Erik Swain03.04.09
Medical tubing looks like a simple component, but it isn't. Most medical tubes are made by extrusion, which is a complicated, dynamic process.
In recent years, the process has gotten even more complicated. New applications sometimes require combinations of properties that previously weren't found together. Not only must a medical OEM and its extrusion outsourcing partner design a tube that can meet these requirements, they must make sure it can be processed properly and consistently.
Michael Badera, president of Precision Extrusion Inc. of Glens Falls, N.Y., noted that "the trend the last few years is for customers to demand properties that you can't get with one material. They tend to want more things in a smaller space. So we look at combination custom blends or do coextrusions to get thinner walls, tighter tolerances and so on. There is never an across-the-board answer to these questions. Sometimes we work with chemists and compounders to come up with the right combination to give our customers the properties they need."
Given that medical device OEMs are asking for higher performance out of their tubing, it is no surprise that a lot of thought is going into material selection, particularly custom blends.
"Customers are trying to exceed the limits of the plastics all the time," said Bob Poirier, vice president of sales for Dunn Industries Inc., a Manchester, N.H.-based custom extruder. "And you have to try to do what they want. Sometimes you achieve it, sometimes you don't. But there are new engineered materials, which are proprietary, that are helping."
"The changes in the industry are to move towards tubing that can perform differently along its length or perform more than one task or function," said Tim Lynch, vice president of operations for Microlumen Inc., a tubing manufacturer in Tampa, Fla."Simply stated, [customers want] composite tubing with many features."
Pradnya Parulekar, custom molded silicones market brand manager for Helix Medical LLC, an extruder in Carpinteria, Calif., says her firm's clients are increasingly interested in custom blends and multi-functional applications. "They want them to withstand high pressures and maintain current temperatures of the fluid material, even if all they're doing is transferring fluid from component to component," she said. "Engineers and designers are looking to build assemblies with fewer components. If you have fewer items, you need the ones you have to be multi-functional. And if you push more of the manufacturing back on the supplier, you can manage your quality system better. This is especially true for companies that still have high manufacturing or labor costs."
Product innovation is the driver behind many of these demands, said Apur Lathiya, chief operating officer of ExtruMed, an extruder in Placentia, Calif. "We've received an increase in requests for multi-lumens and balloon tubing because of that," he said. "Design engineers are getting more and more innovative with what they are trying to do. That means thinking differently about materials. For example, we are seeing more urethane copolymers and specialty urethanes being used, especially by companies in the electrostimulation market that need implantable tubes. They need both the biostability of silicones and the durability of urethanes."
New product designs also present challenges to the process of extrusion. Medical OEMs are demanding that their tubing have thinner walls, thinner diameters and harder or softer durometers. They also expect the extrusion process to hold tighter tolerances-that is, be more consistent-than before.
"With tolerances, we are at the point where we are starting to infringe upon our ability to measure them," said Brad Rabitor, vice president of business development for Putnam Plastics of Dayville, Conn. "We have tapped out our limits."
"Tolerances of medical tubing are more critical than ever before," added Richard Brooks, vice president of sales and marketing for Filtrona Extrusion, which has extrusion facilities in Athol, Mass., and Monterrey, Mexico."A normal tube with a 0.25-inch outer diameter will have a manufacturing tolerance of plus or minus 0.005 inches. Now, medical customers want plus or minus 0.003 inches. That is extremely difficult to hold. Extrusion is a continuous flow and has a surging up-and-down process. You are going to have variance, but the medical OEMs want that controlled as much as possible, because it makes their assembly process easier."
But it makes extruders' lives more difficult. To cut variance, the job may have to be run slower, which increases the project's cost. Or, an engineer may have to be kept nearby to tweak the job as it is running-and his or her pay is higher than a regular machine operator.
The challenge is to keep tighter tolerances and improve manufacturing proc-esses, but not pass on extra costs to the customer. If the engineers say they can't hold the tolerances to the customer's specification, compromise may be an option, but "once they hear that it's not doable, there's a chance that they will," said Brooks.
Some applications require that tubing be much harder or much softer than usual. That creates another set of challenges, said Parulekar.
"People want to push the limits on durometers these days," she said. "It used to be that most were in the middle range of 40-60. Now we are seeing requests for 20, which is very soft, and 80, which is very hard. When it's that soft, it makes it difficult to extrude, because it's harder to maintain shape."
These demands make selecting the right material even more crucial than it has been. The material selection process must be a careful and thorough one. Some medical OEMs prefer to call those shots themselves, but the process can be collaborative, too, as today's extrusion prov-iders are well versed in which materials have which properties.
