Looking into the future of injection molding at NPE

By Mark Stephen, associate editor May 1, 2006

Show-goers at NPE 2006 should expect to see the new capabilities in injection molding machines that were debuted at NPE 2003 running leaner and simpler this time around, and a greater emphasis on inte...

“What injection molders have to look for, in order to stay competitive, is how to incorporate more functions into the mold, and of course the molding machine has to serve that purpose,” Siegfried Niedermair, president of Sharon, Ont.-based Niedermair Plastics Technologies (NPT) Inc., said.

Injection molding machine exhibitors will use North America’s largest plastics processing show to demonstrate that technologies such as all-electric, multi-component and water-assist injection molding — which were all fairly new to the domestic scene in 2003 — have been streamlined in time to help reverse what many see as a trend towards rapid market encroachment by Asian machinery manufacturers.

ALL-ELECTRIC, ALL THE TIME

The biggest injection breakthrough seen at NPE 2003 was the all-electric machines that numerous manufacturers made the centrepieces of their displays.

Because of stress on the servo motors generated by long injection hold times, all-electric machines were once considered special purpose, to be used only on certain smaller applications, Barr Klaus, vice president, technology, Cincinnati Milacron, said.

But with recent developments in direct-drive motor technology, all-electrics have turned the technological corner, he added. They are now practical and cost-effective to run on virtually all mainstream applications, and can “outrun” an equivalent-sized hydraulic machine.

Glenn Frohring of Strongsville, Ohio-based Demag Plastics Group, agreed. “With direct-drive technology, applications with longer hold times and more stressful molding can be accomplished, so all-electric machines are now commonplace above 350 tons,” he said.

And because they consume less energy than either traditional hydraulic injection molding machines or hybrids, and have the inherent ability to overlap such functions as clamp, injection and ejection, all-electric machines are a natural way for manufacturers to run leaner and quicker operations.

Since the NPE 2003, sales of all-electric injection machines have increased worldwide, said Ralph Schreiber, corporate communications officer for Lossburg, Germany’s Arburg GmbH, a vote of confidence that should result in a larger number of them at NPE 2006. Plus Arburg sells the majority of its all-electric machines to North American customers. “At this NPE, everybody will add some of the larger tonnage models and larger sizes than the all-electric machines that they had at the last show,” Demag’s Frohring said.

This ability to run larger tonnage all-electric machines could give domestic molders an added advantage over molders in the Far East, Thomas Betts, Midwest regional manager for South Elgin, Ill.-based Battenfeld of America Inc., said, since larger parts are more difficult and more expensive to ship from Asia.

In addition to running larger sizes, show-goers should expect to see the all-electric machines at NPE 2006 running faster than ever before, said Bill Tobin, owner of WJT Associates, a plastics Louisville, Colo.-based plastics consulting firm.

For example, Sumitomo Plastics-Machinery, headquartered in Norcross, Ga., will run several new lines of direct-drive all-electric machines that feature injection speeds of up to 300 mm/sec and velocity response of 25 milliseconds, which can help reduce cycle times dramatically, the company said.

Show-goers should also expect to see new, faster all-electrics from manufacturers such as Toshiba, Arburg, Engel, Krauss-Maffei, Nissei, Battenfeld, Haitian and Netstal Machinery Inc., among others.

MULTI-COMPONENT = MULTI-FACETED

Another way for injection molders to trim cycle times and increase productivity is through multi-component molding. Multi-component enables parts to be produced from different materials in a single manufacturing step, which not only saves time but also allows for enormous opportunities for new product design of hard/soft combinations and multicoloured components.

As with all-electric, there were numerous multi-component machines displayed at NPE 2003, although they ran a limited variety of applications. “At the last NPE, it was basically just consumer high-volume products that were multi-molded, with just a hard substrate and then a soft thermoplastic elastomer,” Demag’s Frohring said.

Advances in multi-component technology since then should allow show-goers to see more sophisticated products being formed this time around, he added. “Previously, multi-component molding was basically for feel-and-touch applications. Now that the technology has developed, it’s definitely used for look and aesthetic qualities, for cost-effectively putting together different colours that highlight one another when the product goes on the shelf.”

Paul Caprio, executive vice president of Florence, Ky.-based Krauss-Maffei Corporation, agreed. “Multi-component technology has gotten quite good at bonding materials that don’t normally bond together,” he said. Krauss-Maffei will run four multi-component injection molding machines at the show. “We think multi-component machines are very much a growing part of the marketplace,” Caprio added.

Also, an important new market for multi-component injection molding has continued to open up since NPE 2003, as the ‘Big Three’ North American automotive companies fight to stay competitive against overseas manufacturers. NPE 2006 will be a golden opportunity for multi-component machinery suppliers to show visiting automotive manufacturers what these machines can accomplish, injection machine manufacturers say.

NPT’s Niedermair agreed there is an opportunity here for multi-component molders. “If you look at automotive companies, there is still a lot of labour that goes into a part,” he said. By eliminating the need to physically assemble car parts such as roof racks, multi-component molding can help automobile manufacturers increase productivity, he explained.

