To maximize storage space in a facility, various businesses use pallet racks, which are essentially a materials handling system. Individual pallets, or “skids,” are fabricated from variants of wood, metals and plastics and are incorporated into larger racking systems that feature shelves on multiple levels. A decking base (fabricated in different widths) supports the storage objects that are placed on the racks. Decks are composed of wire mesh, which support items and are helpful for surveying inventory. Forklifts are required for the loading process, as some pallet rack constructions measure several feet high. In structure, pallet racks are generally roll formed (columns supported by beams) or structural (beams that are bolted). Standard pallet rack configurations include selective racks, drive-in/drive-through, push-back and flow racks.
Pallet Rack Types & Configurations
Selective racks are the most commonly used pallet system, according to manufacturing experts. Pallets are accessible from the structure’s aisle. In this system, beams act as the support system for the pallets. This system is not limited to one type of storage, but is generally associated with narrow aisle racking, standard and deep reach systems.
Configurations: Narrow aisle racking requires a specialized narrow lift truck and is used to create optimum space, as the structure allows for large storage capacity.Standard systems allow for single deep loading, whereas deep reach systems allow for double the storage amount (of the former unit).
Drive-in racks and Drive through racks are structures capable of high density storage. These systems are typically constructed from steel and allow space for a forklift to move into the structure’s bay, which is essentially a lane of stacks.
Configuration: While drive-in rack structures feature one entry/exit way, drive-through racks have entry access on both sides of the bay. The entryway differences typically affect the way materials are stored in these systems. For example, items stored in drive-in racks are typically loaded via the last-in, first-out process, also known as LIFO. Due to this method, drive-in systems are suitable for nonperishable products and items with a low turnover, as storage is not readily accessible. The drive-through system requires the FIFO (first in first out) system. Both drive in and drive-through systems operate in floor-to-ceiling structures.
Push back racking systems are fabricated in roll or structural form. They are ideal for bulk storage, as they are capable of storing products that occupy/run several pallets deep (2-5) and typically measure several levels high. When a pallet is placed or loaded on the structure, it “pushes” the next pallet back on the rails where it rests. When the pallets are unloaded from the rails, they are pushed to the front of the structure. As with the drive-in racks, these structures are loaded using the LIFO system, and are considered suitable for large storage systems. Configuration: These structures typically feature inclined rails and sliding carts, and are often constructed with double lanes.
Flow racks are also known as gravity flow racks and are generally ideal for high-density storage. Loads are stored at the higher end and removed at the lower end point, employing the FIFO loading system. As the products are loaded, the rotation becomes automatic due to the flow of the racks. Configuration: These systems feature a gravity roller that generates movement based on the rack load, as items are moved on a sloped plane. The lanes feature brakes, or speed controllers, which control the movement of the objects. The rails are generally powered by gravity, so no electric operating system is required.
Selecting a Pallet Rack Configuration
It is helpful to consider a few essential factors when selecting a pallet configuration. Manufacturing experts recommend considering the cost of materials, the space and height available (American National Standards Institute, ANSI, http://www.ansi.org lists approved pallet measurements). The types of storage items and inventory that will be stored should also be assessed, as different loading systems (FIFO and LIFO) must be matched with specific products. Additionally, some food products must fall under FDA regulations. Professionals advise considering environmental factors, as some locations and outdoor settings require heavier or stronger equipment configurations.