Pursuing Perfection

 

More companies are turning to robotics and automation to improve quality and throughput. Should you?

Stacey L. Bell

 

In the pursuit of perfection, orthopedic manufacturers have embraced the use of new materials and processes, management techniques such as Six Sigma and, increasingly, robotics and automation.

For years, robotics have attracted the attention of companies hoping to improve their bottom line while beating competitors to market with superior products. Consider the evidence: According to the Robotic Industries Association (RIA) in Ann Arbor, MI, the number of robots sold in the life sciences/pharmaceuticals/biomedical manufacturing category (which includes orthopedics) had jumped 30% from 2004 to 2005. In 2005, the North American robotics industry set a new sales record, selling 23% more units and ratcheting up revenues by 17% compared with 2004 levels.

Automating the loading and unloading of a machine tool, like this Makino horizontal, improves process stability and increases part consistency while reducing labor costs.  Photo courtesy of Makino.

More than half of all robots sold in North America are used by the automotive industry, but that sector has fared poorly this year. As a result, new robotics orders for January through June 2006 (the latest data available) declined 38% compared with the same period last year. However, during those months, robotic sales to the medical sector grew by 11%.

The medical sector “is a small but growing and promising part of the market,” noted Jeff Burnstein, vice president of marketing and public relations for RIA, which offers educational resources—including conferences and publications—for companies looking to implement and justify the use of robotics and automation in their manufacturing processes. (See www.roboticsonline.com for details.)

In fact, it’s becoming increasingly easy to justify investing in this high-tech solution, experts say. “The real challenge with robotics has rarely been the technology—the technology continues to get smarter and add more capabilities. The challenge was pricing, but the line of capabilities of robotics in comparison to the cost of labor has been crossed,” explained Ernie Bancroft, regional sales manager for Körber Medipak of Clearwater, FL. “The economic rationale has become compelling in a lot of applications.”

 

The Case for Revving Up Robotics Usage

 

Part of the reason the economic rationale is so compelling is because of overseas competition. “The increasing use of robotics and automation in North America is fueled by two fundamental issues: the pressure to improve product quality and reliability and to remain cost competitive with offshore manual assembly,” explained Keith Bocchicchio, director of technology for Integrated BioSciences, Inc. in Lewisberry, PA. “The decision to move to automation is always based on improved quality or safety or reduced manufacturing costs, or a combination of all three of these factors.”

A robot picks up metal parts from one of Adept Technologies’ AnyFeeder units.  Although not visible, the robot is being directed to the parts via a downward-looking, AdeptSight machine vision camera. Photo courtesy of Adept Technologies, Inc.

Most companies will find that robotics offer higher precision, repeatability, process control and productivity while reducing waste and relieving humans from performing dangerous tasks. Take, for example, hand polishing. Not only is it a repetitive, dirty job—which each polisher performs slightly differently, with slightly different results—but it also can lead to numerous problems. Workers often suffer carpal tunnel syndrome or nerve damage, and the parts they’re polishing tend to have a higher-than-acceptable reject rate because polishers can accidentally remove too much material. By automating the process, workers are freed from an onerous task, and the reject rate will virtually disappear.

“It’s pretty difficult for a robot to scrap a part,” noted Fritz Carlson, president of Acme Manufacturing Co. in Auburn Hills, MI. Acme is a strategic partner with FANUC Robotics America, Inc. in Rochester Hills, MI. “Robots provide a consistency and repeatability that you just can’t get out of a human. There is little or no rework on a robot-finished femoral versus on a manually polished femoral.”

Reject rates often fall greatly after robotics are introduced. Phil Beck, vice president of medical operations for Midwest Plastic Components in Minneapolis, MN, noted that one of his company’s clients reduced its bioresorbable bone screw reject rate from 15% to 1% after automating more of its manufacturing process.

As a result of reduced reject rates, material costs can decline dramatically, too. Robot process yield rates typically are in the 95th to 99th percentile, according to John Dulchinos, vice president of robotics for Adept Technology, Inc. in Livermore, CA.

Productivity and its payoff are impressive as well. “It can take 45 to 90 minutes to hand polish and buff a femoral; a robot can do as much or more work—with perfect results—in seven to eight minutes. The return on investment is significant,” Carlson said. “One robot can do the work of 10 to 15 people. The results are repeatable and consistent, and robots rarely get sick.”

