5. FISH BOXES - STANDARD REQUIREMENTS

5.1 Structural Requirements

5.1.1 The wooden box
5.1.2 The plastic box
5.1.3 Aluminium alloy boxes
5.1.4 Fibre board boxes
5.1.5 Expanded polystyrene boxes (isopor)

5.2 Fish Boxes -Description and Area of Use

5.2.1 Returnable boxes
5.2.2 Non-returnable fish boxes

5.1 Structural Requirements

Generally the requirements are the same for boxes used on board fishing vessels, in store, in production units and in transport on the road/railway. Boxes suitable for these uses are made of wood, aluminium or plastic.

However, special requirements are set for boxes to be used in air freight transport, and it is especially important that such packing is waterproof.

The size of a box will be determined by its purpose, type of handling equipment available and the materials used on its construction. Boxes used inside a processing factory should be of a size suitable for one person to handle. Boxes used in transport can be larger of loading equipment such as hoists and fans lifts are available at both ends of the trip. Standard sized boxes should be marked with a distinguishing number.

5.1.1 The wooden box

Dimensions and accepted deviation

The wooden box is generally made from soft-wood but hardwood can also be used although this tends to make it more heavy.

Table 5 Material thickness (pine and spruce softwood)

Construction

Fish boxes must be made from dry materials which should have a plain and smooth surface to enable the best possible cleaning.

Sides, bottom and top are assembled by nailing the boards together. In the bottom the boards are placed with an opening between each piece to enable water to drain from the box. The openings should not be bigger than 10 mm. Wooden boxes for reuse must have stiffening boards to obtain more strength.

Boxes must be nailed with big-headed sharp edges nails of a length and a number that are dictated by material thickness.

Strength.

The boxes must stand normal daily loads. They shall without showing permanent deformation, stand an equally shared load corresponding to a 2.6 m high pile of boxes with 80% of volume filled with fish plus a load 3 times the weight of the pile.

5.1.2 The plastic box

Construction

The box must have a shape that utilizes the strength of the material and that gives stable stacking. The surface should be smooth, plain, without significant damage and have equally rounded corners.

The box should be equipped with drain holes in the bottom or in the walls as near the bottom as possible.

Strength

The box should stand normal daily loads. It shall, without showing permanent deformation, stand a min. of 8 hours with a load corresponding to a 3 m high pile of boxes with 80% of the volume filled with fish and in addition a load 1.5 times the weight of the pile (short time test).

The box should also stand long time loading test carried out under the same conditions as the short time test, but with a load 0.75 times the weight of the pile.

Durability against cracking

A plastic box should resist the following conditions: exposure to hot air at 100°C for seven days, submersion in a solution of 10% and synthetic detergents at 50°C.

5.1.3 Aluminium alloy boxes

Construction

The box should be made of AlMg2 aluminium alloy or of an aluminium material with at least the same properties and corrosion durability.

The box should be of a solid construction with the bottom, sides, and supporting flanges made from one piece of metal. The ends should be solidly jointed to the bottom and sides by smooth welding.

The box should be equipped with drain holes so arranged that the water and slime from a box is led to the outside of the boxes underneath it in a pile.

The surfaces of the box must be smooth, melds must be ground smooth and the box thoroughly washed out after manufacture.

Strength

The boxes should stand normal daily loads. They shall, without showing permanent deformation, stand an equally shared pressure corresponding to a 3 m high pile of boxes with 80% of the volume filled with fish and plus a load of twice the weight of the pile.

5.1.4 Fibre board boxes

The boxes are meant to be used as non-returnable packing material for:

• iced fresh fish;
• freezing of fresh fish;
• frozen fish

Construction

Fibre board material in boxes for iced or fresh fish should be smooth, free of cracks and dents, and humidity resistant on both sides. To obtain this the following treatment is normally used:

• polyethylene coating 10-20 g/m²
• high gloss waxing 10-25 g/m²
• wax coating 20-30 g/m²

If the boxes are glued, waterproof adhesive must be used.

In boxes used for freezing of fresh fish the inner side must be treated to a humidity resistance corresponding to a wax coating of 20 g/m².

