Getting a Grip on Automation and Assembly

More than ever before, automation and assembly go hand in hand (or gripper to gripper)—even at small-scale, low-volume production levels. The quest for higher efficiencies and cost savings is driving manufacturers to add consistency and repeatability to their production lines by reducing manual labor and using automated assembly and zero-defect quality detection methods.

This includes flexible or modular automation, which allows for scale-up, growth and modifications, even within restricted budgets. Automation systems integrators now are capable of automating processes that once were limited to manual assembly. This means that mature products can be optimized, with reduced costs and labor input, by reformatting production into automated production.
Then, as the product lines grow or change, the systems easily can be reconfigured to meet new demands, without long changeover times or cost increases.

“Over the last five years, robotics manufacturers have made their products much more user-friendly, while reducing their footprint and cost,” said Jane Burbach, marketing communications specialist for Aspect Automation, a St. Paul, Minn.-based builder of automation equipment for medical device manufacturers. “As a result, companies that need, or can only afford, a smaller automation system or single machine can now integrate robotics into their designs.”

With recent design advances, automation can be used in more creative ways to provide innovative production and assembly solutions with reduced costs (especially labor).

“We take a high-quality technical approach to molding and assembly through minimal manpower,” said Tim Holmes, vice president of engineering for GW Plastics, an injection molder and contract manufacturer in Bethel, Vt. “We continue this on through pack-out, using vision systems and weigh-count to ensure we meet customer specifications and requirements.”

Contract manufacturers that want to stay competitive—among themselves as well as with lower-cost countries—must be committed to using automation in as many of their processes as possible. Even simple jobs that are well-suited for manual operators often now can be done faster, with fewer mistakes and improved efficiency, through automation.

“For example, inexpensive robots that utilize user-interface technologies can now be used to automate simple tasks that have historically been highly manual operations,” said Rudy Pavlik, product development manager for ASI, a Millersburg, Pa.-based contract manufacturer of medical devices and single-use systems. “In some cases, this gives customers the option to evaluate the re-shoring of product lines because of the reduced labor costs that automated processes can supply.”

ASI works closely with systems integrators to develop automation early in the design process. One approach ASI has incorporated is “flexible” or “agile” automation, which allows for easy reconfiguration to process different products and processes, thus aligning production with variable market demands. Fast changeover, batch control and process integration are the main goals.

“The advantages to flexible automation are the ability to automate processes for intricate parts, scalability and reconfigurability and being able to manage floor space well,” said Pavlik. “For these reasons, flexible automation is suitable for mature products because it can be integrated into existing steps of production. In most cases it does not require special equipment—it is mostly how the equipment is structured and organized, with the ability to expand and integrate into control systems.”

Different Needs, Different Setups
GW Plastics focuses on highly automated precision injection molding, where it integrates cavity pressure transducers and vision systems to ensure high-quality parts go into the automated assembly cell.

“When there is a suspect part, the cavity pressure transducer and vision system detect it and the part is diverted prior to reaching the automation assembly cell,” said Holmes.

The automation cell includes vibratory bowl feeders, pad printers, ultrasonic welding stations, six-axis robots, over/under reversing conveyers, and lift and locate reversing transfer systems to accommodate using tray feeding and vision systems, which assemble and confirm that all components are fully assembled. Much of this approach is required to prevent scratching or denting of cosmetically sensitive parts. For the finished assembly, the product is transferred to the pack-out area, which is done automatically in the final consumer packaging. GW Plastics uses packaging equipment, vision systems and weigh scales to ensure that each package has the correct contents.

Depending on design and budget, the best solution for increasing yields and reducing costs could be an assembly operation that is highly operator-specific, a semi-automated system or a fully automated solution—or even a combination of these.

“We always keep flexibility at top of mind, since a new product’s development cycle is inherently uncertain,” stated David Cocke, general manager for NuPak Medical Ltd., a full-service contract medical device manufacturer based in San Antonio, Texas. “Any manufacturing solution usually involves balancing the competing desires for flexibility, minimal up-front investment and piece part price.”

