By Ron Shinn
Visitors to the Windmöller & Hölscher (W&H) factory in Lengerich, Germany, might have been taken aback when they saw process technicians operating the company’s blown film machines with cameras strapped to their heads.
It was part of a project to improve film machinery startup procedures that have traditionally relied on paper checklists, according to Jonas Schmidt, head of product management at W&H.
The result of the three-year development project is called Easy2 Change, an HMI-based assistant that guides an operator through machine startup and product changeovers in less time and with far fewer mistakes.
The project grew out of a discussion at K 2019 about resin wasted in line changeovers, which typically happen two or three times per day. It has been estimated that as much as 10 percent of a plant’s total resin can be wasted this way.
Experienced machine operators were interviewed, then wore cameras to track their actions as they used paper checklists during product changeovers.
“We found even an experienced operator could miss a step and produce waste for much of his shift,” Schmidt said.
Next, the W&H development team built a program to speed up and foolproof the system. The program includes steps that cannot be completed until the extruder’s control system verifies specific parameters have been met.
Then, W&H developed a new automated air-ring and bubble inspection system that makes it easy for the operator to see on the control panel when the bubble shape and frostline are correct. Previously, bubble rings were set manually.
Schmidt said that W&H’s experienced, in-house machine operators were initially skeptical about the Easy2 Change system but quickly adopted it once they saw how it prevents errors.
W&H estimates Easy2 Change cuts line changeover time by more than half.
Schmidt said a big advantage of Easy2 Change is waste reduction. “It is becoming harder for operators to run lines that are more sophisticated and faster. The process windows are getting more and more narrow,” he said. “Easy2 Change is really about minimizing waste.”
The automated air ring is now standard equipment on new W&H machines, while the Easy2 Change feature is optional. Schmidt said there are plans to make Easy2 Change retrofittable to older lines.
Ron Shinn, editor
Contact:
Windmoeller & Hoelscher Corp., Lincoln, R.I., 401-333-2770, www.whcorp.com
