How to Approach Designing a Pallet Flow System That Will Actually Work!
Pallet Flow Rack systems are perfect for fast moving storage applications that require a first-in /first-out application for the customers product rotation. They also provide the customer with a system that enables them to achieve “High Density Storage” areas within their warehouse which minimizes the required forklift travel aisles. Reducing the required forklift travel aisles simply equates to having the ability to store more pallet positions of product in the warehouse!
Pallet Flow Racking when compared to traditional selective pallet racking and drive-in pallet racking will appear at a glance to be very expensive per pallet position. A pallet flow system “Used” will average around $100.00 to $150.00 per pallet position depending on the application. When compared to a general selective pallet rack system for example, the costs of pallet flow racking can be 2-3 times more. However, if the application calls for a first-in/ first-out stock rotation then this is the way to go. The additional value that generally overcomes the cost is that fact that by creating the high density storage the customer saves money on their real estate cost by simply storing more material in their warehouse. The goal to any type of storage system is to create as many pallet positions of storage as possible within a given space. Utilizing the cubic feet within the warehouse space is always the key.
Pallet flow systems are very finicky and it is always very important that the user and seller work very closely together to gather as much information as they can up front to ensure that the pallet flow system will actually work properly in the end. In addition, setting up a mock bay to confirm that everything does flow property throughout the system is always a good idea before final design and production. This takes a little extra time and cost but in the end the customer and MHE is ensured that when the system is installed in the customer’s warehouse there won’t be any problems. There have been many pallet flow systems that have failed that looked good on paper!
Setting up a mock system will require that the customer send MHE a sample of their pallet or pallets with the product or products that will be on the pallets within the pallet flow system. This enables MHE to confirm that there aren’t any loose boards on the bottom of the pallet and that the bottom surface area in general is large enough to allow the pallet to flow property down the flow lane. Loose boards and/or a minimal amount of boards simply will not work in a pallet flow system. Often times, the customer will have to replace their old pallets due to their condition or they may have to consider a different style of pallet that has enough bottom boards to actually flow properly. It is also important to take a hard look at the product that is going to be on the pallets. For example, bagged products that are stacked neatly on top of each other up to 4 feet tall that have no overhang on the pallet will flow much better down a flow lane than individual boxes that are stacked 6 feet tall on the pallet and have 4” of overhang. The point here is that every application is different. Since it takes gravity to flow the pallets down the flow lane the actual flow lane must be set with a certain amount of fall so that the pallet will actually roll down the rollers to the end of the flow lane. Without getting in to a physics lesson, the heavier the pallet the faster it will flow down the flow lane that is set at a certain degree of fall/decline.
General things to determine when designing the right pallet flow system:
- What is the pallet size?
- What is the pallet made of? Wood, plastic, metal, etc..
- What is the board configuration on the bottom of the wooden pallet that will be riding on the pallet flow rails?
- If the pallet is not wood, then what is the surface configuration that will be riding down the pallet flow rails.
- What is the weight of the pallet?
- How tall will the pallets be?
- Depending on whether or not the pallets are very tall, they may need to be shrink wrapped .
- Are they pallets of product currently shrink wrapped?
- What is the product that will be on the pallets?
- Will there be any overhang on the pallets?
- If so, how much and what sides of the pallets will the overhang occur?
Once all of this information is gathered then MHE can start to put together what the customer will need for their system. Most systems will require either (2) runs of flow rails per lane if the flow rails have the staggered rollers and (3) single rails if they are only inline rollers. MHE typically has both in stock. When building the pallet flow system to support the rails it is generally done a manner similar to building a drive-in system. We will use an upright and/or a mono-post for every other pallet position of depth the system requires. We will typically use 96” beams if there is very minimal or no hangover of product on the pallets or 100”-102” if there is.
Depending on the depth of the system and the weight of the palletized products it may be necessary to include some centrifugal brakes in the system. Any time the system is going more than 3 pallet positions deep MHE will most likely have to install some centrifugal brakes within the flow lanes. Depending on the depth of the system we may have to install numerous brakes in each lane. A centrifugal brake is used to maintain a steady pallet flow throughout the system so that the pallets don’t slam to a stop at the end of the flow lane. Some palletized products will take the flow process much better than others. Especially the pallets that have products stacked 4ft tall or lower. In the case where the product on the pallets exceeds the 4ft height even stretch wrap doesn’t always keep the products from toppling over in the forklift aisle if the pallet is moving too fast down the flow lane. The centrifugal brakes are simple to install and work off of a simple gear design that will only allow the pallets to flow across the brakes at a certain speed. The rubber surface of the centrifugal brake rollers helps the bottom surface of the pallet adhere to the brake as the pallet flows over the brake whereby controlling the speed of the pallet throughout the flow system. The brakes are installed within hanger assemblies that will sell separately to mount the centrifugal rollers in. These assemblies will generally fit in the flue of the rack system or can be spanned within the steps of the beams in a pallet rack bay for example.
The next step, is to get a drawing of the specific area the pallet flow system will be installed in the warehouse and determine the number of pallet positions that can be achieved. If the customer does not have a drawing, then they can simply pick the area in their warehouse where they are wanting to put the system and do some basic field measuring. In this case, they would measure out the area on their floor where they want the system to go while identifying any building columns or any other obstructions. It is very important to know the ceiling clear heights in this area and be fully aware of any obstructions from the ceiling that would pose a clearance problem. Once this information is gathered then MHE can produce engineered drawings on our end showing the layout of the new system within the customers warehouse. These drawings will be preliminary for discussion only until signed off our by the customer for final approval.
Pallet Flow Systems work great if designed properly. There will be some products that will not work properly in a pallet flow system. However, the majority of products will work if all of the proper information and testing is done up front.