DÜSSELDORF, GERMANY (Dec. 7, 12:30 p.m. EST) — Officials of Krauss Maffei GmbH touted its slogan, “technology of the power of three,” during K 2007.
“We're the only manufacturer worldwide who combines know-how in injection molding, extrusion and reaction processing equipment,” said Dietmar Straub, chief executive officer and chairman.
The Munich, Germany-based firm showed its three-technology experience in dramatic fashion at the Dusseldorf show.
Krauss Maffei's MX press, a behemoth with 2,300 metric tons of clamping force, dominated Hall 15 at K 2007 — not an easy task in the massive building jammed with injection molding machines, and a crush of visitors most of the time.
The press was molding interior trim for a car door. First, it injection molded the complex substrate. In the second stage, dubbed the SkinForm process, a two-color polyurethane skin was added, via several reaction injection molding mixing heads permanently docked onto the mold. Since pigment is added in the mixing chamber, the press can change the color of the PU skin sections from shot to shot.
Krauss Maffei cited some statistics for what it said was the largest machine ever shown at a K fair: weight of 220 tons, 70 feet long. KM built the machine at its Munich plant, took it apart, and shipped it to Dusseldorf in three pieces before putting the MX press back together again.
A crowd clogged the aisle when Krauss Maffei fired up the MX machine and the mold spun around to present the door to a giant six-axis robot to remove the part for secondary finishing. The crowd spilled over into the neighboring booth of Engel Holding GmbH.
Right next to the giant MX was a smaller, 300-tonne CX press, but one that demonstrated a first — combining compounding, in- jection molding and RIM molding of polyurethane into a single press.
“This has never been seen before. All processes in one system, ready to be used by our customers,” Straub said at Krauss Maffei's news conference Oct. 25.
The machine was turning out roll restrictors — automotive parts that help reduce vibration from the engine.
First, the press molded the load-bearing nylon part. Then, a Krauss Maffei IMC, or injection molding compounding machine, linking a Berstorff compounding extruder mounted onto the injection press, compounded a thermoplastic PU material, blended with a new cross-linking agent, TPU-X, which is added to the TPU melt as a liquid prepolymer.
Cross-linking occurs as the part cools down in the mold.
The part is not commercial. Straub said the company wants to demonstrate the possibilities by combining all three technologies.
Straub said those types of load-dampening parts typically are made by metal stamping, followed by a secondary step to put on a rubber part. The molded-in TPU replaces the rubber, cutting assembly costs, he said.
“And now it's in one combined machine in a one-step process, the finished part. So the processing time goes down by a factor of 15,” Straub said.
In another part of the booth, Krauss Maffei demonstrated a new way to produce scratchproof transparent parts, called the CoverForm process, on an 80-tonne CX press. The liquid acrylic coating is applied in the mold under clean room conditions right after injection molding, then a final compression molding step spreads the coating over the acrylic part.
That method produces a very thin coating that partially cures in the mold — enough so the parts can be demolded. Final curing happens under ultraviolet light.
Krauss Maffei also introduced its ClassiX series, lower-priced injection presses that can be configured for specific applications by picking out standard options for the CX press. ClassiX machines come in clamping forces of 35-130 tonnes.
The company demonstrated all-electric molding on an 80-tonne EX press, molding wire-end ferrules from liquid silicone rubber. A new, larger-size EX, with 240 tonnes of clamping force, molded polypropylene syringes on a 48-cavity mold, with a cycle time of 11 seconds.
Krauss Maffei's chief technical officer, Otto Urbanek, also announced KM's Primus Network for Innovation, a series of partnerships with several German universities and research institutes.
Under Primus, the machinery maker will participate on research and development teams in three areas: increasing the use of renewable materials reducing carbon dioxide emissions through the use of energy-saving construction products and lightweight auto parts, and new ways to integrate plastics processing steps.
Krauss Maffei is active with the Center for Functionally Integrated Lightweight Structures, which opened in October in Munich. The company is working with experts from the Technical University of Chemnitz, the Technical University of Dresden, and the Rosenheim University of Applied Sciences to develop new applications for fiber-reinforced materials.
“Lightweight structures are the mega-trend of our time,” Urbanek said.