Mark Crawford, Contributing Writer10.01.21
It is a bounce-back year for the extrusion industry. COVID-19 placed immense strain on operations for extruders. Many of the legacy products being made, such as breathing hoses and general transfer tubing, became critical to produce as quickly as possible for medical equipment for COVID-19 patients, which greatly stressed the entire supply chain. “To compound problems, many manufacturers are struggling with staffing and inflationary measures,” said Charles Golub, market development manager for Saint-Gobain Medical Components, a full-solution provider of medical device components. “The last 18 months have been truly exceptional to witness.”
Lead times are still unpredictable due to supply chain issues and shortages of personnel, creating inefficiencies in virtually every segment of manufacturing. Critical inputs are getting more expensive, including raw materials, labor (wages/salaries), and the cost of maintaining pandemic procedures for employee safety. Complying with the Centers for Disease Control (CDC) pandemic guidelines has also decreased productivity, reducing profits and cutting margins.
That said, medical extrusion is rebounding from the slowdown in production caused by the cessation of most elective surgeries due to COVID-19. “Production levels have not only rebounded, but surpassed pre-pandemic levels by about 10 percent or more,” said Tim Steele, CEO and founder of Peterborough, N.H.-based MicroSpec Corporation, which provides medical device companies with a variety of extruded tubing. “It is interesting that, for new product development or prototype extrusion during the pandemic, medical extruders did not see a slowdown. In fact, MicroSpec experienced a surge and moved more parts through the prototype phase to being fully validated than any previous year of the company.”
Christian Herrild, director of growth strategies for Baraboo, Wis.-based Teel Plastics, a custom plastics processor that does both extrusion and injection molding, agreed.
“It’s very busy in many segments,” he said. “We have seen a lot of development work going on with products supporting the response to COVID-19, in addition to the usual work that has come back strongly this year.”
Advanced Materials, Smaller Parts
Medical device manufacturers (MDMs) are constantly looking for ways to reduce product size while still maintaining physical requirements and cost controls. To achieve smaller cross sections and still maintain acceptable physical properties, extrusion houses must be creative in developing more exotic material formulations that will allow dimensional scale-down and still meet functional requirements. This includes finding innovative ways to compatibilize these exotic formulations so they can be processed with more standard materials, thereby allowing them to be bonded to or assembled with other components manufactured from conventional materials.
Advanced types of plastics for making tubing continue to be introduced into the medical device market. For example, new additives are developed that can change the flexibility of the tube, or keep the body from attaching to the tube. “The changes made to the polymers can affect every aspect of the extrusion line, including the air pressure required internally,” said Kay DeWolfe, president On Line Controls, a Shrewsbury, Mass.-based manufacturer of ultra-low air pressure regulators and controllers for tubing extrusion. “Adding lumens to the tubes allows passing of different medications or inserting wires into the body. Every year, we hear from someone adding more and more lumens into one small tube. The latest has over 30 lumens in one tiny tube that is less than 1/8 inch outer diameter.”
For new concept parts, MDMs are making fewer requests for general-purpose polymers—instead they have greater interest in using new and specialized materials, with specific engineered properties. Common characteristics considered by design engineers include stiffness/flexibility, hardness/softness, lubricity/tackiness, column strength, and biocompatibility. “When selecting a polymer for a highly specialized extrusion, design engineers need to find or create a material that watches the requirements for the form, fit, and function of the new part,” said Steele. “The new material is often a custom formulation specific to an individual part. It seems that not too long ago, there were just a handful of materials being used; today, there are too many to mention.”
Producing miniaturized components also requires enhanced capability to inspect these smaller dimensions at resolutions that will provide statistically significant data for validation work. This drives the need for high-resolution optical inspection systems, laser-based topographical inspection systems, and X-ray inspection systems. For example, camera vision systems can be used in-line with advanced 360-degree surface defect detection capability, which can integrate with downstream equipment to segregate bad parts.
What OEMs Want
Aside from the very best quality, consistency, and price, an increasing number of MDMs are looking for rapid product development and speed to market, especially now that they are emerging from the pandemic. “Timelines have been compressed with many of our customers,” said Herrild. “Projects that once took 12 months or more to complete are now expected to be done within three to four months.”
