New Generation of Innovations
Refinements to Materials and Processes Take Medical Offerings to a New Level
Stacey L. Bell - Editor at Large
Improved flow behavior, durability and processing are some of characteristics Eastman is offering in its DuraStar family of resins for use in applications in which resin previously could not be employed. Photo courtesy of Eastman Chemical. |
The mantra is familiar: get better products to market faster than your competitor. Raw materials suppliers and contract manufacturers hear this refrain daily. After all, they're on the front lines as medical device companies seek to create next-generation offerings while simultaneously cutting costs and production time. Advances in materials development and processing continue to make gains possible.
"Medical device companies are leveraging new materials and new technologies to sell more of their products," noted Larry Johnson, director of sales and marketing for Foster Corp. in Putnam, CT. "Technology is what keeps our customers ahead in the global marketplace. They're embracing narrower, more defined specifications and new technologies to develop better products and enhance their competitive edge."
A Team Effort
Also enhancing the competitive edge is a gathering of minds at every stage of product development before the design is finalized. While materials development is largely driven by OEMs, increasingly they are seeking input from their contract manufacturers when choosing materials for new offerings. Determining the best material properties for a product's design, processing, manufacturing, sterilization and shipping methods takes a true team effort.
Jennifer Ponti, director of medical and diagnostic sales for G&L Precision Die Cutting, Inc. in San Jose, CA, said that over the past year, her company has received more requests from medical device companies to meet with device designers and materials suppliers near the beginning of the design phase.
"The earlier a contract manufacturer is brought into the process, the better we can tailor our processing techniques, which also can affect what material properties would be best for a particular product," she explained. "Early meetings drive your productivity and scalability. You can go from design to prototype to production in a much more cost-efficient and timely fashion if all parties are involved early in the process."
For example, she pointed out, on paper a project may look phenomenal, but if the design is too complicated, it may be too costly to manufacture and take more time to produce. A few changes may allow for a device that can be simplified and improved, thereby allowing large-scale, money- and time-saving mass production.
In another example, Paso Robles, CA-based Specialty Silicone Fabricators often sees designs that with a few minor adjustments could allow for extrusion rather than molding. Its patented GEO-TRANS extrusion process reduces the amount of handling and number of secondary operations required, lowering costs and speeding production time, said Paul Mazelin, sales manager. For instance, consider a typical molded "Y" in which two tubes connect to a third piece of tubing. By extruding the part, there is no need for additional hardware or other means of joining the tubes; rather than having three pieces of tubing, there is just one.
Early Review Helpful
Mazelin noted that while materials suppliers are responsible for developing different properties, his company is often called on to test the materials to see if they perform as promised.
Review of the design at an early stage by all parties can also optimize yield. Indeed, experts say yields exceeding 90% can be achieved if partners work together.
G&L, a converter of roll goods including films, adhesives and foam among other items, has worked with customers from a project's outset to ensure that materials will be used most efficiently.
"Say you have a six-inch piece of polyester, but the original product design calls for a 2.2-inch product. Could the product be redesigned so that you can make three, rather than just two, products from each strip? By considering the width of the material specified, the maximum roll size and other parameters, you can reduce waste and cost while increasing throughput," Ponti said.
Some Healthy Competition
Of course, competition among suppliers also can drive cost down. Ponti said her company has seen more cases of OEMs asking several raw materials suppliers to develop new materials simultaneously.
From the OEM perspective, encouraging suppliers to "dig deeper" is exactly the goal. "The more brains we have developing new materials, the better the resulting compound and product will be," said Bruce Kornerup, director of purchasing for Ipsen International in Rockford, IL. "We're searching for the best of the best, so we challenge material suppliers and pit them against each other to see if they can outdo one another."
In addition to developing better properties, material suppliers also are being challenged to create materials that lend themselves to automated processing and maintain consistency from lot to lot so that machine operators don't have to run new tests and readjust parameters after each completed cycle.
"Based on customer input, we're developing a key formulation component that improves the consistency of our silicone's cure and viscosity from a fabrication standpoint," said Steve Bruner, marketing director of NuSil Technology in Carpinteria, CA.
He pointed out that device manufacturers typically don't want to see drastic changes in materials because validation and verification costs can be significant, yet they have sought incremental improvements in silicone's tear strength, tensile strength and clarity. On the manufacturing side, CMs have turned to liquid silicone rubber (LSR) technology, which has been improved greatly over the past two decades, to reduce processing times. However, fabricators have continued to struggle with several issues: how consistent is the material in its uncured state; when does it cure; and does it do so in a predictable period of time?