Experts agreed that the typical return on investment in robotics pays off in nine to 12 months. The more shifts a company runs, the faster the return, of course. Organizations that run three eight-hour shifts might see a return on their investment in eight months, while a company with one shift might take 15 months to fully capitalize on its purchase. 

“The risk of product obsolescence increases exponentially as a product ages, so most companies strive to earn back their capital investment in robotics very quickly,” Bocchicchio said. “They also use robotics as a competitive advantage to get a new product to market more quickly.”

Some companies have standard robotic platforms that they can build on for each customer’s specific requirements, allowing for a lower-cost, complete system that can be delivered relatively fast. “When you’re purchasing systems, you want to buy robotics that can be easily adapted to other tasks with relatively little re-engineering,” Bocchicchio said. So while a robotic system may be used for one task for one product today, in the future the same system may be tooled for additional products or re-tooled for a completely new product line.

From material handling to polishing and cutting metals or plastics, robotics are being applied to more manufacturing and assembly processes than ever before.

Smarter, Faster, Cheaper

Just as you likely are much more knowledgeable and sophisticated than you were a decade ago, so, too, are robots. “Robots are becoming smarter, faster and less expensive,” Dulchinos noted.

By integrating advanced technology such as vision and force sensing into robotic cells, along with increased dexterity, developers have succeeded in making robots more perceptive and better able to follow logic to adapt to changes in their environment.            

Enhanced vision technology also is allowing robots to add another task to their repertoire: inspection. “Robots now have the ability to discern very subtle differences in color so they can provide the same level of inspection quality as a person,” Dulchinos said.

Indeed, automating inspection is one frontier more companies are hoping to explore. “A lot of labor goes into inspecting parts, so we see that as an opportunity to remove some labor from and streamline the process,” Carlson said. “We’re currently working on automating inspection.”

Even with their advanced capabilities, robots today can perform a typical operation or pick-and-place cycle twice as fast as they could five to 10 years ago, while costing half as much.

“At Pack Expo in November, we previewed a new generation of parallel kinematics robot technology,” Dulchinos added. “These robots are capable of 240 cycles per minute, making them ideal for high-volume packaging or handling operations. Because of their fast cycle rates and compact size, they will allow companies to achieve even more output with their current factory space.”

In the past, the job of integrating automation into current processes proved too large a hurdle for some companies. That’s changed, said Mark Rentschler, marketing manager for Makino in Mason, OH. “Enhanced cell control systems allow a single point of operator interface, which makes the transition to automation simpler,” he noted. Rentschler added that machines today are more capable than ever before, allowing for better handling of complex geometries, such as curved features and details on body parts, and an improved ability to cut titanium alloys and other hard-to-cut metals. For example, Makino recently expanded use of its high-torque, high-thrust integral drive spindle to three horizontal machining centers. The spindle is suited to boring and face milling on tough, hard metals, including carbon steel, stainless steel, titanium, titanium alloy, nickel-based alloys, inconel, cast or ductile iron and compacted graphite iron.

Machine accuracy has escalated as well, allowing for far better surface finishes than what could be achieved even five years ago.

Machining Made Better

One of the most dramatic changes to occur in metal finishing in recent years is the introduction of robotics to replace manual operations. Robotic abrasive belt and buffing systems reduce cycle time while producing consistent part finishes with substantially reduced labor and supply costs.  

Robotic systems enable precise control of the finishing process. Although abrasive belts cut sharply at first, with use, dullness sets in. “The pressure control system is very important,” said Bob Penque, president of Pinnacle Technologies, Inc. in Wyckoff, NJ. (This system controls the pressure of the belt on the part during the process.) “After making five or six parts, the belt starts to show signs of wear. To compensate for wear, you can incrementally increase the pressure and/or speed to maintain the proper cutting of the material. We’ve developed specialized contact wheels for our robotic systems to support the belt and aid in maintaining proper pressure. To robotically finish a femoral knee properly, you need the correct combination of the robot end-of-arm tooling, part path, abrasive belts, contact wheels and pressure control.”

