Packaging of the hottest fish and shellfish -- fre

Packaging of fish and shellfish fresh fish packaging (IV)

2.6 transportation packaging of fresh fish

(1) requirements of fresh fish for shipping containers

so far, the operation of fresh fish is more intuitive, simple and safe, and the shipping containers have not yet met all the protection requirements of fresh fish and the requirements of standardized regulations. More ideal shipping containers are still under improvement and development

the shipping containers for the recycling of fresh fish must meet the following requirements

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① the size, weight and capacity of containers should meet the requirements of national or foreign trade related standards

② high strength and light weight. When filled with fresh fish and ice, it can bear the specified weight and is easy to carry

③ low cost of containers

④ small proportion, light weight and low transportation cost

⑤ it has good heat insulation performance to reduce the impact of sudden temperature on the packed material. ⑥ Empty containers are easy to stack to save space and freight

⑦ it is easy to stack, and it is stable after stacking

⑧ the top cover of the container should be equipped with a drainage tank, so that the molten water, fish blood, mucus and other liquids flowing out of the box can be discharged in time

⑨ convenient for forklift handling and pallet shipping

⑩ the surface of the container is sanitary, clean and flat, without large gaps and convex edges, so as to avoid the accumulation of dust and dirt, and it is easy to clean and eliminate pollution

11. The weight of the container itself is stable. Whether it is warm or dry, the weight should be the same

12. The shape of the container is beautiful

13. Try not to cause noise during handling

14 if the damage is easy to repair

15, the average service life should reach 8-10 years

16 has appropriate capacity

17 the bottom of the container should have feet to prevent the container from directly contacting the ground and being polluted by high temperature and the ground

18 the surface structure on the side of the container should prevent adjacent containers from adhering to each other and difficult to separate under freezing temperature. For example, needles and blades also benefit from the lubrication of this material

although the material, size and sanitary conditions of the container have not yet reached standardization, according to the experimental application experience, for the container carrying fresh fish, in addition to the above requirements, the following specific suggestions are put forward:

① the depth of the fish box should not be greater than 30.5cm, so as not to crush the bottom fresh fish

② the volume ratio of fresh fish to ice should not be greater than 3:1

③ the total weight of fish box and fish should not exceed 68kg, which is convenient for two people to carry and operate continuously

④ the shape of the fish box should preferably be rectangular, and the protruding flanges and flanges on the side should be minimized. The stacking is stable and firm, and the stacking will not collapse when the fishing boat shakes vigorously

⑤ the material strength of the fish tank should be able to withstand the stacking pressure of 16 layers of fish tanks, and it will not be damaged even if it is subjected to strong vibration.

in the early stage, the frozen fresh fish in bulk were transported by railway in wooden boxes. In recent years, lighter packaging containers have been gradually adopted. Even in order to shorten the transportation time, fresh fish are also transported by air, but the freight is very high. Moisture proof cartons, which are lighter than wooden boxes, are easy to print, low in cost, have sufficient wet strength and good heat insulation performance, and have been widely used as transportation and packaging of fresh fish. Most moisture-proof cartons are waxed and leak proof. In order to further improve its protective performance, the box can be padded with a layer of heat insulation materials, such as polystyrene foam board. Moisture proof cartons with different structures can be used according to different seasons and transportation distances. For example, in the cold winter, you can not use polystyrene foam board; The package with moisture-proof carton and foam plastic lining only needs a small amount of ice to cool

another packaging form of fresh fish is the container made of expanded polystyrene. This kind of container is very light and has excellent heat insulation performance. The lid of the container is sliding, which is safe and convenient for stacking. dh,! X

in order to transport fresh products to the market as soon as possible, air transportation is also adopted. Therefore, lightweight packaging and perfect packaging containers are more required. It seems that air transportation is a necessary measure for fresh products to achieve rapid turnover

in the transportation and packaging of fresh fish, corrugated boxes with wet strength have replaced some wooden boxes. Compared with wooden cases, corrugated boxes have the advantages of good printability, low cost, good heat preservation and portability. Most of the cartons used for fresh fish packaging are moisture-proof and leak proof. The inner side of the carton with more perfect protective effect is lined with a layer of heat-insulating materials (such as polystyrene foam board). If the temperature of the circulation environment is very low, the thermal insulation (insulation) layer can be avoided. Cartons with good heat insulation performance also consume less ice. Other forms of fish boxes are integral polystyrene foam boxes. The box is lighter and has excellent heat insulation performance. Some structures adopt sliding covers and various cover structures

(2) shipping containers for fresh fish

at present, the materials used as fish boxes mainly include wood, aluminum alloy, plastic and fiberboard. These four types of containers are used repeatedly

① wooden box

the wooden box currently used is made of soft water board nails. The thickness of the plate is generally 12.7-15.8mm. There are rungs on the side of the wooden box and two or three skids at the bottom of the box to enhance the strength of the wooden box and prevent the bottom of the wooden box from directly contacting the floor. The wood surface is generally rough without fine planing. In order to reinforce, some cases are locked with iron wires or door studs at the end of the box. The end plates at both ends of the box are perforated or nailed with wood blocks for hand handling. Since the 1950s, wooden cases have been gradually replaced by other materials because of their shortcomings as turnover containers for fish products

advantages of wooden box: low cost, easy to repair; It can be processed and manufactured near the port, saving freight; It is urgently needed and can be supplied in large quantities at any time

disadvantages of wooden cases: difficult to clean; Bad smell; Short service life, requiring frequent maintenance; Easy to absorb water and parasitize bacteria; Due to water absorption, the weight of the wooden box is increased, which wastes human handling and is easy to cause weight error; Easy to scratch human body; After the wooden box is filled with fish and stacked, the fish juice, fish blood and mucus in the upper wooden box flow into the lower wooden box, which pollutes the products in the lower wooden box; Empty containers are inconvenient to stack, and the turnover and use waste freight

