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Orbetron currently offers four sizes—50, 100, 150, and 200 Series feeders—that provide outputs of anywhere from 1 g/hr up to 800 lb/ hr. Beyond color for markets like wire/cable and medical, Hultquist notes that the company has most recently expanded into the building- products industry, where disc feeders are being used to feed blowing agents, colorants, other additives for siding, profiles, and sheet. PREFORM MOLDER VALUES AGILITY, ACCURACY Quick changeovers are "kind of our deal," explains Jason Christopherson, manager at preform molder Preform Solutions Inc., Sioux Falls, S.D. Specializing in custom preforms for industries such as food and beverages, oil, pharmaceuticals, automotive chemicals, and cosmetics, Preform Solutions targets short-to- mid-range runs on 16- and 32-cavity molds. It avoids chasing the massive volumes associated with preforms for water bottles or soft drinks, which can range up to 144 cavities and higher. "A lot of our projects have colorant," Christopherson says. "Every day of the week, we have probably two, three, four lines running colors and different additives for our preforms." For all those hues, precision feeding of the colorant is a must, made trickier by the let-down ratios the company targets: down to 0.055% on a 672-g shot and a 0.20% ratio on a 54-g shot (the latter represents 98.8% resin and 0.2% color). Preform Solutions began business in 2002 and for most of that time its go-to solution for precision feeding with fast changeovers has been gravimetric Auto- Disc feeders from Plastrac Inc., Edgemont, Pa. (plastrac.com). The company currently has 11 Plastrac units and another four on order. What sold Preform Solutions on Plastrac's technology is the unique design and its impact on accuracy. The feeder uses a blade that essentially meters pellets by slicing. The feeder drops pellets into pockets on a disc, where a blade shaves off any portion of the pellet that extends above the pocket height. "When the Plastrac unit cuts that pellet off and levels off the pocket, and the material drops in underneath the blade, it's extremely accurate," Christopherson says. LOW-RATE FEEDING ON VERTICAL PRESSES Plastrac feeders have also found a home at Weiss-Aug Surgical Products Division in Fairfield, N.J. Weiss-Aug combines preci- sion metal stamping, insert molding, and assembly capabilities QUESTIONS ABOUT FEEDING AND BLENDING? Visit the Feeding & Blending Zone. Plastrac gravimetric Disc Feeders have been modified to run on vertical injection machines performing insert molding at Weiss-Aug's Surgical Products Div. "There's a high visual standard for these components … very specific color standards where you can't really have any variations." @plastechmag 55 Plastics Technology L O W - D O S E F E E D I N G