Despite recent dips, it’s apparent that energy and raw material prices have risen to new and permanently higher plateaus. It’s also apparent that these higher prices will have a profound effect on machine design over the next few years in ways that are sometimes obvious but often obscure.
Let’s start with energy prices, an item that is foremost in the minds of many machine builders. “Energy cost has always been in the equation, but now it’s percentage of the total cost has risen at an alarming rate,” says Paul Brancaleone, manager software/controls at Gloucester Engineering in Gloucester, Mass.
Gloucester Engineering makes plastics processing equipment, specifically film and sheet extrusion systems. “A growing number of our customers are now interested in reducing the energy that our machines consume. Amongst the normal questions on throughput and quality, we now are asked to estimate lbs/kWh. I expect to see more use of power measurements to optimize processes and of advanced control techniques to reduce energy use,” adds Brancaleone.
T-Tek Material Handling in Montgomery, Ala., builds high-speed palletizers, primarily for the beverage packaging industry (Figure 1). It also makes full and empty pallet conveyor, pallet dispensing and stacking systems for the pallet sortation and repair industry.
Figure 1: This high-speed beverage palletizing machine from T-TEK Material Handling not only performs faster than earlier models, it uses less energy with help from a Bosch Rexroth servo system. The three-axis palletizer is designed to handle a wide variety of packaging configurations of cans or bottles in layers containing as many as 32 packages each.
“As machine builders develop new equipment, extra attention will have to be paid to all aspects of energy including minimizing horsepower, using higher efficiency motors and using compressed air instead of other more conventional energy sources,” observes Brian Traff, vice president of T-Tek.
“Regenerative energy drives, such as the Bosch Rexroth solution used by T-Tek in hoist applications, will become more and more common. We expect to use more remote access and Web viewing systems to reduce travel expenses,” comments Traff.
Another machine builder reinforces the points made by Brancaleone and Traff. “We are spending more time and effort to optimize energy consumption through increased efficiency of vacuum generation, increased use of robotics and decreased use of pneumatic equipment,” notes Pete Squires, vice president of Schneider Packaging Equipment in Brewerton, N.Y. Schneider makes automatic case/tray packing and palletizing equipment (Figure 2).
RRR Development in North Canton, Ohio, builds equipment for the tire and rubber industry. “Power source regeneration on motor/drive systems will be increasingly important as a means to recoup energy costs,” notes Bob Irwin, an electrical engineer with RRR.
“Our customers need an increase in the capability to diagnose and react quickly to energy and other inefficiencies on our equipment. This will require additional diagnostic sensors and designs to make the information available,” adds Irwin.
University researchers are also seeing changes in machine design brought on by higher energy prices. “Cost of energy is now becoming an issue with the design, manufacture and operation of machinery used in production,” says Professor David Dornfeld from the Department of Mechanical Engineering at the University of California-Berkeley.
“Energy use can be minimized by recovering energy from machine operation, as well as by novel design concepts such as maintaining stiffness while reducing mass of moving components,” adds Dornfeld.
Optimizing the System
Reducing energy use on a machine-by-machine basis is important, but bigger gains can often be had by optimizing the total number of machines in a production line. “Some of our customers have been looking at new machines and production lines that can outproduce the combined efforts of several of their existing machines; and part of their justification is based on the energy savings of one machine vs. multiple machines,” reports Larry Asher, controls engineering manager at Bradbury in Moundridge, Kan.
“Other customers are developing high-efficiency products, such as insulated building panels, and need machinery with specific capabilities. Looking into the future, we already have engineers exploring low-watt devices, regenerative drives and renewable energy,” adds Asher.
Figure 2: This Schneider Equipment robotic case loader has to adapt to manufacturing techniques that reduce the plastic used in bottles. The company says it takes more engineering to design equipment that can handle more-delicate product and maintain quality.
Per Asher’s comments, the quest for energy efficiency is driving the entire machine builder ecosystem. First, machine builder customers need to make energy-efficient products to satisfy market demand. Second, these customers need to redesign their entire production processes to use as few machines as possible and to reduce overall energy usage. Finally, machine builders have to make their machines more energy-efficient.
One of the best ways to make a system more efficient overall is to reduce design factors and make machines that do just enough. “I see energy prices forcing us to become more efficient designers,” says Rick Moscarino, VP of engineering at Bardons & Oliver in Solon, Ohio.
Bardons & Oliver manufactures CNC turning machines, rotating head cutoff machines, double enders and other special machines (Figure 3). It also builds all of the related handling equipment for the input and output sides of the equipment. “Design output will have to match application requirements very closely with less excess or design factor,” adds Moscarino.
U.S. machine builders have always been noted for building heavy duty equipment that will do the job and a bit more. European machine builders have often taken a more elegant approach and designed lighter-duty machines that are inherently more compact and more energy efficient.
