Long a proponent of "No hydraulic!," Niigata Machine Techno (Niigata, Japan) had a mission at IPF: to prove just what is possible with all-electric injection molding machines.

One particular area of emphasis is extended hold pressure and here, the OEM's Long Pressure Hold (LP) option used on a 130-tonne MD130S6000 press was demonstrated molding an acrylic part with 20-mm wall thickness in a cycle time of 23  minutes. The hold time for this particular product was 45 seconds, which is 50% longer than normally achievable. Extended holding pressure time is achieved through Niigata's Dither Control function that rotates the servomotors on the injection side ever so slightly (at speeds of down to 0.4 mm/s) so that they do not overload.

In the vertical arena, Niigata's MDVR50X all-electric injection press boasts a tool-carrying capacity increased by 20% (to 200 kg for each mold half on the lower platen).  Table rotational speed is at about 1.2 seconds per counterturn. This high speed rotation is realized by an air floating rotational table device. The table is lifted by air for friction-free and high-speed, smooth table rotation. By minimizing the friction wear, precision is maintained for extended periods.

A 150-tonne press has also been added to the MD-S6000 Series of all-electric presses, joining 100, 130, and 180-tonne presses. All machines in the series feature the Niigata's M-Support system on both platens to prevent tilting. The fixed platen tilt on the MD50S6000 after nozzle touch, for example, is one-tenth that of a conventional model. -[email protected]