As a smaller contract manufacturer, NuPak Medical’s niche is the start-up company or medical device entrepreneur who cannot get the service or turnaround time from larger contract manufacturers.

“Given that most of our customers are early in the life cycle of their devices, their focus is on getting to market as quickly and cost-effectively as possible,” said Cocke. “Therefore our solutions tend to emphasize flexibility and lower up-front investment at the cost of higher piece part prices. This tends to work for our customers, as they need the flexibility and are capital constrained, but are offering new technologies that carry higher margins. For example, we often recommend a pouch and backer board sterile barrier solution instead of a thermoformed tray/Tyvek lid combination. The pouch and backer board can be delivered in weeks, often with no up-front costs, whereas the tray requires custom molds, lidding dies and seal fixtures. That adds up to thousands of dollars and months of lead time.”

Manual cell-based and full automation-based production lines are not necessarily exclusive of each other—in fact, sometimes both are required for efficient product launch.

“The push for efficient and cost-effective production starts at the beginning of the product automation process, with the initial manual cell-based manufacturing line,” said Nicholas Mandala, vice president of engineering and quality for Kahle Automation in Morristown, N.J. “The typical design for operator-driven, lean-cell assembly reduces the cost of manufacturing and time to market, while simplifying work flow.”

These lean-cell assembly systems usually are developed by internal engineering groups or local suppliers based on prototype assembly processes. But there is only so much production that can be gained from this approach for initial product launch. With the level of detail required for a complete device master record associated with each medical device, there is an emerging trend to develop cell-type assembly systems with a fully automated solution in mind.

“Utilizing this approach, concepts developed for assembly from launch production to full-scale, completely automated production eliminate the need to update the assembly, testing and inspection processes initially outlined in the device master record,” said Mandala. “This also reduces validation costs and training—companies that develop equipment for fully automated systems tend to design low-volume production cells with scalable solutions for use in high-volume, fully automated production environments.”

In today’s fast-paced market for product development, hitting a target start date for biocompatibility or drug compatibility testing is crucial to a product’s success. A validated assembly system is critical for the production of any samples to be used during testing. A cell assembly system that is critical for complex parts manipulation and assembly can be automated, which improves quality and makes it easier to validate the process; non-critical or easy-to-perform assembly steps can be accomplished manually.

“For example,” said Mandala, “a cell-based production line can target an output of between six to 10 parts per minute with the use of operators. As the product testing runs its course and there is an eye towards launch capability production volumes, if a scalable system is designed with an automation partner used to fully automated systems, the manual operations can be easily replaced with automated cells
allowing the production output to increase by 400 percent, while reducing the overall operator count to two, within a six-month time frame.”

Quality Control and Validation
As the U.S. Food and Drug Administration proposes new rules for unique device identifiers on medical devices, including in-vitro diagnostics regarding labeling requirements, “customers are becoming more focused on validating documentation requirements, software programs and control packages to efficiently collect, process and manage the data,” said Burbach.

This increased regulatory oversight on products brings new challenges on how to get finished devices verified—which opens up more opportunities for automation.

“By incorporating automation into the assembly process, even for lower volumes or for a part of an assembly, we are able to offer 100-percent verification with consistent, repeatable cycles,” said Al Neumann, automation manager for SMC Ltd., a Somerset, Wis.-based contract manufacturer of medical devices.

Customers also increasingly have emphasized the need to reduce the number of final incoming inspections, Neumann pointed out. Although inspection and verification strategies are built into every assembly step, use of final inspection cells has become increasingly widespread as an additional cost-saving measure. These cells inspect each assembly and may include vision inspection modules, pressure test and leak detection equipment, laser identification marking and final packaging.

“The perfect opportunity to final-test the product is when we have the device under control or fixtured during assembly,” said Neumann. “This eliminates additional customer handling and testing costs and reduces the possibility of damage from extra physical contact.”