With the huge emphasis on time to market, MDMs are leaning on their extruders to provide more value-added secondary processes, which shortens the supply chain and accelerates time to market. Extruders that can provide some or all of these additional services, under one roof, will have plenty of business.
For example, MDMs do not just want basic extrusions anymore—they are constantly pushing their supply chain partners to provide additional value-added features, which may be assembly work or other operations such as tipping, forming, side porting, applying various coatings, slitting, and curving. To stay competitive, extruders must step up and provide these opportunities or their customers will migrate to competitors that do offer these value-added features and other vertically integrated services.
OEMs are asking for more lumens in tubes, micro-tubes, and thinner walls. As a result, “we have seen more and more orders for pressures below 0-5 inches of water to hold these small dimensions and more multi-channel models required,” said DeWolfe. “Medical tubing and even automotive tubing are now held to much tighter specifications than ever before, which creates an even greater need for stable air support internally during the extrusion process.”
Many extruders rely on vacuum to size their tubing. However, many of the thin-wall plastics that are in high demand today require controlled precision air pressure internally to keep the tubing from collapsing during the extrusion process. “The air going inside the tube needs to be held in a very stable, low pressure range—any fluctuations can cause the tubing to go out of specifications,” added DeWolfe.
Often the physical and chemical properties that MDMs seek in their devices can be provided through material formulations. “For example, we recognized a need in the market for thermoplastic elastomers (TPE) that could offer coefficient of friction properties comparable to PTFE, while maintaining the softness and flexibility of traditional elastomers,” said Golub. “We launched our Tygon LCF, a very soft and flexible TPE with an exceptional coefficient of friction, to satisfy this need. It has seen some interesting applications since we launched it about a year ago, predominantly in the endoscopy market.”
With an ever-present focus on speed to market, MDMs want anything that will accelerate development and regulatory approval. This especially includes thorough validation. MDMs expect to receive complete validation paperwork demonstrating the product was developed in a robust manner to ensure sustainability of the process. Therefore, it is essential for extruders to have a strong operational qualification [OQ] showing that process limits have been established and challenged, along with a performance qualification [PQ] that confirms process capabilities have been met.
Increasingly, MDMs are requiring their extrusion partners to validate the material and the process used to extrude the part. Supplying parts that simply meet spec is not enough today—with increased focus on risk, installation qualification (IQ), OQ, and PQ studies have become integral for smoothly advancing the part into production mode. With new devices having extremely tight dimensional specifications, along with very specific material specifications, the extruder is challenged with defining the range of operating conditions where the raw material will produce acceptable parts.
“Does the process have statistical capability of producing the part per the part’s specification?” asked Steele. “Showing statistical capability with very tightly toleranced tubes can become an insurmountable hurdle, where the OEM and the extruder must often negotiate the part’s tolerances. In any case, the validation process pushes the extruder to be at its best.”
New Technology Advancements
Extrusion technology must keep pace with the technology advancements for manufacturing medical devices, especially miniaturization and making smaller, more complex parts with greater functionality. Dimensional specifications continue to tighten, with tolerances around 0.0005 inches for an interior diameter (ID) or outside diameter (OD). Wall thickness specifications continue to get thinner for thermoplastic tubes, with walls as thin as 0.0007 inches with tolerances of ±0.0002 inches.
“The challenge with these very small dimensions is not so much extruding the part, but measuring the part at inspection,” said Steele. “Inspection equipment is getting very sophisticated and also very expensive. At such small scales, inspection procedures for extruders are becoming more complex and time-consuming.”
Inspection can be either on-line or off-line. With on-line inspection, the extruder typically measures the moving target with a laser, which continuously measures the outside diameter of the tube being extruded. Ultrasonic measuring devices can also be used the same way when wall diameters of the tube need to be continuously monitored; these two methods are commonly integrated to work together to give a complete graphic readout of the part being extruded. “For final inspection, we are concerned about snapshots of the part, rather than a moving trend, so the equipment is typically a camera with programmable software that can measure one piece at a time, or hundreds of pieces fixtured on a moving stage,” said Steele. “Not too many years ago, a multi-lumen tube with over 50 inspection points would take an inspector 20 to 30 minutes to inspect, but with today’s equipment that same task can be done in seconds.”
