Two mammoth hybrid-electric machines, both with direct-drive electric motors on the injection unit, are now available here from Mitsubishi Heavy Industries of Japan, represented here by MHI Injection Molding Machinery Inc., Bensenville, Ill.
Two mammoth hybrid-electric machines, both with direct-drive electric motors on the injection unit, are now available here from Mitsubishi Heavy Industries of Japan, represented here by MHI Injection Molding Machinery Inc., Bensenville, Ill. First announced last year at the International Plastics Fair in Tokyo, new 3300- and 3900-ton models top off MHI’s “em” line of hybrid-clamp, two-platen presses. Five of these units have been sold in Japan to automotive molders. They reportedly can produce a 9.5-lb bumper fascia in 30 sec, and have overall position accuracy of 0.01 mm or better. These units have four direct-drive motors for injection. The motors were developed by Mitsubishi specifically for injection machines and are coupled directly to the ballscrews, eliminating the need for drive belts and pulleys. A separate AC servomotor drives screw recovery and plastication, and another servo handles part ejection. Two AC servos with belt drives operate clamp traverse at speeds up to 1.3 times faster than MHI’s hydraulic models. Clamp tonnage is built up by two servos driving a hydraulic pump system. Both machines also have the MAC-VIII control system and a 12-in. LCD touchscreen.