FUNCTIONS OF COLD STORAGE

PALLET LAYOUT AND STACKING PATTERNS

DEFINITION OF COLD STORAGE

Cold store is known as a cool store, a warehouse where the interior of which is maintained at below ambient temperature, typically well below freezing point.

COLD STORAGE FACILITYAn installation intended for the cooling, freezing and cold storage of perishable food products and other perishables. A cold storage facility, comprises a cold storage warehouse with truck and railroad platforms, compressor and condenser for a refrigerating systems, a cooling tower, and a pumping station for a circulating water supply, administration and residential buildings… etc.Cold storage facilities contain refrigerated rooms maintained at various temperatures. All the refrigerated rooms have insulated doors.

The air temperatures ranges from 4˚C to -5˚C in cold storage rooms, from -20˚C to -30˚C in frozen food storage room, from 0 ˚C to -30 ˚C in general purpose storage rooms,down to -10 ˚C in cooling rooms, and from -30 ˚C to -40 ˚C in freezer rooms. All such refrigerated rooms have insulated doors.

COLD CHAINIt’s a logistic system that provides a series of facilities for maintaining ideal storage conditions for perishable foods from the point of origin to the point of consumption in the food supply chain.It extends and ensures shelf life of products such as fresh agricultural products, seafood, frozen foods, etc.

FUNCTIONS OF COLD STORAGE• Protect perishable foods• Protect perishable nutrient products• Storage of dairy products• Storage of foods and vegetables

PALLET LAYOUT AND STACKING PATERNS

PALLETStacking containers onto a pallet is the most common way of loading and despatching a number of containers to the same location.There are a number of types of pallets which are made from different materials and with a variety of designs.Wood is the most common material used, pallets can also be constructed from metal or plastic.Pallet designs can be either:• 2 - way entry or• 4 - way entry

2- WAY ENTRY PALLET- This pallet is a low cost stable pallet. This pallet comes in a number of types and sizes.4- WAY ENTRY PALLET-This is a very common pallet; its made in variety of sizes and types to meet the needs of customers.

PALLETIZING A LOADPalletising a load involves stacking the cartons onto the pallet. It is important when palletising a load that you make sure that:• The load is stable• The load is within the safe lifting limits of the materials

handling equipment you will use• The pallet will fit into the transport vehicle 

STACKING A PALLETOne of the most important factors that needs to be considered when stacking a pallet is the strength of the cartons to support the load.The strongest part of a carton is in the vertical edges of the carton. 2/3 of the load bearing strength is in these edges with the panels only supplying 1/3 of the strength of the container.The best stacking pattern is for cartons to have the vertical edges lined up with the cartons in vertical columns.

CARTON STACKING PROBLEMSThe best stacking pattern is for cartons to have their vertical edges lined up with other cartons so they form vertical columns.If the edges are not aligned the strength of the stack is reduced.Cartons that overhang the edges of the pallet are not able to support the load of the stack and reduce the stability of the stack.Failure to use the strength of the carton structure can result in excessive damage in the warehouse and during transportation.

PALLET STABILITYThe stability of a stack on a pallet can be achieved by the pattern in which the cartons are stacked. There is a tendency for vertical columns of cartons to fall apart.An interlocked pattern can increase stability by holding the cartons together.Interlocking the cartons however can reduce the load bearing strength of the stack.

STACKING PATTERNSThere are several different patterns in which cartons can be stacked on a pallet. The pattern for stack depends upon the shape of the cartons to be stacked. Square items are usually stacked as columns.• Rectangular cartons can be stacked in:• Row pattern• Brick Pattern• Pinwheel pattern.• The use of interlocking patterns should only be

used when the weight of the loads will not exceed the load bearing strength of the cartons when stacked in this way.

INTERLOCKED UPPER LAYER• A combination of column and

interlocking cartons can provide stability with only minimal loss of load bearing strength of the stack.• In this example the second top

layer is interlocked to provide stability but the lower layers are all column stacked to increase load bearing strength.• This pattern reduces the load

bearing strength by only about 5%.

IMPROVING PALLET STABLITYOther methods used to increase the stability of a stack of cartons on a pallet include:• Interlayer sheets• Banding• Shrink wrap• Stretch wrapThe use of shrink and stretch wrap can cause a disposal problem if there is a large quantity used.

IRREGULAR CONTAINERS• When a pallet is to be stacked with a mix of

different containers the following rules should be followed as much as possible.• Heavy items are placed on the bottom of the

stack• Containers of similar height are stacked

together if possible• Irregular shaped objects are placed on the

top of the stack• Large items placed on the bottom of the

stack• Shrink or stretch wrapping a pallet of

irregular shaped containers can increase the stability.