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Solution Spotlight: SpanTrack Wheel Bed

unex spantrack wheel bed carton flow beds

What is Carton Flow?

Carton flow, also known as flow racking, roller racking, and gravity flow, is a dynamic storage solution that can dramatically improve space utilization and order picking efficiency within a warehouse. Carton flow tracks are roller or wheel-based conveyors that are designed to create lanes of storage within pallet racking. These storage lanes use gravity to flow products through the rack for more efficient order picking and inventory replenishment.

Most carton flow is designed to be added to new or existing pallet racking and most commonly replaces static shelving like wire decking or flat metal shelves. Installing carton flow into pallet racking is relatively simple. Carton flow tracks are cut to the appropriate size, and, depending on your racking requirements, they are designed to sit in between or on top of pallet rack beams, creating a flow-through rack. 

Most carton flow comes in a variety of options like light-duty, standard-duty, and heavy-duty; steel and aluminum rollers; plastic wheels or steel skatewheels. In this article, we are going to explore all things carton flow beds as we dive deep into the world of SpanTrack Wheel Bed!

UNEX-Spantrack-Carton-Flow-BedUNEX SpanTrack Carton Flow

SpanTrack carton flow helps operations across industries maximize space utilization and increase efficiency. SpanTrack is ideal for facilities with case picking or each picking operations, or manufacturing facilities in need of flow-through workstations, lineside storage racks, and manufacturing supermarkets

SpanTrack carton flow provides the most surface contact with items. Unlike older-style carton flow and plastic wheel rails, SpanTrack carton flow tracks prevent hang-ups that disrupt flow, ensuring products move seamlessly to the point of pick.

SpanTrack Benefits

  • Versatility: Add SpanTrack to any new or existing pallet rack. No shelving or intermediate support is required. 
  • Superior Flexibility: SpanTrack provides the flexibility to store products with a wide variation in size and weight. 
  • High Capacity, Durability: SpanTrack takes the abuse of active warehouses and assembly plants. 
  • Unrivaled Flow: Compared to plastic wheel rails, SpanTrack provides up to 300% more product contact, resulting in better flow, fewer hang-ups, and increased throughput.

Get The Definitive Guide to Carton Flow Storage and The Ultimate Order Picking Checklist. Download the guide today!


All About SpanTrack Wheel Bed

SpanTrack wheel beds are flexible carton flow beds that drop into existing structures to create the ultimate flow rack system for order picking operations, manufacturing facilities, and more. Durable and dependable SpanTrack carton flow beds maximize space and throughput for inventories of varying shapes and sizes. UNEX universal carton flow beds create superior flexibility and increase space utilization throughout operations.

Carton flow beds are highly configurable with different flow options, capacities, and end treatments. Infeed guides, guide rails, and more can help further optimize performance based on your needs. Plus, all SpanTrack carton flow tracks come with a comprehensive seven-year warranty. 

SpanTrack Wheel Bed Key Features

  • Maximum flexibility left-to-right for reslotting
  • Store products with a wide variation in size and weight
  • Shark fin infeed guides ease replenishment
  • Hex hub wheel design promotes optimal flow 
  • Freezer/cooler rated to below zero

Like all UNEX solutions, SpanTrack Wheel Bed is engineered to order, meaning we offer full, free engineering support on all projects. Our team of experts will work with you and your preferred material handling reseller to create carton flow solutions that will utilize every square inch of your space and increase efficiency in all areas.

To provide these tailor-made solutions, UNEX offers many ways to outfit your SpanTrack Wheel Bed to meet the unique needs of your operation.


Choosing Optimal Widths for Your SpanTrack Wheel Bed

SpanTrack Wheel Bed widths are determined by the best track combination that fits within the width of the racking. For example, in a 96" wide bay, you can use (4) 18" wide beds and (2) 12" wide beds. This will create a total 96" wide level of carton flow.

SpanTrack Wheel Bed Width Guide

SpanTrack Wheel Bed Flow Options and Capacities

SpanTrack Wheel Bed is offered in 3 main capacities or “series”:

  • 98 Series: Our 98 series wheel beds are our lightest capacity tracks. 98 Series SpanTrack carton flow beds are made with 1.6” hex hub wheels. These plastic wheels offer low friction to ensure smooth flow. 98 series SpanTrack Wheel Bed is rated starting at 35 lb. per square foot.
  • 99 Series: Our 99 series carton flow beds are considered standard-duty. Like the 98 series, 99 series SpanTrack Wheel Bed is also made with 1.6” plastic hex hub wheels. This series is rated starting at 50 lb. per square foot.
  • 100 Series: Our 100 series carton flow beds are our heaviest-duty, wheel-based carton flow solution. 100 series SpanTrack Wheel Bed is made of 1.9” skatewheels. These skatewheels are made of steel and each wheel has a bearing, making it one of the most rugged solutions on the market. SpanTrack 100 series Wheel Bed is rated starting at 100 lb. per square foot.

For a more detailed look into our light, standard, and heavy-duty carton flow roller options, you can refer to this handy chart to help determine capacity per square foot depending on the length of your tracks. This and more can be found in our SpanTrack brochure!

SpanTrack Capacities-1

SpanTrack Wheel Bed End Styles

In addition to capacity, it’s important to consider which carton flow bed end styles you need. End styles refer to how the tracks are situated within your pallet rack beams. Will they overhang your rack beams or rest on the ledge of the step beams? Do you want to angle SKUs or parts toward pickers for increased visibility? Then perhaps knuckled-end treatments are right for you. No matter your need, you will want to ensure you are selecting the end style that meets the needs of your application while maximizing your space savings.


