Netstal-Maschinen AG showed what company officials called a first: running the MuCell process on an in-mold-labeled container, on a four-by-four stack mold.
The combination of high speed - a 4.8-second cycle - and weight reduction, thanks to MuCell, came together on a press that debuted at K 2007 in Dusseldorf, Netstal's newly designed hybrid, the Evos. The injection press molding the rectangular polypropylene containers had 350 metric tons of clamping force.
MuCell technology is from Trexel Inc., based in Woburn, Mass. The process uses compressed nitrogen or carbon dioxide to create microscopic bubbles that form as the melt goes into the mold.
Bernhard Merki, Netstal's president and chief executive officer, said without MuCell, it would take a 500-tonne press to mold the containers.
``The challenge is to do MuCell on a stack machine,'' he said at the company's K show press conference on Oct. 25.
A second Evos was running in Dusseldorf, a 500-tonne machine molding a threaded pour spout on a 144-cavity mold, on a cycle time of just 3.75 seconds. That's a lot of spouts: 138,000 an hour. Every single one was checked by an IMD Ltd. vision system.
The NÃ¤fels, Switzerland-based press maker plans to replace its SynErgy line with the Evos, which comes in clamping forces from 200-500 tonnes. Merki said every Evos comes with a servoelectric screw drive as standard.
Netstal has cut lead times significantly for the Evos, by implementing a modular system so component manufacturing and assembly processes can be operated in parallel. The clamping unit, plasticizing unit and drive are configured to the molding application of each specific press; they get installed right before each press is commissioned and delivered.
Customers can specify different clamping units with injection units, to tailor a press for the exact molding job.
All five axes of motion are digitally controlled, with independent control circuits. Netstal said that means machine movements can be operated at the same time.
The Evos clamping unit is based on a five-point toggle lever system. The inclined toggle lever system, located in the center of the mold mounting space, reduces bending of the moving platen, Netstal said. Thanks to its minimal mass, the toggle clamp can reach higher speeds.
K show-goers also saw the smallest PET-Line yet, with 200 tonnes of clamping force, molding PET preforms on a 48-cavity mold, on a 12.5-second cycle. Merki said Netstal engineers cut cycle time simplifying pare removal and increasing injection pressure on the machine.
Merki said Netstal remains a solid No. 2 in PET preform machines, even as Engel Holding GmbH makes inroads. The No. 1 spot is held by Husky Injection Molding Systems Ltd.
``I'm convinced that we can remain in this position, with all the activities we have already done. We are able to defend this No. 2 position,'' Merki said.
Two all-electric Elions graced Netstal's booth. A 80-tonne Elion turned out medical pipettes at a cycle of 7.5 seconds.
A 175-tonner cranked out thin-wall flower pots, four per shot, every two seconds.