Penque added that orthopedic manufacturers, in their search to improve products, have experimented with a variety of proprietary hard coatings. Such coatings are much more durable and harder than cobalt chrome, which poses a problem for finishers. “We’ve developed a robotic process using a combination of specialized abrasive belts and lubricant that produces a mirror finish on hard coatings without requiring buffing,” Penque said.

Structured abrasives, used almost exclusively for orthopedic implants, are another newer development. “Belt life with structured abrasives is much better than with conventional abrasives,” Carlson said, adding that their lifespan is three to four times longer than that of their older counterparts. Structured abrasive belts also provide a more consistent finish on parts. “Structured abrasives give you the opportunity to skip a few steps to get to the final finish, requiring fewer robotic finishing systems,” he said. “What normally may have been an eight-step operation is now five or six when you’re using structured abrasive belts.”

More companies also are moving into offline programming, in which they import CAD models directly into the program and translate the perfect part path into robot language, Penque noted. Such programs are enabling orthopedic product developers to create devices with ever-tighter tolerances.

“Most hips are near-net-shaped forgings, and if you polish them by hand, there’s a greater chance of a rejected part because of removing too much material,” Penque said. With offline programming, in combination with closed-loop measurement systems, it is possible to completely eliminate manual finishing because the robot can adjust the path specifically for each part.

While offline programming is still in its infancy at many companies, active force control is becoming much more advanced, Penque said. “Our robotic systems incorporate sophisticated, electronic closed-loop feedback systems for pressure control, allowing the buffing wheel to follow the contour of the part while maintaining a constant pressure and surface speed and automatically compensating for wheel wear. It’s possible to control pressure on parts with much more precision than in the past.”

Of course, at the end of the day, robots are only as good as their end-of-arm tooling, the way parts are fed to it and the end-part inspection results, Bancroft noted.

The way parts are fed to robots has been an area of concern for companies over the years. Until this point, companies had to use a customized (read “pricey”) vibratory bowl feeder. Parts would be dropped into the bowl, which would oscillate—moving the parts around so the robot could pick them up and place them. Bowls often were single use only.

Adept Technology has created the AnyFeeder flexible parts feeder, which allows users to feed a variety of different parts—typically one to two inches in size—into a reusable feeder device that shakes the parts, allowing vision-enabled robots to then grasp a particular part at any given time.

“We’ve combined vision and feeding technology to allow a robot to replicate a person performing a function that historically robots couldn’t perform,” explained Craig Tomita, director of medical products business for Adept Technology. “With vision-based feeders, robots can find random parts that they can pick up, without having them fed to them. It’s a great technology for assembly processes.”
Additional Services

In addition to helping their customers automate more processes to speed time to market while improving product quality and reducing costs, orthopedic outsourcing partners are expanding their portfolio of services to meet more needs.

“The biggest issue about incorporating robotics into any manufacturing process surrounds requalification,” Beck said. “Any time you start making changes to the process around which product is made, you must validate again, which is a hurdle. You really must be able to show the customer the economic gains that will result. We will perform all the internal qualifications and validations, which helps ease their concern in that area.”

One other cost-saving area is in inventory management. Midwest Plastics had a customer that used to carry $750,000 worth of product in its inventory. Midwest Plastics helped the firm move from large batch  to small batch molding to remove inventory from its supply chain. “We mirrored our production process to their sales demand,” Beck explained. “We work to take cost out of their business—not just out of the product, but out of tools, inventories, etc.”

Success Follows Success

The successful implementation of any robotics system will be only as good as the people involved.

After all, “robots are not artificially intelligent. They require people to perform well,” Bancroft said. For robots to be as flexible and re-deployable as possible, companies must make sure they staff that is capable of reprogramming the robots to extend the value of the investment, Bancroft noted.     

“Management needs to consider the human element before purchasing a new system,” he explained. “Include people in the decision process and then train them to excel in a new environment and culture, which robotics will most certainly bring.

“Rather than look at robotics as a way to eliminate positions, look at it as an opportunity to grow your company,” Bancroft concluded, adding that robotics allow current workers to engage in more meaningful work. In the end, by leveraging robotics properly, your bottom line, employees and product end users will benefit.
 

Stacey L. Bell is a freelance writer who specializes in business and marketing issues. She is based in Tampa, FL.