Here is a quick walkthrough of our SpanTrack Wheel Bed end style options, what each is for, and when to use them:

  • Low Profile: Low profile carton flow tracks nest between beams on hangers for maximum use of vertical space. Low profile tracks can be used for full case or each picking applications, and are perfect for racks with pallet storage above.
  • Low Profile Knuckle: Low profile knuckled tracks can be made in 12", 16", 20", and 24" lengths. At the pick face, a 20-degree angled front end tilts cartons forward for increased efficiency in each pick applications within the rack structure.
  • Hangerless: Hangerless tracks do not require the use of a hanger to sit within your pallet rack beams. With hangerless SpanTrack, an adjustable length track sits on the ledge of step beams in the front and rear, keeping the face of the beams clear.
  • Pushback: To create pushback racks using SpanTrack Wheel Bed, notched tracks can be placed on top of your step beams with stops on the front and rear of the tracks. Pushback carton flow is ideal for applications where items are loaded and picked from the front of the rack.
  • High Profile: High profile carton flow beds rest on the top of rack beams. High profile tracks can easily be adjusted for various contouring options. Because these tracks overhang the structure, you can significantly increase storage capacity.
  • High Profile Knuckle: High profile knuckled tracks also rest on top of rack beams but they also incorporate a knuckled end treatment. High profile tracks can overhang structures up to 24" with a 20-degree angled front end for increased efficiency in each pick applications.
  • Add-On Pick Trays: In addition to various track end treatments, UNEX also offers pick trays that can be added to your SpanTrack Wheel Bed.
    • Pick Trays come in 12” and 15” depths with 2” lips and can be up to 96” wide.
    • Adjustable Pick Trays come in 18” and 24” depths and can be made with 2” or 4” lips.


Selecting the Correct Roller Centers

What the heck are roller centers?! Simply put, when someone mentions carton flow “roller centers” they are referring to the spacing between each roller or axle. As product increases in length, additional space can be added between rollers or wheel axles to optimize flow. Other factors like humidity, condition of boxes, bottom surfaces of totes, the weight of your boxes, and more need to be considered when choosing the right roller centers for your SpanTrack Wheel Bed. Having closer centers can increase flow reliability with these other factors. 

SpanTrack Wheel Bed roller centers are offered in standard 2” or 3” spacings. Below is a quick breakdown that can help guide you on roller center selection based on the minimum length of the objects you’re flowing:

  • 2” Roller Centers: 2” roller centers offer a moderate amount of spacing between axles. We recommend a minimum carton length of 8” up to 12” for flowing objects on 2” roller centers.
  • 3” Roller Centers: 3” roller centers offer a significant amount of spacing between axles. We recommend a minimum carton length of 12” for flowing objects on 3” roller centers. 

Centers Guide

SpanTrack Wheel Bed Accessories and Options

SpanTrack Wheel Bed accessories can be used to further tailor the solution to your specific needs:

*Shown on SpanTrack Lane

Impact Plate: The impact plate is a sheet metal plate that goes on the front or rear of your SpanTrack Wheel Bed to strategically slow product down. These plates create friction for more surface contact to reduce impact on your carton flow tracks. Impact plates can be used to reduce impact when loading products and can also be used for slowing down product flow at the pick face. Impact plates simply snap on over your carton flow wheels.

*Shown on SpanTrack Lane

Raised Pressure Relief Ramp Stop : A Raised Pressure Relief Ramp Stop is a sheet metal plate that easily snaps onto your SpanTrack carton flow beds at the front of your bay. It is used to lift the front of your product so it does not become wedged against the front beam or end stop. Ramp stops are effective in slowing down material flow and relieving back pressure from the foremost carton on longer spans.


*Shown on SpanTrack Lane

Slow Down Strips : Slow Down Strips are one-inch wide sheet metal strips that easily snap onto SpanTrack carton flow beds. They create friction to slow product down before it reaches the front of the rack to prevent product from crashing into the front beam or stop.

spantrack-carton-flow-accessories-wheel-bed-infeed-guides“Shark Fin” Infeed Guides: SpanTrack Wheel Bed Infeed Guides are plastic yellow “shark fins” that snap onto axles to guide product replenishment. These infeed guides allow employees to place product in the correct locations when loading product from the rear of a SpanTrack bay.


spantrack-carton-flow-accessories-wheel-bed-guide-railGuide Rails: SpanTrack Wheel Bed Guide Rail is an aluminum extrusion that runs the full length of span over a row of SpanTrack Wheel Beds. Guide rail simply snaps over carton flow wheels and is used to create individual lanes for products on carton flow bed levels.


carton-flow-spantrack-wheel-bed-accessories-1Product Stability Support: The SpanTrack Wheel Bed product stability support is a metal bracket that attaches to your step, channel, or box beam to stabilize products at the pick face. We recommend using the product stability support when the items you are flowing are shorter than recommended or have a very high center of gravity.


Related Reading: SpanTrack Carton Flow Accessories and Options

Discover the Difference with UNEX SpanTrack Wheel Bed

UNEX has been in the business of creating world-class carton flow solutions for over 30 years. SpanTrack Wheel Bed offers some of the best benefits in the industry, including:

  • Increased storage capacity and pick facings
  • Full-depth storage
  • Safe, ergonomic picks
  • Easy restocking and FIFO stock rotation
  • Superior flexibility for reslotting

Contact our team of SpanTrack Wheel Bed experts today to see if this solution is right for your next project!

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