Tubing made for vascular access can be very small in diameter. “This varies largely based on material,” said Golub. “For silicones, we can consistently get down to 0.02 inches OD with 0.01-inch ID; for TPEs and most thermoplastics, we can get down to 0.004 inches. Once you start getting into some of the microfluidic applications, these small sizes really become critical.”
“When you get down to that size and still require high volumes, measurement and accuracy become an issue,” added Herrild. “We have a part in commercial production that is less than 0.03-inch OD with an ID of roughly 0.026 inches. We are in development on a part with an ID of 0.002 inches with a tolerance ±0.0002 inches. It can be hard to find equipment that will pass gauge R&R at those levels.” Herrild uses a Keyence digital microscope (up to 6,000x) for quality assurance/quality control (QA/QC) and Zumbach for inline gauging to measure most small OD/ID parts.
The Internet of Things (IoT) helps attain such small dimensions by providing increased process controls, automation, sensor technologies, and in-line and off-line optical inspection methods (300x and higher). Two systems that are essential for utilizing live machine data from the shop floor are: 1) the manufacturing execution system (MES), which communicates to the enterprise resource planning software (ERP), and 2) a supervisory control and data acquisition (SCADA) system that provides real-time operational information. SCADA’s digital and manufacturing floor interface provides real-time production output and removes manual recording of production activities. With SCADA, continuous data is collected over the entire run. “The ability to pull up trustworthy validated electronic processing and inspection data is critical when producing high-precision medical components,” said Golub. “The closed loop system can also become almost entirely virtual, where an extruder is directly tied into our SCADA and ERP systems, tracking material inventory and scrap in real time, rather than manually counting and entering at the end of each shift.”
Additive manufacturing (AM), another Industry 4.0 technology, helps extruders in several ways. First, it is an excellent method for making solid prototypes and getting them into the hands of stakeholders quickly—sometimes within a day or less. More commonly, AM and 3D printing allow the extrusion house to develop tooling that is not possible to make with conventional machining or electrical discharge machining (EDM) methods, including complex shapes or cooling or heating channels within the tool.
Regulatory Challenges
Regulatory demands are always a challenge for any extrusion house that provides design input or material recommendations to their customers. EU Medical Device Regulation (MDR) compliancy is a must and regulations are constantly changing. Upfront discussions between MDMs and their extruders regarding their overseas expectations are absolutely critical. Therefore, it can be highly beneficial to have a regulatory engineer on staff who is on top of the constantly changing regulatory landscape and can provide recommendations regarding the regulatory impacts of certain materials.
How a medical device is categorized has significant impacts for both the OEM and its suppliers. Understanding if an extruded product is a component, a sub-contracted finished device, or finished medical device requires a thorough partnership between supplier and OEM. “For example,” said Golub, “if you buy bulk tubing for your device, it’s a component because you will take that tubing and manipulate it in a further step such as cutting or assembly. However, if you buy a pre-cut tube and all you do is put it in a kit, or sterilize it, then that is categorized as a sub-contract finished device, which has large regulatory implications for both suppliers and OEMs.”
Most extruders are not FDA-registered facilities, although they are expected by their MDMs to have full knowledge of FDA standards and are often held to those standards in customer audits. ISO 13485: 2016 is the regulatory standard for the medical extrusion industry. A greater variety of international-related requests is being fielded by extruders as MDMs become more involved in global sales and distribution. “For example, more customers have an increased interest in environmental, social, and governance [ESG] factors and want to know how they can meet ESG standards in a way that matches their corporate policies and goals,” said Herrild.
Moving Forward
MDMs will continue to seek customized extrusion solutions with very precise material characteristics and performance parameters. These increasingly small and complex designs are pushing the technology limits of extrusion with smaller extrusions, tighter tolerances, and multilayers/multi-materials, along with new materials with a large range of physical characteristics, including strength, flexibility, and durability. These challenges typically require the development of hybrid tubing innovations—for example, using polymers of different durometers to create variable or transitional flexibility along the length of the tube.
