Sumitomo Heavy Industries (Tokyo) has unveiled its latest all-electric series comprising 50, 75, 100, 130, and 180-tonne presses under the Sumitomo Demag EV Series banner at the IPF Show in Tokyo. Taking over from where the DUV series left off, Sumitomo says it has further upped the ante in terms of energy savings, environmental credentials and ease-of-operations with its latest offerings.

"We've reduced servomotor inertia and friction, for example, and thereby enabled a 20% saving in energy consumption," says Hiroyuki Sawaishi, Acting General Manager of Sumitomo's Technology Center. "The new machines also use less than half of the grease [of the preceding series]," he adds.

The performance enhancements on the servomotor side have also led to greater machine precision according to Sumitomo. At IPF, a 100-tonne SE100EV machine was molding coil bobbins from PBT in an eight-cavity tool. Comparisons with the previous DUV series of machines have shown that part weight standard deviation can be improved by up to 30%.

Mold opening and closing is also reportedly smoother than before.  Another area that Sumitomo has focused on is energy consumed in heating the barrel, which has been reduced by half through using an insulating cover.

The machine controller has also received a makeover. The NC10 controller features a vertical 15-inch panel with screens that are customizable depending on the type of user. "The screen for an engineer shows a lot more detail than that viewed by a machine operator, for example," says Sawaishi. A third party assessment rating usability of the new controller found it to be 35% more efficient in terms of speed and ease of access to data, etc.

Sumitomo's SE350HSZ press has also received and upgrade, with a Pack Specification model now available for molding of thin-wall PP packaging. Previously Sumitomo offered a hybrid machine of the same tonnage for such packaging applications but the latest all-electric's injection speed of up to 550 mm/s is more than up to the task, as demonstrated on the show floor where PP cups weighing 15.1 g each were being molded in a 12-cavity tool in a cycle time of 3.9 seconds.

The cup wall thickness of 0.65 mm compared to cup height of 136 mm translates to an "l/t" of 209 according to Sawaishi, which is an indication of the machine's power. "With the availability of this all-electric machine, we now intend to phase out our last remaining hybrid offerings, although we will build such machines if a processor really wants one," says Toshihiko Ohashi, General Manager of Sales at Sumitomo.

A third highlight at Sumitomo's IPF stand was the CL9000U all-electric press for molding 40-inch LCD light guide panels Previously, such panels were fabricated from extruded acrylic sheet. The shot weight for a 40-inch panel is 1330 g, with cycle time of 65 seconds. "What's challenging about this applications is that you need to inject from the side for light guide panels," says Sawaishi. "For molding similar sized diffusion sheets used in LCDs, center injection is possible so you can get by with a much smaller machine."-[email protected]