Through the ’90s and the past decade, PCs became indispensable to every business, and naturally, many people and vendors started looking at using them to control machines and processes on the factory floor. Now, some automation vendors and systems integrators are saying PCs can be used for machine and process control in an increasing number of applications. For example, in 2004, McCain Foods of New Brunswick implemented a PC-controlled refrigeration system in its new frozen foods plant in Maine to precisely control temperature and optimize energy consumption of multiple compressors. Systems integrator TechCold International, based in Keswick Ridge, N.B., wrote a sophisticated control system in a computer language easily processed by a PC but not by even a top-of-the-line PLC. The software also communicates with almost every PLC from every manufacturer on the market, and developing interfaces and drivers is relatively straightforward — not true for PLCs. Not only does the system reduce costs, energy consumption and greenhouse gas emissions, says TechCold president Ernie Adsett, it also can be duplicated in McCain’s other plants around the world. The project attracted a lot of attention in the automation world. In the ’90s, Siemens, a longtime player in the PLC and automation field, brought out “soft PLCs,” software that runs on a Windows PC and emulates sophisticated PLCs. Its Simatic line reduces control costs by 20 to 30 percent compared to traditional PLCs, says product manager Ehab Rofaiel. The idea of using a PC to drive automated systems was originally met with considerable skepticism. PCs, after all, crash, which could lead to production downtime and critical data loss. Siemens’ solution was its RTX real-time operating system, an OS that runs alongside Windows in the PC that keeps going even if Windows stops for some reason. Siemens has been demonstrating it in operation for years and is making headway in convincing the market that it’s viable. “Every month, we see more acceptance of PC-based controls in the market,” Rofaiel says. Some, however, maintain that PCs just aren’t cut out for real-time manufacturing automation control. Very early on, some manufacturers noticed PCs weren’t always performing as quickly or reliably as their old-fashioned PLCs. “Some customers who switched from PLCs to PC control have gone back to PLCs,” says Bill Black, controller product manager with GE Fanuc, a major supplier of PLCs. “They’ve found that it’s more difficult to get support for PC control.” One reason is that regular updates to the operating system or control software often requires updates to all the drivers. And costs of PLCs have fallen recently, as well. “Controllers have gotten more sophisticated, faster and able to handle larger programs today,” he says. Today, manufacturers who want to automate can choose between PLCs, PCs and a hybrid of the two to control processes and machines, monitor factory floors and ensure safety. But how do they choose? Strengths and weaknesses PLCs were developed specifically for the manufacturing plant: dedicated to a limited set of tasks, they’re rugged, resistant to the rigours of the factory floor, such as vibration, heat and dust. “PLCs are reliable. They do their job well,” TechCold’s Adsett says. A PLC’s main advantage, though, is not so much that it’s fast — today’s PCs have processing speeds that are orders of magnitude faster — but that its simple operating system (OS) means its main processing power is always available for the unit’s main task, explains Nicolas Arel, a systems integrator based in Montreal. Windows, the most popular PC operating system, demands priority on the central processing unit’s attention. In other words, if the machine that the computer  controls sends a signal at the same time that the OS sends a routine instruction to the CPU, the OS instruction will be processed first, forcing the machine’s signal to wait. If you’ve ever been frustrated by the hourglass symbol when you’re doing fairly simple work on your PC, imagine if that happens when a critical alarm signal from a manufacturing operation has to wait for the OS to refresh. Worse, conflicts for computer processing cycles from different processes can cause the computer to crash, which can halt production lines or critical operations and even put people at risk if the system is controlling a safety-related process. Because PLCs have been around for more than 40 years, their use is well known in manufacturing settings; programming them is relatively simple, and in most manufacturing plants, electricians know how to set them up and troubleshoot them. But their functions are limited, like their programming language. They can handle input and output, but complex tasks are difficult to program using ladder logic. Setting up different responses to a wide range of circumstances that might occur is far easier in one of the richer, more modern programming languages used in personal computers. Another limitation is that PLCs are proprietary systems; while manufacturers can choose from a wide range of suppliers, Allen-Bradley’s PLCs are not compatible with Omron’s or Siemens’. This limits the manufacturer’s choice and flexibility. The personal computer, however, is (if anything) flexible. A multi-purpose device, it’s well suited to handling a wide range of tasks and integrating data in a way that’s easy to understand. And while PLCs are well accepted and widely understood on the factory floor, PCs are equally well understood in the office. PCs are good at linking information from the factory to the front office. They’re often used for monitoring efficiency and displaying activity to management. Today’s PCs use very powerful computers with extremely high data speeds compared to PLCs. They can handle images at high speeds and can be made compatible with many other computers, networks and even PLCs. And because they’re so widely known, there are a lot of people available who know how to program them. But PCs are not typically rugged systems; they’re susceptible to heat, dust and vibration and have to be “hardened” or “ruggedized” for use on the factory floor. They’re also susceptible to computer viruses (something PLCs don’t have to worry about) and being hacked. And worst of all, they’re prone to crashing. This can lead to loss of data, which can be a huge problem and cause expensive delays when the PC is controlling critical manufacturing operations. “PLCs are good for interlocking operations, and fast decisions. They’re not so good with high-speed data collection or complex programs,” Adsett says. “PCs are better suited to monitoring, optimization and analysis — making sure you’re getting out of a process what you should be.” The hybrid approach However, PCs and PLCs are not an either-or choice. Almost every systems integrator advocates using them side by side. Even Simatic’s Rofaiel says PCs cannot completely replace PLCs. “PLCs are best suited, for example, in fault-tolerant applications, where you have two PLCs running side by side so that if one goes down, the second kicks in instantly,” he says. Systems integrator Arel says there is a place for both PLC and PC control systems. “The PLC’s computer power is not as good as a PC’s,” he says. “Their speed is limited.” He worked on an installation for a printing company that prints numbered lottery tickets. Quality control is essential, so the company needed a fast and precise way to track all production and any wasted paper or tickets due to paper breaks or other production problems. Managers also wanted to link all the different equipment for a real-time, accurate picture of productivity in their plant. “Printing goes at 1,000 feet per minute, and they want to take it up to 2,000 feet per minute,” he says. That means they need very fast data exchange between the plant floor and the front office systems. “The amount of data is humongous.” The solution was using PLCs on the equipment for tracking of lottery numbers, with a PC system on top of that for the data exchange and quality control applications. TechCold’s Adsett agrees with this hybrid approach. “When we go into a customer’s plant, we don’t say, ‘You have to replace all your PLCs with PCs.’ Instead, we add a layer of control on top of the PLC system.” PC in a PLC Luckily, manufacturers don’t really need to choose between PLCs and PCs anymore. “The evolution of the programmable automation controller (PAC) has removed the barriers between PCs and PLCs,” says GE Fanuc’s Black. PACs combine PCs and PLCs, adding the newest high-speed and flexible microprocessors to the rugged, reliable operation of PLCs and using newer, reliable, customized operating systems. Combining the two types of controllers means PACs are being used not only for process and machine control but also data acquisition, machine vision and remote monitoring. They can handle multiple communications protocols, including PC protocols from TCP/IP to OLE for process control (OPC), and PLC Fieldbus networks such as Profibus, RS-485 and others. They can also have USB ports and Ethernet connections. “PACs can use more sophisticated programming languages like structured text, which makes programming them for math functions more intuitive. And they can handle tasks that can’t be programmed with ladder logic,” Black adds. Simply put, choosing a side is not a necessity. With ever-evolving technologies and hybrid approaches, it’s just a matter of settling on an approach that fits the application. Scott Bury is a freelance writer based in Kanata, Ont.
