Sustainable Machine: More Than an Add-On

Green Isn't an Afterthought. New and Old Machines Demand Solutions in Which Energy and Raw Material Conservation Are as Important as Throughput and Safety

By Jim Montague

April 2011 CoverGreen must be real to deliver real savings. It can't be tacked on. Even though sustainability means many things to different people, you can't fake it and expect it to work. Phony sustainability is easy to spot — like a Hummer painted turquoise. It might look pretty, but it still wastes energy.

Green and sustainability must be more than buzzwords for "efficiency" because efficiency is just the beginning. Just like biological waste and toxic home loans, difficult problems all roll downhill until they reach someone who can solve them. Consumers demand green and less costly products from retailers. Retailers demand green products and energy-and-material-saving solutions from manufacturers. And, finally, manufacturers demand that builders give them machines that do both. Lucky you.

Cap Conservation

Reducing raw materials might seem straightforward, but actually doing it can get mighty complex, especially when you're trying use less plastic in the plastic water bottles produced for much of a continent.

For example, Nestlé Waters North America recently asked its high-speed, rotary bottle-capping supplier, Pro Mach's Fowler Products division, to redesign and change out the cap-handling components on more than 50 of its machines at more than 12 plants in North America to accommodate smaller caps and lighter-weight bottles, but still allow them to run at up to 1,200 bottles per minute to keep up with demand. Located near Cincinnati in Loveland, Ohio, Pro Mach manufactures 15 brands of primary and end-of-line packaging machines and identification and tracking equipment.

Beginning in 2009, Nestlé's huge capping retrofit required Pro Mach to cooperate with other machine builders and equipment suppliers to update their devices to handle the smaller caps. Cooperation, planning and design took two years, initial execution took six months, and final retrofits are continuing this year.

"This was a very involved project that took a lot of collaboration and a lot of time," says Mark Anderson, Pro Mach's president and CEO. "The blow-molding and filler builders had to redo their machines. The cap supplier had to make smaller caps. Fowler added its proprietary positioning and orienting technology to the capping heads to prevent the smaller caps from getting jammed. And the material handling system had to handle bottles that were more floppy and less stable. As a result, more sustainable packaging can be more difficult to handle because you also can't sacrifice productivity or give up low costs."

Doug Newcomer, Fowler's after-market services manager, adds, "We've all worked with Nestlé for a long time, so we were able to have a team effort with them, the cap manufacturers, and the filler companies. The 36-head capping turrets were already in production, so this was a retrofit project. It was still very challenging because the new caps were so lightweight, and the machines had to run at their normal production rate of up to 1,200 bottles per minute. We had to be more precise with the tolerances of the new parts and in setting up the capping machines. We used gauges to check and correct the flatness of surfaces and the alignment of the heads to the bottles. We then used high-speed cameras to check the transfer of the caps into the chucks through our transfer star. The caps were more affected by air when transferring to the capper, but still had to be perfectly aligned to the heads as they transferred out of the star, and the heads had to be perfectly aligned to the bottles as the caps were being applied. Working together, we made it a success."

To further handle the lighter-weight bottles, Newcomer says Fowler also redesigned and tightened the star-wheel-based handoff process between the filling machine and its capper. He adds that the filler and other devices use control systems from Siemens Industry, Schnedier Electric and Rockwell Automation.

Consequently, Nestlé and its partners report their joint capping retrofit was a huge success. "We helped reduce plastic in the caps by about one third, save 95 million pounds of PET resin per year, and save Nestlé about $60 million per year," Anderson adds.

Ramped-Up Recycling

Besides designing machines to use less raw material, some builders construct equipment that can use a greater percentage of recycled content or more biodegradable material. In fact, Husky Injection Molding Systems, Bolton, Ontario, reports that its new HyPET Recycled Flake (RF) molding platform can manufacture plastic preforms (which are plastic forms before they're blow-molded by another machine) with up to 100% post-consumer, food-grade recycled plastic extrusion technology (PET) flake (Figure 1). The company began by optimizing HyPET RF to manufacture preforms with up to 50% recycled flake, and then continued to tighten its performance to increase the quality of preforms made using the PET flake.

"As a company committed to sustainability, it's our responsibility to invest in solutions that reduce the environmental impact of beverage packaging," says Jeff MacDonald, Husky's marketing vice president. "The challenge in the past was to increase recycled flake content and still maintain the highest quality and performance. We've been able to push the performance of our HyPET RF system to use up to 100% recycled flake, and initial trials with  global customers have been very encouraging." The first commercially viable HyPET RF system is running at a customer facility in Europe to support a leading bottler.

Husky reports that HyPET RF's innovations include an extruder design for improved processing of pellet and flake blends, two shooting pots, and inline, continuous melt filtration, which enables the system to offer excellent material homogeneity and eliminate non-meltable contaminants for superior bottle quality. "These features allow manufacturers not using recycled PET flake to introduce this material into their products," MacDonald says. "For those already using recycled PET flake, this can eliminate some of the manufacturing and quality challenges while enabling an increase in flake content."

