In the warehouse environment, the terms "heavy and bulky materials" can refer to any number of items. These include concrete blocks, palletized bricks, drums, barrels, kegs, lumber, steel components, manufacturing raw materials, and even beverages in a food distribution center. The question is: How can manufacturing facilities and distribution centers effectively store these items and still drive warehouse efficiency?
A variety of ways to store bulk materials exists, including floor stacking, rack storage, and automated storage and retrieval.
This article will take a closer look at some of the most common forms of pallet racking and how each application helps drive more efficient warehouse operations.
Selective pallet rack
Selective pallet rack uses uprights and cross beams as a shelf to support and store a pallet. It is one of the best solutions for warehouses when it is necessary to store a wide variety of products (SKUs). This type of pallet racking offers:
- Direct access to all stored pallets all the time
- An ability to handle any pallet from any rack position without the need to move others
- Easy stock control because each place is a one-pallet position
- Load flexibility in terms of weight and volume
Despite being the most versatile pallet racking option, selective pallet rack requires numerous aisles and has the lowest storage density of any racking alternative. It is best for faster moving products and delivering maximum access to stored pallets in spaces where space is not the primary concern.
Drive-in & drive-through pallet rack
Drive-in racks allow a lift truck to enter the rack from one side to pick up or pull out pallets.
Drive-in racks are typically subject to more abuse than selective racks due to the way they are utilized. Lift trucks must enter the rack structure to pick or restock, which takes more time than picking from the front of a rack. It also creates more possibilities for a forklift/rack collision.
Drive-in solutions are very high-density, storing up to 75 percent more pallets in the same space than selective racks. This means more pallets per square foot, fewer aisles and more effective use of the cubic storage.
Drive-through racks are similar to drive-in racks, except they allow a lift truck to enter the rack from either side to pick up or pull out pallets. They are open at both ends, allowing more flexibility in loading and restocking and near first-in, first-out storage.
Among other benefits, drive-through racks offer the ability to store a large amount of similar loads in a smaller area. Selectivity is sacrificed, but storage density is enhanced because many pallets are stored and are available through a single pallet position.
Push back racks
In contrast to drive-through racks, push back racks function last-in, first-out. Forklifts place pallets on nested carts riding on inclined rails, and then
subsequent pallet loading pushes each pallet back.
When removing product, the forklift takes out the front pallet, allowing the pallets on carts behind it to roll gently to the front of the rack. The nested carts make placement and retrieval easy.
Additional benefits of push back racking systems include:
- Better use of warehouse space with up to 90 percent more product storage than selective rack systems
- Greater versatility with up to 400 percent more selectivity than drive-in racks
- High storage density coupled with selectivity for faster pick rates
No easy method exists to determine the right approach for stacking bulk materials in the warehouse. Each individual warehouse will need to consider facility space requirements/layout, type of product being stored, handling equipment costs, and other factors.
While floor stacking may make more sense for some operations, the long-term space savings from pallet racking solutions can help warehouses drive operational efficiency and better inventory management for many years to come. Pallet racks also help by removing potentially unstable stacks of bulk materials from the floor and placing them in rack systems designed to hold exactly the right load in a stable, safe manner.
Scott Stone is the director of marketing for Cisco-Eagle Inc., a provider of integrated material handling and storage systems for industrial operations. He has 25 years of experience in industrial operations and marketing.