Although traditional fixed conveyor systems have been one of the leading factors in lean management over the last two decades, they have lost their luster—not just to those who control the purse strings, but also for engineers who have long dealt with the headaches of inflexible systems, long lead times, and production shutdowns while the systems are installed.
As conveyors have become a necessity on the plant floor, conveyor manufacturers have attempted to respond to end-users’ needs for flexibility by creating modular systems. “But most attempts at modular systems fall short in the eyes of engineers who know that once a traditional modular conveyor is taken apart, configuration and integrity are lost forever,” says Timm Ducey, engineering sales manager at Barry Sales Engineering, Inc. (barrysalesengineering.com), a St. Louis firm that distributes equipment for plastics processing, factory automation, and process control. (Barry handles products from Dynamic Conveyor and many other suppliers.)
One of the fastest ways a conveyor system becomes obsolete is when a new piece of equipment is added to the process. Although many manufacturers identify their conveyor systems as modular, most of their components need substantial alteration, such as cutting and welding to make them adaptable, and once a component has been cut down, there is no way to lengthen it again and that component becomes scrap.
Comparing modular conveyor systems to reconfigurable modular systems is like comparing Lincoln Logs to Legos. Lincoln Logs come in a limited amount of fixed-length pieces with a standard groove that limits configuration choices, whereas Legos come in a variety of lengths, heights, and supplemental pieces that can be snapped together at staggered intervals to achieve a desired result.
Modular, reconfigurable conveyors are composed of short standard modules (as little as 6 in.) that can be mixed and matched. Angles and bends can be reconfigured quickly in the plant, unlike standard fixed conveyors
Just as Legos provide ultimate reconfigurability, the key factor in a truly reconfigurable modular conveyor system is the ability to connect and reconnect a wide variety of modules and accessory modules that allow engineers the freedom to tweak production lines when necessary without the cost of a brand-new conveyor or the risk of losing the conveyor’s integrity.
“Standard modular conveyors are never really the same once you take them apart to move them or replace a belt,” says Ducey. “There are leftover parts, the settings are lost, and they just never seem to be squared-up like when they first came from the factory. Truly reconfigurable modular conveyors can be reconfigured over and over again. That’s the thing about reconfigurable systems, you can’t really mess them up.”
With reconfigurable modular conveyors, changes are made simply by swapping out modules with the release of a few bolts and snapping the modules in or out. Ducey adds, “I deal with a lot of customers in the medical industry, and they specify reconfigurable conveyor systems because the flexible systems allow for quick response to changes in production volume, movement of departments and equipment, and the ability to modify the system in-house without the additional cost of engineering assistance. Two guys can put a system together in about an hour.”
REACTING TO PROCESS CHANGES
In the medical manufacturing industry, change is pretty much a constant and process engineers are tasked with implementing changes in the most efficient manner with the lowest total cost of ownership. With standard modular conveyors, equipment changes often mean purchasing an entirely new conveyor or major overhauls of the existing system that habitually require downtime and additional engineering expertise from the conveyor manufacturer in order to cut down the unit to fit the new configuration.
One manufacturer of plastic medical supplies had been using three reconfigurable modular conveyors to transfer parts from the injection molding press to printers in different areas of the plant and then to inspection areas. One conveyor went to a mezzanine, passing up and over to another conveyor with a 90° turn.
After three years, the process was changed and high-speed printers were added to increase production. The entire printing process was moved down to the production area for convenience, which completely changed the conveyor configuration.
“If they had been using a standard modular conveyor system, that manufacturer would have had to pretty much purchase a new conveyor system,” says Ducey. “But, the company had a DynaCon system, so they took the three existing conveyors that no longer met their needs, reconfigured them to make four conveyors that worked with the new process, and all they had to do was buy one motor module to do that.”
Interchangeability allows manufacturers to share equipment between facilities. Some organizations use DynaCon components to standardize conveyor systems in their plants, allowing them to call their sister facilities if they need a particular module.