Molding Silicone
Bruner explained that when molding silicone, one lot may take two minutes to cure, and the next lot may cure in two-and-a-half minutes. NuSil Technology is working on tightening up that difference so that molders can avoid adjustments to their processes between lots, allowing for faster, more reliable production. The formulation component can be applied to NuSil's current materials as well as to new LSR technology it anticipates launching later this year.
Borla S.p.A., a Torino, Italy-based manufacturer of plastic and rubber components for disposable medical devices, found CYRO Industries' CYROLITE CG-97 acrylic-based, multipolymer compound easier to mold and sterilize. Photo courtesy of CYRO. |
Another company responding to processing challenges with new technologies is Eastman Chemical Co., headquartered in Kingsport, TN.
"We've been developing improved co-polyester grades for improved performance in terms of flow behavior, durability and processing," noted Thijs Jaarsma, global market development manager, specialty plastics. The company's new DuraStar family of resins was designed to be used in applications in which resin previously could not be employed.
"With co-polyesters, drying has always been an issue," explained Eric Moskala, Ph.D., Eastman senior research associate. "DuraStar resins require very little drying before molding, so they process much easier than other co-polyesters. They are more hydrolytically stable, maintaining their molecular weight even in the presence of moisture. They also show faster injection-cycle molding times due to their higher glass transition temperature and a broader processing window than other polymers."
That is, a common grade polymer typically can handle a processing temperature of 480º to 520ºF, whereas the DuraStar resins can be processed at temperatures of 450º to 530ºF.
Customers also are calling for tighter and tighter tolerances. On the silicone tubing forefront, "10 years ago, customers wanted you to hold +/- .003 inches. Today, they're asking for +/-.001 inches on dimensions," Mazelin said.
Ponti noted that in the films and adhesives area, some manufacturers' tolerances of +/- 1 mil have been reduced to .05-mil, a significant advancement, particularly for high-end electronic medical applications.
Demand for Customization
Some companies are experiencing greater demand for specific formulations. Curtis P. Smith, Ph.D., principal and director of R&D for New England Urethane, Inc. (NEU) in North Haven, CT, said his company has seen increased interest in soft polymers, particularly in softer urethanes.
"Urethane polymers and compounds are formulated without plasticizers, which can possibly leach out," he explained. "Urethanes are ideally suited to replace rubber because with urethanes, one knows exactly what is in the material, and users can obtain the strength and hardness wanted or needed. We can formulate or alloy in the hardness desired, so it won't change."
Even as materials suppliers expand off-the-shelf offerings for OEMs, medical device manufacturers frequently seek specialized materials to help differentiate their product from others.
Ticona U.S.-which recently relocated its North American headquarters to Florence, KY, where it opened a new technology center in April-has launched two new resin product lines for medical applications: Topas (COC), a clear, amorphous resin, and its Medical Technology resins. The MT product line includes medical-grade resins based on its Celcon (POM), Celanex (PBT), Riteflex (TPE), Vectra (LCP) and Fortron (PPS) resins. They are FDA-compliant and meet biocompatibility requirements for medical device and drug delivery products. Because they are engineering resins, these MT products can be used in automatic assembly processing. Yet, even with all of these choices, medical customers frequently ask for a resin tailored specifically for them, said Hedden Miller, healthcare marketing specialist for Ticona.
Smith noted that while some companies suggest that customers try an off-the-shelf formulation first, NEU has trained its staff to ask better questions early in the process to see if a custom formulation would actually be the best solution. "Our goal is to get the formulation right the very first time, so everyone gains and saves," he said.
On the fabrication side, too, customers are calling for customization. "Most of our customers seek custom sizes, not standard tubing," Mazelin noted.
What's New With Metals
Over the past two years, applications for nitinol components have grown tremendously, said Rich Molnar, lead manufacturing engineer for Norman Noble, Inc. in Cleveland. Nitinol is a shape-memory, or super-elastic, alloy comprised of 50% titanium and 50% nickel.
Traditionally, parts with complex geometries such as certain implantable medical devices were made out of tube stock, which would be processed by EDM, machined or laser cut. Newer technology and the use of nitinol now allow wires, tubes or bar stock to be wound or constrained into a shape and heated to a specific temperature to retain that shape. "Nitinol holds up better than stainless steel for certain applications, and it can perform different functions at different temperatures. It's amazing some of the shapes into which you can contort it and have it hold," Molnar noted.