Extruders must work closely with MDMs to fully understand product manufacturability and develop innovative and/or custom extrusion solutions. Sometimes, this requires an approach that is even completely new to the industry. For example, research is being conducted on developing an in-line measuring and control system that is capable of real-time dimensional monitoring of multi-lumen extrusions. Currently, there are ultrasound-based systems that can provide real-time dimensional monitoring of single-lumen and multi-layered extrusions, but to date, this is not possible for multi-lumen at the medical tubing scale.
To keep up with these and other complex demands, extruders are utilizing the latest tools, including online measurement, software processing, Internet of Things, lasers, material blending, and other technologies. As walls become thinner and IDs get smaller, these methods—often creatively combined in the hands of experienced engineers and technicians—continue to improve product consistency, quality, and manufacturing efficiencies.
Perhaps the greatest improvement will be seen in software. Computer-aided engineering (CAE) modeling has made huge improvements over the last 10 years, making it much easier to use and understand. It can be integrated with other IoT technologies to streamline engineering analysis tasks such as finite element analysis (FEA), computational fluid dynamics (CFD), multibody dynamics (MBD), durability, and optimization.
According to ResearchAndMarkets.com's “Global Medical Tubing Market Report 2021,” the global market for medical tubing, valued at US $7.1 billion in 2020, is expected to grow at a compound annual growth rate of 7.6 percent to reach a value of $11.9 billion by 2027.1 This growth will be supported by the integration of different technologies—especially production and inspection systems—for making advanced custom medical tubing that is suitable for a growing number of applications, including catheters, electric medical devices, analytical equipment, fluid transfer, drug delivery, and medical instrumentation. Smaller, flexible, and more steerable catheters are increasingly vital to the success of a growing array of minimally invasive surgical procedures.
Herrild is impressed by the enhanced process controls and data functions in the next generation of extrusion equipment. “Extruder providers and downstream equipment providers are pushing the envelope with controls and data collection,” he said. “Eventually, having that access will continue to take the art out of extrusion and make it more science-based, with more predictable outcomes.”
Reference
Mark Crawford is a full-time freelance business and marketing/communications writer based in Madison, Wis. His clients range from startups to global manufacturing leaders. He also writes a variety of feature articles for regional and national publications and is the author of five books.
Lead times are still unpredictable due to supply chain issues and shortages of personnel, creating inefficiencies in virtually every segment of manufacturing. Critical inputs are getting more expensive, including raw materials, labor (wages/salaries), and the cost of maintaining pandemic procedures for employee safety. Complying with the Centers for Disease Control (CDC) pandemic guidelines has also decreased productivity, reducing profits and cutting margins.
That said, medical extrusion is rebounding from the slowdown in production caused by the cessation of most elective surgeries due to COVID-19. “Production levels have not only rebounded, but surpassed pre-pandemic levels by about 10 percent or more,” said Tim Steele, CEO and founder of Peterborough, N.H.-based MicroSpec Corporation, which provides medical device companies with a variety of extruded tubing. “It is interesting that, for new product development or prototype extrusion during the pandemic, medical extruders did not see a slowdown. In fact, MicroSpec experienced a surge and moved more parts through the prototype phase to being fully validated than any previous year of the company.”
Christian Herrild, director of growth strategies for Baraboo, Wis.-based Teel Plastics, a custom plastics processor that does both extrusion and injection molding, agreed.
“It’s very busy in many segments,” he said. “We have seen a lot of development work going on with products supporting the response to COVID-19, in addition to the usual work that has come back strongly this year.”
Advanced Materials, Smaller Parts
Medical device manufacturers (MDMs) are constantly looking for ways to reduce product size while still maintaining physical requirements and cost controls. To achieve smaller cross sections and still maintain acceptable physical properties, extrusion houses must be creative in developing more exotic material formulations that will allow dimensional scale-down and still meet functional requirements. This includes finding innovative ways to compatibilize these exotic formulations so they can be processed with more standard materials, thereby allowing them to be bonded to or assembled with other components manufactured from conventional materials.