“The U.S. has probably lagged a little behind foreign manufacturers in building lighter-duty equipment. Tightly engineered rather than overbuilt has been the province of Europe and Asia. Americans tend to like the look and feel of heavy-duty equipment, but this will change,” predicts Traff of T-Tek.
As design factors are reduced, up-front planning becomes ever more important for individual machines, as well as entire production lines. “There is a strong movement to standardize engineering methods in order to increase efficiency, reduce errors and produce better-designed products,” notes Mark Taylor, executive vice president and general manager for Eplan Software & Services.
“Even machines that are custom-built can usually be configured from a set of standard options as opposed to starting from a blank sheet of paper. This significantly reduces the time to design equipment, the errors associated and the subsequent downstream costs incurred during equipment build,” observes Taylor.
Figure 3: This rotating head cutoff machine is manufactured by Bardons & Oliver. The machine cuts blanks to length and chamfers both the outside diameter and the inside diameter from tubing stock sized from 1 in.-7 in. diameter by 24 ft.-40 ft. long. Cut lengths range 1 in.-15 ft.
Coping With Higher Raw Material Prices
Reducing energy consumption may be at the forefront, but cutting raw material usage is not far behind. “The running cost of energy for our injection-molding machines is a concern, but does not impact the entire product cost as much as the raw material costs do,” says Chris Choi, the director of technology for Husky Injection Molding Systems in Bolton,Ontario.
Husky makes injection-molding machines, and various plastic and metal products are the raw materials used by their customers as inputs to their machines. “Higher raw material prices will accelerate the development of new technologies to reduce material use,” adds Choi.
One of the ways to reduce raw material costs in plastic injection molding applications is to make finished products such as plastic bottles thinner. “Packaging is already changing in response to commodity price increases as plastic bottles are becoming progressively thinner and lighter. Plastic resin costs are driving the move to replace plastic shells with shrink wrap,” observes Traff of T-Tek.
“We are designing equipment to stay ahead of these changes by using servo driven systems to soften the case handling of thinner packaging. As we design equipment, we will be re-examining structural materials for weight or wall thickness to ensure that the system is as energy-efficient as possible,” explains Traff.
Another packaging machine builder is also seeing the effects of the drive to thinner, lighter and less expensive materials. “As our customers decrease the amount of supplies purchased, it makes our automation task much more difficult because the packages are less sturdy. It takes more engineering to produce equipment that can handle the more delicate product while still maintaining highest quality with low scrap rates,” says Squires of Schneider Packaging Equipment.
Using thinner plastic directly reduces the amount of raw material used. Another way to cut raw material costs is come up with ways to use lower-grade materials to produce quality end products. “Coil processing is an area where we have seen large growth because our leveling technology allows our customers to purchase a lesser grade of steel. They then can level or condition the steel to a degree not attainable on other equipment, thus reducing their raw material cost,” explains Bradbury’s Asher.
Cut Energy Consumption
1. Use regenerative motor drives
One of the best ways to reduce raw material costs is through recycling not only materials but even entire machines. “Rebuilding older equipment that in the past was destined for the graveyard will become even more prevalent than it has already become,” predicts Brancaleone of Gloucester Engineering.
Rebuilding an old machine represents a huge savings in the raw materials used to construct the machine when compared to building new. One of the major tasks in a rebuild is usually a complete replacement of the automation system. This is just one of the ways in which expenditures on automation can reduce raw material or energy costs.
Automation Reduces Resource Consumption
Automation is employed in manufacturing operations to reduce labor, improve throughput and boost quality, which cuts energy and raw material costs directly and indirectly. “Higher resource prices will absolutely drive further automation. Any automation that can eliminate or simplify a downstream process will improve quality, yield less scrap, require less rework and reduce man-hours. We have to reduce overall cycle time by cutting part-to-part reduction time and setup time. Setups must be reduced to minutes, with setup via pushbutton our goal,” says Moscarino of Bardons & Oliver.
Campbell Wrapper in De Pere, Wis., manufactures horizontal flow wrappers, feeding equipment and complete packaging solutions for many industries (Figure 4). It makes extensive use of Rockwell Automation products to optimize the energy and raw material usage of its machines. “Although automation has always been integral to our machines, higher resource prices make automation far more important,” comments John Dykema, president of Campbell Wrapper.
Figure 4: This Campbell Revolution horizontal flow wrapper produces up to 600 packages per minute for a wide variety of food and non-food applications. Products handled can include granola bars, pancakes, school lunches, sandwiches, wet wipes, greeting cards/envelopes, cosmetic samples and fire logs.
“Increased commodity prices have posed tough challenges for our customers since grain, corn and other commodities are often a big part of their cost equation. We have seen a redoubling of effort by many food and consumer product companies to offset their commodity price increases with automation that reduces their other cost factors,” adds Dykema.
Automation can cut wire consumption dramatically when digital networks replace home run wiring. “Communications, networking and distributed controls will continue to grow as the cost of copper and wiring make these automation technologies even more attractive,” notes Brancaleone of Gloucester Engineering.
