A routine safety audit at Clarks Summit, PA-based Akzo Nobel Salt turned up a hot problem: the high temperature of the hot melt adhesive used to seal cases posed too much of a burn risk to operators. By switching from an adhesive applied at 350°F to a special cool-running hot melt applied at 250°F, the company's St. Clair, MI, plant was able to eliminate injuries. It even eked out a $13귔 annual savings due to more efficient application. The Cool-Lok(TM)adhesive from National Starch and Chemical Co. (Bridgewater, NJ) is used on two case sealers for cases that hold two dozen 26-oz paperboard canisters of table salt. After a little more than a year of using the new adhesive, plant officials confirm that there have been zero injuries related to hot melt burns. "It's so safe that you could run your finger under the dispenser and peel the glue right off," says David Shovan, plant buyer. "If you tried that with the previous adhesive, when you peeled it off you'd take the skin with it. The 100-degree difference is a lot." Aside from plant safety, Akzo reports the adhesive saves money, even though it carries a slight upcharge. How? The lower operating temperatures permit the bead width to be reduced in size since viscosity is more consistent and controllable. This more efficient application means a slight decrease in the amount of adhesive used on each case. "We're now able to use nozzles on one case sealer where we couldn't before," says Shovan. "Before, it was so liquid at 350 that you couldn't control it-it didn't matter how big a blob you put on." Shovan says that the adhesive was virtually a drop-in replacement, with no impact on packaging machine speeds. Other cost savings come from lower energy use and a decrease in maintenance needed on hot melt applicators. Greater ease of cleaning and longer nozzle life are also benefits. Shovan confirms the positive impact on the equipment. "At 350 degrees we got a lot of charring in the tanks. Today we have none. We haven't had to clean our tanks since we made the switch."
