Push-Back Style Warehouse Pallet Rack Storage Systems
Push-back pallet rack systems are high-density storage rack solutions using dynamic pallet carts that travel on a rail system. Great for pallets with little or no time sensitivity, a push-back rack system permits high-density storage and flexible picking. A lift truck places each pallet on a cart, which is then pushed back by the next cart of goods stored in the push-back rack system. The pallets in push-back pallet storage racks can be stored up to six pallets deep.
We recommend a push-back rack system for LIFO (Last In, First Out) storage of multiple SKUs with multiple racks per SKU. The push-back rack system allows optimum use of space while enabling flexible picking of SKUs as required.
Our experienced team at Carolina Material Handling Inc. will help you design the right lane depths and SKU zones to optimize your use of storage space and minimize excess material handling for high warehouse efficiency.
Pallets are unloaded from the push-back pallet rack by the forklift operator picking up and slightly moving forward to allow space for the front pallet to clear the front pallet load stops and then slowly moving back with the load as the next pallet on the cart follows along until it is resting on the pallet load stops. The forklift operator then can back up more and lower the pallet to the transportation level. The push-back system is designed so that the forklift is the transmission of the pallets and carts. The speed of the carts is determined by the control of the forklift. So slow and gentle loading and unloading of the pallets in the push-back system are imperative.
There are 3 major components to a push-back system:
- Pallet rack structure, including uprights, mono post, and horizontal load beams
- Push-back rails for support and riding of carts
Pre-System Loading Inspections:
- Inspect pallets before loading into the push-back system. Defective or damaged pallets with loose boards and pallets of the incorrect size should not be loaded into the push-back system, as they can prevent the push-back system from operating correctly.
- Product should not overhang from the pallet more than the allowable amount due to possible hitting of the upright frames or hitting the other pallet load in the next lane. The pallets should be securely wrapped and/or banded to prevent the load from shifting while in the push-back system.
- Forklift operators should inspect the flow lanes for debris and obstacles that prevent the push-back carts from flowing properly. If there is debris on the push-back lanes, the operator should unload the push-back in that section and clean the rails.
Proper Forklift Loading Procedures:
- Prepare to load the pallet squarely into the push-back lane.
- Pick up the pallet and slightly tilt the forks back. This allows the operator to keep the pallet on the same plane as the slightly inclined slope of the push-back lanes.
- Gently load the pallet onto the first empty cart and set the load centered on the cart and back out with the forklift.
- The load should sit right at the front of the cart and rest against the front pallet load stop with the pallet sticking up above the load stop.
- When loading the second pallet into the system, you should square up to the lane and bring the pallet with the forklift up to touch the existing pallet resting on the cart in the push-back system.
- The pallet should be up high enough to clear the front load stop and still be touching the pallet that is already in the system. You want to push pallet to pallet, not push the load or product on the pallet.
- Once lined up pallet to pallet, slowly push the existing pallet with the pallet on the forks back until the pallet clears the front load stop and gently set the pallet down on the next cart or the final position or rails of the system.
- Follow this same procedure to load the push-back pallet rack system.
- Always use the same size pallets in the push-back pallet rack system.
- If the forklift operator senses resistance when loading, stop and inspect the push-back lane for potential problems.
Proper Forklift Unloading Procedures:
- When unloading a pallet, the forklift operator should tilt their forks slightly back once they have entered the pallet successfully. This allows for the forks to be on the same plane as the push-back lanes slope.
- Raise the pallet slowly and clear the front pallet load stop. Slowly drive back out of the system in a straight-back motion. Keep the speed slow while backing out of the lanes as the next pallet in the system will be controlled by the speed the operator traverses back with the pallet being unloaded.
- The forklift operator is the speed controller of the push-back system.
- Follow the same procedure to unload the remaining pallets in the push-back system.
- Removing jammed pallets in the push-back system can be achieved by gently taking a pallet and going into the system and pushing the pallet forward slightly to square the pallet onto the cart and then slowly reversing out of the system slowly to allow the jammed pallet to traverse to the next open position. If there is a jammed pallet in the system, the pallet must be removed before this lane or section is loaded or unloaded again. The whole section may need to be unloaded to safely remove the jammed pallet from the system. Inspect the issue and make adjustments as needed to create a proper flow.
- Pallet inspection is key to overall maintenance. Pallets being placed square in the system and centered over the cart is key. Loads overhanging the pallets and not wrapped properly will create issues in the system. Debris on the push-back rails, like old wood pallet debris, can cause issues with cart flow.
- Do not have operators climb into the rack to release jammed pallets. The pallet could release at any time and roll forward.
- Use the forklift with a pallet as a brace in front of the jammed load to block the potential hazard.
- If the operator cannot clear the lane, then the adjacent lane can be used after being fully unloaded. A secure platform can be placed in the system to allow the maintenance work to be done. The load on the jammed pallet may need to be hand-unloaded on a new pallet that is blocking the flow lane in order to get the pallet unjammed.
- Use all safety precautions while working on the push-back pallet rack system.
- Periodically inspect the wheels on the push-back carts to make sure they are installed tight and riding on the rails smoothly.
- Inspect the load beams and upright frames from damage and determine if they are still structurally capable of holding the loads designed for the system. If there is damage to the load beams, carts, rails, or uprights, then keep that section unloaded until the problem can be repaired or replaced.
Advantages of push-back warehouse pallet rack storage systems:
- High use of available pallet positions
- Use a single aisle to store multiple pallets deep
- Lift trucks never enter the rack, which decreases damage
- High pallet storage capacity of up to 3,000# per pallet
- Many design options and storage capabilities
- Store large numbers of pallets in a small space
- Components can be structural steel rack or roll-formed teardrop style rack material