Process changes don’t have to be as drastic as in the case described above to render a conveyor obsolete. Replacing older equipment with more efficient machines that don’t have the exact footprint of the existing equipment creates major headaches for engineers when traditional modular systems are in use.
“A couple of inches makes a big difference,” says Ducey. “With standard systems, a few inches increase a company’s downtime significantly because they have to have someone come out and fabricate a module on location. With a reconfigurable system like Dynamic Conveyor’s, where unprecedented 6-in. modules are available, the change can happen in 15 minutes.”
Most conveyors that are labeled “modular” come in modules that are usually a minimum of 3 ft long, and the shortest are 18 in. DynaCon conveyor modules come in units as short as 6 in.
CUSTOMIZATION ON THE FLY
Getting the equipment to line up without gaps isn’t the only factor that engineers must consider when purchasing new equipment. Often conveyor systems, even so-called modular systems, come with standard internal drives and motors, forcing engineers to battle with getting the controls to work within their plant. With complex modular systems, the conveyor is spec-ed out at the factory and is virtually unadaptable to new equipment.
Reconfigurable modular systems offer drive systems and motors that are external, allowing engineers the option to purchase the motors with or without the drive system, giving them the flexibility to use their existing controls to manipulate the conveyors.
When drives and motors fail on traditional conveyor systems, it is not uncommon that replacements for a particular model are unavailable. “When that happens, the engineering department is left with a conveyor that has a wire hanging from it, which is totally useless,” says Ducey.
Truly reconfigurable, modular systems accommodate engineering departments’ desire to purchase AC or DC motors as modules that integrate with their existing systems. “Sometimes engineers want to spec their own motors in order to have equipment that is common to the systems in their facility. It allows them to have replacements on hand without having to store a lot of extra equipment, and the reconfigurable modular systems fit that need.”
For process and production engineers, flexibility is crucial when deciding on a plant layout. The ability to liberate floor space by hanging lightweight modular conveyors from the ceiling does more than just save space, it also reduces trip hazards and allows for other machinery or pallets to be pulled under them.
Traditionally, conveyors are sensitive pieces of equipment needing frequent belt realignment, belt replacement, and lubrication. Because DynaCon reconfigurable modular conveyors are maintenance-free, engineering departments can hang the systems overhead without the additional concerns of taking the conveyors down to work on them.
“With traditional conveyors, belts often need to be replaced every 18 months. Over 10 years that can mean an additional $4000 to $5000 in equipment cost, not to mention the downtime and labor to replace the belt,” notes Ducey. “One of my clients, who suspended a DynaCon system from the ceiling, had the system in place for eight years and never once had to perform maintenance. The system only came down when they reconfigured their system after changing their process.”
The DynaCon system uses impact-grade polypropylene link-style belting that is self-tensioning, requires no maintenance, and is warrantied for five years. If ever a portion of the belt is damaged, there is no need to take apart the conveyor or replace the entire belt. With the release of a few pins, the damaged links are removed and new links are replaced.
Belting options, including a variety of flat-top, perforated, and friction designs, are available in widths from 4 in. to 72 in. Drive flights (cleats) may be installed at any location along the belt and are available in 1-, 2-, and 3-in. heights for all belt widths.
These belting options give manufacturers solutions to common problems such as small plastic parts being pinched between flights. Because the belt is also modular in design and links can be easily changed with the release of a couple pins, one manufacturer was able to solve this issue by staggering the cleats left, right, left, right, eliminating the gap.
Just as only damaged sections of belts need to be replaced, with a truly reconfigurable modular conveyor system, the same is true for the modules themselves. When damage occurs to traditional metal conveyors, the entire conveyor commonly needs to be replaced, and waiting for replacement of a traditional conveyor could affect production for weeks. The DynaCon reconfigurable system is made of lightweight, high-impact polycarbonate that flexes. If the conveyor does happen to get damaged, only the broken pieces need replacement, not the entire conveyor. It may even be possible to “borrow” an idle module from another section of the plant.
