the corner protectors and is preferably approximately 2 cm. Since the cases 2 are smaller than those in polystyrene, there will also be a free area round the entire pallet load secured by stretch film and the pallet. A layer of air is thereby also created between the different pallet loads secured by stretch film, and also between the pallet loads and the walls of the truck when they are loaded into the truck. The cooling effect that is necessary in addition to the cooling effect achieved by the small amount of water ice in the cases (the main object of the water ice is to add moisture to the cargo), is provided by the truck's cooling unit. This may be controlled from the driver's cab in the truck. The different layers of air round the pallet loads cause the cold from the vehicle's cooling plant to circulate round the reefer goods, ensuring adequate cooling of the goods.

Since the cases according to the invention have a smaller outer volume than the polystyrene cases, and moreover so little ice is required in the cases, with the present invention more cases with more goods (fish) are povided per pallet compared to the polystyrene system. With the present invention the amount of cargo is limited by the weight, while with the polystyrene case system it is limited by the truck's height. Lower pallet heights are thereby obtained with the present invention, thus providing good cooling circulation and benefits in handling the pallets.

On account of the small amount of water ice that is required in the cases with the present invention, pollution of the lorries and the external environment is prevented, since very little ice melts. The cases, moreover, are watertight.

Furthermore, if necessary the cases 2 can be provided with holes, preferably in the upper part of the cases' walls to permit a sufficient amount of cold to be supplied to the goods. In a preferred embodiment of the invention, the material that forms the main constituent of the cases is corrugated plastic. Figure 3 illustrates a section of a piece of corrugated plastic material. It consists of two outer, preferably flat layers 7 of a plastic material, together with an intermediate layer 8 preferably of the same material that is crumpled up to form corrugations. The material has a low weight (approximately 700g/m ).

Corrugated plastic, of which the pallet 1 when it is a lightweight pallet, the cases 2 and the corner protectors 6 are composed, is an environmentally friendly and combustible material that can be recycled or used for heating.

As mentioned earlier, the set will be equipped with a heat-insulating cover when used, for example, for air transport. A cover of this kind in the form of a hood is illustrated in figure 4a. The hood 9 in this figure includes locking elements 10 on the edges to enable the hood to be closed round the stack. The locking elements consist preferably of Velcro fastenings. For air transport, the hood 9, which is made of thermally insulating bubble plastic with a reflecting metallic surface, is pulled over the cargo. The hood is airtight. In order to obtain good circulation of the cold between the cases 2 and the hood 9, there must be a layer of air of approximately 2 cm between them. This layer of air is provided by using corner protectors 6 of this thickness. The corner protectors are also preferably made of corrugated plastic. The hood 9 may alternatively be composed of a light corrugated plastic container, which may be provided with a lid.

Figure 4b illustrates a second possible design of the hood 4. This variant is called a "salmon hood" and is only opened at one corner. The opening can be closed by means of tape or the hood may have a tongue 1 1 for closing, which in turn is attached to the side of the hood by means of tape.

Figures 5a and 5b illustrate a cooling element, which will also form a part of the set in connection with air transport. The cooling element 12 is provided with holes on the bottom.

The cooling elements 12 are placed on the top of the corrugated plastic cases 2 and can be designed for controlled emission of cooling effect. Along the edges of the cooling elements 12 are a number of holes 13 for dosing of the coolant. The elements 12 normally contain dry ice, which gives a 3 times more efficient cooling effect than water ice. The elements 12 permit packing and transport of reefer gods over long distances with little addition of coolant, as well as the correct dosage of coolant during reloading. The cooling elements 12 may advantageously be made of corrugated plastic.

Figure 5b illustrates a variant of the cooling element 12 with holes 13 on the sides as well as on the bottom.

