Dakota Growers Pasta Co.'s Carrington, ND, production plant doubled its pasta-making capacity to 240 million lb/yr early this year with the addition of a new Multi-Axis Conveying system. It transports more than 300 different SKUs of "long goods" in buckets from processing to three form/fill/seal machines (two vertical, one horizontal). "This addition represented a substantial change for us," notes David Tressler, plant superintendent for the growers cooperative. "It's the second material handling system we've put in, and it helps us meet increased product demand by providing the critical link in moving product to our various packaging machines." The first system for long goods was added when the Carrington facility opened in late '93 (see Packaging World, Jan. '95, p. 22). Each Pasta Elecon® system, which measures approximately 400 linear feet, is made by Gough Econ (Charlotte, NC). The systems are customized for Dakota Growers to carry long goods vertically, horizontally and around numerous bends. Among the key components that make this possible are bearings that measure 1/2" long, with a 9/16" outside dia and a 7/16" inside dia. Small as they are, they make a big impact in the system's ability to transport product. The Pasta Elecon system includes a frame with two tracks somewhat like that of a roller coaster. Pasta-carrying buckets are attached to chain and rollers on both sides of the frame. The injection-molded plastic buckets are mounted to metal spindles that are attached to rollers. These rollers must ride freely along the frame. Bearings are critical in allowing that to happen. Tackling trouble Freedom of movement had become a problem with an earlier prototype Elecon system used by another pasta producer. "We had two areas that we needed to improve with respect to wear damage on our former phosphorous bronze bearings," admits David Risley, vp of manufacturing at Gough Econ. The bearings that keep the rollers free, he says, had tended to wear and corrode, sometimes to the point where rollers would "seize" or lock up. Instead of rolling freely in the track, they could only slide with the rollers "frozen,"preventing the buckets from pivoting freely. That lead to occasional pasta spillage. The second problem was even a greater concern to Risley. This difficulty occurred on the opposite side of the frame, where some 3귔 bearings are used on a "bi-planar" chain. This chain, made up of numerous components, relies on bearings to again keep rollers moving freely, though on a more complex track. This track includes considerably more bearings and rollers than its counterpart on the other side of the track. In the past, the bearings used with the chain tended to corrode, rust, wear and sometimes crack, says Risley. If enough bearings seized, it could stop the chain and shut down the system. Thermoplastic bearings Recalling similar difficulties that occurred when he worked with another company, Risley consulted bearings supplier igus, inc. (East Providence, RI), in an effort to find a solution. Gough Econ decided to replace the metal bearings used for the prototype system with igus's iglide® L280 thermoplastic bearings. These bearings are used with both of Dakota Growers' Elecon systems. "Though these are considered thin-walled bearings at one-sixteenth of an inch thick, they're wear-resistant and they don't require lubrication," contends Risley. The characteristics of the plastic produce a bearing that's slippery to the touch and needs no lubrication. That's important in a pasta plant where the presence of flour could cause serious problems with lubricated bearings. Dakota Growers' primary concern is that the system carries pasta through the plant as required. "We bought the system as a whole unit, so we don't specify individual components that make up the Elecon, but Gough Econ added new bearings to optimize performance of the two Elecon systems we use," says Dakota's Tressler. "In both cases, the igus bearings reduced friction between parts," says Gough Econ's Risley. "That's helped extend chain life on the bi-planar chain, and enabled buckets and rollers to move more freely. We've been extremely pleased with the bearings on the Pasta Elecon systems," he says. Better yet, so has Dakota Growers Pasta.