The boxes material must not contain dangerous chemical or bacteriological substances which can be dissolved into the contents.

The boxes should be delivered flat from the factory and in forms that are easy to put together by nailing, glueing or using special closing mechanisms. The boxes can also be made of combinations of massive fibre board/wood or massive fibre board/plastic.

Boxes for iced, fresh fish should be equipped with drainage holes in the bottom corners or in end walls as close to bottom as possible.

Strength

The boxes should stand normal daily loads.

Boxes for iced and fresh fish

The boxes shall without showing permanent deformation stand an equally shared load corresponding to a 1 m high pile of boxes with 80% of the volume filled with the goods in question, plus an additional load of 3 times the weight of the pile.

Special boxes in massive fibre board shall, without showing permanent deformation, stand an equally shared load corresponding to a 1.5 m high pile of boxes with 80% of the volume filled with the goods in question, plus an additional load of 3 times the weight of the pile. However, boxes with wood and plastic reinforcement when strapped should stand a 2.6 m high pile of boxes with 80% of the volume filled with the goods in question plus an additional load of 3 times the weight of the stack.

Boxes for freezing fresh fish

The boxes shall without showing permanent deformation, stand an equally shared load corresponding to a 1.5 m high pile of boxes with 80% of the volume filled with the goods in question, plus an additional load of 3 times the weight of the pile.

5.1.5 Expanded polystyrene boxes (isopor)

Construction

The material should be homogeneous without any dirty particles and discolouring.

The boxes should stand the use of common cleaning and sanitation treatments and washing with hot water. The box material must not contain dangerous chemical and bacteriological substances which can be dissolved into the contents.

Drain hales should be located along the sides and in the end walls as close as possible to the bottom. These hales should be of sufficient number and size (approx. 15 mm diameter) to allow complete removal of water and slime. The surface of the material should be plain and smooth with no jagged edges around the hales.

Boxes meant for air freight transport should be watertight or equipped with water absorbent material.

Strength

The boxes should stand normal daily loads. They should, without showing permanent deformation, stand an equally shared load corresponding a 3 m high pile of boxes with 80% of the volume filled with fish, and in addition a load corresponding to the weight of the pile. They should also be able to withstand the impact of being drapped from a height of 3 m.

The load on the wall must not exceed 2 kg/cm².

5.2 Fish Boxes - Description and area of use

5.2.1 Returnable boxes

General

Within the world's fisheries there are great differences in vessel standards and sizes, fish species, methods of fish handling, etc. This means that a fish box will have to meet many different requirements so as to be suitable for use in different parts of the world.

There are several types of boxes/containers that are used in the fishing industry, although only a few of these are designed and suitable for such use. Problems are encountered with the type of material, strength and construction/design.

The design of returnable and non-returnable fish boxes is in most cases fairly similar. The difference is mostly found in type of material and method of construction (strength).

In the following some types of returnable boxes are described. The size and design characteristics apply mostly to boxes used in parts of the world with a relatively high technological level.

Wooden boxes

A selection of wooden boxes is shown in Table 6.

In developed countries labour costs for these types of wooden boxes are relatively high while the price will be quite favourable in most developing countries.

Aluminium alloy boxes

A selection of boxes is shown in Table 7.

These boxes are supplied in different shapes and sizes, and they are classified as returnable due to high price and durability.

Boxes of polyethylene (plastic boxes)

A selection of boxes is shown in Table 8. The boxes can be ordered in several shapes and sizes and are made of HD-polyethylene (High Density polyethylene).

These boxes are classified as returnable due to high price and durability.

Table 6 Loading data on wooden fish boxes

Fish boxes made in wood
Returnable and non-returnable

Examples on wooden box constructions

Type B: For small fish (herring)

Type C: Export box

Type D: transport box

Table 7 Loading data on aluminium fish boxes

Table 8 Loading data on polyethylene fish boxes

Fish boxes made of HD-Polyethylene
Returnable

5.2.2 Non-returnable fish boxes

General

Non-returnable boxes are usually made from massive fibre board or styropor but may also be made from thin wood. Wooden boxes are not so widely used in industrialized countries due to the high cost level.

