DÜSSELDORF, GERMANY (Dec. 17, 4:35 p.m. EST) — Fanuc Ltd. showed three of its all-electric injection molding machines at K 2007, all three with Fanuc robots doing part removal or assembly.
A new press, a Roboshot S-2000i 50B with 50 metric tons of clamping force, molded very fine, narrow-pitch connectors in a four-cavity mold, from liquid crystal polymer. A robot removed the connectors and put them into bags separated by a cavity. A vision system checked the parts.
Fanuc, of Oshino-Mura, Japan, has sold 28,000 all-electric presses since it introduced the first one in 1984. In the U.S., the Roboshot presses are distributed by Milacron Inc. of Cincinnati, under a long-standing agreement.
Fanuc also has played a key role in introducing all-electric injection molding machines to Europe. It hasn't been easy, since all-electrics account for just 10 percent of injection presses sold there, according to Klaus-Ulrich Schmid, sales manager at Fanuc Roboshot Europe GmbH in Neuhausen, Germany.
In Asia, the numbers are nearly flip-flopped, with 75 percent all-electrics and just 25 percent hydraulic machines. The United States is now about split 50-50.
Fanuc targets five markets: medical, connectors, automotive, microparts and precision parts.
At K, Fanuc also molded parts on two other B series machines. A model 100B, with 100 metric tons of clamping force, molded clear polystyrene into clear card cases, the top and box sections, then a robot assembled them together. A 150-tonne press in a portable clean room, model 150B, molded polypropylene medical cannula tubes in a 96-cavity mold, running a 7.5 second cycle.
Fanuc developed the B series because customers asked for a machine that could accommodate larger tools. Engineers increased the tie-bar spacing, and boosted the stiffness of the machine, so it could handle heavier and more-complex molds.
Two-platen technology on the moving side of the clamp gives a uniform clamping force on the mold, good for producing small, high-precision parts in multicavity molds, Fanuc said.
Takeshi Oda, chairman of Fanuc Roboshot Europe GmbH, described the company's manufacturing operation during a K- show press conference Oct. 25. Fanuc builds both robots and injection molding machines — and uses robots heavily to build press components. The highly automated plant has three times as many robots as people.
“Unmanned operation is realized even in the large machining factories by the machining cells,” Oda said.
All of the parts of the Roboshot — including the clamp, injection unit and servomotors — are made by fully automated production machines.
Oda said the all-electric technology allows the press to make two or three movements at the same time, such as mold closing and injection; metering and mold opening; mold opening and ejecting; and mold closing and ejector recovery. That minimizes cycle time.
Oda said the presses boast fast injection speeds, of up to 1,000 millimeters per second, in a stable press, which is required to mold very thin-wall parts.
All three machines at K 2007 ran injection speeds of 330mm per second.