SumiHybrid, a new hybrid injection molding machines line by Sumitomo Heavy Industries is designed for extremely high-speed but stable molding, which is especially important for thin-wall packaging production
“Know-how” from Sumitomo SumiHybrid machines with 230-450 tons clamping force are equipped with three servomotors for plasticization, clamping and ejection. A special hydraulic system moves injection unit, produces pressure during exposure time, backpressure and returns screw by means of hydraulic accumulators; oil inlet is regulated by a servovalve. With a combination of electric servodrives and powerful hydraulic accumulators machine performance lasts longer and working cycles grow shorter, while electrical energy consumption is very moderate. Injection unit operates a new low-inert Sumitomo plasticization servomotor and a hydraulic drive with an accumulator regulating its every movement. Injection volume velocity ranges from 1571 cubic cm per sec. to 3976 cubic cm per sec., depending on the selected screw standard size and diameter. With a servovalve, working in feedback mode, and an accumulator, the hydraulic drive can provide exquisite request reaction – SumiHybrid picks up from 0 to 800 mm/sec for 30 µs. Particular design of the novel Sumi-Melt screw by Sumitomo allows to avoid overheating and material destruction, ensure more careful mixing and reduce cooling time by 8-10% compared with standard screws. A 90-mm screw of a C3300L injection unit in SumiHybrid 450 gives this machine best plasticization efficiency rate that amounts to 137 g/sec, distinguishing it from 420-450 tons class high-speed hybrid injection molding machines produced in Western Europe. Japanese reliability SumiHybrid operates a popular toggle mechanism and two Sumitomo designed servomotors for clamping to ensure swift and soft movements at opening/closing the mold and lifter actions. Clamping precision is guaranteed by full digital feedback during mold opening/closing speed and position. Powerful servomotor by Sumitomo ensures swift mold opening/closing at speed up to 1500 mm/sec. In comparison with hydraulic clamping unit hybrid machines, SumiHybrid picks up this speed rate consuming much less energy. SumiHybrid 350 dry cycle (1.9 sec) ranks among the fastest in its class, and SumiHybrid230 and 260 can have dry cycle length of 1.5 sec, which is 0.2 seconds lass then in any high-speed machine in 230-280 tons class. Low vibration of the electrical clamping unit (amplitude is less than 0.3 mm, over two times better than in hydraulic counterparts) contributes to the long-lasting and typically reliable for Japanese technical products, equipment and tooling performance. Platens and lifters movements are monitored by precise optical sensors to ensure best mold protection and secure steady cycle time. For three-platen molds and unloading robots mold stopping accuracy and cycle repeatability are important characteristics. Mold opening/closing position is set at 0.1 mm pitch, and the real final mold position deviates from the set parameters for no more than 20 microns, which guarantees secure process without impacts on the mold even at high speed. Therefore, SumiHybrid injection molding machines are a good solution that gives short production cycle at the same level as accumulator injection molding machines from leading suppliers, combining high speed with low energy consumption and exceptional care for mold. By its characteristics SumiHybrid is an excellent solution for making thin-wall articles and other items produced in short cycles.
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