Advanced types of plastics for making tubing continue to be introduced into the medical device market. For example, new additives are developed that can change the flexibility of the tube, or keep the body from attaching to the tube. “The changes made to the polymers can affect every aspect of the extrusion line, including the air pressure required internally,” said Kay DeWolfe, president On Line Controls, a Shrewsbury, Mass.-based manufacturer of ultra-low air pressure regulators and controllers for tubing extrusion. “Adding lumens to the tubes allows passing of different medications or inserting wires into the body. Every year, we hear from someone adding more and more lumens into one small tube. The latest has over 30 lumens in one tiny tube that is less than 1/8 inch outer diameter.”
For new concept parts, MDMs are making fewer requests for general-purpose polymers—instead they have greater interest in using new and specialized materials, with specific engineered properties. Common characteristics considered by design engineers include stiffness/flexibility, hardness/softness, lubricity/tackiness, column strength, and biocompatibility. “When selecting a polymer for a highly specialized extrusion, design engineers need to find or create a material that watches the requirements for the form, fit, and function of the new part,” said Steele. “The new material is often a custom formulation specific to an individual part. It seems that not too long ago, there were just a handful of materials being used; today, there are too many to mention.”
Producing miniaturized components also requires enhanced capability to inspect these smaller dimensions at resolutions that will provide statistically significant data for validation work. This drives the need for high-resolution optical inspection systems, laser-based topographical inspection systems, and X-ray inspection systems. For example, camera vision systems can be used in-line with advanced 360-degree surface defect detection capability, which can integrate with downstream equipment to segregate bad parts.
What OEMs Want
Aside from the very best quality, consistency, and price, an increasing number of MDMs are looking for rapid product development and speed to market, especially now that they are emerging from the pandemic. “Timelines have been compressed with many of our customers,” said Herrild. “Projects that once took 12 months or more to complete are now expected to be done within three to four months.”
With the huge emphasis on time to market, MDMs are leaning on their extruders to provide more value-added secondary processes, which shortens the supply chain and accelerates time to market. Extruders that can provide some or all of these additional services, under one roof, will have plenty of business.
For example, MDMs do not just want basic extrusions anymore—they are constantly pushing their supply chain partners to provide additional value-added features, which may be assembly work or other operations such as tipping, forming, side porting, applying various coatings, slitting, and curving. To stay competitive, extruders must step up and provide these opportunities or their customers will migrate to competitors that do offer these value-added features and other vertically integrated services.
OEMs are asking for more lumens in tubes, micro-tubes, and thinner walls. As a result, “we have seen more and more orders for pressures below 0-5 inches of water to hold these small dimensions and more multi-channel models required,” said DeWolfe. “Medical tubing and even automotive tubing are now held to much tighter specifications than ever before, which creates an even greater need for stable air support internally during the extrusion process.”
Many extruders rely on vacuum to size their tubing. However, many of the thin-wall plastics that are in high demand today require controlled precision air pressure internally to keep the tubing from collapsing during the extrusion process. “The air going inside the tube needs to be held in a very stable, low pressure range—any fluctuations can cause the tubing to go out of specifications,” added DeWolfe.
Often the physical and chemical properties that MDMs seek in their devices can be provided through material formulations. “For example, we recognized a need in the market for thermoplastic elastomers (TPE) that could offer coefficient of friction properties comparable to PTFE, while maintaining the softness and flexibility of traditional elastomers,” said Golub. “We launched our Tygon LCF, a very soft and flexible TPE with an exceptional coefficient of friction, to satisfy this need. It has seen some interesting applications since we launched it about a year ago, predominantly in the endoscopy market.”
With an ever-present focus on speed to market, MDMs want anything that will accelerate development and regulatory approval. This especially includes thorough validation. MDMs expect to receive complete validation paperwork demonstrating the product was developed in a robust manner to ensure sustainability of the process. Therefore, it is essential for extruders to have a strong operational qualification [OQ] showing that process limits have been established and challenged, along with a performance qualification [PQ] that confirms process capabilities have been met.