"Normally the customer has a base material they prefer, and then we expand on that, depending on what properties they're looking for-kink resistance, elongation, and so on," said Poirier. "We will make it for them if we can extrude it. We may have to make five to 10 runs before we get it. We have to do a lot of R&D to improve what they do."
"Most of the time, customers that come to us already have a good idea of what they want. They may not know the exact grade or trade name, but they know they want a nylon or a PEEK or a polyurethane," said Badera. "We will take that information and refine it, based on physical, temperature and chemical requirements. If they don't know what family of material they want, we ask them what characteristics they most require. Are they worried about burst strength? Kink resistance? How hot is the manufacturing process? Is there a problem with drug interaction?"
He adds that Precision Extrusion has seen a rise in requests for PEEK. "PEEK is desired for its stiffness, strength, and chemical inertness," he said. "It has a thin wall tubing but some kink resistance."
"The most important considerations include clarity, flexibility, non-kinking element, solvent bonding, sterilizability, cost, and availability," said Brooks. "Some materials require a 10- to 12-week lead time from the resin supplier, and that's inappropriate."
"Finding the right material is almost a process of elimination," said Rabitor. "Start with what is most critical, then factor in what else you need. Hopefully it will come down to one to three options. Then you can choose between them based on processability and pricing."
Environmental considerations also arecoming into play, Brooks added.
"Eighty-five percent of the medical tubing is PVC, mainly for fluid and gas administration sets. Customers are asking to move away from traditional PVC to a more expensive PVC without DEHP, a plasticizer," he said. "Some have gone farther and asked for a non-phthalate material, as phthalates are potentially carcinogenic-causing. In the 50-plus years that PVC tubing has been used for medical products, there has never been one illness or casualty ever recorded that can be related to the use of normal PVC tubing. But some in Europe and California are big on this issue. In tests with lab mice, some of them have gotten sick from normal PVC, so there is a potential risk. As an alternative, there is a polyolefin-based material from Europe that is very expensive. It has the clarity of PVC, solvent bonds like PVC, and does everything else it does. Some customers are very interested in it, especially if they have small, lightweight tubes. If they have a big tube, it might not make sense because of the cost. Thermoplastic elastomers also are still popular. One is Krayton, a styrenic buterate copolymer. It has tremendous elasticity and contains no PVC."
Tooling also plays a major role in helping medical OEMs find a proper extrusion process for the tubing they have designed. Lathiya notes that while extrusion equipment has not changed much in recent years, tooling has.
"The processes currently in place are able to make the desired products. Customers want thinner walls, smaller diameters and tighter tolerances. We look at our tooling to help us meet these challenges," he said. "But we don't see any revolutionary equipment on the horizon. Customers are not involved in decisions about the processing machinery unless there are secondary processes that they need us to do."
Rabitor added that advances in tooling have a lot to do with how extrusion providers can meet difficult specifications from customers.
"There is a lot of competition, and people are trying to lower their costs. In the old days, it was common to raise your prices every year. Now, even if your costs go up, medical customers want the prices to come down. So you have to find process improvements that give the same quality while reducing costs," he said. "You have to improve cycle times, line speeds and yields. A lot of that has to do with knowing your raw materials. We have a lab where we research various polymers to get a better understanding of how they run. And we have invested greatly in our core competency of building tooling. You can get process improvements out of better tooling design."
The process of making tubing isn't a simple one, so sometimes tubing prov-ders look to other service providers for solutions, said Lynch.
"The key is to take on win-win, value-added processes and to use others when their capabilities exceed your own," he said. "Do what you choose to do well, and develop key relationships with complimentary suppliers to do the rest while providing the customer a part that is as well-developed and finished as possible."
It is no surprise that there is extreme price pressure right now. With the financial markets in chaos, companies want to make their bottom lines look as good as possible. There is only so much that extrusion suppliers can do about the cost of raw materials, however. So some of them are finding creative solutions regarding inventory and delivery practices.
"In 2008, there were huge raw material price increases," said Brooks. "The medical-grade resins we use are all petro-chemical related. So medical extruders like us had to raise prices, because material costs are a big determiner of our prices. Now, resin prices have just started to slide-the effect takes longer than it does for gasoline. And medical OEMs are saying 'cut your costs and reduce our prices.' These days, no OEM wants to keep a lot of inventory, because they want to improve their cash flow. They want us to keep inventory for them. So they request that we stock more of their high-volume products so we can use a Just-in-Time or Kanban delivery system."