A key part of any automation and assembly operation (and its validation) is the use of sophisticated, automated vision inspection systems. For example, Okay Industries Inc., a New Britain, Conn.-based contract manufacturer of metal stampings, assemblies and machined components, recently purchased a VisionGauge digital optical comparator from VISIONx that uses edge recognition to position parts in any orientation within the field of view.

“An additional feature that is very beneficial to our operation is that all images produced can be compared to actual geometry using imported CAD files,” said Shawn Russell, vice president of engineering for Okay Industries. “The system can then be programmed using the CAD files as a benchmark to compare against an actual image. Prior to this technology, manual overlays needed to be produced and were limited in size. We also use a visual coordinate measuring machine. We can now inspect 80-plus complex contours in less than one minute using this machine.”

Russell noted that for applications where Okay Industries has upgraded to robots and vision systems, cycle times have decreased about 20 percent compared to mechanical transfer, with less downtime. Data collection and monitoring using vision systems has allowed real time statistical process control compared to post-data collection.

“Engineering and build cost are reduced about 30 percent, with further cost reductions expected,” added Russell. “A further benefit in utilizing this technology is simpler designs, with 25 percent reduced lead time.”

Vertical Integration Saves Time, Money
OEMs are looking to partner with medical device contract manufacturers (CMs) that provide both full-service manufacturing and in-house assembly and test solutions. OEMs can realize significant savings in engineering time by partnering with a CM that has internal engineers, programmers, machinists and designers who specialize in automation and testing challenges.

“For example, we recently built a piece of equipment that picked, tested, inserted and fastened a light-transmitting device we produced into a sub-assembly,” said Neumann. “When the machine was nearly finished, the customer’s marketing department changed the design, adding serrations to the part surface. We were able to quickly disassemble the machine and start to redesign components that would work with the new serrated part. By the time the mold revisions were made, our equipment was ready and time-to-market was not affected.”

In the catheter world, balloons are the most expensive component of balloon catheter production. There is increasing demand for higher-pressure balloons spanning multiple clinical applications, which creates a wide range of manufacturing challenges. For example, will the balloon-shaft tube weld be strong enough to hold at the balloon-rated burst pressure? Is the balloon wall thickness thin enough to achieve the desired sheath compatibility and the burst pressure? Will the balloon manipulations during the catheter manufacturing process, such as folding, wrapping and welding, negatively affect balloon performance?

The demand for higher burst pressures in balloons is pushing balloon manufacturing science to new limits. A successful solution often requires a combination of new innovations in materials, balloon forming, and folding and wrapping.

“For example, many companies still do folding and wrapping by hand,” said Mark Geiger, vice president of sales and marketing for Interface Catheter Solutions, a Laguna Niguel, Calif.-based contract manufacturer of balloon catheter components and sub-assemblies. “Even with using folding and wrapping machines that perform this function, it is very difficult to fold and wrap long balloons (>150 mm) like the ones used in below-the-knee procedures. The alignment inside the module that contains the heated blades that make the pleats in the balloon can be tricky. Manufacturers have had to innovate to address this issue, as with tensioning elements that grab and hold the balloon from the back side of the module to guarantee the correct balloon alignment.”

Balloon inspection is one of the most critical (and expensive) aspects of balloon manufacturing. Automated balloon inspections are essential for maintaining quality and reducing costs. Interface Catheter Solutions has designed its own in-house inspection system called Auto-i 360, which is capable of identifying and classifying tiny visual defects, embedded materials and other defects with high precision.

“Through the use of an automated process, full dimensional and defect measurement, including wall thickness, can be completed in 30 seconds,” said Geiger. “As an example, this automated process for the inspection of 50,000 balloons at a labor rate of $35 per hour and reduction from two minutes per balloon to 30 seconds per balloon would equal a cost savings in the range of $43,000 per year.”