Increasingly, MDMs are requiring their extrusion partners to validate the material and the process used to extrude the part. Supplying parts that simply meet spec is not enough today—with increased focus on risk, installation qualification (IQ), OQ, and PQ studies have become integral for smoothly advancing the part into production mode. With new devices having extremely tight dimensional specifications, along with very specific material specifications, the extruder is challenged with defining the range of operating conditions where the raw material will produce acceptable parts.
“Does the process have statistical capability of producing the part per the part’s specification?” asked Steele. “Showing statistical capability with very tightly toleranced tubes can become an insurmountable hurdle, where the OEM and the extruder must often negotiate the part’s tolerances. In any case, the validation process pushes the extruder to be at its best.”
New Technology Advancements
Extrusion technology must keep pace with the technology advancements for manufacturing medical devices, especially miniaturization and making smaller, more complex parts with greater functionality. Dimensional specifications continue to tighten, with tolerances around 0.0005 inches for an interior diameter (ID) or outside diameter (OD). Wall thickness specifications continue to get thinner for thermoplastic tubes, with walls as thin as 0.0007 inches with tolerances of ±0.0002 inches.
“The challenge with these very small dimensions is not so much extruding the part, but measuring the part at inspection,” said Steele. “Inspection equipment is getting very sophisticated and also very expensive. At such small scales, inspection procedures for extruders are becoming more complex and time-consuming.”
Inspection can be either on-line or off-line. With on-line inspection, the extruder typically measures the moving target with a laser, which continuously measures the outside diameter of the tube being extruded. Ultrasonic measuring devices can also be used the same way when wall diameters of the tube need to be continuously monitored; these two methods are commonly integrated to work together to give a complete graphic readout of the part being extruded. “For final inspection, we are concerned about snapshots of the part, rather than a moving trend, so the equipment is typically a camera with programmable software that can measure one piece at a time, or hundreds of pieces fixtured on a moving stage,” said Steele. “Not too many years ago, a multi-lumen tube with over 50 inspection points would take an inspector 20 to 30 minutes to inspect, but with today’s equipment that same task can be done in seconds.”
Tubing made for vascular access can be very small in diameter. “This varies largely based on material,” said Golub. “For silicones, we can consistently get down to 0.02 inches OD with 0.01-inch ID; for TPEs and most thermoplastics, we can get down to 0.004 inches. Once you start getting into some of the microfluidic applications, these small sizes really become critical.”
“When you get down to that size and still require high volumes, measurement and accuracy become an issue,” added Herrild. “We have a part in commercial production that is less than 0.03-inch OD with an ID of roughly 0.026 inches. We are in development on a part with an ID of 0.002 inches with a tolerance ±0.0002 inches. It can be hard to find equipment that will pass gauge R&R at those levels.” Herrild uses a Keyence digital microscope (up to 6,000x) for quality assurance/quality control (QA/QC) and Zumbach for inline gauging to measure most small OD/ID parts.
The Internet of Things (IoT) helps attain such small dimensions by providing increased process controls, automation, sensor technologies, and in-line and off-line optical inspection methods (300x and higher). Two systems that are essential for utilizing live machine data from the shop floor are: 1) the manufacturing execution system (MES), which communicates to the enterprise resource planning software (ERP), and 2) a supervisory control and data acquisition (SCADA) system that provides real-time operational information. SCADA’s digital and manufacturing floor interface provides real-time production output and removes manual recording of production activities. With SCADA, continuous data is collected over the entire run. “The ability to pull up trustworthy validated electronic processing and inspection data is critical when producing high-precision medical components,” said Golub. “The closed loop system can also become almost entirely virtual, where an extruder is directly tied into our SCADA and ERP systems, tracking material inventory and scrap in real time, rather than manually counting and entering at the end of each shift.”
Additive manufacturing (AM), another Industry 4.0 technology, helps extruders in several ways. First, it is an excellent method for making solid prototypes and getting them into the hands of stakeholders quickly—sometimes within a day or less. More commonly, AM and 3D printing allow the extrusion house to develop tooling that is not possible to make with conventional machining or electrical discharge machining (EDM) methods, including complex shapes or cooling or heating channels within the tool.
