TYPES OF PALLET RACKS

There are several pallet storage methods you can choose from. However, the first thing to do is to be aware of the most commonly used types of pallet racks:

FLOOR POSITIONING WITHOUT PALLET RACKS

While not technically  "pallet racking," the floor position can be an important part of the storage system. Floor positioning is a very flexible system, not only because almost anything can be placed there, but because there is no structure that defines limits for the height and width of the load. This can be beneficial when used for temporary storage of a fast-moving product (ie cross-docking). Although, some product characteristics may limit the stacking height and space between the top of the product and the warehouse ceiling structure, which represents unused storage capacity. A big advantage of the floor positioning is the low capital cost. All that is needed is paint or tape to mark the place where the goods are placed.

UNIVERSAL PALLET RACKS

The most common type of pallet racks are universal pallet racks. They are designed to store three pallets in each cage between the frames. One advantage of the universal pallet rack is its selectivity, since the product is stored only one pallet deep from the work aisle, and each storage level is independent from the other, making pallets accessible at any time. Universal pallet racks are the least expensive type of pallet racking systems. However, a disadvantage of using the universal pallet racks is that the share occupied by the work corridors, necessary for the operation of the warehouse equipment, can easily exceed 50% of the warehouse area.

DOUBLE DEEB PALLET RACKS

DOUBLE DEEP pallet racks are similar to universal pallet racks, but their modules are designed so pallets can be stored two depths from the work aisle, rather than one. This system provides increased storage density, while maintaining a good degree of selectivity. Notably, Double Deep pallet racks require special electric trucks with telescopic fork extensions.

DRIVE IN PALLET RACKS

In drive in pallet rack systems, pallets are supported at the edges by rails that are installed perpendicular to the work corridor. The pallet loading compartment is as large as one pallet, as the pallet support rails are under the sides of each pallet. There is a gap between the support rails, which allows storage equipment to enter or pass through the rack structure. The biggest advantage of the DRIVE IN rack is its high storage density. As the speed of product movement in warehouses and distribution centers has increased over the past few years, DRIVE IN racks have become less popular, but in some situations they are still the most appropriate solution.

PUSH BACK PALLET RACKS

PUSH BACK racking uses a series of nested carriages or roller beds that are mounted on inclined rails in the racking structure. When the first pallet is stored in place, it is placed on the top carriage. When the second pallet is ready for storage, it is used to push out the first pallet. When this is done, the pallet and cart move up the inclined rail, pushing the first cart onto which the first pallet is placed. This process is repeated until each cart is loaded and pushed back, with the last pallet resting on the rails. The process is reversed when the racks are unloaded. The advantages of the PUSH BACK pallet system include: high storage density, good selectivity and a performance advantage over some other high density systems, because the warehouse equipment works in front of the rack unit.

FLOW RACKS PALLET RACKS

In this type of racking, the pallets pass through the racking structure on rollers or wheels. The rails that support the rollers/wheels slope from the input to the output side of the rack unit, using gravity to move the pallets from one end to the other. The greatest advantage of the FLOW RACK shelving system is the ability to maintain maximum output movement of the product in each channel. The system is effective in high-throughput operations for shipping products.

WAREHOUSE PROFILE AND PALLET RACKS

Choosing the pallet racking system that is best for your operation depends on several factors, the biggest of which is your stock profile. In order to for the pallet system to be determined, analysis of your products now and in the recent past, will be required. If your business has seasonal fluctuations in order volume, information about the consumption of the products for different periods of the year will be collected. This inventory information must go down to the SKU (Stock Keeping Unit) level to identify the number of pallets for each SKU in your warehouse facility. Forecasts of future product consumption can then be applied to this base number. After you create an inventory profile, then you can determine the type of rack you need.

Pallet racking and the rule of THREE

A common guideline for choosing the right racking system is the “Rule of Three”, which suggests that when pallets are stored in very deep locations, each SKU (Stock Keeping Unit) should occupy at least three locations for proper efficiency. For example, a SKU stored in locations with two pallets in a rack depth must have a minimum of six pallets in stock. In addition to storing spare pallets, you should make plans for picking operations. If they are in the same place as the storage area, the need for picking positions may be the main determining factor for choosing a pallet racking system, especially if the picking positions need to be accessible from floor level. These positions should be arranged so that the pickers have little movement (circulation) in the storage space, so that the declining number of stocks is sufficient to support the replenishment of the picking area.

Racks for pallets and work corridors

Another factor to consider when determining the storage layout is the width of the work aisle, which is usually determined by the type of warehouse material handling equipment. Generally speaking, the narrower the work aisle, the higher the utilization of the warehouse volume. Too narrow a corridor, however, will limit the choice of warehouse equipment used. If multiple types of material handling equipment or racking systems are used, the slowest of them will set the pace of movement of the goods. In both cases, the speed at which pallets can be placed and removed from the rack in the work aisle complies with the requirements of other zones. High storage efficiency is achieved at the expense of product movement speed.

AUTOMATED WAREHOUSES FOR PALLET STORAGE

The highest storage efficiency is achieved through highly automated storage and retrieval  systems (ASRS). Although, these systems have a lot to offer, there are some caveats to their use. First is the capital expenditure, these systems are not cheap, and if land costs and labor costs are relatively low, it may be difficult to justify the investment. On the other hand, a lack of manpower may make automated systems the only option. The second caveat concerns capacity. The automated system must be designed for full entrance - exit throughput and storage capacity from the outset. Although it may take several years before the volume reaches its maximum. Additionally, changes to rack construction can be challenging, but some systems offer flexibility in rack type selection or the ability to add equipment as volume increases.