These conditions are also having an impact on long-term projects.
"Customers are being very cautious about placing purchase orders. More engineering is being done before we cut any tooling," said Parulekar. "And good contract manufacturers with engineering know-how can support that."
"We do an awful lot of R&D work, and the economy is having an impact on that," Badera said. "When everything starts to go south, the big companies cut back on R&D, because it's a short-term expense with long-term payback, and by cutting it they can make their books look good now. But one-third of our business is international, and there are not quite the same economic woes abroad. In fact, our international sales volume almost doubled last year. That helped offset the U.S. downturn and cutbacks."
But despite the poor economy, the medical extrusion business isn't exactly suffering.
While some extrusion companies are cutting costs and implementing efficiencies to improve the bottom line, most are not seeing any downturn in sales.
Some of that has to do with the demand curve for medical products. Patients still get sick enough to be hospitalized, so IV lines, catheters, and other tubing applications aren't exactly sitting on shelves unused. But some of it has to do with the nature of how products are approved and their components are specified.
"When an extrusion company is specified as an extruder for a medical device manufacturer, it will service them for many years. It is very difficult for a non-specified competitor to steal business. It is a heavy cost to revalidate a supplier," said Brooks. "As long as we service customers well and provide consistently good quality, we can retain our customers. However, we are at risk if we raise prices, have our quality fall, or have lead times take longer. The dichotomy is that for those same reasons, it's difficult to get new business."
Extrusion providers understand that tubing has to be more versatile than it was in the past, and are working very hard to help medical OEMs make it so.
An incredible amount of research has been put in to everything from compounding custom blends to designing new tooling. And, provided their customers continue to understand how this research benefits them in the long run, these efforts will persist.
"Imagine being asked to build a faster car that doesn't use as much gas. That's what our customers do to us," said Poirier. "Of course, they don't use just one supplier, and will give the business to whoever can figure it out. So you have to stay abreast of the industry and figure out how to do new things."
Erik Swain is a freelance writer based in Phillipsburg, N.J. He has covered the medical device industry for 12 years.
In recent years, the process has gotten even more complicated. New applications sometimes require combinations of properties that previously weren't found together. Not only must a medical OEM and its extrusion outsourcing partner design a tube that can meet these requirements, they must make sure it can be processed properly and consistently.
Medical tubing companies are facing new challenges with customers demanding "properties that you can't get with one material. ... So we look at combination custom blends or do coextrusions to get thinner walls, tighter tolerances and so on," said Michael Badera, president of Precision Extrusion. Photo courtesy of Precision Extrusion. |
Michael Badera, president of Precision Extrusion Inc. of Glens Falls, N.Y., noted that "the trend the last few years is for customers to demand properties that you can't get with one material. They tend to want more things in a smaller space. So we look at combination custom blends or do coextrusions to get thinner walls, tighter tolerances and so on. There is never an across-the-board answer to these questions. Sometimes we work with chemists and compounders to come up with the right combination to give our customers the properties they need."
Material Selection
Given that medical device OEMs are asking for higher performance out of their tubing, it is no surprise that a lot of thought is going into material selection, particularly custom blends.
"Customers are trying to exceed the limits of the plastics all the time," said Bob Poirier, vice president of sales for Dunn Industries Inc., a Manchester, N.H.-based custom extruder. "And you have to try to do what they want. Sometimes you achieve it, sometimes you don't. But there are new engineered materials, which are proprietary, that are helping."
"The changes in the industry are to move towards tubing that can perform differently along its length or perform more than one task or function," said Tim Lynch, vice president of operations for Microlumen Inc., a tubing manufacturer in Tampa, Fla."Simply stated, [customers want] composite tubing with many features."
Pradnya Parulekar, custom molded silicones market brand manager for Helix Medical LLC, an extruder in Carpinteria, Calif., says her firm's clients are increasingly interested in custom blends and multi-functional applications. "They want them to withstand high pressures and maintain current temperatures of the fluid material, even if all they're doing is transferring fluid from component to component," she said. "Engineers and designers are looking to build assemblies with fewer components. If you have fewer items, you need the ones you have to be multi-functional. And if you push more of the manufacturing back on the supplier, you can manage your quality system better. This is especially true for companies that still have high manufacturing or labor costs."
Product innovation is the driver behind many of these demands, said Apur Lathiya, chief operating officer of ExtruMed, an extruder in Placentia, Calif. "We've received an increase in requests for multi-lumens and balloon tubing because of that," he said. "Design engineers are getting more and more innovative with what they are trying to do. That means thinking differently about materials. For example, we are seeing more urethane copolymers and specialty urethanes being used, especially by companies in the electrostimulation market that need implantable tubes. They need both the biostability of silicones and the durability of urethanes."
