All-in-one drug delivery systems. Needleless devices. Implants. These are just three of the product categories expected to see strong growth within the next few years, and medical molding is helping to make advances in these categories possible.
For decades, OEMs have turned to molding suppliers for help in shortening their product manufacturing times. Recent advances in molding machinery, technology and business processes are expected to continue to fuel strong growth in the area. Industry experts report that annual growth has ranged from 8% to 25% over the past few years, and double-digit gains are predicted for the coming year.
"Molding is the fastest way to encapsulate. It can be done in 10 to 15 seconds, whether you're encapsulating a board, a connector or a sensor," said Greg Feuerborn, technical sales and research and development manager for molding supplier National Cable Molding in Los Angeles. "It's also the fastest, best way to allow for non-ingression of dust, water and other contaminants into products, allowing for easier cleaning of devices."
Machines Make a Difference
Increased automation and improvements in robotics and technology are some of the driving forces behind medical molding's growth. Jignesh Amin, director of sales and marketing for Advanced Scientifics, Inc. in Millersburg, PA, estimated that there are between 7,000 and 8,000 injection molding companies in the U.S. today. The growth of this sector has been accompanied by an increase in the number of manufacturers serving molders' needs.
Several years ago, high-quality machines were available from just a few companies. Today, market demand has resulted in multiple manufacturers developing increasingly sophisticated presses. "Machines offer much more precision today than they did a few years ago, and they're also more competitively priced," Amin reported.
The use of cavity pressure transducers to give molders more information about what is occurring inside the mold is also becoming more prolific. Pressure transducers monitor pressure in the cavity, providing vital information about machine performance. If the readings drift outside of control limits, an alarm sounds. The out-of-spec product is automatically rejected by the machine's attending robot, and trained personnel immediately begin performing a root cause analysis.
Cavity pressure can change for many reasons, including variations in melt viscosity, cooling performance, injection pressure and melt temperatures. It benefits molders and OEMs to know right away if any condition has changed because injection molding is a very fast process-8, 16 or 32 parts can be formed every 10 to 20 seconds, Podesta explained. By monitoring the molding of each part, variations are spotted-and corrected-immediately, resulting in less waste and lost manufacturing time.
Many molding presses have seen additional improvements in the past few years.
Advances over the past 10 years include faster, more accurate injection systems, improved hot manifolds and more efficient mold cooling. "These advances save a few seconds here and there, and these seconds add up and make a critical difference in helping OEMs reduce costs," Podesta said.
While molding traditionally has achieved tight processing tolerances, improvements in tooling technology and mold processing in the past few years have allowed for ever-tighter tolerances. Indeed, micromolding, whose popularity is soaring because devices continue to be made smaller and smaller, can hold much tighter tolerances today than five years ago, noted Trygve Thompson, opportunity development coordinator for Phillips Plastics in Phillips, WI.
"In the past, we considered +/- .001-inch a tight tolerance," Thompson said. "Today, we can go much tighter than that."
Just as machine capabilities have improved, so, too have their accompanying robotic elements. "Injection molding is so globally competitive today. To be competitive in a higher-priced labor area, like the United States and Europe, you have to take labor out of the system as much as possible. That's why molders are automating everything from inserting materials to molding to assembly," noted Tim Haen, injection molding manager at CoorsTek, Inc. in Golden, CO.
Most presses equipped with robotics today are capable of performing more complex tasks than ever before. In addition to cutting unit cost by eliminating expensive human labor from the process, robots also are more exact in replicating a function, faster and able to handle delicate, intricate parts more adeptly than workers.
New processes that save time and allow for enhanced manufacturability are gaining favor with OEMs, molders said. Consider two-shot overmolding.
"Two-shot molding is becoming more and more popular," said Gerry Duggan, vice president for healthcare sales for Precise Technology in Pittsburgh, PA. "We can produce parts with multiple materials from one press. It's economical at the right volume."
Many manufacturers are turning to two-shot overmolding to meet user comfort needs such as molding a softer grip material over a hard plastic or metal. In addition, a growing number of OEMs are asking for two-shot overmolding to differentiate their products from those of competitors, noted Jim Meier, vice president of marketing for Scientific Molding Corp. in Somerset, WI.
"We're seeing a lot of development in new materials, especially for two-shot molding," Meier said. "But there is still a need for softer materials that will improve grip and be autoclavable. Many of the materials used today will discolor, get too soft or develop other problems when they go through an autoclave. We're still looking for a material that can overcome that challenge."
The need for autoclavability will lead more OEMs in the future to use silicones and fluoropolymers such as Teflon, said Feuerborn.
