While the job of parcel shipping and distribution remains essentially the same, conveyor and sortation technology is evolving to keep pace with the demands of the modern distribution center. Getting the right package to the right person at the right time and at the right price has always been the name of the game in parcel shipping and distribution. While the mechanisms, technology and level of automation have evolved to change the nature of the game, the rules remain the same quickly and efficiently process an order, convert it to a shipment, get it into the customers hands and do it better than the competition.
Doing it better than the competition, however, is not an easy task. Without modern material handling equipment and systems to streamline the process, the job of parcel shipping and distribution would take a giant step backward.
That step back would mean that an amazon.com customer could wait weeks for her bestseller to arrive. The manager at a local Wal-Mart might have to order his inventory months in advance. The global economy could crawl to a halt under the load of todays order fulfillment volume. Luckily, parcel shipping managers have the benefit of automated conveying and sortation equipment, which helps them avoid such delays.
Drivers for Change
There are numerous drivers for change in material handling productivity, equipment and systems, including the demands of the Internet economy, the rising costs of energy, the high costs of skilled and loyal labor and customer expectations for fast and accurate order processing. Perhaps the greatest force for change is the movement to just-in-time inventory and the many demands it puts on the supply chain. Moving products more quickly, more accurately and more cost-effectively is a requirement in todays global economy, not a wish.
And while there have been few true innovations in conveyor and sortation solutions in the last decade outside of the development of the linear belt sorter, material handling equipment companies have provided continual product improvements. Speed, throughput, efficiency, maintenance requirements, noise levels and power usage are areas in which iterative improvements have been made to conventional equipment designs.
Moving Boxes
The task of moving products through a distribution center (DC), whether they are in a package, carton or other container, belongs to the conveyor. Conveyors come in many forms, from live (powered) rollers to belt conveyors. While conveyors are often used for package accumulation, their primary purpose in most large DCs is to transport packages within the facility.
In many DCs, this translates into miles of conveyors required to move products from receiving to shipping. Miles of conveyors, in turn, translate to substantial noise, power usage, floor space and maintenance. It can also mean a long implementation time to get a new system or upgrade online.
One of the most important developments to address these problems is the recent move to 24-volt conveyor system designs. These systems eliminate the need for high-voltage power drops, consume significantly less energy, are safer to use and produce much less noise than conventionally powered conveyor systems that rely on compressed air to drive rollers.
Modular systems are another innovation in the world of conveyors. Built-in standard sizes and types and with standard parts and drives, modular conveyor systems shorten implementation times and speed replacement. Because one modular unit can be swapped out for another, system design is shortened and installation and repairs are simpler, reducing downtime.
Many Requirements, Basic Choices
A requirement for easy maintenance has driven change as well and has spurred the use of belt-driven conveyors in place of chain-driven ones, particularly for accumulation. Because belt-driven conveyors do not need the constant lubrication that chain-driven systems require, they are increasingly used in DCs as a way to decrease maintenance hours and maximize uptime.
Belt-driven conveyors also run more smoothly than chain-driven models, and advances in modular plastic belt drives have dramatically reduced maintenance times and costs. Similar advantages in maintenance are seen in conveyors manufactured with sealed gear reducers, which do not require regular lubrication.
Whether belt-driven or chain-driven, the choice between the two basic types of conveyor carrying surfaces belt and roller is largely determined by the nature of the item being conveyed. Hard-to-grip items in non-standard containers or those with unusual packaging call for belt conveyors, while conventionally boxed items can be easily moved using roller conveyors. In mixed-use environments, such as those in overnight and parcel delivery companies, belt conveyors are generally preferred. Furthermore, since parcel companies dont require that their customers ship in standard box sizes or even in boxes at all, they need material handling equipment that is very flexible.
Limitations and Maximizations
Todays conveyor market is further driven by physical and financial limitations. Belt conveyors are generally less expensive than roller conveyors, for example, but require more drives to sustain conveying at longer distances. That means more wiring and controls, which ultimately affect cost, maintenance and noise production.
Speed and throughput levels are perhaps the ultimate technical hurdles. While most DC conveyors travel at moderate speeds until they ramp up to get to the sorters, the faster the overall speed of a conveyor system, the more product it can get out the door in a set amount of time. Today, speeds of 600 feet per minute and throughputs of 300 cartons per minute are common requirements for new DC material handling projects.
But speed is not the key. Customers dont care how fast their conveyors go. They actually want them to go slower because thats less noisy, saves energy and theres less wear-and-tear. But they need a certain throughput, and speed is one factor that determines that. As a material handling supplier, we have to make sure merges are efficient, that we gap product accurately and that we generally optimize a systems performance at the lowest possible speed.
Heavy Loads
Particularly in manufacturing applications and supporting distribution operations, pallet load conveying is an important part of how goods move through a material handling facility. A lot of our customers are interested in reducing the need for fork lifts to handle pallet loads. They are looking for automated alternatives to fork lift operation for a number of reasons, including worker safety, decreased maintenance and the management of labor requirements. These alternatives can be found in pallet conveyors as well as automated storage-and-retrieval systems that utilize cranes.
We also see a trend toward rainbow palletizing, an application in which pallet load stackers and articulated-arm robots work with pallet conveyors to stack and configure mixed layers of product. Pallet stacking enables better warehouse, cube and trailer space utilization and fits both manufacturing and distribution settings where pallets are the major storage platform. Pallet conveyors for typical manufacturing distribution operations generally have weight limitations of 3,500 pounds. In heavier industrial settings, specially designed equipment supports more robust loads.
Other trends we see are increased automation at the receiving and shipping docks using pallet conveyors, as well as pre-wired, plug-and-play modular conveyor systems for both pallet and conventional case conveyors. One of the most beneficial features of plug-and-play is the ease of installation and reduced time it takes to bring the system online.
Material handling automation solves many problems for parcel shipping managers. In the next article of this two-part series, we discuss further trends in the field, including automated sortation.
Gary Cash is Vice President of Product Management and Marketing, Ray Guasco is Vice President of Parcel Systems and Mike Hale is Product Manager of Pallet Conveyor Products for FKI Logistex North America. For more information on material handling systems from FKI Logistex, including conveying and sortation, call toll-free 877-935-4564 or e-mail info@fkilogistex.com. Visit FKI Logistex on the Web at www.fkilogistex.com.
