| RexMover rodless pneumatic cylinders provide durability and consistent performance on an extremely contaminated acoustical-tile production line. |
Production at the USG Interiors Walworth, Wis., facility was repeatedly shut down due to failing cylinders. A subsidiary of Chicago-based USG Corp., the company is a leading manufacturer of building materials for the construction and remodeling industries.
The facility manufactures Acoustone acoustical ceiling tile formed from a pulp made primarily of mineral-wool fiber. The production line directs a continuous stream of pulp into permanent molds. Previously, an operator manually cut the pulp and paper backing at the end of each mold with a sharpened spatula. This process was automated using a high-pressure waterjet cutter guided by linear bearings and driven by magnetic rodless cylinders. Due to high-volume operations and the contaminated environment -- mineral-wool fiber is generally regarded as more abrasive than most foundry sands -- magnetic cylinders failed within about 20 to 24 hr.
Jim Maass of Motion Industries Inc. suggested a change to RexMover rodless pneumatic cylinders from Bosch Rexroth Pneumatics, Lexington, Ky., due to their robust design, high-speed capability, and virtually leak-free performance. Since installed on the acoustical-tile production line, each cylinder has made approximately 6.3 million strokes covering a travel distance of approximately 4,800 miles, without failing.
"In the extremely contaminated environment these cylinders have been exposed to, this has surpassed all expectations of everyone who has seen the machine run," comments Pat Heppert, a USG engineer. "It is also noteworthy that neither of these cylinders has been lubricated since they were installed, and they perform as consistently as when they were new."
The RexMover cylinders were recently removed due to an unrelated equipment redesign and, according to Heppert, close inspection showed them in excellent condition and ready for additional service despite the contaminated, abrasive operating environment.
The cylinders require about half the space of conventional piston-rod cylinders. Additional features include NPT or ISO-G (BSPP) ports, which permit air connections on the cylinder's side at both ends, on the rear of the end covers, or with one end cover that allows dual porting. The cylinders operate at speeds to 16 fps with bore sizes from 0.62 to 3 in. (16 to 80 mm). Grooves for sensors are on three sides, and an oval-shaped piston offers lower overall height and greater resistance to side load. The cylinders handle air pressures to 120 psi and temperatures from 14 to 140°F.