Regulatory Challenges
Regulatory demands are always a challenge for any extrusion house that provides design input or material recommendations to their customers. EU Medical Device Regulation (MDR) compliancy is a must and regulations are constantly changing. Upfront discussions between MDMs and their extruders regarding their overseas expectations are absolutely critical. Therefore, it can be highly beneficial to have a regulatory engineer on staff who is on top of the constantly changing regulatory landscape and can provide recommendations regarding the regulatory impacts of certain materials.
How a medical device is categorized has significant impacts for both the OEM and its suppliers. Understanding if an extruded product is a component, a sub-contracted finished device, or finished medical device requires a thorough partnership between supplier and OEM. “For example,” said Golub, “if you buy bulk tubing for your device, it’s a component because you will take that tubing and manipulate it in a further step such as cutting or assembly. However, if you buy a pre-cut tube and all you do is put it in a kit, or sterilize it, then that is categorized as a sub-contract finished device, which has large regulatory implications for both suppliers and OEMs.”
Most extruders are not FDA-registered facilities, although they are expected by their MDMs to have full knowledge of FDA standards and are often held to those standards in customer audits. ISO 13485: 2016 is the regulatory standard for the medical extrusion industry. A greater variety of international-related requests is being fielded by extruders as MDMs become more involved in global sales and distribution. “For example, more customers have an increased interest in environmental, social, and governance [ESG] factors and want to know how they can meet ESG standards in a way that matches their corporate policies and goals,” said Herrild.
Moving Forward
MDMs will continue to seek customized extrusion solutions with very precise material characteristics and performance parameters. These increasingly small and complex designs are pushing the technology limits of extrusion with smaller extrusions, tighter tolerances, and multilayers/multi-materials, along with new materials with a large range of physical characteristics, including strength, flexibility, and durability. These challenges typically require the development of hybrid tubing innovations—for example, using polymers of different durometers to create variable or transitional flexibility along the length of the tube.
Extruders must work closely with MDMs to fully understand product manufacturability and develop innovative and/or custom extrusion solutions. Sometimes, this requires an approach that is even completely new to the industry. For example, research is being conducted on developing an in-line measuring and control system that is capable of real-time dimensional monitoring of multi-lumen extrusions. Currently, there are ultrasound-based systems that can provide real-time dimensional monitoring of single-lumen and multi-layered extrusions, but to date, this is not possible for multi-lumen at the medical tubing scale.
To keep up with these and other complex demands, extruders are utilizing the latest tools, including online measurement, software processing, Internet of Things, lasers, material blending, and other technologies. As walls become thinner and IDs get smaller, these methods—often creatively combined in the hands of experienced engineers and technicians—continue to improve product consistency, quality, and manufacturing efficiencies.
Perhaps the greatest improvement will be seen in software. Computer-aided engineering (CAE) modeling has made huge improvements over the last 10 years, making it much easier to use and understand. It can be integrated with other IoT technologies to streamline engineering analysis tasks such as finite element analysis (FEA), computational fluid dynamics (CFD), multibody dynamics (MBD), durability, and optimization.
According to ResearchAndMarkets.com's “Global Medical Tubing Market Report 2021,” the global market for medical tubing, valued at US $7.1 billion in 2020, is expected to grow at a compound annual growth rate of 7.6 percent to reach a value of $11.9 billion by 2027.1 This growth will be supported by the integration of different technologies—especially production and inspection systems—for making advanced custom medical tubing that is suitable for a growing number of applications, including catheters, electric medical devices, analytical equipment, fluid transfer, drug delivery, and medical instrumentation. Smaller, flexible, and more steerable catheters are increasingly vital to the success of a growing array of minimally invasive surgical procedures.
Herrild is impressed by the enhanced process controls and data functions in the next generation of extrusion equipment. “Extruder providers and downstream equipment providers are pushing the envelope with controls and data collection,” he said. “Eventually, having that access will continue to take the art out of extrusion and make it more science-based, with more predictable outcomes.”
Reference
Mark Crawford is a full-time freelance business and marketing/communications writer based in Madison, Wis. His clients range from startups to global manufacturing leaders. He also writes a variety of feature articles for regional and national publications and is the author of five books.