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Illuminating the Line for Highway Safety

Potters Industries’ Iowa Plant Standardizes on Motorized Torque-Arm II™ for More Reliable Glass Bead Production

Potters Industries Inc., an affiliate of PQ Corporation, is a leading producer of engineered glass materials used for metal finishing, a reinforcing additive for plastics and conductive particles.

However, the majority of the company’s glass bead production is used for highway safety, providing the light-reflective lane markings found on highways around the world.

Starting with recycled glass, the Potters facility in Muscatine, Iowa, produces 23 different sizes of glass beads that are then mixed per customer specification. The end product is a truly round glass sphere that optimizes reflectivity. Potters Highway Safety Marking Spheres are applied, or dropped on, when marking lines are applied to a roadway.

In late 2007, part of the plant was renovated, adding all new bucket elevators at the front end of the beadmaking process. Company engineers say the new construction gave them a unique opportunity to select and standardize on a product they believed would solve existing maintenance problems and help the plant improve its productivity. They installed the totally enclosed, shaft-mounted speed reducer, the Baldor-Dodge Motorized Torque-Arm II, a product that has delivered the reliability the engineers were looking for.

In the past, belted shaft-mount reducers were used on bucket elevators moving glass through the initial stages of the process, which includes grinding and pulverizing. In this environment, the glass grain dust, even in minimal amounts, is abrasive to rubber belts, sheaves and sprockets.

Bob Schult, plant production manager, says the belts would wear quickly and then begin to slip, creating a constant maintenance issue. Belts would have to be re-tensioned on a regular basis, but even with the extra time spent to keep the product running, he says they would go through a set of belts on each unit about every three to six months.

“It’s not just the expense of the belts, it’s the expense of shutting down to allow our maintenance staff to make the change,” explains Schult. “We tried to monitor belts through a structured preventive maintenance program, but I would say there was a good 30% of the time we would have belt issues that would cause us unplanned downtime. Dealing with the problem was costly and time consuming.”

The issues of uptime and reliability are critical to the plant, according to Muscatine Plant Manager Glenn Amundson. He explains that the plant operates 24/7, 360 days a year, to meet the demand for its product, and unplanned downtime disrupts the beadmaking process.

“Once the raw material comes into the plant and we start the process of making glass beads, there is limited storage capacity in any of the process areas along the way,” explains Amundson. “So any time the belts failed and we had unexpected downtime, it took away from what we were doing downstream. This issue had a tremendous impact on our ability to get our product out the door.”

Both Amundson and Schult were intrigued when they learned that company engineers were specifying the Baldor-Dodge Motorized Torque-Arm for the project. While neither of them knew all the product details, Schult says the concept of an enclosed gear reducer made sense for this application, and he was certain it would work because the Baldor-Dodge brand of gearing is well known for quality. Amundson says based on what he knew about direct drive products, he was confident that this gear reducer would provide the reliability he needed to keep the plant up and running.

“This product has met all my expectations,” says Amundson. “The MTAs have been running since January 2008 with absolutely no issues. All we have done is the regular maintenance, but other than that, we have not had to do anything. They run trouble-free, which is an ideal situation for us.” It’s clear the product has had a major impact on increasing uptime at the plant, but Amundson says making the switch has helped save time and money in other ways as well. For example, the plant did not generally staff maintenance personnel on weekends or off hours. Instead, operators had to take time away from their regular duties to be trained to handle some of the maintenance issues, including changing belts. Now, all that has changed.

“Today, we don’t have to spend the time to train operators to work on replacing belts and sheaves,” explains Amundson. “Our operators can focus on their job, which is to make quality product. In addition, our maintenance staff is no longer tied up with constantly inspecting, tensioning or replacing belts. Instead, they can spend their time on other critical areas in the plant, helping us become even more productive.”

After more than three years of reliable performance, Amundson says he’s grateful to the company engineers who made the decision to standardize on the MTA. He says he still doesn’t know all the engineering details of why the reducer works so well. But then again, he doesn’t need to. He just knows that the MTAs work without fail, and that makes him a very happy plant manager.