Smart motion design helps packaging machine maker

For more than 30 years, Exton, Penn.-based Omega Design Corporation has manufactured container handling and packaging equipment systems for the pharmaceutical, food and beverage, chemical and other industries.

In the spirit of improvement, the company sought to enhance the performance of one of its flagship products-the “Classic” series of shrinkbundlers, a pneumatic-driven, PLC-controlled machine designed to automatically shrink or stretch packaging of glass, plastic and metal containers, boxes and cartons into predetermined bundle configurations. After incorporating several machine upgrades, which resulted in a 50 percent 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. Inherent in this pneumatic-driven actuator was excess play and uneven motion control, resulting in increased set-up time and maintenance.

But that was just the tip of the iceberg. With many of 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 a difficult proposition 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 into profit loss.

“Frequent changeovers on a packaging line often require you to stop production for re-tooling, sometimes taking up to several hours,” says Devendra Shendge, a product development specialist, Omega Design. “We needed an intelligent yet cost-effective solution that could handle a variety of packages.

Omega needed to reduce the amount of air that the existing actuator system used. “The more air we could take out of this or any our machines, the better,” says 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. The company also needed a system 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.

In a quest for such a system, Omega engineers contacted Kerk Motion Products, a manufacturer of non-ball lead screws. After discussions with applications engineers, Omega decided to go with Kerk Motion’s Rapid Guide Screw (RGS) 10000, a screw-driven slide. While the RGS is not an actuator, Omega used the RGS 10000 as the centerpiece of a new assembly. Omega’s product development engineers worked with Kerk to incorporate a servo motor and a few additional components, to create a new “intelligent motion” system that would replace the existing pneumatic system. The easy insertion of the RGS 10000 made the unit more attractive. “It was a simple swap-out,” says Shendge.

Using Kerk’s RGS 10000, Omega produced a new machine with benefits for itself and its customers. The new bundler demands less maintenance and requires less labour to maintain. Omega also realized significant cost savings, as less labour was needed to assemble the machine, and reduced the number of components. Omega and its customers will no longer need to stock various sensors and pneumatic parts, which the company has replaced with the intelligent actuator.

“Before it was just a continuous motion, zero-to-50 inches per second,” says 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.” Changeover time between products also decreased, since technicians can program the machine to adjust to various products through recipe-driven settings that are specific for each product’s handling needs.

Shendge also says that in the original testing, the RGS 10000 was generating 150 pounds of force, while the original air cylinder only produced 80 pounds. 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 the company was 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,'” Shendge says. “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.”

Upgrades to Omega machinery do not stop at the bundler’s “pusher” unit. Kerk is designing a new actuator that features a round shaft. According to Shendge, Omega is considering using these new actuators to replace the remainder of the pneumatic cylinders on the machine.