The cooling system set according to the invention can be used both for airfreight and truck transport. This means that the same reefer goods' cases are employed whether the goods have to be transported by road or air. This is a great advantage compared to the situation with the traditional polystyrene- water ice system, where the cases that are used are not of the same type for road and airfreight. For airfreight, polystyrene cases are used with holes in the corners to allow the melt water to run off, while for airfreight, watertight cases must be employed. This means that the goods must be repacked in new pallets when the goods are transported by air. As stated, the present invention provides a cooling system in which it is not necessary to repack the goods, thus facilitating the handling of the goods and giving savings.

When transporting salmon, the amount transported per truck increases by over 20% when the set according to the present invention is employed compared to the polystyrene system.

In the case of airfreight the cargo is first transported to the air terminal where the cargo is kept in cold storage until flight departure. The cooling effect is achieved in cold storage by means of the cold storage room's cooling plant. In the event of flight delays, this will not cause any problems for the chilled cargo, since it is cooled by the cold storage room's cooling plant and not by the ice in the cases, as is the case with polystyrene cases.

Before loading on to the plane, 3 cooling elements 12, with a total of 3- 12 kg of dry ice are preferably placed on top of the pallet. The amount of dry ice that is necessary in order to chill a specific cargo in a given time can be calculated in advance so that the correct amount of dry ice is filled in the cooling elements 12. A cover or thermohood 4 is pulled over the cargo. The hood 4 is passed about 10 cm down the sides and the whole stack is sealed by stretch film, thereby ensuring that the carbon dioxide gas/cold from the dry ice is guided down along the sides of the stacked cases 2. The hood 9 may go all the way down in order to make the unit lightproof and thereby better insulated. This is useful if the reefer goods have to continue transport by road after the plane has arrived at its destination. If the hood 9 is composed of a light container with a lid, the lid can be opened and the cargo can be raised if so desired. This means that the cooling elements 12, which after the transport by air no longer contain any appreciable amounts of dry ice, are supplied with sufficient dry ice for the further transport or storage before the lid is placed on the light container.

In order to achieve sufficient cooling in the lower part of the cargo, if necessary slices of dry ice may also be placed along the sides of the stacked cases on the inside of the thermohood 9 and the stretch film.

The preparation of the reefer goods before loading on to the plane is carried out according to the invention at the air terminal. Thus there are only a very few people who have to be trained in order to be able to employ the cooling system according to the invention for airfreight. This is highly advantageous compared with having to train one or more people, for example, at every single fish slaughterhouse.

When loading on to the plane, the cooling system according to the invention is handled as pallets, which is more cost-effective than handling as cases, which is the case with the polystyrene system.

In the case of airfreight of salmon, the amount transported increases by up to 50%) more fish per pallet with the cooling system according to the invention compared to the polystyrene system.

Claims

PATENT CLAIMS

1. A set for transport of reefer goods in a cooled means of transport, comprising:

- one or more cases (2) for containing the reefer goods and arranged for stacking,

- a pallet (1) for supporting a stack of one or more cases (2),

- stiffening elements or corner protectors (6) for placing on the corners of the pallet with the object of stiffening the stack of cases and creating a free space round the stack of cases, characterised in that the cases (2) are made substantially of a heat-conducting material.

2. A set as indicated in claim 1 , characterised in that the material is corrugated plastic.

3. A set as indicated in claim 1 or 2, characterised in that the corner protectors (6) and/or the pallet (1) consist substantially of corrugated plastic.

4. A set as indicated in claim 1 adapted for transport in a non-cooled means of transport, characterised in that the set further comprises cooling elements (12) for placing on top of the stack of cases together with a thermally insulating hood (9) for pulling over the stack with the object of heat-insulating the stack against the environment.

5. A set as indicated in claim 4, characterised in that the cooling elements (12) contain air holes (13) on the bottom.

6. A set as indicated in claim 5, characterised in that the cases (2) are collapsible.

7. A set as indicated in claim 6, characterised in that the lids (5) are collapsible.

8. A set as indicated in one of the preceding claims 4-7, characterised in that the cooling elements are made of corrugated plastic.