Researchers from the Ishikawa Komuro Laboratory at the University of Tokyo presented the video of a high-speed robotic hand at the 2009 IEEE International Conference on Robotics and Automation. The laboratory's website has many more videos related to this project, called Sensor Fusion. PLAY High-Speed Robot Hand The video shows the manipulator dribbling a ping-pong ball, spinning a pen, throwing a ball, tying knots, grasping a grain of rice with tweezers, and tossing and catching a cellphone. "These videos show that high-speed sensor-motor fusion has great potential to produce new control strategy and new robotic skills," the narrator says.
Amber Hiuser was injured on the job while working for a manufacturing company three years ago. She recounted her traumatic experience recently at the 2009 Machine Safety Conference. Watch this video to hear her story.
Pistons and hydraulics systems lay at the heart of ceramic tile equipment in a process that has undergone huge changes from original operations a thousands years ago in the city of Foshan in Guangdong Province, China.Today, Trelleborg Sealing Solutions provides the seals for a large proportion of the ceramic presses built in China and supplies all of China’s main ceramic press manufacturers. The largest of these is Foshan Henglitai Machinery (HLT), which was established in 1957 and produced China’s first hydraulic ceramic press in 1988. The company currently has the largest market share and exports to numerous countries.Advanced technology, according to Trelleborg, ensure smooth, efficient operation for hours on end, all year round in machines that can measure up to 10 metres (or 33 feet) high and four metres (or 13 feet) wide, exerting a force of thousands of tons, as the tiles are mass produced. A powder consisting mainly of clay and feldspar is pressed into a mold using a piston. Then another piston pushes the tiles out of the mold and away for drying, glazing and firing in a kiln."Our seals are critical components for these machines," says Elton He, application engineer with Trelleborg in southern China. "We supply all the seals used in the cylinders, and since these provide the power used to press the tiles, they are of crucial importance to the functioning of these machines. Most of the cylinders move at a rate of about ten or 15 cycles per minute and the machines normally operate about 20 hours a day."They might only be shut down at the end of the year to perform maintenance, so these are very tough operating conditions."High-tech materials are crucial for the demanding conditions under which they must perform, an example would be HLT’s biggest ceramic press which exerts a maximum pressing force of 72,000 kN and contains between 100 and 150 Trelleborg Sealing Solutions seals, ranging in size from just 50 mm (or two inches) to 1.6 metres (or five feet, three inches). These include many high-performance Turcon-based PTFE seals – engineered thermoplastic compounds that offer low friction to reduce power loss and minimize wear over a long life. Orkot wear rings are also used, which are composite bearing materials that incorporate advanced polymer technologies. Trelleborg offers 100-plus seals can be divided into four basic types:• Piston seals, such as those installed on the groove of the pistons that press the actual tiles• Turcon seals, such as patented Glyd Ring T, Stepseal 2K and Excluder• Orkot and Turcite wear rings• Large-diameter O-Rings, which function as static seals on all the cylinders and flanges in the ceramic pressThe seals have to be durable to seal in the mineral oil-based hydraulic oil as well as strong, wear-resistant and capable of handling pressures up to 35 MPa / 5,075 psi and withstanding temperatures in the range of 60°C to 80°C.
Manufacturer G&W Products has found itself well positioned to weather the current economic storm, thanks to recent expansions in technology that increased capabilities while maximizing productivity. For the last five years, Lincoln Electric Automation has been a key partner in contributing to this effort.Despite the worldwide slowdown in manufacturing activity, the Fairfield, Ohio-based company is on track to achieve year-over-year growth between 2008 and 2009. Automated welding plays a big role in the company’s growth plan, says CEO Gary Johns."There is no question robotic integration has allowed G&W to be more competitive in the marketplace," Johns notes. "It has allowed us to swiftly complete medium-to-large-volume welding work. It also has allowed us to realize significant gains in the consistency and quality of overall productivity. Automation and other initiatives have allowed G&W’s business to grow approximately 35 percent over the last three years while maintaining nearly the same number of employees." G&W, which employs 120 workers on three shifts, offers a full range of fabrication services for such industries as material handling, military hardware, retail displays, power distribution and construction equipment.The company produces metal stampings and fabricated metal parts to customer prints and specifications. Its engineering department also works closely with customers to turn concepts into manufactured parts, and assemblies.In addition to MIG, TIG and spot welding, G&W provides a full range of manufacturing capabilities, including laser cutting, stamping, metal forming, tool and die manufacturing, and even powder coating. This gives customers a total solution of value-added production options in a competitive marketplace. These services take the concept of traditional job shop operations to a higher level.In the past four years, the use of robotic welding systems has become firmly integrated into the company’s list of well-established capabilities. At G&W Products, automation is not just a passing fancy; it’s now an important part of the company’s production process and a strong contributor to its competitive bottom line."There are many jobs we have quoted that are ideally suited for robotic welding and often it is an advantage when we are competing with companies without this capability," explains the company’s vice president of sales, Randy Sagraves. "More importantly, this technology has fit in well with our value-added operations. As customers come to us for welding requirements, they are introduced to many other areas that can add value to their purchase. Evidence to our success with robotic welding is introduction of four additional Lincoln systems in the past two years."Ahead of the curveG&W Products offers its customers more than 2,500 available welding hours each week in MIG, TIG and spot welding in both stationary and portable environments. Five Lincoln Electric robotic welding systems help the company keep pace with higher volume MIG welding demands, particularly in light of the well-documented shortage of skilled welders in the United States.Reports from the American Welding Society (AWS) say this shortage, combined with the drive for higher productivity and reduced costs, will continue to boost the popularity of automated welding systems on shop floors. In fact, the market for welding robots is growing at a higher rate than any other industrial market. The industrial sector, as a whole, boasts sales of more than 15,000 robots a year, including welding robots. A report released in June 2008 from the International Federation of Robotics notes the supply of robotic welding systems in use in both North and South America increased 42 percent over the previous year. That’s not to say manual welding performed by the G&W’s highly skilled team of 20 welders doesn’t have its place in the company’s production process. The size of a job plays a determining role, allowing the company to employ the substantial skills of its manual welding team more efficiently – where they are most needed."Most items we are welding robotically can be manually welded, as well. The factors driving us to robotic welding are related to cost and capacity, rather than capability," Sagraves says. "Volume is the most important variable in determining a fit for robotics. With some parts, we make several hundred pieces of a particular item each month, so it makes sense to robotically weld it. This allows us to be cost effective by spreading the cost of the equipment and the fixturing over the cost of the job and while involving our highly skilled welders with jobs of varying volumes or items that are too large or complex for the robotic cells."Integrated systemThe robotic welding area at G&W features three System 50HP Dual Headstock Robot Cells, a System RCT TurnTable Robot Cell and a System 40 TurnTable Robot Cell, all from Lincoln Electric Automation. The company produces more than 20,000 parts on its robotic systems each month, some of which can be welded six times faster than they could be welded manually."Our robotic line handles MIG welding of aluminum parts, high-tensile-strength steel and weldment geometries that require creative fixturing," says Doug Keehn, G&W’s director of advanced manufacturing. "Once the fixture is proven out and the programming is completed to meet these challenges, the production and quality are quite consistent."Pre-engineered, the System 50HP units are dual-headstock workstations designed for medium-sized parts that can be welded using the flexibility of reorientation – something that fits well with G&W customers’ varied parts orders, which can include structural, plate, tubing, sheet metal extrusions and even special shapes."These cells can handle our larger, more complex parts," Keehn explains. "Its rotary design also helps us more effectively process aluminum parts."The System 40 TurnTable Robot Cell, another pre-engineered solution, provides short delivery times and reduced variable costs to enhance standard parts production. Its indexing, two-position turntable workstation works well with G&W’s small- to medium-sized