Customers are being extremely cautious about purchasing tubing because of the economy. Photo courtesy of Precision Extrusion. |
New product designs also present challenges to the process of extrusion. Medical OEMs are demanding that their tubing have thinner walls, thinner diameters and harder or softer durometers. They also expect the extrusion process to hold tighter tolerances-that is, be more consistent-than before.
"With tolerances, we are at the point where we are starting to infringe upon our ability to measure them," said Brad Rabitor, vice president of business development for Putnam Plastics of Dayville, Conn. "We have tapped out our limits."
"Tolerances of medical tubing are more critical than ever before," added Richard Brooks, vice president of sales and marketing for Filtrona Extrusion, which has extrusion facilities in Athol, Mass., and Monterrey, Mexico."A normal tube with a 0.25-inch outer diameter will have a manufacturing tolerance of plus or minus 0.005 inches. Now, medical customers want plus or minus 0.003 inches. That is extremely difficult to hold. Extrusion is a continuous flow and has a surging up-and-down process. You are going to have variance, but the medical OEMs want that controlled as much as possible, because it makes their assembly process easier."
But it makes extruders' lives more difficult. To cut variance, the job may have to be run slower, which increases the project's cost. Or, an engineer may have to be kept nearby to tweak the job as it is running-and his or her pay is higher than a regular machine operator.
The challenge is to keep tighter tolerances and improve manufacturing proc-esses, but not pass on extra costs to the customer. If the engineers say they can't hold the tolerances to the customer's specification, compromise may be an option, but "once they hear that it's not doable, there's a chance that they will," said Brooks.
Some applications require that tubing be much harder or much softer than usual. That creates another set of challenges, said Parulekar.
"People want to push the limits on durometers these days," she said. "It used to be that most were in the middle range of 40-60. Now we are seeing requests for 20, which is very soft, and 80, which is very hard. When it's that soft, it makes it difficult to extrude, because it's harder to maintain shape."
The Decision Process
These demands make selecting the right material even more crucial than it has been. The material selection process must be a careful and thorough one. Some medical OEMs prefer to call those shots themselves, but the process can be collaborative, too, as today's extrusion prov-iders are well versed in which materials have which properties.
Tubing customers are increasingly taking the environment into consideration. Photo courtesy of ExtruMed. |
"Normally the customer has a base material they prefer, and then we expand on that, depending on what properties they're looking for-kink resistance, elongation, and so on," said Poirier. "We will make it for them if we can extrude it. We may have to make five to 10 runs before we get it. We have to do a lot of R&D to improve what they do."
"Most of the time, customers that come to us already have a good idea of what they want. They may not know the exact grade or trade name, but they know they want a nylon or a PEEK or a polyurethane," said Badera. "We will take that information and refine it, based on physical, temperature and chemical requirements. If they don't know what family of material they want, we ask them what characteristics they most require. Are they worried about burst strength? Kink resistance? How hot is the manufacturing process? Is there a problem with drug interaction?"
He adds that Precision Extrusion has seen a rise in requests for PEEK. "PEEK is desired for its stiffness, strength, and chemical inertness," he said. "It has a thin wall tubing but some kink resistance."
"The most important considerations include clarity, flexibility, non-kinking element, solvent bonding, sterilizability, cost, and availability," said Brooks. "Some materials require a 10- to 12-week lead time from the resin supplier, and that's inappropriate."
"Finding the right material is almost a process of elimination," said Rabitor. "Start with what is most critical, then factor in what else you need. Hopefully it will come down to one to three options. Then you can choose between them based on processability and pricing."
Environmental considerations also arecoming into play, Brooks added.
"Eighty-five percent of the medical tubing is PVC, mainly for fluid and gas administration sets. Customers are asking to move away from traditional PVC to a more expensive PVC without DEHP, a plasticizer," he said. "Some have gone farther and asked for a non-phthalate material, as phthalates are potentially carcinogenic-causing. In the 50-plus years that PVC tubing has been used for medical products, there has never been one illness or casualty ever recorded that can be related to the use of normal PVC tubing. But some in Europe and California are big on this issue. In tests with lab mice, some of them have gotten sick from normal PVC, so there is a potential risk. As an alternative, there is a polyolefin-based material from Europe that is very expensive. It has the clarity of PVC, solvent bonds like PVC, and does everything else it does. Some customers are very interested in it, especially if they have small, lightweight tubes. If they have a big tube, it might not make sense because of the cost. Thermoplastic elastomers also are still popular. One is Krayton, a styrenic buterate copolymer. It has tremendous elasticity and contains no PVC."
