Injection molding (August 01, 2003)

Compact footprint, higher torque from all-electric

Negri Bossi’s Elma all-electric line of injection molding machines is now fully available in North America in capacities ranging from 50 to 1000 tons of clamping force. The machine line, which was first introduced at K 2001, features a patented injection and clamping technology which allows for a smaller machine footprint in comparison to most other all-electric machines. The key design feature of the injection unit is an all-servo driven, Gleason gear double helix drive system that significantly boosts torque. Additionally, the injection unit provides better control of back-pressure, enhancing processing performance. According to general manager Larry Pascucci, the Elma line is cost competitive, carrying a “modest” price premium in comparison to a standard Negri Bossi hydraulic.

Negri Bossi Inc. 905-625-7257

Mold height adjustment cuts energy use, cycle time

The largest of Arburg’s Allrounder series, the 820 S, was operating at NPE as a two-component molding machine, producing briefcases. The horizontal injection unit has a maximum shot capacity of 1860 g (65.6 oz.) of polystyrene, while the vertical unit used for this application had a capacity of 97 g (3.4 oz.).

The Allrounder is a modular line, so the 820 S is available with screw diameters of 70, 80 and 90 mm (2.76, 3.15 and 3.54 in.).

Fully automatic mold height adjustment on the larger Allrounders allows the entire clamping unit to be adjusted to the relevant height. This involves a drive unit on the support platen to accommodate for adjustment of the distance between the fixed and movable mold platens. The advantage is lower energy consumption and reduced cycle time as the stroke is now only needed to open the mold and not to level out mold height differences.

Hamilton Avtec 800-590-5546