parts that can be welded without re-orientation. For higher volume jobs involving medium-sized production parts, programmers at G&W rely upon Lincoln’s System RCT, a flexible turntable robotic welding and cutting workcell. This unit features a patented, center-mounted positioner design that maximizes the robot work envelope by bringing it closer to the workpiece."Both of these units are versatile and can handle some of the simpler parts we have at a higher volume, delivering increased cost effectiveness," Keehn says.All of the robotic systems, which are equipped with fume exhaust hoods and Fanuc Robotics® arms, deliver superior weld quality and consistency, a plus in medium-to-large volume parts production. The other most notable benefits come in setup and programming, particularly if the weld isn’t too complex, Keehn points out."If a part requires only a few welds, we can get sets of eight to 10 parts completed in two minutes," he says. "What’s more, every robotic cell has two stations. While one station is welding, we can load the other side with the same part, or a completely different part, provided the filler metal and gas are the same. This allows nearly uninterrupted production."Programmers behind the productionThe fixturing of the robotic systems are critical to the success of each product. They must be accurately designed and programmed to hold critical tolerances; easy to load and unload; designed to hold as many parts as possible; and robust enough to withstand the rigors of consistent use. G&W management relies on its team of specially trained programmers to oversee this crucial element of its robotic operations.Some members include journeyman welders, while others on the team are experts in automation and know how to run the equipment and program it for maximum weld quality, consistency and speed. Those who were not welders by trade have received welding training so that they can know how to recognize good weld penetration and quality. Two senior operators oversee the operation and programming of all the cells, but all of those on the robotics team have been trained in the proper operation of the units. All operators attend Lincoln’s Welding School, and the senior operators have also attended Lincoln’s Advanced Training program. The team also participates in regular internal training sessions on welding and weld inspection.""Our programmers’ backgrounds are varied. When we identify who is best suited to run the robots, we realize they might require additional welding training, or they might need training on the equipment and how to run it," Keehn says. "It requires both skills. You don’t necessarily need to have a welding background, but you do need to have a strong knowledge of good welding and programming and know how to manage those cells to deliver a superior quality weld. We’re not just welding sheet metal. Our work involves many different aspects of welding."This move towards automation was driven by the desire for higher volume weldments and also the desire to increase value-added capabilities as a competitive advantage, Sagraves notes. He stresses that robotics isn’t just for large fabricators. Making the move to robotics has helped reshape and strengthen G&W Products’ business, despite the challenges of a struggling economy. Johns says he believes adding robotic welding to the shop’s service offerings was one of the best strategic moves the company management has made. He says they only wish they had integrated them sooner."Integrating automation into our operations reflects our company’s overall direction and growth plans," Johns says. "Efficiency is an overall theme. We’re looking to become leaner, more flexible and more competitive. Robotic welding fits perfectly into this plan. Robotics is more than a fad in this industry. It’s an ingredient to a plan to stand above the competition."www.gandwproductsinc.comwww.lincolnelectric.ca
Jägermeister has, behind its modern image, a very long and traditional history. The company Mast-Jägermeister AG has been producing its signature alcoholic beverage since 1935, and it is enjoyed in more than 80 countries around the world.The drink is made from a total of 56 herbs, blos soms and roots and has always been produced and bottled in Wolfenbüttel, Germany. More recently, Mast-Jägermeister AG opened production sites in Kamenz, and Wittmar, near Wolfen­büttel. The company says that its continuously rising sales figures prove that Jägermeister is a market success with more than 81 million bottles being filled in 2007 alone."Quality is one of the key factors to the brand's success. "Quality assurance is an extremely important subject in the Jägermeister production," explains Jens Rießen, head of the Kamenz plant. "Due to our strong brand reputation, we are committed to making sure that our customers will always get the very best quality." At the Kamenz site in Saxony, over 20 million litres of Jägermeister is bottled per year – and since this modern facility commenced production, the company has been relying on checkweighers from Mettler Toledo Garvens.Mettler Toledo Garvens supplied the "dynamic" weighing technology for "completeness" checking in the end-of-line packaging process where the weight of cartons filled with either "1 litre" or "0.04 litre" bottles is verified. This ensures that incomplete cartons or those containing bottles with too little content are detected and rejected, preventing them from leaving the factory. Moreover, the weight check ensures that damaged bottles with leaks are immediately detected."Garvens checkweighers can be integrated in near to every production line as their design can be easily adapted to the given technical requirements of any production line. An example of this is where two weighing terminals of two separate E Series checkweighers, integrated into different production lines, were installed side by side, allowing for easy operation of both checkweighers from one position. This solution, according to the company, was appreciated by the staff operating the Jägermeister production lines.An XE3 checkweigher weighing 60 cartons per minute is also in use. In this application, the XE3 can weigh products up to 6,000 grams with an accuracy within one gram. The XE3 automatically rejects underweight cartons by means of a pusher, enabling the line staff to check the carton and replace bottles where necessary. This method ensures that only full bottles reach the end consumers. ca.mt.com
Whether running a small operation lights out to keep costs down or operating a large corporation that produces custom products, manufacturing already runs on tight profit margins and have narrow margins for error. When a process is implemented, it is done with care and precision; that line must run with a minimum of input and maintenance, and certainly no unexpected surprises. After the considerable engineering it takes to link together machinery, conveyors and stations, it is expected (and rightly so) that everything will simply hum along.Meanwhile in the front office, new clients are sought and landed, and new business is solicited from existing clients. Either one likely means a new process or production runs. The orders make their way over to the engineers, who then must work within slim budgets to add in or change existing lines. With traditional conveyors, this can mean extensive downtime as the new equipment is installed and lines rearranged. Where it can break down is in taking apart and reconfiguring conveyors; for the most part, they never go back together the same way again, necessitating the ordering of whole new systems. Although it appears that the conveyor industry has solved most integration issues and addressed the issue of inflexible systems that are costly to alter, most conveyors touted as "modular" have not technologically advanced to current industry needs.Taking an analogy, if someone owns a "modular" home and decides a few months or even a year down the road that they want the bathroom on the other side of the house, or want to expand the kitchen, they can’t just snap in a module and rearrange their home. In a similar way, most conveyor systems that are labeled "modular" require some type of extensive construction or deconstruction that can entail cutting and welding–and what’s to be done with parts that are cut away? They simply become very expensive waste as they cannot be used again. This is even true when only small changes are made, such as adding a corner or changing an angle.Even the smallest task of cleaning a belt, let alone removing, changing or altering belts can also be a major issue. Even today, most belts are normally made in fixed lengths, and if they must be changed in any way, "fixes" must be arrived at with which sections of belt can be fitted together in such a way that the line can continue to run. It’s either that or ordering a whole new belt; obviously not a cost-effective solution.In industries such as pharmaceuticals, in which processes must be maintained at a certain level of cleanliness, ease of manipulating conveying systems is also a serious issue. In cases in which areas can’t be easily reached for cleaning, belts must be removed or other parts must be taken off." If conveyors are not specifically built to accommodate these measures, it is a labor-intensive activity when it comes to putting it all back together again; the few dollars saved on initial cost is lost on backend maintenance.An Adaptable "Snap in Place" ApproachHenry Tamangi, Maintenance Manager, with Comar Inc., a company that manufactures packaging and liquid dispensing solutions for the pharmaceutical industry, has found a reconfigurable modular conveyor system that opens up whole new vistas in "changing on the fly." Because The product line Comar produces is so diverse, those new processes being ordered by the front office are not such problems after