When a manufacturer of plastic medical supplies was setting up and locating a reconfigured system to hang from the ceiling, a 40-ft section of conveyor fell during installation. “If it had been any other system beside a DynaCon, they would have been ordering a new conveyor. But in this case, there was no damage,” says Ducey. “Even if there had been damage, most of those modules can be purchased and replaced within 24 hr.”
When an outdoor gear manufacturer developed a new production system that included recycling production scrap, it needed special conveyors to bring it to fruition. After long experience with traditional conveyors, engineers at the facility wanted conveyors that would be adaptable to other projects in the future.
A portion of the manufacturing plan included conveyors that could be wheeled out of the way to perform maintenance on molding machines and then put back together into a continuous system of conveyors that fed into one another. After some research, the company decided that modular conveyors were best for the new concept.
Before purchasing, the engineers needed to know that the reconfigurable conveyors could stand up to the rigors of the facility, which operates three shifts, five to six days a week to produce coolers, jugs, and ice substitutes from HDPE. They wanted to be sure that hot plastic scrap would not stick to the conveyors, as can sometimes happen when conveyors are installed under the molding machines. To address these concerns, a DynaCon representative took a small conveyor module to the molding plant and put it under the blow molding machine that was dropping hot tips and tails trimmed from the parts. Satisfied that this would not be a problem, a design was agreed upon, and the conveyors shipped in less than five weeks.
Almost immediately after receiving the conveyors, the flexibility of the modular system became evident. Since the customer was implementing an entirely new production plan, its engineers had tweaked the plan to make it more efficient, which eliminated the need for one of the six conveyors. With another type of conveyor, the molder would have paid for something it could not use, but with the modular conveyors, the unused conveyor could be adapted in-house for use in another area.
With modular conveyors, manufacturers are not locked into one production design. When processes change, or a piece of machinery is moved, modular components can be removed or added to adapt to the new production configuration. With a few minor changes and a couple of additional components, the outdoor gear manufacturer’s original flat conveyor system was converted into a custom Z-style conveyor with a 45° angle at minimal cost.
Standard DynaCon conveyor system packages include all straight, incline, decline, and radius turn modules, as well as drive flights, retaining walls, and legs. A variety of primary accessory modules such as metal detection, box filling, cooling tunnels, separators, and water baths can be added.
Since the outdoor gear manufacturer’s facility takes scrap from the molding process and conveys it to a grinder and then back to the molding machine, DynaCon suggested the inclusion of a metal-detection module to prevent tramp metal from being introduced into the molding machines. The customer explained that if metal shavings entered their machinery, it would necessitate a major teardown requiring an entire day.
The metal-detection module is part of the last conveyor of the four that work together to form a continuous system. When the unit detects any metal, even a minute shaving, it stops all the conveyors simultaneously for removal of the metal. The customer reports that the metal detector has paid for itself more than once.
In addition to the metal detector, this customer opted to have all the controls installed in a single panel rather than on the conveyor itself. Unlike traditional conveyors that require a special order for the controls to be located somewhere other than on the conveyor, genuine modular systems treat drives and motors as modules that can be either internal or external. This affords engineers the option to purchase motors with or without the drive system, providing flexibility to use existing controls to run the conveyors and to place them all in a single panel.
Energy savings are also possible. A traditional 10-ft-long conveyor typically uses a 0.5-hp, 480V motor, but DynaCon uses a 1/30th-hp motor that runs on 100V.
The angled modules are one of the biggest benefits in a modular system, since typical conveyors ordered with angles are unique pieces of equipment of fixed configuration. If a processor orders a conveyor with a 45° angle and then decides that he wants a 30° angle instead, instead of being stuck with an obsolete conveyor, the user can change the reconfigurable conveyor’s angle on the fly.