As assembly and testing requirements become more demanding, equipment also becomes more complex and challenging to operate. To reduce learning curves and improve efficiencies on the production floor, SMC has invested considerable resources in designing its own intuitive human machine interfaces that make operation easier. 

“This software, written in-house, provides a very intuitive interface so existing personnel can operate and troubleshoot our work cells,” said Neumann. “For example, screens show current input/output (I/O) conditions next to a table that shows what I/O should be in to advance to the next logical step. This troubleshooting aid greatly reduces downtime and simplifies cell troubleshooting.”
Medical device contract manufacturers that can offer in-house automation have a big competitive advantage—even against offshore companies.

“We can respond quickly to a customer’s needs,” said Neumann. “Because the design, machining, wiring and programming are all done internally, product changes are quickly addressed and equipment down-time is minimized, keeping costs down. As a dedicated department, we only build equipment for our own or our customers’ use and do not offer these services to outside companies.”

Future Trends
As OEMs develop new products that are smaller, more complex and more specialized, often with lower-volume production targets, assembly cell requirements can change frequently. Also, for new launches from start-ups, limited capital investment is a top priority until the product takes hold in the marketplace. These types of scenarios are why more medical device companies are embracing flexible or modular automation. Where feasible, modular cells give customers a way to introduce automation to a new assembly line. At a later date, they can cost-effectively add more cells to expand the automated line. Modular cells also offer greater flexibility—they can be made to fit changing floor layouts and are not restricted by the initial assembly line layout.

“Modularity also gives us easier access for troubleshooting and maintenance activities and allows us to automate operator-dependent cells at a later time,” said Neumann. “It also breaks one-piece assembly lines into more manageable cells and allows a slow station to be doubled up, eliminating a bottleneck.”

Automation is absolutely critical for making American manufacturers competitive with offshore locations.

NuPak Medical has used automation to compete favorably against overseas contract manufacturers, whose labor costs are far below those in the United States.

“Our customers prefer the flexibility and responsiveness they get in the U.S.,” said Cocke. “They have been willing to invest in custom solutions that keep the all-in costs competitive, with the lead times and flexibility only available when dealing with a domestic company.”

Neumann agreed.

“Instead of moving projects into a low-cost country to reduce labor costs, we have been able to utilize automation cells helping reduce the overall costs while keeping the products closer to the final distribution point,” he said. “Some customers initially think that automation is too costly or unobtainable because their programs are lower in volumes; the truth is value-added processes can be incorporated into the automation cell, helping to off-set the automation cost.”

Cocke believes that three-dimensional printing in the near future will make it easier and less expensive to create the assembly fixtures his clients need as their production volumes ramp up.

“There are also some intriguing, low-cost robotic assembly applications being marketed that could bring the cost of this technology down to the level where NuPak’s smaller customer base could take advantage of fully automatic assembly,” he said. “There is a company called Rethink Robotics that is offering a robot for $22,000 that can be trained by line operators, and operate without safety cages, right next to humans. As that technology matures, the opportunities for our customer base to quickly automate assembly tasks may bring robotic assembly to the low-volume start-up. That’s something I never thought would happen.”

According to Geiger, one of the biggest challenges in the industry is demonstrating value for the investment in automation. For example, return-on-investment analyses for automated equipment often show a payback period of less than six months. However, this does not include the opportunity cost of the customer’s labor to re-validate a manufacturing process.

“This makes many companies with well-established product lines resistant to change,” said Geiger. “Companies refer to it as ‘soft savings’ and nobody wants to be on the hook if it isn’t easily measurable. In addition, automation typically provides more benefit in high-volume applications.”

This, however, is starting to change.

“The development of cost-effective automation for lower-volume applications will address a broad base of lower-volume applications that are currently under-served by automation today,” concluded Geiger. 

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Mark Crawford is a full-time freelance business and marketing/communications writer based in Madison, Wis. He also writes a variety of feature articles for regional and national publications and is the author of five books. Contact him at [email protected].