He added that demand for tungsten components also has grown, particularly in the radiation-shielding business. "Tungsten is one of the most difficult metals to machine, but we've developed proprietary methods of machining and processing this metal," he said. For example, Norman Noble has enhanced electrochemical grinding as well as waterjet cutting capabilities. The latter uses high-pressure (50,000 to 60,000 psi) jets of water to cut metal in a process that is faster than traditional wire EDM for metal removal rates.
Better Machines
While changes to machinery, like materials, tend to be incremental, the accumulation of improvements over the past few decades equals large gains for all concerned.
"Medical products today are better beyond the ability of the substrates assembled. They're better because the manufacturing processes themselves are improved," Kornerup said. "There are more, better defined control processes; the plus-minus parameters are narrower; and lean manufacturing, kaizen and other quality improvement systems have tightened controls.
"The machine tools-mill or lathe-that make other machines are holding tighter tolerances. Every machine on down the line is holding better, tighter tolerances so that the full life cycle of manufacturing, on every level, is improved. That means today's machines are better able to produce products with tighter tolerances and that results in fewer deviations over the course of a production run than they were able to obtain even 10 years ago."
Steve Magaziner, marketing manager, modified acrylic polymers, for CYRO Industries in Rockaway, NJ, agreed that advances in machinery are making a difference, and he noted that developers are taking these differences into account when formulating new offerings.
"The trend in medical device processing is higher and higher tool cavitatio--developing a higher number of parts that can be made from a single mold and improving efficiency by allowing more products to be produced with one shot," he said. "CYROLITE, an acrylic-based multipolymer, was developed with this trend in mind. It is a very consistent material, and unlike co-polyesters or polycarbonate, it doesn't tend to stick to core pins, but it does work well in hot runner systems and allows thin walling, resulting in material savings."
More to Offer
OEMs, in addition to desiring ever-improved materials and processes, also are asking suppliers of every ilk to provide more services. From engineering and design consulting, to testing and validation and verification, to packaging and distribution, material suppliers and contract manufacturers are offering more to OEMs to eliminate supply chain redundancies and improve controls and costs.
"Today, typically the OEM thought process is that more offloading is better," explained Kornerup. "Five years ago, 50% completely built was fine, but today, we want 90%, if not 100%. There's a twofold reason for this change. First, OEMs want to focus on their core competencies, but also we are striving to manage our costs and continually reduce inventory."
Material suppliers and contract manufacturers continue to invest in innovation in response to OEMs' requests and questions. For instance, Ponti said G&L will at customers' request assemble a small research team to determine if it makes sense to offer a new product or service. Its GL-187 diagnostic adhesive was a direct result of this practice. Several customers had lamented that there were no adhesives on the market guaranteed not to interfere with the chemistry of test strips. GL-187 was developed to meet that need for myriad substrates and chemistries.
Chemical resistance also has been a concern for customers of CYRO. In response to customer requests, several years ago it developed the CYROLITE CG-97 compound, the first lipid-resistant acrylic. Customers then said they needed an acrylic that was also alcohol-resistant, so CYRO created CYROLITE Med. The second generation of the alcohol- and lipid-resistant compound, CYROLITE Med 2, which has higher flow properties to ease injection molding, debuted in 2004. Magaziner said that these new chemical-resistant properties allow device designers to use advanced acrylics as substitutes for other, more expensive high-performance materials such as polycarbonate and polysolfone.
Also in response to customers, CYRO created Vu-Stat, an acrylic-based, static-dissipating product that prevents static from building up within an inhaler device. (Static can cause medication to stick to the device's side walls rather than being dispensed to the patient.)
More Advice Sought
Eastman Chemical noted that over the past two years, its customers have sought more design and material advice for medical device and pharmaceuticals packaging. Answering customers' desire for an environmentally friendly alternative to PVC that was also processor-ready and had high clarity, the company heavily promoted its Ecdel elastomer. A co-polyester ether elastomer that offers clarity, toughness and chemical resistance, it can be film extruded and sterilized by steam as well as with EtO and gamma.
This ongoing innovation may be a "budding start" to stemming the U.S. trade imbalance, said Smith, adding: "With all the talk of foreign competition, we are seeing a steadily increasing growth in sales to foreign markets-including Asia and Europe. Why is this? Because here in the United States we continue to have more and deeper expertise, technology, resources, equipment and the desire to solve problems."
Whether they are targeting devices, drug delivery systems or packaging, material and process developers' quest for the next generation of innovation marches on. "Our continued challenge will be to provide materials that have tighter specifications and better physical properties while providing the highest yields possible," concluded Bruner. Better materials should result in better products, which will mean a healthy bottom line for innovators on all sides.
Stacey L. Bell is a freelance writer who specializes in business and marketing issues. She is based in Tampa, FL.