Although numerous companies have made and sold servo-driven, all-electric blow molding machines over the past 20 years, all-electric technology has not enjoyed the same widespread acceptance as it has in injection molding. News from the show floor at last month’s NPE2012 in Orlando, Fla., indicates this could soon change.
Bekum America Corp., Williamston, Mich. reported that it is expanding its Eblow series of twin-station, all-electric, extrusion blow molders and making them fully available in North America. The company introduced the first commercial machine, the Eblow 307D/L with 10-metric-ton clamp force at the K 2010 show in Dusseldorf, and has since been testing and optimizing the clamping system, drive, and controls at its world headquarters in Berlin.
Three new models (Eblow 407D, 507D, and 607D) will have clamps of 15, 20, and 24 m.t. respectively. Maximum mold widths are 500 mm for the 407D and 507D, and 700 mm for the 607D.
Across the Eblow line, Bekum claims a 30% to 40% reduction in energy consumption compared with similar-sized hydraulic machines. They also boast positioning accuracy of ±0.01 mm and noise reduction to a max. of 68 dB.
The company has yet to sell one of these in North America, where all-electric blow molding machines are less prevalent than in other parts of the world, but national sales director Gary Carr says molders at the show expressed interest in their potential to trim production costs significantly.
Meanwhile, another firm expanding its all-electric blow molding line is Automa S.p.A. of Italy. The Electro AT 480 DE continuous-extrusion shuttle machine is the latest addition to its BM series of all-electric machines.
With a 480-mm horizontal stroke and clamp force of 10 m.t., the Electro AT 480 DE was launched in Europe last October but was shown to North American molders for the first time at NPE. Stefano Elmi, PET business unit director, says Automa is aiming the machine at 2-liter bottles for detergents, motor oil, coolants, and other products.
The machine can mold bottles of up to 6L in a 1 + 1 cavity arrangement, and down to 0.5L in 7 + 7 cavities. Automa also offers the AE series of all-electric accumulator-head machines, as well as its NSB series of hybrid electric/hydraulic injection-stretch-blow machines for production of PET bottles and jars.
Kautex Maschinenbau built its first all-electric machine in the 1990s, when it was part of Krupp Group, but decided the technology was not yet robust enough for 24/7 production. With subsequent advances in electric servo drives and motors, the company has decided to revisit the technology and is planning on introducing a new line of all-electrics at the K 2013 show.
Bill Farrant, president and CEO of Kautex Machines Inc., North Branch, N.J., says the electric machines will have a modular, lightweight clamp designed for flexible production of large packaging products. “We are predicting our all-electric line will provide a 10% to 11% improvement in productivity in comparison to similar-size hydraulic machines,” Farrant states. “The proliferation of servo drives across all industries means that the hardware is more cost-effective, and that there’s a more mature range of suppliers and new ways to get an electric drive to produce a mechanical movement.”
Italian machine builder Plastimac Group, represented here by American Jetstream Inc., E. Brunswick, N.J., discussed its all-electric Plastiblow machines at NPE. Five models can mold containers from 1 to 30 liters. They are designed for easy and rapid maintenance, low energy consumption, and precise repeatability of clamp movements.
ELECTRIC/HYDRAULIC HYBRIDS, TOO
Nissei ASB Co., Atlanta, has been offering all-electric machines since 2006, when it introduced the ASB-15N/10E all-in-one injection-stretch-blow machine. With an injection clamping force of 15 m.t., this machine was built primarily for clean-room production of small (less than 4 oz) pharmaceutical and healthcare packaging with a maximum of 10 cavities.
At NPE, Jamie Pace, v.p./general manager, reported that Nissei has in the works a hybrid line of machines. The first model, ASB-12M, is slated to arrive in the third quarter. It will have servo-driven hydraulic pumps and is primarily targeted for molding of wide-mouth jars with necks up to 83-mm diam. “All-electrics have a lot of servo motors, and when servos break that can create a lot of problems, especially with a semi-skilled work force,” Pace says.
Uniloy North America, Tecumseh, Mich., incorporates hybrid technology on its two largest-selling machine lines, reciprocating-screw extrusion units and machine and injection-blow models. Richard K. Smith, v.p. of commercial operations, says the machine builder is still exploring ways to develop an all-electric solution for these machine platforms.
“On these machines, which have high clamp-tonnage capability, it has been problematic and unfruitful to date finding any electric system that will generate the required clamp tonnage at the cost point we need,” he says. (Note: Uniloy Milacron Europe does offer all-electric injection-blow and extrusion shuttle machines.)