DIY Carton Flow for Existing Pallet Rack

3 Steps to Optimize Your Space with Carton Flow and Existing Pallet Racking

In most fulfillment and warehouse facilities, the operation begins with storing products, or SKUs, on industrial pallet racking. However, as you optimize your operation for speed, accuracy, and storage density, you’ll need to incorporate carton flow solutions to maximize space utilization, and ultimately, reach your goals.  

Carton flow for pallet rack

Before you start your search for an off-the-shelf solution, did you know you can analyze your own operation and design your own carton flow solution based on your unique needs? All you’ll need is a tape measure, a calculator, and a little help from us.

In this article, we’ll cover the step-by-step process of designing a DIY carton flow system that will reduces pick times, reduce travel times, and dramatically improve the efficiency of your operation.

Follow these 3 steps to optimize your space with carton flow for existing pallet racks:

1. Determine your pallet rack details.

Not all pallet racks are created equal. While pallet racking may seem like a commodity product, every rack manufacturer's process results in slightly different finished products that aren’t always interchangeable. It’s important to keep your equipment consistent as your business grows. Understanding the specifics of your current pallet rack will help you determine how many additional beams you need.

Once you familiarize yourself with your rack manufacturer, you’ll need to focus on three additional items:

  1. Dimensions
    Your length, width, and depth are crucial specifications you need to measure to design your own carton flow system. At certain depths, most carton flow tracks will need to be supported by an intermediary beam. Without properly measuring your dimensions and making appropriate design decisions, you’ll likely invest in a carton flow product that will fail after extended use.

  2. Beam Style
    Different pallet rack uprights require different styles of beams. They come in three different styles: structural, step, or box beams. Step and box beams are roll-formed and welded shapes, while structural beams are made from “C” channels. Structural beams typically feature a bolted connection to the pallet rack uprights, while roll-formed beams feature a tear-drop shaped drop-in connection to the uprights. This is important for two reasons: Beams are secured to uprights through different methods - securing the wrong beam to the wrong upright can create a major safety hazard. Also, the type of beam informs the type of hanger you need to mount carton flow lanes or beds in your pallet rack. Make sure to note the beam style and the manufacturer when taking all your measurements.

  3. Weight Capacities
    Industrial pallet rack is typically very sturdy equipment, but just like beam styles, many manufacturers have racks with different weight capacities - and capacities can change depending on the width of the beams you need. Capacity is typically expressed in pounds per pair of beams and assumes the weight is evenly distributed across the beams. While you can always get shorter or longer beams, make sure you know the weight of the products you’ll be placing on them, and ensure your beams can handle it.

    Related Reading: Pallet Picking: Getting on Track

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2. Analyze your SKUs to determine track requirements.

Once you’ve measured your dimensions and consulted with your rack manufacturer’s documentation to confirm beam styles and weight capacities, you can begin to analyze the throughput of your SKUs. The design of your carton flow system depends on your volumetric throughput - the rate of production or the speed at which something is processed. Building a carton flow solution without analyzing throughput could mean not having enough space to store your SKUs, or buying more or fewer carton flow lanes or wheel beds than you really need.

How to measure volumetric throughput:

  1. Identify the number of times a SKU is picked in a shift and multiply it by the volume of the SKU - this will determine how much physical space your inventory of that specific SKU occupies.
  2. Divide that number by your time frame for replenishment - this can be a shift, a day, or even a week. 
  3. Your final number represents your volumetric throughput for a given SKU.
Once you’ve analyzed your entire inventory this way, you can use this information to determine more specifications for your ideal carton flow system, including:
  • Type of carton flow
    There are several different types of carton flow on the market. Some of the most common include roller lanes, wheel beds, and plastic wheel rails. UNEX offers SpanTrack Lane (dedicated lanes) and SpanTrack Wheel Bed (universal wheel beds). Your throughput will help you better understand the variation of your SKU dimensions and which SKUs move quicker than others. This informs the type of carton flow solution you need - the more variation in dimensions and throughput, the more universal wheel bed carton flow you’ll need in your facility.

  • Weight capacities
    The amount of product moving through a lane or bed of carton flow will create variations in total load weight for different SKUs. Understanding how much your carton flow solution needs to hold will allow you to identify where you need light, standard, or heavy-duty beds or lanes.

  • End styles
    Knowing your throughput also helps you identify which type of end style best fits your application. Your each picks (split case picks) will need to be picked from knuckled carton flow track, while your full case picks will require low-profile track. If your operation requires conveyor to move picked products out of the aisle, high-profile tracks can be used to store SKUs below the conveyor.

  • Roller centers
    Roller centers refers to the spacing between rollers within the sections. As product increases in length, additional space can be added between rollers/wheels. Having closer roller centers will increase the conveying surface and make the system more flexible. Analyzing your inventory and throughput will allow you to identify the dimensions of your SKUs that need to be placed in carton flow and help you make the right choice for roller centers. The general rule of thumb for roller centers is as follows:

Minimum length of SKU

Maximum roller centers







To learn more about understanding throughput and what it means for your operation, you can check out our free guide!

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Properly capturing and analyzing your throughput data is critical in ensuring you are making informed decisions when designing your carton flow solution. This will help you avoid headaches and wasted costs down the line. By investing in a system that is tailor-made to your unique application and scrutinizing every detail, you’ll be sure to make the smartest investment possible.

Related Reading: Carton Flow Helps You Grow

3. Design your carton flow solution.

Once you determine your existing pallet rack details and carton flow track requirements, it’s time to start designing your solution! We know this is easier said than done. That’s why our team of space optimization experts created the SpanTrack product configurator.

This tool makes it easy for you to build your ideal carton flow solution from scratch. Using your recorded pallet rack dimensions, the configurator will determine how many lanes or beds per level you can use, as well as the number of intermediary beams required. Identifying your rack manufacturer will automatically configure which style of hanger is needed to secure your carton flow system, as well as the total weight your solution can support.

You can then use inventory data and throughput to identify how many levels of carton flow you need, which also determines how many additional pallet rack beams are required and the total amount of carton flow lanes or beds you need. This allows you to ensure your slow, medium, and fast-moving SKUs are stored in their proper storage medium with the proper end style. When your work in the configurator is complete, it provides a customized configuration based on your inputs that increases your storage density and dramatically reduces your operation’s footprint.

Build a Storage Solution in Minutes with UNEX SpanTrack Configurator

No matter the size of your facility, your throughput, or your rack manufacturer, these are steps you must take to ensure your DIY carton flow project is a success. As always, our team of engineers and experts can help you make determinations based on your unique needs or special circumstances in your facility - things like pillars and low ceilings can throw a lot of variables into the mix. Give us a call at 800-334-8639 or click here to contact us and we’ll help develop the ideal carton flow solution for your specific application.

Posted by: UNEX