all.Comar’s processes consist of three departments: blow molding, injection molding and a secondary operations department that performs offset printing, hot stamping, silk screening and assembly of all molded components. The parts are molded, go through finishing in secondary operations and are then shipped out. Comar integrates their processes and departments using DynaCon reconfigurable conveyor systems, produced by Dynamic Conveyor Corporation of Muskegon, Mich. "What is so nice about them is that they are modular," Tamangi said. "You can take them apart shorten them, lengthen them, change the angles, or change the drive motors to be constant speed or variable speed. You can change the configuration of them quite easily."Reconfigurable modular conveyors are used to connect different machines. For example, if a molding machine is connected to a printing machine, the conveyor is used to connect the two so there is an inline process; parts do not need to be placed in a box and physically moved. In two different applications, a molding machine, an offset printer, an assembly machine and a wrapper have all been linked. Tamangi estimates there are 50 reconfigurable conveyor systems throughout his facility. "We’ve tried other conveyers that were touted as similar, but I wouldn’t say that they are modular like the DynaCons. We have so many because we have good success with them," he says.Because these systems are specifically made to be pulled apart and reassembled as needed, maintenance is quite easy. "Because we serve the pharmaceutical industry, the systems have to be cleaned and doing that with the DynaCon system is very easy," Tamangi said. "We just clean them from time to time when needed." We can pull the conveyors apart, take the belts outside, and power wash them. Each conveyor gets power washed once or twice a month, depending on the job."Although they are dreaded, malfunctions do occur in from time-to-time in every manufacturing process. Recently, Comar experienced a substantial water leak on a 550-ton press and had to roll the conveyor out. But because the conveyor system was so easily removed and put back in place, the event was much less dramatic than it might have been. "Because it was a DynaCon conveyor, the cleaning time was cut at least in half," Tamangi reported. "We just rolled it away from the press" power washed, cleaned, and sanitized the entire conveyor and put it back in service. With metal conveyors you really can’t power wash them down, so a lot of hand wiping would take place; a lot of elbow grease."Another company in a similar industry utilizing the same conveyor technology had an instance of having to move an entire process to a different floor. The process utilized three conveyors, but once it was moved to its new location and rearranged for the new work area, the flow had been reduced to two conveyors and there were considerable leftover parts. With traditional conveyor technology, those parts would have gone to waste, but because of the versatile nature of these conveyors the parts were able to be re-utilized for an entire new system in another area of the plant.Versatility of BeltsThis same company had a problem with belts on previous systems, specifically with diagonal vulcanized seams that were damaged or came loose, causing the belt to come apart. Attempts to repair the belts created seams causing uneven product flow, pinching and part damage. "DynaCon systems utilize interlocking belt systems that are formed in links allowing the belt to be taken apart and reassembled easily, every inch. Maintenance and repair are never a problem. Ideal for Today’s OperationsSuch conveyor systems are ideal for operations with frequent layout changes or those who need to quickly change process lines, but also ideal for operations that are competing with larger corporations with greater budgets. For example, Air Support Medical Company, manufacturer of parts for anesthetic and respiratory circuits, wanted the ability to run their molding machines 24X7, but that was challenge for the small corporation. "To do that would we would have needed two operators on at night, but then you need to have supervisors and it gets to be financially difficult." said Kathy Walters, Air Support Medical Company’s owner. The solution has been to evolve lights-out operations at night, using a simple video surveillance system, similar to one used in a convenience store, and the internet to monitor the molding machines. However, before discovering the DynaCon modular conveyor system, the company’s ability was limited. "Sometimes if we had small parts, we might run it in a Gaylord, but it had to be something that wouldn’t make a lot of parts because we couldn’t get it away from the machine fast enough. The DynaCon gave us the ability to run a lot of the parts and be able to control the flow of parts that came off of it," said Walters. Being able to quickly set up and reconfigure conveyor systems has been a major source of help for them. "We just bought our fifth conveyor system," said Walters. "The flexibility is great; you can move them around, or you can add parts to go higher or remove them if you need a lower conveyor. They give us the cost-effective ability to run and control the flow of the parts during lights-out operations."Their formula has worked; in a declining economy, they are expanding and having to hire additional personnel. To remain competitive in today’s tough markets, manufacturers should take every measure possible to ensure they can replace, change or add new processes "on the fly" with technologies such as reconfigurable modular conveyor systems.Bruce Boyers is a freelance writer based in Glendale, Calif.
Leading technology providers offer insights into how modern tools are making machines safer. Machine safety standards are also discussed.
This online version has been modified from the print version to include a solution to harmful VFD currents: the shaft grounding ring.With the rising cost of energy, the use of variable frequency drives (VFDs) is growing. By optimizing the frequency of a three-phase alternating-current (AC) induction motor's voltage supply, a VFD controls the motor's speed and torque, while providing energy savings. These savings can be quite substantial - 20 percent or more - making VFDs a "green" solution as well as a wise money-saving investment.To be truly "green," however, a technology must be sustainable as well as energy efficient. Yet the currents induced on motor shafts by VFDs can wreak havoc with motor bearings, dramatically shortening motor life and severely diminishing the reliability of systems. To mitigate these currents and realize the full potential of VFDs, a cost-effective method of shaft grounding is essential.Whether used to save energy or increase the accuracy of process control, VFDs only achieve their full potential when carefully matched to the application and installed with appropriate safeguards. Safeguards will eliminate the need for expensive repairs and enable VFDs to fulfill their promise of energy and cost savings.Energy-saving potentialIn today's typical VFD, a rectifier converts the AC utility feed to direct current (DC), a filter smoothes the current's waveform and then a pulse-width modulation (PWM) inverter turns it back to AC in variable form using insulated gate bipolar transistors (IGBTs). Typical output frequency is two to 12 kHz, or 2,000 to 12,000 on/off cycles per second. VFDs may be used to directly drive one or more motors in constant-torque applications, to ensure that they do not use any more power than necessary. With encoder feedback, a VFD can also be used to control the speed of a motor by modulating the voltage and frequency of power to the motor according to programmed parameters. In the field of flow control, the potential for increased efficiency with VFDs is especially dramatic. Many centrifugal fans and pumps run continuously, but often at reduced loads. Because the energy consumption of such devices correlates to their flow rate cubed, the motors that drive them will use less power if controlled by a VFD. In fact, if a fan's speed is reduced by half, the horsepower needed to run it drops by a factor of eight. With rising energy costs, restricting the work of a motor running at full speed through the use of dampers and other throttling mechanisms seems needlessly wasteful.In constant-torque applications where the main objective is more accurate process control, a VFD can be programmed to prevent the motor from exceeding a specific torque limit. This protects the motor, and in some cases associated machinery and products, from stress and damage. If a machine jams, for instance, the motor that powers it will, without the moderating influence of a VFD, draw excessive current until its overload device shuts it down.Regardless of the application, the VFD must be compatible, not only with the motor, but also with every other system component. Potential problemsBecause the waveform from a VFD is generated by pulse-width-modulated switching, it has high-frequency components that are capacitively induced onto the motor shaft and discharged through the bearings. These are not pure sine waves; they contain high-frequency currents and voltages called harmonic content, the potential effects of which are many. And even when the motor is designed for inverters, it is vulnerable to bearing failure from VFD-induced currents.Motor shaft currents induced by VFDs can damage motor bearings. Although best addressed in the design stage of a system, these currents can usually be mitigated by retrofitting previously installed motors. Without some form of mitigation, shaft currents discharge to ground through bearings, causing pitting, fusion craters and "fluting." This unwanted electrical discharge machining (EDM) leads to excessive bearing noise, premature bearing failure and subsequent