Husky's proprietary, PC-based Polaris controls manage HyPET RF's functions and its other PET molding systems, and these controls have optional packages for integrating auxiliaries and downstream parts-handling equipment. The company reports that the advantages of its controls include faster cycle times, highly repeatable shot-to-shot performance, remote connectivity through ServiceLink communications, and control of its molding system and auxiliaries from one interface.

"The preforms produced on Husky's HyPET RF system reduced black specks and minimized failures during bottle blowing compared to preforms produced on standard, non-specialized systems using the same blend of recycled flake," adds Bruce Sampson, general manager of Southeastern Container (SEC), one of Husky's development partners. SEC is owned by a group of Coca-Cola Bottling companies, and produces PET bottles at 10 plants in nine states to meet the packaging needs of those bottlers.

Preserving Power

Still, although some innovative builders design machines that make greener products, the most popular path toward sustainability remains finding ways to reduce energy consumption.

The most popular path toward sustainability remains finding ways to reduce energy consumption.

Winpak Lane in San Bernardino, Calif., has been producing its W-18 four-axis vertical form-fill-and-seal (VFFS) pouch machine since 2002, and says its servo-driven unit has a reputation for high throughput and reliable sealing of a range of products from applesauce to yogurt. However, Winpak wanted to design a new W-18 series with simpler and more user-friendly operation, faster and more precise control, and reduced energy and material waste (Figure 2). Winpak worked with automation distributor Applied International Motion (AIM) and Bosch Rexroth to implement W-18's new electric drive and control, pneumatics, and linear motion components. "We'd already achieved greater efficiency by going to servos, but we wanted to take the next step, and increase our accuracy and efficiency at higher production speeds," says Mark Griffin, Winpak's sales and marketing director.

The new W-18 is designed to form, fill, seal and date-code up to 1,500 packages per minute with accurate and repeatable weight control. Rexroth's servo drives and motors are used on the pump, pullwheel, rotor and seal bars, with the date-coder as an optional fifth axis. AIM recommended adding Rexroth's SERCOS-based IndraMotion MLC controller, which has built-in motion, logic and Flex Profile capabilities for the seal axis. This allows cycle times to be optimized for velocity, acceleration, position or time, which means W-18's users don't have to rebuild cams each time a parameter changes. In fact, all four axes are synchronized to a common virtual axis, which enables coordinated and repeatable filling and high-speed registration.

In addition, Rexroth's modular pneumatic valve manifold with Profibus is used to open the pull wheels and relax the packaging material film web between each machine cycle. The manifold provides high flow in a compact unit with low power consumption. As a result, the W-18 machine saves up to 18 cfm of air compared with previous mechanically and pneumatically controlled machines.

Cooperation Aids Sustainability

Because green manufacturing evolved from traditional efficiency, some builders note that earlier collaborations assist later sustainability efforts. Okuma America in Charlotte, N.C., organized its four-year-old, 35-company Intelligent Numerical Control (THINC) partnership program to give its end users more complete manufacturing solutions by interconnecting and sharing information from its Windows-based OSP P200 proprietary CNC controller with other automation systems, robots, bar feeders, tooling and cutting groups, workholding arrangements, gauging and metrology solutions, tool management systems and adaptive controls. However, these collaborations also helped its sustainability efforts, according to Jeff Estes, director of Okuma's partners and THINC program. 

"We can use our THINC-enabled controller to take dielectric gauging data, and use it during cutting cycles to automatically compensate for problems that can cause bad parts," Estes explains. "This gives us better surface finishes, improved safeguarding against tool wear and damage, and better material handling, which all help save energy and resources. For instance, as our machine cuts through material, it can run into harder or softer spots, but this controller allows the machine to speed up or slow down to maintain its ideal cutting force."

Estes adds that servo-driven turning stations and tool changers on Okuma's lathes and machining centers save energy because they only use electricity when they need it, unlike compressed-air tools that were powered up for much longer periods. More recently, Okuma developed its LBEX series lathes, which use its four-year-old Prex motors. "Prex provides the same horsepower and torque as a traditional Vac motor, but does it in a footprint that's 30% smaller," Estes says. "These motors also generate a lot less heat and heat distortion, so they also use about 10% less energy. As a result, these machines also are less affected by trample, which is excess oil and grease getting into their coolant. This, and moving from box ways to linear guides, allows us to use less lubricant, which means we can use the same amount of coolant for longer periods. We're even working with our THINC partners to test liquid CO2 and liquid nitrogen coolant that eliminate residue."

Likewise, as we first reported on last year (www.ControlDesign.com/change), MAG Industrial Automation Systems recently demonstrated its new cryogenic machining method, which uses a through-spindle, through-tool system that cools its cutting edge far more efficiently, enabling much higher cutting speeds, increased metal removal and/or longer tool life. The liquid-nitrogen (-321 °F) cooling system also can combine with minimum-quantity lubrication (MQL) to reduce tool friction and adhesion, enabling even higher metal removal rates or longer tool life.