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

How does one go about matching the correct sortation conveyor technology to their specific application?

Sortation Technology Features

Let’s start by defining a few key elements:

1. Product – What are you sorting?  Is the product contained in corrugate boxes, totes or 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 or truck change outs? 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 solutions 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 or RH Brown Co. to better understand the proper equipment to utilize.

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

High Speed Pusher Sorters

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 takeaway 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.

Pivot Wheel Sorter

These are sometimes associated with “pop-up wheel sorters” which feature a series of wheels raise as the product that is to be diverted passes over them. The wheels, in this case, are powered and transfer the product off at a 30-degree angle. Pivot wheel sorters are similar but feature a 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 pivot wheel sorter is very modular in design and can replace a zone inside any belted or roller conveyor by bolting to the underside of the standard frame. Sortation rates vary based upon product sizes. The pivot wheel sorter can commonly achieve rates of 75-100 cases per minute.

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)™

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. ARB-equipped conveyors can change the direction, alignment, location, and speed of an item independently without using rails or complicated mechanical controls. Sortation rates can in excess of 200 parts per minute with a gap as small as 4 inches.

Sliding Shoe Sorter

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

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

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 media and movie industry. It can reach sortation rates of 500 cases per minute.

Push Tray Sorters

Like the tilt tray sorter, the push tray sorter is a high-speed continuous-loop sortation conveyor that uses a bar to physically push items off individual trays. The sorter is very versatile and is great for handling material of varying shapes and sizes making it an applicable solution across multiple industries. Also available as a dual sorter, this sorter can obtain a speed of 250 cases per minute.

Robotic Sortation Systems

tSort

A robotic sorter like Tompkins tSort performs similarly to tray sorters but is not fixed to a track. The sorter consists of a raised platform on which independently moving robots travel freely along the shortest path to sort goods from an induction station to a designated divert. tSorts are fast to implement, low in capital cost and offer flexibility for expansion.  Available in three load sizes ranging from 5 to 33 lbs. These sorters can reach a sortation rate of 800 cases per minute.

Sure Sort

Another robotic sorter system is the OPEX Sure Sort. It is an automated put wall for small items that weigh less than 5 lbs. An operator feeds product onto a belt that inducts items through a six-sided scan tunnel. The product is then deposited into an assigned bin location by an iBOT, a wireless multi-direction vehicle. When the bin contains all items needed to complete an order an LED light illuminates, alerting an operator to an order that is ready to be packed for shipment. With the option of adding up to 22 iBOTs to a system, the system is easily expandable and can reach a sorting speed of 40 cases per minute.

Improve Reliability and Accuracy

As one of the newest Toyota member companies, RH Brown Co. is the newest Toyota member company giving Bastian Solutions the ability to provide extended support to current Pacific Northwest customers, while offering advanced automation capabilities to RH Brown’s existing clients. Speak to one of our consultants to explore your material handling and automation needs and goals.

Author: Kyle Eubanks, Sommer Miller