motor failure.Motors are never fully compatible with the VFDs that drive them unless these shaft currents are addressed and mitigated. Various other negative effects can also manifest themselves if the driven motor is not designed for use with a VFD, or if either the motor or the VFD is not rated properly for the application or the load. For example, when required to maintain a constant torque, a motor tends to lose some efficiency, running hotter at lower speeds but hotter still when controlled by a VFD. If such a motor must be operated at less than 30 percent of its maximum speed, it may need extra cooling or thermal protection. Similarly, a VFD-controlled motor's capability to produce torque drops more quickly at lower motor speeds than a motor using pure sine wave power. For constant-torque loads, a VFD should be rated for 60 seconds at 150 percent of the load. A VFD's current rating also limits the load-acceleration rate.Another rule of thumb is that the cable connecting a VFD with a motor should not be more than 50 feet long, or else two different wave types could meet at the motor terminals and in effect double the voltage received by the motor. If a longer cable is required, extra line filtering is recommended to protect the motor and other sensitive equipment nearby from harmonic content and radio frequency interference (RFI). RFI can also be reduced by enclosing motor leads in a rigid conduit. Regardless of its length, the cable between a VFD and the motor or motors it regulates can be enclosed in a corrugated aluminum sheath or another kind of grounded, low-impedance shielding.VFDs may also not be appropriate for systems that must maintain high pressure. During periods of low flow, a VFD-controlled pump motor may not be able to slow down enough without reducing pressure. For systems that require dynamic braking, VFDs are available with an optional power load resistor that can shunt excess energy from the DC bus.A closer look at bearing damageEvery VFD-controlled AC motor develops a parasitic capacitance between the stator and rotor. Short of dismantling the motor, there are two main ways to check for bearing damage from induced shaft currents - by measuring vibration and voltage. Both are best used to establish a baseline early on, so that trends can be monitored later. Neither method is foolproof.By the time vibration tests confirm bearing damage by identifying particular energy spikes in the range of two to four kHz, the damage has usually reached the "fluting" stage. Likewise, the main benefit of voltage tests may be the relief they provide when the results indicate no bearing damage. If a baseline voltage measurement is taken right after a VFD has been installed, successive tests may provide early warning of harmful current loops, but there are many variables. Induced shaft currents can be measured by touching an oscilloscope probe to the shaft while the motor is running. These voltages repeatedly build up on the rotor to a certain threshold, then discharge in short bursts along the path of least resistance, which all too often runs through the motor's bearings to the frame (ground). Serious bearing damage is thought to be more likely in systems that operate with high carrier frequencies, a constant speed or inadequate grounding.A high carrier frequency means a high discharge rate. For this reason, it is advisable to purchase a VFD that permits fine tuning of the carrier frequency in increments no larger than one kHz. There is no doubt that inadequate grounding significantly increases the possibility of electrical bearing damage in VFD-driven motors. Without proper grounding, VFD-induced electrical discharges can quickly scar the race wall. During virtually every VFD cycle, these induced currents discharge from the motor shaft to the frame via the bearings, leaving small fusion craters in ball bearings and the bearing race wall. These discharges are so frequent that before long the entire bearing race becomes riddled with pits known as frosting. The damage eventually leads to noisy bearings, but by the time such noise is noticeable, bearing failure is often imminent. Since many of today's motors have sealed bearings to keep out dirt and other contaminants, electrical damage has become the most common cause of bearing failure in VFD-controlled AC motors.Mitigating bearing damageElectrical damage to AC motor bearings often begins at startup and grows progressively worse. As a result of this damage, the bearings eventually fail. To guard against such damage and thus extend motor life, the induced current must be diverted from the bearings by means of mitigation technologies, such as insulation, shielding and/or an alternate path to ground. Insulating motor bearings is a partial solution that more often than not shifts the problem elsewhere. Blocked by insulation, shaft current seeks another path to ground. Attached equipment, such as a pump, often provides this path and it frequently winds up with bearing damage of its own. In addition to being expensive, insulation is subject to contamination. Worse yet, some types of insulation can be totally self-defeating. In certain circumstances, the insulating layer has a capacitive effect on high-frequency VFD-induced currents, allowing them to pass right through to the bearings it was supposed to protect.A Faraday shield can be created by installing grounded conductive material, such as copper foil or paint, between the stator and rotor. If built to the proper specifications for the motor, this can block most of the harmful currents that jump across the motor's air gap. However, this mitigating measure is often expensive and difficult to implement, and attached equipment could still be vulnerable to deflected currents.Likewise, nonconductive ceramic ball bearings divert currents from the main motor's bearings but leave attached equipment open to damage of its own. Ceramic bearings can be costly and usually must be resized to handle mechanical static and dynamic loadings.Yet another mitigation attempt comes in the form of conductive grease, which, in theory, bleeds off harmful currents by providing a lower-impedance path through the bearings. In practice, however, the conductive particles in the grease increase mechanical wear.Metal grounding brushes certainly help. They contact the motor shaft to provide alternate paths to ground. Unfortunately, they also wear out and corrode, thus requiring regular maintenance.Alternate discharge paths to ground, when properly implemented, are preferable to insulation because they neutralize shaft current. Techniques range in cost and sometimes can only be applied selectively, depending on motor size or application. The ideal solution would provide an effective, low-cost, very-low-resistance path from shaft to frame, and could be broadly applied across all VFD/AC motor applications, affording the greatest degree of bearing protection and maximum return on investment.Avoid damage with a shaft grounding ringA shaft grounding ring (SGR), such as the AEGIS SGR from Electro Static Technology (www.est-aegis.com), meets all these criteria–the company's patent-pending Electron Transport Technology uses the principles of ionization to boost the electron-transfer rate and promote extremely efficient discharge of the high-frequency shaft currents induced by VFDs. Without some form of mitigation, VFD-induced shaft currents can cause considerable motor/bearing damage.It's scalable to any NEMA or IEC motor regardless of shaft size, horsepower or application. The company says these grounding rings have been successfully applied to power generators, gas turbines, AC traction and break motors, cleanrooms, HVAC systems and a long list of other industrial and commercial applications.For VFD-equipped motors of less than 100 HP (75 kW) with shaft diameters of less than two inches (50 mm), a single SGR on the drive end of the motor shaft is typically sufficient to divert harmful shaft currents.Large AC motors (100 HP/75 kW or more) and even large DC motors, especially those with shaft diameters of more than two inches (50 mm), are more likely to have high-frequency circulating currents (as well as EDM-type discharges) that can damage bearings. Motors with roller bearings are also more vulnerable to damaging circulating currents because roller bearings have a greater surface area and their lubricant layer is usually thinner. Such motors benefit from the combination of an shaft grounding ring on the drive end and insulation on the non-drive end to break the circulating current path." This may also be the solution in situations where installing an SGR on the non-drive end would be impractical because of encoders, fans, or other special circumstances. For most large motors, the best bearing protection may be obtained by installing an SGR on the drive end of the shaft and insulation on the non-drive end.This is also a common solution for motors above 500 HP (375 kW), and most manufacturers already take this approach." However, when insulation on the drive end is not designed into the motor or cannot be easily installed, two SGRs are recommended – one on the drive end (DE) and one on the non-drive end (NDE).In critical applications where motors with two ceramic bearings are specified, at least one SGR should be used to ensure that shaft voltage does not pass down the line to attached equipment such as gearboxes, pumps, encoders, pillow block bearings or break motors.The AEGIS SGR is available in two versions–a continuous ring for most NEMA- and IEC-frame motors and a split-ring design, which allows installation in the field, around larger shafts, without the need to disassemble attached equipment.Adam Willwerth is the development manager for Electro Static Technology.
Like many manufacturers, S&C Electric Canada is looking for ways to tighten its belt during the economic downturn.