Indeed, there is an emphasis on exotic materials such as high-temperature and implantable plastics and bioresorbable materials, CoorsTek's Haen pointed out. He added that standard injection molding of common plastics is being adopted more readily in developing countries, but in the U.S. manufacturers are examining how alternative materials can provide performance and cost advantages. Some standards such as stainless steel and titanium remain widely used because of their track record in the medical industry. However, stronger materials such as ceramics for use as insulators in the electrosurgical industry for laparoscopic and arthroscopic procedures is grabbing designers' attention. For instance, he added, it's not uncommon for a manufacturer to overmold a ceramic or molded injection part with plastic for a better grip or feel, aesthetic purposes or facilitate attachment to another part.
Phillips Plastics' Thompson noted that his company has seen customers using PEEK as a replacement for metals such as titanium and using more thermoplastics because they offer more durometers and softnesses. He also expects nitinol to play a larger role in the future.
"Ideally, medical devices should be lightweight, provide radiolucency and allow for multiple sterilization," said Gil Reich, vice president of contract manufacturer The MedTech Group in South Plainfield, NJ. "Today, medical device makers are beginning to recognize that high-temperature resins are more than just functional alternatives to metals and metal alloys. They are, in many respects, decidedly superior in terms of cost and ultimate product performance."
Reich said that these advantages come at a cost of processing challenges, including preprocessing treatment of raw materials, achieving and maintaining a consistent, high-processing temperature and modifications to conventional injection molding equipment and tooling.
"We are now working with a number of manufacturers whose product components are comprised of high-temperature resins," Reich noted. "These customers are enjoying the ability to explore new and flexible ways of designing products while enhancing their overall functionality and long-term profitability."
Secondary operations-including labeling, pad printing and in-mold decorating-have also seen advancements. Scientific Molding's Meier pointed out that pad printing and in-mold decorating recently gave way to a heat-transfer printing process that gives medical customers more flexibility at a lower cost.
"You don't see a lot of in-mold decorating anymore because the initial tools are expensive," Meier explained. "Pad printing has lost some OEM interest because for every color you add, you're adding another step to the process. Lining up all the colors is a problem. It's like when you see a newspaper ad where the colors are out of alignment. As a result, that technology tends to limit customers, economically and practically, to one color."
Not so for heat transfer printing. Meier noted that this process allows for the use of a multitude of colors simultaneously, with precise, crisp reproduction on the actual product. "Customers can use smaller fonts and get more information (such as a part number, brand or logo) on a smaller area with this process," Meier said.
Feuerborn added that marking and decorating options have become more automated, and more customers are asking for laser and permanent markings that will withstand caustic conditions such as repeated sterilization cycles, exposure to temperature extremes or scrape abrasions that may occur with use.
Molders are finding that to command a larger market share, they need to respond to OEMs' newest concerns.
"Several years ago, it was more common for OEMs to do product development in-house and outsource manufacturing," Dolan reported. "Now they outsource from the beginning-concept to tooling to final device. And they're seeking one-stop shopping and consolidating their vendors because that speeds projects and lets them manage more projects simultaneously. Today you need to be more than a medical molder. You need to be able to support development through final assembly."
Even if a contract manufacturer doesn't have all the capabilities on-site, OEMs expect the vendors they hire to manage the entire supply chain-from finding qualified, capable partners to overseeing their work and making sure projects are delivered on time and at top quality.
Widespread, savvy automation OEMs want vendors who have automated every step of the design, manufacturing, assembly and shipping processes. "We are robotically managing parts, materials, inserts, assembly-everything we can to improve quality and reduce unit cost," said Meier.
Excellent quality systems. "To be a serious player today, vendors need to understand and implement appropriate medical device and documentation systems. ISO 2000 doesn't cut it," emphasized Haen.
The development of validation of manufacturing protocols for new molds is on the rise, Meier added. Indeed, numerous vendors are embracing Process Excellence and Six Sigma process improvement programs to move their manufacturing operations to ever-higher levels of precision.
Most of The Tech Group's personnel are trained in Six Sigma's quality improvement principles, and many have earned colored belt designations, similar to karate, in recognition of their mastery of the concepts. The Tech Group has three Master Black Belts, more than 20 Black Belts, 50 Green Belts and 80 White Belts on staff.
Precise Technology also has taken Six Sigma to heart, offering this training to select employees throughout the organization. "Six Sigma improves not only quality, but with the extreme cost pressures in healthcare now, OEMs use Six Sigma to lean out of their processes for cost improvement," said Michael Cullen, business unit manager for healthcare sales for Precise Technology.
Molders also are seeking certification in previously untapped arenas. Precise Technology is working toward total compliance with the FDA's 21 CFR Part 11 regulations on computer software validations.
Once these needs and the accompanying priorities for quality and on-time delivery are met, perhaps the final supplier selection criterion is ensuring that the vendor is simply a good fit. "Sometimes it's easier to buy technology than it is to buy a culture and customer service that most meets your particular company's needs," said Advanced Scientifics' Amin. "Service and flexibility still differentiate the good suppliers from the great suppliers."
About The Author
Stacey L. Bell is a Tampa, FL-based freelance writer who specializes in business and marketing issues.