Others agree. “It will be easier to justify open architecture device level bus systems due to the expense of copper wire. Wireless Ethernet will also become a more widely used platform, not only for plant-floor data acquisition, but also for machine-to-machine control and communication,” says Brian Traff of T-Tek.
Pepperl+Fuchs sees the same trend. “AS-Interface technology frequently allows cable reduction by 90%,” claims Helge Hornis, Ph.D. and manager of intelligent systems at P+F.
“Also, other secondary cost factors can be reduced because fewer cables mean less conduit and cable trays. Placing devices in the field directly on the machine reduces the size of controls cabinets and possibly eliminates junction boxes,” adds Hornis.
Another supplier chimes in with similar observations. “Many companies have yet to understand the savings that a high-speed, deterministic Ethernet-based network can bring in material costs,” explains Graham Harris, president of Beckhoff Automation.
Cut Raw Material Costs
1. Use digital networks to save wiring, conduit and cable tray costs
“For example, compare 1 ft of Cat. 5e cable to a copper-based wiring system with individual wires for every sensor and actuator. Cabling for Beckhoff’s EtherCat I/O network costs about $1.50/ft and can handle thousands of top performance I/O points,” points out Harris.
Higher energy and raw material prices are changing the machine builder automation landscape. Machine design will have to adapt to minimize energy and raw material consumption. Automation will become even more important to overall machine design because the cost of automation will rise more slowly than the cost of energy and raw materials. This will make it easier to justify automation expenditures that increase energy efficiency and that reduce raw material consumption.
|BACK TO THE GRID
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Will Higher Resource Prices Favor European Machine Builders?
Over the past two decades, there has been a fundamental difference between North American and European manufacturing. North America has focused relentlessly on labor productivity, while Europe has been more concerned with efficient use of resources.
In North America, it is relatively easy to cut labor in response to manufacturing productivity improvements. Capital expenditures for automation can therefore be directly justified by reduced need for labor.
The result is evident when manufacturing labor productivity for North America vs. Europe is examined over the past two decades. From 1990-2000, European labor productivity rose at a rate of 3.1%/year, while U.S. labor productivity increased 4.0%/year; and over the 2000-2007 period, only Korea, Taiwan and Sweden had greater productivity growth in manufacturing than the U.S., according to reports from the U.S. Bureau of Labor Statistics in 2002 and 2007, respectively.
European manufacturers find it hard to cut labor; and they are used to paying much higher prices for resources including land, energy and raw materials. Higher resource prices have forced European manufacturers to focus on automation and other manufacturing investments that reduce these costs as opposed to cutting labor.
Inevitably, the focus of manufacturers worldwide is going to shift from labor productivity to efficient use of resources. Because European machine builders have been more focused on this efficient use of resources, as compared to U.S. machine builders, they may have an edge in this new era.
A factor mitigating this edge will be rises in shipping and other transport costs due to higher energy prices. Higher transport costs will favor local manufacturers, as explained in this September 2008 Control Design editorial (www.ControlDesign.com/bulges). For example, higher shipping costs due to increased energy prices have rendered Chinese-made steel uncompetitive in the U.S., with other low value-to-weight products sure to follow.
Cutting Energy Use in Motion Systems
“One of the largest consumers of energy for machine machines is the motion system,” says Scott Hibbard, vice president of technology for the electric drives and controls division of Bosch Rexroth. “Fortunately, there are many energy saving opportunities in this area.”
Brushless drives, as true energy converters, supply energy to a motor during acceleration and driving, and they return energy to the amplifier during deceleration or while being driven by another force, he explains. “That returned energy can be fed back into the power supply, where it is converted to heat with resistors, stored in capacitors or returned to the incoming power lines via regeneration for sale back to the power company,” explains Hibbard.
When multiple axes of motion need to be controlled, modular converter-based systems with a shared power supply can offer a tremendous power advantage because power can be shared, as power returned from one motor can be used by another—this happens when one motor fights another such as in a tensioning application or when a vertical axis is dropping while another is driving—and power can be regenerated more cost effectively for resale to the utility.
A regenerative power supply does add some cost to the system over a standard power supply, but the payback can be very quick. Regenerative power supplies also don’t dissipate returned energy as heat, so energy use to cool cabinets is greatly reduced.
According to Hibbard, Bosch Rexroth often collaborates with customers on best machine and process design to leverage energy saving alternatives. “Slightly shifting the acceleration/deceleration profiles of multiple machine axes so they overlap can make use of the returned energy from one to accelerate the other,” comments Hibbard.
Synchronous permanent magnet motors, which are common in servo applications, provide an energy consumption advantage over asynchronous induction motors in that no energy is consumed generating a field. Bosch Rexroth reports an increase in use of permanent magnet servos in areas where induction motors were the norm.