PLC-based control systems are enabling engineers, production managers and skilled labour to produce higher quality products in less time with fewer resources. This benefits those producing durable goods who are hardest pressed to streamline production while expanding product line depth. Nordson Corporation, an international producer of precision dispensing equipment that applies adhesives, sealants and coatings to a broad range of consumer and industrial products, saw huge benefits when it implemented a PLC-based control system."With advanced controls, we've developed the Prodigy HDLV Color-On-Demand system, a powder coating product that changes colours in just 18 seconds," says Nordson's senior project engineer, Jim Khoury. "That's several times faster than manual change out. Another major development [is] we've eliminated operator error arising from improperly cleaning those lines during a colour switch, leading to higher quality products."A manual colour change can cause specks of the old colour in the newly applied colour if lines are improperly purged between colour changes. The Ohio-based company developed a control system that rapidly changes between 28 colours while eliminating cross-contamination of coloured powder through a sophisticated purge cycle. Nordson's Prodigy HDLV (high-density powder, low-velocity air) Color-on-Demand powder spray system then electrostatically applies coloured powder faster, with high-efficiency coverage in typically difficult-to-coat areas."The genesis was the need to shorten line gaps necessary for changing colours, which helps increase productivity," explains Khoury. "The number of colours used for everyday products is dramatically expanding. Customers are running single part, part family, customer order scheduling - a Lean manufacturing philosophy. Here, the painting operation is typically the bottleneck."Breaking the bottleneck Nordson based the Prodigy HDLV's Color-On-Demand control system on a WAGO Ethernet Programmable Fieldbus Controller (PFC) and WAGO digital input and output modules. The system utilizes Ethernet MODBUS TCP communications between controller and HMI touch screen, which has a colour display and a user-configurable interface. The HMI resides in front of the spray operator, tracking and displaying key process data.Items bearing material ID tags are conveyed to an end-user equipped with a manual spray gun. The control system automatically selects one of 28 colours from a code embedded on the item's tag. Users can also manually select colour via HMI. For example, if a product line, such as oven doors, requires different colours, the system will change out colours in approximately 18 seconds - a significant improvement over the two to three minutes (depending on operator skill) it previously took to manually switch colours.The touch-screen also plays a vital role in product quality and waste elimination.Patented rubber pinch valves accommodate high flow rate requirements while being easy to clean. Valve and seal rubber is a commodity item with a finite number of uses; degraded rubber valves can mix powders in the machine. Understandably, even a small amount of mixed powders is unacceptable for the quality levels required by some users. In the past, monitoring the service life of rubber bladders and seals had been difficult - replacement relied on a user's own tracking system. Solving this mandated integration of a life cycle counter into the machine's WAGO PFC. The cycle counter tracks rubber life cycle and usage, notifying the system head (the HMI displays a warning) when a replacement valve or seal is needed. This ensures high product quality and consistency while eliminating costs associated with waste and refinishing.As the earliest Prodigy HDLV models were installed, Nordson identified a few opportunities to improve performance. In addition to optimizing quality assurance testing procedures (uniform observation of LED blink codes and ensuring both Ethernet connectivity and proper machine sequencing) and improving wiring documentation, Nordson replaced the touchscreen to eliminate an emerging electromagnetic discharge issue."The powder is electrically charged to tens of thousands of volts," Khoury explains. "As you can imagine, most off-the-shelf equipment isn't particularly well-suited to that environment."In addition to reducing colour change times by nearly 90 percent, the controls also eliminated a previously substantial area of opportunity for human error - improperly cleaned colour lines. As with degraded seals, improperly cleaned and/or switched valves and lines mix coloured powders (e.g. white powder particles from the previous colour combine with the new black powder, resulting in salt-and-pepper sheet metal and costly scrap)."The goal was quickly purging the old colour and loading a new colour in the system without cross-contamination," Khoury says. "If a quick colour change system does not properly clean the powder delivery lines, thousands of dollars of scrap and rework will be created."Thus, Nordson's challenge became programming the proper system purge cycle to clean the entire colour feed line from powder hopper to manual spray gun (which features continuous or pulse purge). This was particularly daunting, since the Prodigy HDLV can accommodate 28 colours. The additional colours provide just-in-time manufacturing for zero inventory, improved efficiency and higher throughput than previous machines."We knew there would be a problem with establishing a standard time sequence for cleaning all powders and system configurations; some powders are more difficult to clean than others," Khoury explains. "Also, the length of the system delivery lines can impact cleaning. Nordson engineering developed the hardware and software that allows the purge timing sequence to be configurable based on the customer installation. Just supporting the large number of colours makes the system complex, mandating custom diagnostic screens so individual valves can be tested."As engineers grappled with programming the purge cycle parameters, they built upon the pinch valve technology used in the product's pump and adapted it to a manifold responsible for powder flow."We developed a custom pneumatic manifold to pressurize and expand the valve bladders, which pinch off powder flow passages in the custom quick-change powder manifold," Khoury says. "When the air pressure is removed, the pinch valve's bladder collapses, allowing the system to control the powder flow paths."With initial Prodigy HDLV deliveries, engineers closely observed performance and how the purge cycle faired. The Prodigy is equipped with 32 valves, and engineers believed increased functionality for valve timing would maximize purge efficiency, ensuring all lines would be perfectly purged every time."We learned from an early install that we needed to incorporate variable timing into the Prodigy to accommodate more purge cycles and different line lengths," explains Khoury.As part of the controls design, Nordson engineers selected the WAGO PFC because it could also support ancillary components such as the iControl and Prodigy Automatic Powder Spray systems, as well as the gun movers and part identification systems.Lean methods fatten profits Nordson estimates the control system and machine provide up to 35 percent increased efficiency on 90 percent of powders sprayed. Additionally, faster colour change capability allows same-day coating and shipping for approximately 80 percent of received parts.The controls behind Prodigy HDLV enabled Nordson to create an effective workaround, allowing users to efficiently produce several variants within one product line. Khoury revealed Nordson is going one step further by developing a fully automatic Color-on-Demand System that includes the control of gun movement."We are actively developing an automatic version that automatically articulates the spray guns (they move in/out, up/down)," Khoury explains. "This is intended for higher-volume applications, such as coating outside furniture, barbecues or anything requiring high-temperature powder paint. The auto system provides faster throughput."Among system details Khoury shared, the WAGO-based control system will be adapted from the Prodigy Color-On-Demand system and evolved to supervise the automatic control system, including the articulating guns. For instance, there are X and Y mechanisms responsible for moving the guns up/down and in/out to properly coat large quantities of metal."The human factor with the manual Prodigy HDLV can provide that special quality," he says. "The automatic version, on the other hand, is being developed for manufacturers with production scales calling for a higher-capacity system."Regardless of Prodigy variant chosen, Khoury maintains that substantially improved throughput and quality will allow users to embrace Lean principles such as just-in-time production."The old way of coating was not economical," he says. "If you had a 25- or 30-foot long spray booth that's 10 feet tall, you'd spend hours blowing it out, collecting waste powder for use in non-colour sensitive products. Then you'd have to clean out the booth, wipe out and ensure every speck of black powder was out before switching colours. This is just the booth, then there's line prep. Imagine powder-coating 1,000 black barbecue grills, then prepping the room for a run of 1,000 white, 1,000 red and 1,000 grey grills."In addition to labour savings and eliminated rework and scrap, Khoury points to the Prodigy's ability to save the actual coloured powder used to coat metal, effectively lowering material costs."There's also powder transfer efficiency," he explains. "The Prodigy spray gun uses a lower velocity spray, allowing paint particles to collect during dispersal and more effectively coat metal. The metal enjoys a higher-quality coat, while operators save on powder costs because there is 10 percent less wasted powder." Mark DeCramer is the WAGO-I/O-SYSTEM product manager for WAGO Corporation. Contact Mark at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or 1-800-DIN-RAIL.
