New Direct-Drive Electrics Unveiled in Tokyo

September’s Tokyo International Plastics Fair saw the launch of a new line of all-electric machines from the Japanese parent of Sumitomo Plastics-Machinery, Norcross, Ga.

September’s Tokyo International Plastics Fair saw the launch of a new line of all-electric machines from the Japanese parent of Sumitomo Plastics-Machinery, Norcross, Ga. The SE-DU (Sumitomo Electric Direct Ultimate) machines have four direct-drive servomotor systems—one each for plasticating, injection, clamping, and ejection—in which the ballscrew is an extension of the motor shaft. Developed by sister company Sumitomo Power Transmission Control, separate, independent direct-drive systems reportedly deliver more accurate and responsive operation than a belt-driven system, and with less maintenance. The horizontal toggle press line comes in seven models from 20 to 200 tons. The new N-9 controller is standard with higher processing speed and more SPC/SQC functions than the N-8 controller. The injection unit is responsive and quick, going from zero to 300 mm/sec in 20 millisec. It hits top injection speed of 500 mm/sec in 38 ms. Platens are 50 mm wider than on earlier models, and the fixed platen has beefed-up rigidity. A clamp-force feedback system measures actual clamp force using tiebar sensors. Sumitomo also rolled out SE-DU-HP (high-performance) versions for very thin-wall parts such as light-guide plates, battery cases, speaker cones, or memory cards. These faster, high-response models (55 to 200 tons) can hit 800 mm/sec injection speed. At the show, a 143-ton model SE130DU-HP produced 0.16-mm-thick, 0.21-g polycarbonate memory cards in eight cavities with a 740-mm/sec injection rate and 14.8-sec/cycle. Sumitomo also added a smaller 80-ton model to its all-electric, two-component Double-shot SED-CI series, which extends to 220 tons. A new direct drive is used for the twin injection units and rotary platen. Sumitomo introduced an upgraded version of its smallest all-electric direct-drive system, designed for precision micro-molding applications such as connectors. Its SE7M is a new 7.7-ton unit incorporating a more powerful direct drive for faster injection (300 mm/sec) and faster response (14 ms). It uses a newly designed 14-mm screw for smaller shots. Platen speed is up to 1000 mm/sec, said to be the fastest in the industry, which reduces mold-opening/closing time to less than 1 sec at full stroke. Frame rigidity is said to be 50% higher than on a conventional press At the IPF show, it produced LCP connectors in a four-cavity mold on a 3.3-sec cycle. Parts weighed 0.035 g and the total shot was 0.48 g.