Extrusion: Compact Extruder Is Potent, Energy Efficient
R&D firm Omachron Plastics Inc., Pontypool, Ont., has launched its first commercial extrusion equipment, including a modular extruder line based on new screw, barrel and feed designs. They combine low-shear, high-mix, low-pressure melt handling with high-precision, closed-loop computer control driven by high-accuracy temperature- and pressure-measurement subsystems. The result is a compact machine that reportedly uses up to 95% less energy/lb of material processed and can typically achieve a dimensionally stable product within 20 min of being turned on, thereby minimizing the expense of startup and product changeover. A typical 5-hp system with the unique auto-start sequence can be purged between colors with 10 to 20 lb of material, and startup also typically requires 10-20 lb of material to make dimensionally stable product.
The Omachron extruders are small and the subsystem components are light enough to enable all maintenance to be carried out by one or two people in minutes, not hours, without the need for a crane or other lifting equipment. Omachron has also developed compact, low-cost, low-pressure downstream equipment with low power consumption, including dies for thin film, sheet, profiles, tubing, pipe, corrugated pipe and other products. The company says its proprietary plasticating system and associated downstream equipment produce geometrically accurate parts with little or no internal stress, yielding excellent mechanical, physical, optical and chemical properties.
Current product offerings include desktop systems (1-in. and 1.25-in. screw diam.) with 1 to 20 hp that provide outputs from 10 to 600 lb/hr. All these systems can operate from single- or three-phase power, enabling their use in rural areas where three-phase power is not available. A new, compact system to provide 2400 lb/hr is planned for later this year. The firm’s first injection molding machines are due next year.
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Around three dozen, mostly European, processors are pushing commercial development of high-speed single-screw extrusion. They have installed more than 100 of the small hyper-drive machines whose screws turn at up to 1500 rpm, about eight to 10 times faster than standard extruders. At least two German machine builders are working on machines that will go to 2000 rpm and even higher. The goal is to raise output without increasing extruder size.