This year, with all of the economic challenges facing manufacturers, staying competitive is going to require cost reductions, increased productivity and efficiencies, innovation and the quick adoption of new technologies to help achieve these goals. What tools do you need to survive this challenging environment? We asked five industry experts to name the top five technologies and trends that will impact Canadian manufacturers in 2009 and beyond. Thank you to Jim Pinto, Sherman Lang, Sal Spada, Sivakali Prasad Dasari and Michel Ruel for sharing their thoughts and expertise.
Introducing a new robotics system in any manufacturing environment automatically places the robot at risk. Protecting the machine’s sensitive components from the work environment becomes a priority. But if you work in the food sector, you have an additional responsibility: just as the food mustn’t harm the robot, the robot mustn’t introduce contaminants into the food.Sanitation is everything, so the robot must be able to withstand daily high-pressure wash downs with hot water and sanitizers. It must be rustproof for protection from corrosive cleaning chemicals. The electronics box of the robot, and wherever possible its arm, must be covered during wash-downs.These are the relatively straightforward challenges of an industry that is otherwise, thanks to technology that can increasingly handle food directly, a rapidly growing market for robotics.What lies beneathAn investigation into the listeria outbreak at Maple Leaf Foods in Toronto that killed 20 people in the summer of 2008 concluded that the bacterium likely originated from deep within the inner workings of a robotic meat-slicing machine. But the machine was not to blame, says its manufacturer. The nearly 300 Formax S-180 meat slicing machines at processing plants around the world have produced an estimated 2.3 billion kilograms of sliced meat for 13 years without incident, a spokesman for Formax said in a press release.Officials found the listeria only when they disassembled the meat slicer. The company had exceeded Formax’s sanitization instructions, but had not regularly dismantled the machine, a "very significant mechanical process." Since the investigation, Maple Leaf will now disassemble its 14 Formax S-180 meat slicers every week for cleaning, but might have to replace the equipment if that process proves impractical.Food contamination starts with a particle of something – meat, a human hair – that might, under certain conditions, harbour the formation of bacteria. Depending on factors such as temperature, humidity and how long before someone washes that microscopic particle away, it can grow and spread. In worst-case scenarios, the mass production or processing of food causes the contaminant to be folded or distributed into food on a grand scale.Food particles don’t stay fresh for long. Gauri Mittal, an engineering professor at the University of Guelph who has done research related to food safety, says there are more pathogens [disease-producing agents such as viruses or bacteria] in a person’s kitchen than in the bathroom. "Sometimes we do get microorganisms, and we don’t get sick," says Mittal. "But if there is a high concentration of them, or if our immune systems are weak, they can kill us."He says one drop of milk contains up to 4,000 microorganisms, and one glass of milk contains millions. "We get them every day, but when you get more that are pathogenic, there may be a risk. If there’s moisture, pathogens can linger for a long time. If they’re around for a long time, some pathogens become spores that have defence mechanisms and can survive for years. Under the right conditions, they can germinate and start to reproduce."If you’re automating your food plant, the good news is that machines tend to be cleaner than people. Dick Motley of FANUC Robotics America, Inc. recalls that when an e-coli outbreak in a U.S. fast food chain in the '90s made a lot of people sick, experts were certain that only a human being could have caused such a high incidence of the bacteria."There is no absolute control over accidental contamination by an employee," he says.Now we’re cookin’Food processors have a responsibility to regularly inspect and clean their machines, but it’s up to the robot’s manufacturer to make that process as foolproof as possible. Besides wanting details of the design, exterior, shape and form, Motley says, "the USDA (United States Department of Agriculture) had a couple of key concepts that they really kept after us on: inspectability and cleanability." Those concepts, he says, went right into the design of FANUC’s new LR Mate 200iC Food Option robot and its M-430iA/2F Food Robot. FANUC has been in the palletizing business for decades, but has moved more into the upstream applications thanks to technological advances that make higher speed applications possible.The intelligent LR Mate 200iC series of mini robots is designed to handle products in various industries and working environments, including food. It has no area where food particles can be trapped. A special coating can handle wipe-down and low-pressure rinsing and sanitizers.Similarly, the FANUC M-430iA is capable of picking primary food and packaged products at speeds up to 120 cycles per minute on a continuous basis using visual line tracking. It, too, has a clean design with no food particle retention areas, to resist bacteria growth and rust, and can withstand the rinsing process after the caustic washdown.Motley says robots in the food industry are a positive change from the alternative: the human hand. "Until recently, no technology has been able to replace some of these applications where human operators are dealing with raw materials that occur in nature, where no two pieces are alike."He still believes nothing can surpass the dexterity or the gentle touch of a human hand. The best the industry can hope for, he says, is to equal it with vision-guided systems. "Machines, however, are more consistent. Robots don’t get tired or distracted," he says. Nor do they incur traumatic or repetitive motion types of injuries on the job. Robots can survive dull and dangerous work.Another robot that meets the rigid requirements of the upstream food sector is the new Meat Gripper from Applied Robotics Inc. The light-weight, end-of-arm tool allows for high-speed robotic pick and placers to pick up non-uniform pieces of food.It can handle all types of meat, fish and cheese in various fresh, cooked, frozen and sliced forms, and can withstand hygienic wash-downs. The Meat Gripper is easily inspectable and cleanable, says Applied Robotics’ engineering manager Clay Cooper. "For any automation design involving food, you typically look at it from immediate contact to the food going outward into zones."Any machine part that touches meat must not harbour bacteria. "The machine must be cleanable down to every facet, so there can’t be any cracks or crevices that bacteria can hide in." Sounds like common sense, but some machines might have a small cavity built in that could allow a puddle of water to foster bacteria. "All areas of a tool or machine should be washable," says Cooper, "and have drainage by gravity where everything just flows."Because contaminants can linger, even the environment where robots are manufactured must be sterile. Automated Packaging Systems has created a robotic system that puts food into bags. The new FAS Sprint SidePouch Bagging System can bag at speeds up to 120 bags per minute. Its manufacturing environment was recently certified by AIB International, an independent international auditing organization, as being conducive to food safety. The robotic system can be washed down every day for food packaging. Both the machine and the bags are manufactured in a clean room environment, which means there are no food or drink at workstations, and workers use hair and beard nets and other controls to prevent contamination. The plant also uses positive air pressure to prevent contamination from small airborne particulate and insects. The machine’s stainless steel construction, one-touch clean-out switch and 90-degree tilt action make the FAS Spring easy to clean. While equipment producers must design cleanable and inspectable robots, food plants have a responsibility to follow manufacturer’s instructions for maintaining and sanitizing the machines daily, and to exceed these requirements as needed to comply with food safety laws. If you’re inviting robots to the dinner tables of North America, they are welcome–but make sure they wash their hands. Michelle Morra is a freelance writer living in Toronto.
Manufacturing was changed forever because Dick Morley liked to ski.
