For over 30 years, Omega Design Corp has been manufacturing a broad range of high-quality container handling and packaging equipment systems. One of the Exton, PA-based company's flagship products, the Classic Series of Shrinkbundlers, is a pneumatically driven, PLC-controlled machine designed for automatic shrink or stretch packaging of glass, plastic, or metal containers, boxes, or cartons into predetermined bundle configurations. The design of the Classic series helps to eliminate the high cost of cardboard boxes and creates a more efficient, secure package, which lends itself to further automation down the line, such as case packing.
Omega continued to seek ways to enhance the performance of the Classic Shrinkbundlers. After incorporating several machine upgrades -- resulting in a 50% increase in output -- the company focused on the product pusher, a pneumatic-driven actuator that literally "pushed" the product into the film or other packaging material. Excess play and uneven motion control in the actuator resulted in increased setup time and maintenance.
And that was just the tip of the iceberg -- with Omega's customers increasing their demands for unique packaging, the company needed to accommodate an increase in alternative package designs, sizes, materials, and configurations. This was proving to be difficult with Omega's current pneumatic system, because the uneven motion control produced inconsistent product flow through the pusher area, and could cause the products to become misaligned, creating a machine stoppage. Stoppages result in downtime, which translates to a loss of profits.
"Frequent changeovers on a packaging line often require you to stop production for retooling, sometimes taking up to several hours. We needed an intelligent yet cost-effective solution that could handle a variety of packages," said Devendra Shendge, a product development specialist with Omega Design.
Omega also needed to reduce the amount of air being used in the machine. "The more air we can take out of this or any of our machines, the better," said Shendge. "Air can be expensive, and the existing actuator system used quite a bit of it."
Omega needed an actuator that would produce higher speeds, yet would have intelligent motion control capabilities to accommodate a broad spectrum of product dimensions. They also needed a solution that would require little or no maintenance, and one that would greatly reduce the use of costly air, as well as the occurrence of air leaks.
Kerk Motion Products provided the solution. After discussions with applications engineers and a thorough examination of the company's offerings, Omega saw tremendous promise in the Kerk RGS™ (Rapid Guide Screw) 10000, a new screw-driven slide that offers exceptional linear speed, accurate positioning, and long life in a compact, value-priced assembly.
Although the RGS 10000 is not an actuator, Omega used it as the centerpiece of a new assembly. Omega's product development engineers worked with Kerk to incorporate a servomotor and a few additional components, creating a revolutionary new "intelligent motion" solution to replace the existing pneumatic system. The easy insertion of the RGS 10000 made the unit even more attractive.
"It was a simple swap-out," said Shendge. "Kerk's RGS was retrofittable to the unit we were already using, easily meeting the machine's space constraints."
The length and speed of the Kerk RGS is not limited by critical screw speed, allowing high RPM and linear speeds, even over long spans. Standard leads include .100, .200, .500, and 1.00 in. travel per revolution. With Kerk's wide range of available leads, speeds over 60 in. per second (1.5 meters per second) are possible, rivaling belts and cables while offering superior positioning accuracy, repeatability, and axial stiffness.
The Kerk RGS includes a precision aluminum guide and carriage and is driven by a precision rolled stainless steel lead screw. The moving surfaces include Kerkite® high performance polymers running on Kerkote™ TFE coating. Its unique, compact profile provides exceptional torsional stiffness and stability for its size and weight, and the integral mounting base allows support over the entire length, if desired. The Kerk RGS 10000 also comes standard with a wear-compensating, anti-backlash driven carriage.
Using Kerk's RGS 10000, Omega Design has produced a new machine with benefits for both Omega and its customers. The new bundler demands less maintenance and requires less labor to maintain. Omega has also realized significant cost savings, as less labor is needed to assemble the machine, and the number of components has been reduced. Various sensors and pneumatic parts have now been replaced by the intelligent actuator.
"Before it was just a continuous motion, 0-50 in./second," said Shendge. "Now we can accelerate or decelerate the machine. This is critical, [because] when [you're] dealing with some of the unusual shapes and heavier mass of some products, you can't just thrust them through the machine at top speed. You can damage the machine as well as the product."
Additionally, changeover time between products has decreased, since the machine can be programmed to adjust to various products through recipe-driven settings that are specific for each product's handling needs, and thus, accommodate alternative package shapes. "Plus," said Shendge, "we can take the feedback from this intelligent motion and use it to improve the overall operation of the machine."
Shendge also said that in the original testing, the RGS 10000 was generating 150 lb of force, while the original air cylinder only produced 80 lb. Omega first purchased an RGS 6000, but it was too small to do the job. Omega asked Kerk for a bigger unit; one did not exist at that time, Kerk explained, but they were in the process of tooling up for the RGS 10000.
"We told Kerk to start making it fast, before the Pack Expo show where we were exhibiting the Classic," recalled Shendge. "Kerk was able to meet our deadline, and we were able to get the RGS 10000 into one of the bundlers at the show. So we actually purchased the very first one."
