Technology alert: the 12-screw extruder has arrived.
Century Inc. shipped its first 12-screw extruder to an undisclosed U.S. customer, which started production in mid-March.
Separately, the U.S. Army National Automotive Center is using the exotic technology for research into fuel cells.
Called a ring extruder, because the 12 screws are set up in a circle around a fixed core, the machine was developed by ExtriCom GmbH of Lauffen, Germany. The company used to be called Blach Verfahrenstechnik GmbH.
Century, based in Traverse City, Mich., has the rights to manufacture, sell and service the ring extruder in North and South America. Century has started building the RE machines, according to Bob Urtel, president and chief operating officer.
In a telephone interview, Urtel said ExtriCom has sold 14 ring extruders, mostly to customers in Europe. A few have gone to Asia. Century introduced the 12-screw machine to the United States at the 2000 NPE show, and interest here is growing, he said.
The 12-screw design provides less shear for gentle melt processing of heat- and shear-sensitive materials, like thermoplastic elastomers, or highly filled materials. It is well-suited for reactive extrusion and devolatization, according to Asmut Kahns, a business adviser and member of Century's board of directors.
Urtel said he could not give many details about the first U.S. customer for Century's 12-screw machine. He said the firm is running a highly filled polymer - 85 percent filled - that requires a high level of devolatization and dispersion. Each screw has a 30-millimeter diameter. The length-to-diameter ratio is 32-to-1.
Urtel said Century sold an entire system, including the compounding extruder, six feeders, and a pelletizer from Gala Industries Inc. of Eagle Rock, Va. One of the feeders does liquid feed.
The sale was made after a series of trials at Century's technology laboratory in Houston.
Century also has a 12-screw machine at its Traverse City headquarters, dedicated to fuel cell work. Century has a $2 million contract from the Army for researching ways to improve production of plastic bipolar plates for proton exchange membrane fuel-cell systems.
``They're evaluating the technology and looking at opportunities,'' said Robert Roden, technology manager for Century, during a March 8 interview at the Society of Automotive Engineers 2004 World Congress in Detroit.
Fuel-cell stacks for vehicle use are made by passing hydrogen and oxygen through thin polymer sheets sandwiched between pairs of bipolar plates. Part of the research to produce cheaper fuel cells focus on ways to make cheaper components, including injection molding the plates.
The Century extruder is intended for use in an in-line mixing system to turn out the raw materials precisely in a highly automated process, Roden said.
``We're trying to improve the manufacturing efficiencies,'' he said.
The Army's automotive center, in Warren, Mich., is investigating fuel-cell technology and reliability. The plates cost $8-$10 to make currently, but researchers are trying to reach a target cost of $2 per plate.
``Our challenge is to overcome processing limitations such as cost, reliability and functionality necessary before commercialization of current technology can occur,'' said William Janis, chairman and chief executive officer of Century.
Kahns, the former vice president of sales and marketing for Coperion Corp.'s Werner & Pfleiderer compounding extruders, joined Century in February.
Kahns said the unique technology passes the polymer from one screw to the next, around the circle. ``As we learn more about this, I'm sure we'll find more and more applications,'' he said.