NPE2012 was held in sunny Florida but it rained every day — a cascade of bottle caps raining down from injection molding machines in the Orange County Convention Center.
Most of the cap machines are faster and more energy efficient than those shown at the previous NPE, in 2009.
“It seemed like this was the year of the cap,” said Mike Sansoucy, president of Netstal Machinery Inc. of Devens, Mass.
PET preforms get a lot of attention. But caps are very important — especially if they leak.
“The engineering, if you look at a bottle and a cap, the cap is far more technical than the bottle. That's where all the sealing is done, that's where all the tamper-evidence is done,” Sansoucy said. “So if that cap should fail, you get a flat soft drink. There's a lot of work that goes into that cap.”
Major changes like lightweighting have fueled advances in the technology of injection molding, molds and hot runners. Lighter, thinner water caps now weight less than 1 gram.
At NPE, Netstal molded liner-less caps for soft drinks on a 72-cavity mold running a 3.4-second cycle on an Elion press with 280 metric tons of clamping force. Sansoucy said liner-less high density polyethylene soft drink caps are used in Europe and Asia, but not yet in the United States.
“Pretty much all soft drink caps today have a secondary process to put a liner in there to ensure that it seals against the bottle,” Netstal's Sansoucy said.
Cycle times have steadily improved. A Netstal official said the cycle time for the 2.18-gram closure was five seconds just four years ago.
Some machinery companies made news in North America and China, thanks to tight scheduling of international trade shows this year. NPE2012 was held April 1-5 in Orlando. Just a week-and-half later came Chinaplas in Shanghai, from April 18-21.
Husky Injection Molding Systems Ltd. introduced the latest generation of the HyCap injection press for molding closures at NPE2012. Then at Chinaplas, Husky debuted the HyCap HPP (for high performance package).
At NPE, a 300-ton HyCap press molded water-bottle closures every 2.2 seconds on a 96-cavity mold from KTW Group. Jeff MacDonald, Husky's vice president of marketing, said the 96-cavity press the firm ran in Orlando marks a 45 percent improvement in productivity over the original HyCap at NPE2009, which molded caps on a 72-cavity mold on a 2.4-second cycle.
And MacDonald said Bolton, Ontario-based Husky can make even more improvements.
“If you think about where process time is wasted in producing a closure, there's a lot of unnecessary movement. Things like open and close and ejection time, are significant wastes that we've addressed. There's also a lot of energy wasted through some of those motions. And we set a big target to reduce that energy,” MacDonald said at Husky's NPE news conference April 2.
Advantages of the new HyCap include direct-drive technology, giving improved plasticizing speed and control, for improved shot-to-shot repeatability and better-quality parts. The screw and check valve were specifically adapted for direct-drive. Husky engineers adopted an electrification of the clamp lock.
At Chinaplas, Husky debuted the HyCap HPP press. MacDonald said Husky leaders gave engineers the goal of a 20 percent improvement in productivity and a 20 percent reduction in energy consumption. (See related story.)
At NPE, York, Pa.-based Engel Machinery Inc. molded caps on a 460-ton, all-electric, e-cap press running a 96-cavity mold. The cycle time was 2.7 seconds. All-electric presses have become fast-running machines for thin-wall packaging, which has been dominated by hydraulic accumulator technology, according to Walter Jungwirth, global business development manager at the Austrian parent company, Engel Holding GmbH of Schwertberg.
“Cycle times of less than three seconds and injection speeds of 450-millimeters per second can be realized,” Jungwirth said.
And the all-electric e-cap press reduces energy consumption by more than 40 percent compared to a hydraulic machine, he said.
The e-cap press in Orlando was equipped with an IMDvista vision inspection system.
At NPE, the cap mold was supplied by French mold maker Plastisud SA — and the two companies teamed to set up a joint venture in China that debuted at Chinaplas, called Green Cap.
Like Engel's NPE exhibit, Green Cap's Chinaplas stand also ran a 96-cavity Plastisud mold on an e-cap press.
Sumitomo (SHI) Demag broke the two-second cycle barrier, clocking 1.9 seconds to mold lightweight water bottle caps on a 96-cavity Sch"ttli mold, running on a 500-ton El-Exis SP injection molding press. An IMDvista system checked the inner and outer diameters, seal area and tamper-evident band.
Norcross, Ga.-based Sumitomo's SP presses are up to 30 percent more energy efficient that other high-speed hybrids, and sport injection speeds (up to 1,000mm per second) up to 30 percent faster that the El-Exis S, launched at NPE2009. The El-Exis SP uses a hydraulic accumulator for injection, a servo-electric motor for plasticization and screw drive and hydrostatic power transmission for clamping.
Advances in cycle times and overall cap output have helped injection molding gain market share against the mainstay, compression molding machines, which use a rotary process where a large turret of molds revolves continuously. At NPE2012, Imola, Italy-based machinery maker Sacmi Imola S.C. cranked out 1,600 caps a minute on a CCM48SB compression molding press. A CVS 052 vision system inspected each cap as it zipped by into a box.
Most of the injection press booths that were molding caps used a conveyor to move them to a vision system.
Sansoucy said caps molding cells are a good choice for a trade show — they're super-fast, compact and the vision inspection is impressive. “It adds some sex appeal to the show,” he said.
High-volume cap molding requires specialized molds. Progressive Components International Corp.'s Roehr Tool showed the new ProtoBridge tool at the show. The four-cavity mold system uses collapsible cores to make caps and closures with internal undercuts. Progressive is based in Wauconda, Ill.
PackSys Global (Switzerland) Ltd., part of the Brückner Technology GmbH, focused on the tamper-evident band, which breaks when you first open the bottle. PackSys builds equipment to make folded and slit bands, as an alternative to caps with the perforated band molded-in.
According to Rick Shaffer, a closure and packaging consultant who represents PackSys, a folded and split band offers a high level of quality at a lower price. It also makes it harder for someone to get around the tamper-evident band, “especially for a lighter-weight water closure where the amount of material you have is pretty minimal,” said Shaffer, president of InterTechRX LLC in Lancaster, Mass.