CHICAGO — Krauss-Maffei Corp. announced at NPE 1997 that it is offering an electric screw drive and eject option on its C-Series injection molding machines. In extrusion, the company is showing a new sheet system.
An alternative to hydraulic drive, the electric drive option saves about 10-15 percent of an injection molding machine's energy consumption and makes plastication independent of other machine movements, so the process can continue while the mold opens and closes and during ejection and clamping force buildup. Melt quality also improves, Krauss-Maffei said.
Krauss-Maffei also is showing its two-platen injection molding press, the MC series, which was first introduced at K'95 in Dusseldorf, Germany.
The machines are available in clamping forces of 1,124-4,500 tons.
Interviewed at Krauss-Maffei's NPE booth, Guido Radig, head of marketing communications, said the two-platen machine has become the firm's standard design for very-large-tonnage injection presses.
Customers still can get three-platen models for those machines, but they have to order them, he said.
In Chicago, a 1,000-ton MC press molded crates for soda bottles in a four-cavity mold in less than 30 seconds.
Krauss-Maffei also demonstrated multicomponent injection molding. In one application, an 80-ton CZ press turned out coasters.
Turning to extrusion, Krauss-Maffei showed a new parallel twin-screw extruder, the 26D, a further development of its 23D series. The new extruder comes with screw diameters of 90, 114, 130 and 160 millimeters. A higher length-to-diameter ratio gives the optimum compromise between improved melt quality and higher performance, according to the company.
Extending the processing zone of the screw has resulted in better energy transfer, so polymers can be processed more gently, with less mechanical stresses.
In polyurethane equipment, Krauss-Maffei announced a new Pentamix pre-mixing station for mixing pentane into polyol.
The firm also is displaying another technology first shown at K'95 — long-fiber injection for polyurethane, which chops glass fibers directly at the mixing head and meters them into the reaction mix during pouring. The process eliminates the need for a glass-fiber mat.