Cleveland — Much of rotational molding still relies on machine operators scooping resin, putting the scoop onto a scale and then dumping it into the mold. But Wittmann Battenfeld Canada Inc.'s Rotoload brings the correct amount of material, correctly mixed, weighed and conveyed, automatically.
"You get the exact, right material into the exact, right mold every time," Wittmann Battenfeld Canada's president, Rob Miller, told attendees at the Society of Plastics Engineers' Rotational Molding Conference June 3-6. Bar codes and RFID make that happen, he said.
Rotoload fills standard home improvement store buckets with material. The buckets move down a conveyor belt to the filling station, then on to the operator area to fill the next arm.
A rotomolding plant can also take advantage of a centralized vacuum conveying system to move resin away from the production floor, Miller said.
"How many times have you seen a bucket containing one color thrown into a gaylord of another material, immediately contaminating that material?" he said.
Rotoload has precise dosing through Wittmann Battenfeld Canada's proprietary pulse dispensing system, he said.
Miller said Rotoload also records the exact mix of powder for each chart and provides detailed charts.
Rotoload uses gravity dispensing of the material into a mixer or directly into the mold. But Wittmann Battenfeld Canada has also developed a way to pressure-dispense a small batch of material, for example, for multilayer molding, Miller said.
Miller pointed out another benefit to automatic weigh powder dispensing: It reduces stress on the operators, reducing employee turnover.