In developing countries wooden boxes will, in many cases, be most convenient to use and the cheapest alternative. The limitation will mainly be that wooden boxes are not waterproof and therefore unsuitable for air transport of fish without waterproof lining.

Boxes of fibre board and styropor are used to dispatch fish to wholesale and retail markets. These boxes are also the most commonly used when dispatching fish by air. The volume/weight designed to allow handling by one person, i.e., up to approx. 25 kg.

Some examples of practical uses of fibre board and styropor boxes for fish products follow.

Fibre board boxes

This box is delivered from the factory in 'knack down' form and erected prior to use by folding, stapling, stitching and glueing as required.

Fibre board boxes to be dispatched by air (Airenabox)

When air freighting fresh iced seafoods the main concerns are quality, safety and economy.

Two systems which satisfy the requirements of Scandinavian Airlines System (SAS) and other airlines will now be described.

The Airenabox is made of a special type solid fibre board with a very high water resistance because both surfaces are polyethylene lined.

The box has a telescopic design, and is water tight, even when turned upside down.

The instructions for assembly and use (stitching, taping and marking) must be followed closely as to get the box to function satisfactorily.

Table 9 Dimensions of Airenabox fibre board boxes

Standard sizes and prices:
Internal dimensions:

a/ No. 6422 is especially designed for lobster
b/ No. 8323 is especially designed for salmon
c/ No. 8425 is designed especially to fit into a standard expanded polystyrene box

Standard dimensions L= 600, W= 400, H= 155. (500 lid per pallet - 500 boxes per pallet)

Figure 6 Fibre board boxes in telescopic design

Figure 7 Stitching machine

Figure 8 fibre board box

Table 10 Prices of non-returnable boxes (approx.)

Expanded polystyrene boxes (styrophor)

Boxes made of styrophor must be regarded as unsuitable for rough treatment and handling and are difficult to clean for re-use.

Because of good insulation qualities the box is suitable for transport of fresh iced fish as well as frozen products. When dispatched by car, ship or railway the box is used as it is, with the lid taped to the box. When dispatched by air sometimes the box is enclosed in a fibre board box (see Figure 9). The standard box has dimensions L= 100, W= 400, H= 18 (mm) and will take 20 kg of fish and 10 kg of ice.

The above mentioned standard box costs with cover approximately US$ 1.85.

1. Flat packing material in store. Insignificant volume
2. The box (and lid) is stapled together, 2 staples in each corner as near the corners as possible.
3. Two side liner is placed in the box. The liner can be procured both with and without styrofoam. The styrofoam gives better insulation
4. An acceptable water absorbent pad is placed on the bottom plate of the box
5. A second bottom plate is placed on top of the absorbent pad. This to spread the pressure of the fish equally on the absorbent pad.
6. The fish is put in the box
7. Crushed ice is thrown directly on the fish. For extra insulation a top plate of styrofoam is used
8. A lid is finally put on and taped to the box, with approved water absorbent the box is acceptable for air transport without the tape. The box is finally sealed with tapes if requested.

Figure 9 Fibre box for air transport

1. Flat packing material in store. Insignificant volume.
2. Box (and lid) is stapled together, 2 staples in each corner as near the corners as possible.
3. An approved absorbent pad is placed on the bottom plate of the box.
4. A standard expanded polystyrene box is placed on top of the absorbent pad in the fibre board box.
5. The fish is put in the box.
6. Crushed ice is thrown directly on the fish.
7. Cover is placed on top of the polystyrene box.
   Alt. I
   A clear plastic or a massive fibre board cover is used.
   Alt. II
   A common polystyrene cover to suit the box is used.
   The reason why the polystyrene cover in Alt I is left out is that the box takes less space in height.
8. The lid is put on and taped into position.

This packing system is well suited for fresh as well as frozen products.

Figure 10 Expanded polystyrene box for air transport

Figure 11 Expanded polystyrene box

Figure 12 Examples of stacking on pallets