Sorting Through Sorters: Your Guide to Sortation Conveyor

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The heart of most distribution centers today is sortation.  If it is applied correctly, products are efficiently routed to appropriate areas of the facility.  Applied incorrectly, and the consequences can be catastrophic, often times costing companies millions of dollars in wasted labor and non-value added processes.

But how does one go about matching the correct sortation conveyor technology to his or her specific application? First, let’s start by defining a few key elements:

  1. Product – What are you sorting?  Is the product contained in corrugate boxes, totes, bags?  Are the contents fragile?  What is the maximum, minimum and average length, width, height and weight of items you are wanting to sort?
  2. Rate – How many products do you need to sort per minute, per hour, per shift? What inefficiencies need to be considered such as breaks, shift changes, wave stops, truck change outs, etc.? Do you envision the required sortation rate increasing in the future?
  3. Number of diverts – How many product destinations are required? Will all of these be located on one side or both sides of the sorter? What is the overall footprint of the facility that can be utilized?

There is a vast array of sortation conveyor available today ranging in price from a few thousand dollars up to multi-million dollar complex solutions.  All are designed to be integrated into specific applications.  Utilizing the wrong technology can prove disastrous.  It’s important to consult with an experienced systems application engineering company such as Bastian Solutions to better understand the proper equipment to utilize.

Below are many of the most common sortation conveyor and sortation technologies available.

High Speed Pusher

Pusher sorter at book DC

Pusher sorters are often the least expensive form of sortation.  One or more pusher arms are positioned alongside a conveyor belt.  These pusher arms divert product 90 degrees onto a take away conveyor.  Generally used for medium to slow rate applications where products are not fragile in nature, pusher sorters can achieve throughput rates of up to 60 cases per minute.  Small item pusher sorters have the ability to sort up to 120 items per minute.

Pivoting Wheel Sorter

Pivot wheel sorter at Dollar Shave Club

Other industry suppliers refer to these as “pop-up wheel sorters” in which a series of wheels raise as the product that is to be diverted passes over them.  The wheels are powered and transfer the product off at a 30-degree angle.  Bastian Solutions’ ZiPline VECTOR Sorter is a vastly superior design.  Angular rotation is powered by servo motors with a resolution of less than a degree for customized angles between 0 and 30 degrees.  Tight roller centers allow for packages with a rigid footprint as small as 5” X 7”.  Additionally, it features polyurethane coated wheels which provide positive product contact during transfer.  The divert cycle is not only extremely quick (less than one second) but also highly customizable to fit specific application needs.  The VECTOR sorter is very modular in design and can replace a zone inside any belted or roller ZiPline conveyor by bolting to the underside of the standard frame.  Sortation rates vary based upon product sizes but the ZiPline VECTOR sorter can commonly achieve rates of 75-100 cases per minute.

Narrow Belt Sorter

Narrow belt sorter

The Narrow Belt Sorter is a sorter for medium-sized items. As the name implies, product is transported on multiple narrow belts. Rollers raise up between the belts to transfer items at either 90- or 30-degree angles off sorter.  The minimum package size is 8″ x 6″ wide, maximum package length is 28″ with a maximum unit package weight of 75 lbs.

Narrow belt sorters are designed for 2-sided transfer of items. Product can be transferred off either side of the conveyor to other right angle conveyors, workstations, packing operations, ticketing stations, shipping departments, or other similar operations. The unit is capable of handling medium to high throughput requirements of around 100 cases per minute.

Activated Roller Belt Sorters (ARB)

Intralox activated roller belt sorter

The term ARB stands for Activated Roller Belt™ and is known in the conveyor industry as the patented technology made by Intralox. On an ARB™ conveyor, products rest on free-spinning angled rollers rather than on the belt surface. These rollers extend above and below the belt surface and are positioned at an angle in relation to the direction the belt travels. Rollers that are activated by the carryway surface below move products across the belt in the direction of roller orientation rather than the direction of belt travel. Because it is possible to move conveyed products selectively, ARB-equipped conveyors can change the direction, alignment, location, and speed of an item independently without using rails or complicated mechanical controls. All of these features are made by Intralox.  Sortation rates can be up to 100 cases per minute with a minimum gap ranging from 12” to 36”

Sliding Shoe Sorter

Shoe sorter

Sliding Shoe Sorters are most commonly associated with high speed sortation.  The carrying surface is comprised of conveyor flights (slats or tubes), each of which is attached to a drive chain running inside each sorter side channel.  Sliding divert shoes, which are supported by the conveyor flights, push the load off the sorter at the appropriate sort destination.  The number of shoes used to divert a load is determined at induction and is dependent upon the length of the product.  Shoe sorters are great for sorting fragile products prone to damage.  They are also great for handling a wide variety of product sizes, shapes and weights.  It’s not uncommon for sliding shoe sorters to achieve rates in excess of 250 cases per minute.

Tilt Tray Sorter

Tilt tray sorter

A tilt-tray sorter is a high-speed, continuous-loop sortation conveyor that uses a technique of tilting a tray at a chute to slide the object into the chute. It is used to expedite the process of order fulfillment to consolidate line items of an order, and to process returned products for immediate updating of inventory in real time.  It is great for handling not only cartons and totes, but also soft goods that are difficult to sort with other technologies such as bags.  Sortation rates in excess of 375 cases per minute can be achieved.

Cross Belt Sorter

Cross belt sortation conveyor

The cross belt sorter is very similar to the tilt tray sorter.  The main difference is that the tilting trays are replaced with short belt conveyors positioned perpendicular to sorter flow.  Loads are inducted individually onto these belt conveyors.  The short belt conveyor is indexed as it passes the load’s destination in order to discharge the load to its takeaway destination.  This type of sorter is commonly used in the “M and M” (media and movie) industry, and can reach sortation rates of 500 cases per minute.

Bastian Solutions has more than 60 years of conveying and sortation design experience.  Our team of talented engineers are ready and able to help you with your sortation conveyor application.  Contact us today to get started.

Kyle is a Field Application Engineer with Bastian Solutions out of the Atlanta, GA, office. He graduated with a degree in Mechanical Engineering Technology from Southern Polytechnic State University. In his time at Bastian, he has gained experience with inside/outside sales, project management, systems engineering, and customer service.

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