② aluminum alloy fish tank

is usually made of aluminum alloy resistant to salt water corrosion. Some are stamping processing, and some are composed of single pieces. The combined fish tank can be welded or riveted. The riveted structure is easy to accumulate dust and dirt due to many gaps. The box plate has convex ribs to improve rigidity and bending resistance. The top edge adopts a corrugated structure and is equipped with a drainage channel. This kind of aluminum alloy fish box can be overlapped with empty boxes to save space. The general service life can reach 8-10 years

advantages of aluminum box: from the perspective of service life, the cost is not high; Convenient for welding repair; Easy to clean, no odor; As a food packaging container, it is beautiful and clean; When the aluminum box is full of fish, the stacking is stable; Light and convenient to carry; The weight is stable

disadvantages of aluminum box: if it is not cleaned properly, it is easy to corrode and hide bacteria; The noise is too loud when moving, especially when empty boxes collide with each other; Poor heat insulation performance, easy to lead the external high temperature to the product, and accelerate its decay speed. If it is not handled, it is easy to crack from the edges and corners when it is impacted violently

③ plastic fish boxes

most of the plastic fish boxes currently used are made of high-density polyethylene plastic injection molding. Because the low-temperature impact toughness of high-density polyethylene plastic is better than that of polypropylene, and it also has sufficient stiffness. The production of plastic fish boxes is mainly limited by the cost of injection mold. Unless the output is large, it is not easy to change the mold because of the large investment in the mold

advantages of plastic fish boxes: if the production batch is large, the cost is not too high, and the service life can generally reach 6-7 years; Easy to clean, no odor; Clean and beautiful appearance; Light weight, easy to handle; No water absorption, stable weight; When full of products, the stack is stable, and empty boxes can be stacked to save space; Thermal insulation performance is better than aluminum box; It is convenient to set drainage channels; The bottom can be directly made into footings or horizontal bars at the same time, which is convenient for forklift handling and pallet transportation; Low noise during handling; It can adapt to low temperature refrigeration at a temperature of - 4O ℃ without embrittlement. "

disadvantages of plastic fish boxes: if the cleaning is not proper, the white plastic fish boxes will gradually turn yellow, affecting the appearance, so appropriate pigments can be added; when rough loading and unloading, the edges and corners are easy to crack, and the surface is easy to scratch; if a small amount of production, the cost of plastic boxes is high.

④ fiberboard boxes

fiberboard boxes are made of hard fiberboard. Both sides of the board are compounded with kraft paper. Kraft paper is polymerized, that is, according to some evaluation Method ethylene film composite to improve its waterproof performance. The center of the fiberboard also contains hydrophobic agent (or hydrophobic agent), so the water absorption is very low. The thickness of the plate varies according to the size of the box. The plate thickness of the small box is about 2mm, and the plate thickness of the large box is about 2.16mm. There are drainage holes at the bottom of the box. After the product is filled, the waist of the box is tied with strapping or waist. For the waterproof performance of most fiberboard boxes, the fiberboard is treated with polyethylene plastic coating or wax coating in advance. Printing shall be carried out before plastic coating

fiberboard boxes are sometimes made of corrugated fiberboard, which is also waterproof. No matter what type of fiberboard box, the quality should be strictly controlled, usually according to the detection method of paper products. For example, after the fiberboard is immersed in water for one day and night, the Mullen strength and other indicators are measured

fiberboard boxes used to pack smoked fish products do not require a high degree of waterproof performance. The products are wrapped in parchment or polyethylene film paper in advance, and then packed in boxes to achieve moisture-proof and oil-proof effects. Some fiberboard boxes can be used to pack both frozen fish and smoked fish products. Polyethylene coated fiberboard boxes are widely used abroad.

most of the above fresh fish shipping containers are used for many times, and their service life ranges from 5 to 10 years. This kind of container is suitable for railway transportation and road transportation. In order to avoid the pollution of fish juice and ice water, some use disposable packaging containers, which are no longer recycled. The Federal Republic of Germany "flechtenmacher" adopts a reusable outer package, while the inner package is a disposable fresh fish packaging structure. The inner package is watertight and can contain melted ice water and fish juice, or the bottom of the inner package container is padded with absorbent lining material (fiber or foam plastic to absorb ice water and fish juice) 。

at present, some countries are testing and developing new types of disposable packaging containers, mainly including the following types:

① polystyrene foam boxes, which are reinforced with wooden frames. The fresh fish and ice cubes are placed on the wooden frame, and the melted ice water and fish juice flow to the bottom of the box (stored at the bottom of the box) along the gaps on the four sides of the wooden frame, so as not to pollute the fresh fish. The external dimension of the box is 600mm × 400mm × 48ommm, with a volume of 52L, and the bottom can hold 12.5l of molten ice water. The thickness of foam plastic board is 25 mm

② the polystyrene foam box is covered with a layer of cartons to protect the foam box from damage during transportation. There is no wooden frame in the box. Sometimes, in order to strengthen the carton, a wooden frame can be padded between the carton and the plastic box

③ waterproof folding carton, carton board