Niedermair also believes that changing automobile safety regulations overseas could present even more opportunities for multi-component machines to service the industry. “The European Union is giving us a chance with their new pedestrian requirements that hoods, etc. have to crumple in a certain manner. There is a great opportunity for North American plastics processors to get into that using multi-component injection molding,” he said.

For these reasons, automobile parts will probably prove to be the production item of choice for many multi-component machine suppliers at NPE 2006. Demag, for example, will mold multi-component car parts on its 1100 Titan series machine.

MAKING A SPLASH

Water-assisted injection molding (WAIM) is the newest way to mold hollow or partly hollow parts.

Although similar to gas-assist, it has the advantage of allowing direct cooling inside the part, since the thermal conductivity of water is 40 times greater than that of gas. As a result, cooling cycle times can be reduced to only 25 per cent of that of gas, said Helmut Eckardt, technical director for low-pressure injection molding at Battenfeld Injection Molding Technology in Meinerzhagan, Germany.

WAIM received international attention at the 2001 K show in Dsseldorf, and had its first real showing in North America at NPE 2003, when machine companies such as Guelph, Ont.-based Engel Canada Inc., working with Cinpres Gas Injection Ltd., produced water-assisted parts. Although Engel will not be running WAIM this time around, machine manufacturers such as Larry Pascucci, director of sales and marketing for Negri Bossi Inc., expect to see it on display at NPE 2006. “Actually, I think you will see more water-assisted technology at this NPE,” he said.

NPT’s Niedermair agreed and said that WAIM could be a
further tool in helping injection molders run quick and lean. “Water-assist reduces labour, because instead of making two parts and welding them together, you can use (WAIM) to make one part. Plus, the cycle time is reduced dramatically because the cooling time is a lot quicker,” he said.

WAIM can also be integrated to serve several functions, further streamlining the molding process. “You can hook water assist up to any machine as long as you can interface. The WAIM unit can be used as a gas-assist unit, it can control the mold temperature, the hot runner system, and up to six to eight zones,” Niedermair said.

WJT Associates’ Tobin agreed that WAIM can allow molders to achieve faster cycle times while lowering costs, but stressed that the technology’s relative newness is a handicap. “It’s still a boutique arrangement, and you have to argue with your customer to use the technology,” he said. Also, research still needs to be done to precisely define grey areas like proper water temperature, pressure and flow rate, he added.

Although a niche process at present, it seems likely that WAIM technology will become more widely applicable with time, as has happened with all-electric, multi-component and gas-assist molding.

THE END OF THE LINE

The trend towards injection machines running lean and simple at NPE 2006 will also be evident through a better integration between molding and automation. “I expect at NPE we’ll see injection machines that will allow molders to program the proper process settings faster,” Tobin said. “The idea (at NPE 2006) will be automate everything and I expect the injection machines to have more automation but easier automation, that you can train simply and quickly,” he added.

NPT’s Niedermair also expects to see greater integration of injection machines and automation at the upcoming NPE. “Injection molders have to combine manufacturing steps into the mold; that’s where the future lies, otherwise we can’t compete with processors from the Far East”, he said. “I see a trend towards reducing labour cost, and that happens in the molding machine and the secondary operations.”

Negri Bossi’s Pascucci agreed, and said that he expects to see a lot of peripheral technology better integrated with injection machinery than at previous NPEs. “It’s the wave of the future, integrating engineering services to make a completely automated package. It’s the way all of North America has to go, and I think we will see a lot of it at this NPE,” he said. Negri Bossi, for example, will be running injection molding machines at NPE 2006 that will be fully integrated with six-axis KUKA robots.

Another example is Toshiba Machine Company, headquartered in Elk Grove Village, Ill., which will run its EC45NII injection machine with a Toshiba Scara style robot. “This is an improvement of productivity through high-precision molding and automation,” Michael Werner, Toshiba technical sales manager, said.

Show-goers should also expect to see automation more fully integrated with the multi-component machines. Engel, which will be molding a two-component sunroof at NPE, will rely on greater integration to trim production time, Joachim Kragl, manager, processing technologies at Engel, said. “Streamlining the communication between our robots and machines (will allow for) part removal a few tenths of a second faster than with non-integrated robots. Considering packaging cycle times, this could mean a significant advantage for the molder,” he added.

ON WITH THE SHOW…

At the end of NPE 2003, one molder said that the show had been a celebration of survivors, of all the processors who didn’t either choose to sell out, liquidate their assets, or merge themselves away. “We’re here with our chequebooks. Now we’ve got three years until the next show to make it all work,” he added.

Resource List

Arburg Inc. (Newington, Conn.)

www.arburg.us; 860-667-6500

SMW & Associates (Kilbride, Ont.); 416-558-6526

Turner Group (B.C., Alta.); 206-769-3707

Battenfeld Canada (Mississauga, Ont.)

www.sms-k.com; 905-670-9384

Cincinnati Milacron (Burlington, Ont.)

www.milacron.com; 888-254-1919

Accuplast Solutions (Kirkland, Que.)

www.accuplast.com; 866-630-0808

Demag Plastics Group Corporation