Sumitomo Plastics Machinery of America LLC showed a new all-electric vertical press and a 20-ton micromolding size of its SED press at NPE. The company also announced its first hybrid injection molding machine, the SE-HY, with accumulator-assisted hydraulics to deliver a high-speed blast of injection at 500-1,000 millimeters per second.
Sumitomo has had hydraulically driven toggle presses equipped with an electric screw drive, but SE-HY is Sumitomo's first true hybrid press, said Jerry Boggs, executive vice president.
``Ours is an electric machine with a hydraulic modification,'' he said.
Sumitomo offers the hybrid machine in clamping forces of 385 tons and 495 tons.
``The reason is to provide high-speed injection,'' Boggs said in an interview at NPE 2003, held June 23-27 in Chicago. Sumitomo is aiming the press at packaging, closures, personal-care products and other superhigh-speed, thin-wall applications.
SE-HY uses three, Sumitomo-built, alternating-current servomotors with digital closed-loop control for plasticizing, clamping and part ejection. Accumulator-driven hydraulics, with digital servo valve, are used for injection unit movement, injection, hold pressure, back pressure and screw pull-back.
Boggs said the hybrid press brings together technology from Sumitomo's SES series of all-electrics and the SGM line of accumulator-assisted toggle-clamp machines.
Two accumulators work together with a digital valve and a sophisticated measuring and feedback system for quick response and precision control of injection. Digital sensors provide direct digital control.
A direct-drive motor powers plasticizing on the 385-ton injection press. Sumitomo uses a motor and drive belt on the 495-tonner, to keep the machine reasonably sized.
Sumitomo announced, but did not display, the new hybrid press during NPE 2003. Instead, Sumitomo's booth was dedicated to nine all-electric presses. Sumitomo now is making the 55- to 200-ton SED all-electrics and SES all-electrics from 253-385 tons at its factory in Jefferson, Ga.
In NPE news, Sumitomo insert molded an automotive sensor housing on the new 55-ton SR vertical press. Each press in the SR line uses five servomotors. The machines consume up to 50 percent less power compared with hydraulic vertical presses.
An electrically gear-driven table rotates 180 degrees in less than 1.6 seconds. The press has a top injection speed of 300mm per second.
Sumitomo and Makuta Technics Inc., a micromolder in Columbus, Ind., teamed up on a 20-ton press to mold a surgical device used for suturing organs. NPE visitors viewed the part under a microscope. It measures just 6.4mm long, with tiny fingers extending out.
Sumitomo recently added the 20-ton model to its SED line of direct-drive, all-electric presses.