Tooling's Role
Tooling also plays a major role in helping medical OEMs find a proper extrusion process for the tubing they have designed. Lathiya notes that while extrusion equipment has not changed much in recent years, tooling has.
"The processes currently in place are able to make the desired products. Customers want thinner walls, smaller diameters and tighter tolerances. We look at our tooling to help us meet these challenges," he said. "But we don't see any revolutionary equipment on the horizon. Customers are not involved in decisions about the processing machinery unless there are secondary processes that they need us to do."
Rabitor added that advances in tooling have a lot to do with how extrusion providers can meet difficult specifications from customers.
"There is a lot of competition, and people are trying to lower their costs. In the old days, it was common to raise your prices every year. Now, even if your costs go up, medical customers want the prices to come down. So you have to find process improvements that give the same quality while reducing costs," he said. "You have to improve cycle times, line speeds and yields. A lot of that has to do with knowing your raw materials. We have a lab where we research various polymers to get a better understanding of how they run. And we have invested greatly in our core competency of building tooling. You can get process improvements out of better tooling design."
The process of making tubing isn't a simple one, so sometimes tubing prov-ders look to other service providers for solutions, said Lynch.
"The key is to take on win-win, value-added processes and to use others when their capabilities exceed your own," he said. "Do what you choose to do well, and develop key relationships with complimentary suppliers to do the rest while providing the customer a part that is as well-developed and finished as possible."
Economic Issues
It is no surprise that there is extreme price pressure right now. With the financial markets in chaos, companies want to make their bottom lines look as good as possible. There is only so much that extrusion suppliers can do about the cost of raw materials, however. So some of them are finding creative solutions regarding inventory and delivery practices.
"In 2008, there were huge raw material price increases," said Brooks. "The medical-grade resins we use are all petro-chemical related. So medical extruders like us had to raise prices, because material costs are a big determiner of our prices. Now, resin prices have just started to slide-the effect takes longer than it does for gasoline. And medical OEMs are saying 'cut your costs and reduce our prices.' These days, no OEM wants to keep a lot of inventory, because they want to improve their cash flow. They want us to keep inventory for them. So they request that we stock more of their high-volume products so we can use a Just-in-Time or Kanban delivery system."
These conditions are also having an impact on long-term projects.
"Customers are being very cautious about placing purchase orders. More engineering is being done before we cut any tooling," said Parulekar. "And good contract manufacturers with engineering know-how can support that."
"We do an awful lot of R&D work, and the economy is having an impact on that," Badera said. "When everything starts to go south, the big companies cut back on R&D, because it's a short-term expense with long-term payback, and by cutting it they can make their books look good now. But one-third of our business is international, and there are not quite the same economic woes abroad. In fact, our international sales volume almost doubled last year. That helped offset the U.S. downturn and cutbacks."
But despite the poor economy, the medical extrusion business isn't exactly suffering.
While some extrusion companies are cutting costs and implementing efficiencies to improve the bottom line, most are not seeing any downturn in sales.
Some of that has to do with the demand curve for medical products. Patients still get sick enough to be hospitalized, so IV lines, catheters, and other tubing applications aren't exactly sitting on shelves unused. But some of it has to do with the nature of how products are approved and their components are specified.
"When an extrusion company is specified as an extruder for a medical device manufacturer, it will service them for many years. It is very difficult for a non-specified competitor to steal business. It is a heavy cost to revalidate a supplier," said Brooks. "As long as we service customers well and provide consistently good quality, we can retain our customers. However, we are at risk if we raise prices, have our quality fall, or have lead times take longer. The dichotomy is that for those same reasons, it's difficult to get new business."
The Quest for Versatile Tubing
Extrusion providers understand that tubing has to be more versatile than it was in the past, and are working very hard to help medical OEMs make it so.
An incredible amount of research has been put in to everything from compounding custom blends to designing new tooling. And, provided their customers continue to understand how this research benefits them in the long run, these efforts will persist.
"Imagine being asked to build a faster car that doesn't use as much gas. That's what our customers do to us," said Poirier. "Of course, they don't use just one supplier, and will give the business to whoever can figure it out. So you have to stay abreast of the industry and figure out how to do new things."
Erik Swain is a freelance writer based in Phillipsburg, N.J. He has covered the medical device industry for 12 years.