With expert timing, a worker deftly reaches inside a machine to clear a jam while the machine is still running. Over the years he gets away with it 1,000 times, but 1,001 takes his hand off.It's against the law to expose workers to moving machine parts. Whether you remove safeguards, fail to lock out equipment or just let old, outdated equipment lurch along without any safety features, you take your chances. Not only are workers' lives and limbs in danger, but the law has no tolerance for plants that operate in the dark ages of safety, especially when the technology exists for vastly safer, more efficient manufacturing.Machinery must be guarded. It's plainly written in the Occupational Health and Safety Act and in the CSA Standard. Not only that, but now under Bill C-45 of Canada's Criminal Code, a company owner, manager or supervisor can be criminally fined, charged or even imprisoned for having failed to prevent a worker's serious injury or death on the job."If you're not in compliance with the law, you're looking at risk," says Michael Wilson, machine guarding specialist with the Industrial Accident Prevention Association (IAPA). "A lot of people sort of hope and pray no one comes to the door, but when you do get caught, you get caught bad." Safety technology such as light screens, safety mats, interlocking gates, switches and motion sensors are designed to stop a machine within milliseconds if a worker's body part gets too close. Newer machines feature redundant control systems, where if one aspect fails, another kicks in to continue the safeguarding. And today's more passive safety systems prevent the sort of injury that happens when someone reaches into a machine to clear a jam. Creators of these advanced technologies have removed the temptation to reach in by making it physically impossible. They have gone to great lengths to prevent workers from coming near dangerous parts. Too many manufacturers choose to take their chances, however, rather than upgrade to a safer work environment. Why aren't they making the switch?One maintenance manager, Anicete Goncalves, admits that guarding all of his plant's equipment involved a few growing pains, at least in the beginning. Management at Vintex, the Mount Forest, Ontario-based vinyl textile coater, made the proactive move of hiring a consultant to audit the plant, assess against current standards and, if possible, provide recommendations."We had various pieces of equipment needing upgrades," says Goncalves, the company's maintenance manager. "The bulk of our work involved in running nips, where engineering solutions were not readily available." The plant had quite a task ahead, but management didn't hesitate.The company hired S.A.F.E. Engineering Inc. to conduct a hazard assessment of the plant's equipment. Based on the assessment, management set priorities of what equipment to retrofit, which pieces to decommission and which key new pieces of equipment to purchase. S.A.F.E. helped design a plan and tailored the new equipment safety features to the workplace, and continues to work closely with Vintex.While adding new guards, Vintex also removed some standard fixed guarding that impeded worker's productivity and replaced them with area scanners that work much better for their operations and for their people.Were the workers concerned that guarding would change the way they did their jobs? "Yes," says Goncalves, "and it has."In its decision to shape up for safety, Vintex staff and management had to be flexible and open minded. If a retrofitted machine wasn't operating as smoothly as before, S.A.F.E. took it back to the drawing board. They made adjustments, with input from workers and management, ensuring compliance to legislation and worker satisfaction. Now, says Goncalves, the company is operating at the same rate as before and is achieving the same high-quality finished products. Vintex is not alone. Other companies that commit to a safer manufacturing environment experience a similar learning curve, but ultimately benefit. Unfortunately, injury and fatality statistics indicate there are still companies that choose to put workers at risk, rather than get with the times. Some may think they have good reason.Six common excuses for exposing workers to moving machine parts1. "It'll never happen at our plant."Sadly, too many plants learn the hard way that accidents can happen. Machines killed 223 Canadian workers from 2002 to 2006 across several industry sectors. During that time there were 90,059 machine-related injuries, 36,066 of them in manufacturing alone. Machines and human flesh don't mix. Besides surface wounds and bruises, statistics from the Association of Workers Compensation Boards of Canada (AWCBC) list open wounds, intracranial injuries, traumatic injuries to bones, nerves, spinal cord, muscles, tendons, ligaments and joints among the machine-related injuries–and the victims are often young or inexperienced workers.2. "We had to remove the guards because they were hard to work with."It's right there in the Health and Safety Act: workers may not intentionally defeat or otherwise bypass the safety device as required by the employer. "It's flat out illegal. I don't care why you do it," says Wilson.When workers remove guards, it's often because the equipment wasn't professionally designed or installed. It's important to consider productivity and a worker's specific tasks long before you purchase the equipment. Otherwise, says Wilson, people who cannot work well with the new system will invariably find a way to make it work. "And it's usually not the best way. It's the nature of the beast that production rules, but be careful."Vintex has a policy that removing a guard results in immediate discipline, and depending on severity, possibly termination of employment. "It's in the code, and it's in the safety regulations," says Goncalves. "Guards cannot be removed."3. "The law only applies if I buy new equipment."Wrong. Many employers learn the hard way that there's no such thing as "grandfathering." According to health and safety law, if you bought a machine in 1980 and it was built to 1980 standards and you're still using it in 2008, there's no requirement to rebuild it to that standard. As long as you don't replace it, technically you don't have to add safety features to it. None of this matters, though, if someone gets hurt or killed. The law expects you to be compliant to today's standards, period.Besides, using outdated equipment is just plain irresponsible. "Imagine you had two pieces of equipment, one new and one old, side by side," says Simon Fridlyand of S.A.F.E. Engineering. "One machine is safe, the other terribly unsafe. Now you as a manager have to decide who works on which machine. Do you value one worker's safety more than another? Of course that's an impossible decision. You have to do the utmost to protect everyone."4. "Safety is a luxury we can't afford."Goncalves admits his plant's up-front investment to protect its people may have seemed high. "People may have wondered why we made such a sizeable investment," he says. "But the way the legislation is written, everybody's liable, from the worker to the owner. In our company, employee safety is of the utmost importance. Exposing an employee to any sort of hazard is not an option."A simple guarding application may cost $3,000, and if someone were to become entangled in a machine, once you're done with the litigation and fines from the ministry, etc., we're talking potentially hundreds of thousands of dollars," he says. Today, looking at the bigger picture, Goncalves sees it as an excellent investment.It's not just something safety professionals have been preaching for decades. Safety actually saves you money at the end of the day, which is what large companies are finding out. Some have actually made money by upgrading to safer equipment. The money they don't pay in workers' compensation insurance premiums can offset any adjustment in productivity.A Cadillac solution isn't always necessary. Fridlyand says that while nobody can afford to retrofit their entire plant, they can retrofit some equipment and replace a few key machines with newer, safer ones.5. "We can't be productive if our machines are guarded."Fridlyand suggests there's a huge lack of understanding of the relationship between safety and productivity. With the right consultation, design and installation by a qualified person, manufacturers can find the most efficient path to operate the machine with the new safety system. If that's done correctly, he says, at the end of the day you're not only much safer and in compliance with safety standards, you also have a much leaner, more efficient machine.When Vintex invested in safety, the initial drive was to protect our people and to avoid the cost of an accident. "Another benefit from the guarding process has been the need to automate certain parts of the equipment and change our methods," says Goncalves. "It really forces you to evaluate current operating conditions, and we've had certain instances where the change has actually improved productivity."6. "We don't need help."Retrofitting old equipment with a safety guard, or installing brand new equipment, is no simple task. You can't just buy a safety device, plug it in and forget about it. That's why Ontario requires companies to find either a safety consultant with engineers on staff, or an engineering firm that specializes in safety-related issues, to conduct a pre-start health and safety review (PSR) of any new or retrofitted equipment.Engineers don't come cheap, so to get more from the investment, enlist help sooner than later. It's better than buying a used machine for $5,000, then finding out it needs a $30,000 upgrade to comply. Compliance lies with the equipment owner, not the supplier. Even a brand new machine isn't guaranteed to be compliant with safety standards. So if you hire an engineer, do it before purchasing, not after.One big advantage to getting help is that the engineer takes on the responsibility for compliance. "At the end of the day, we sign and seal the document," says Fridlyand. "We're taking the liability away from the customer, and we feel comfortable doing that because we're familiar with the codes and standards. And what we basically certify is that the equipment is compliant with current standards."Companies can also ask the Industrial Accident Prevention Association (IAPA) or any other workplace safety association for assistance. The Canadian Standards Association also publishes resource documents that explain the standards in detail.Michelle Morra is a freelance writer based in Toronto.

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