Mark Crawford, Contributing Writer02.03.21
Machining and laser processing continue to gain traction in the medical device industry, thanks in part to the growing need for microscale medical devices—especially for minimally invasive procedures, which require smaller devices with unique dimensions and tight tolerances. As medical devices get smaller and more complex, machinists must have the equipment, skills, and know-how to deliver the micron-scale features and precision these products require.
Whether machining requires a computer numerical control (CNC) machine or a laser depends on the design and feature requirements of the device. To be competitive, machine partners must stay current on the technology advancements in the machining/laser processing world and have the knowledge and expertise to push their processes to the limit.
“The state of machining is quite advanced in the medical industry, due to a willingness to embrace process improvement in all areas and to push the current manufacturing systems to get the quickest and most cost-effective process,” said Florian Dierigl, business development manager for the medical industry for TYROLIT, an Austria-based manufacturer of bonded grinding, cut-off, finishing, drilling, and dressing tools.
CNC machine manufacturers continue to add more capabilities to their equipment, such as better processing control of raw materials, Internet of Things (IoT) connectivity, advanced but easy-to-use interfaces, and improved software and cloud interactions. CNC machines are hard to beat for bulk material removal; lasers tend to be more efficient for profiling and drilling fine features, particularly through thin materials. Steady advances in laser micromachining, especially the use of femtosecond-pulsed laser systems, make them competitive with conventional machining methods, including electrical discharge machining (EDM).
“Lasers are very effective for holes and slots—two-dimensional features that are through features,” said Tim Hoklas, senior director of technical solutions for Viant, a Foxborough, Mass.-based strategic design and manufacturing partner to the medical device industry. “CNC is better for three-dimensional features such as turning, milling, and blind holes/features.”
Latest Trends
“Miniaturization continues to be a driving trend in the medical device industry, especially for medical procedures that require micro-scale components such as ophthalmic, neurovascular, cardiovascular, and structural heart therapies,” said Kevin Hartke, chief technology officer for Resonetics, a Nashua, N.H.-based micromanufacturer of components and assemblies for medical device and diagnostics companies.
Both conventional CNC machining and laser processing are valuable manufacturing methods for these devices. Although standard machining is generally preferred for cutting, lasers can make features as small as 10 µm (0.0004 inches). OEMs often request features with single-micron tolerances, which is difficult to achieve with conventional machining. Although CNC micromachining is becoming competitive for cutting extremely fine features, lasers also have other valuable applications, such as texturing and welding.
“For the range of feature sizes and the soft polymer materials we specialize in, the laser is often the only manufacturing solution for the features our clients desire,” said Matthew Nipper, director of engineering at Laser Light Technologies, a Hermann, Mo.-based full-service laser solutions provider to the medical device, life science, and microelectronics industries. “Laser machining does not necessarily displace conventional machining, but it is absolutely critical for achieving designs with a continuously shrinking form factor.”
“Laser machining is being used more frequently as medical devices get smaller and more complex,” agreed Mike Chmura, operations manager medical for the Litron Division of Hermetic Solutions Group, an Agawam, Mass.-based provider of laser services and package fabrication to the medical device industry. “This can create new challenges, such as with work holding. Being able to hold the pieces together with high precision for laser machining or welding means tighter tolerances and higher accuracies.”
Femtosecond lasers are increasingly popular because of their speed, precision, and ability to cut small features with no heat alteration zones (HAZ). The shorter the pulse width, the greater the effectiveness of the cut, with fewer burrs or thermal defects. Ultrafast lasers—those defined as having pulse widths equal to or less than 10E-12 (10 picoseconds)—strip electrons from the atoms in the material, ionizing the atoms and forcing them to explode out of the bulk material, with virtually no heat transfer. “Femtosecond lasers—with a pulse width of 10 femtoseconds (10E-15s)—produce the least amount of heat damage and are critical for the high-precision manufacturing of medical devices,” said Nipper.
Femtosecond laser processing is trending toward higher power and pulse energy. “This allows for faster material removal rates and makes shorter wavelength options, such as green and UV, more viable for industrial applications,” said Zane Wyatt, new product introduction engineer for laser applications for JM Medical Device Components, a San Diego, Calif.-based provider of custom-machined parts for the medical device industry.
Machine tool suppliers have started integrating lasers and traditional machining methods into a single “hybrid” machine. For example, by combining laser cutting and welding with traditional Swiss turning, laser-Swiss machines can perform multiple processes in a single set-up, improving efficiency, reducing costs, and streamlining validation. A CNC/laser welding platform can be equipped with multiple lasers and even a plastic printer to help with model and fixture construction.
Automation also helps CNC machines and lasers stay competitive with additive manufacturing (AM). The integration of automation across multiple processes, including CNC machining and laser processing, results in higher quality, performance, and efficiency. Automation and IoT enable lights-out machining, which helps to counteract the lack of qualified workers and keep overall costs down.
“With lights-out machining, which combines several operations in one, multiple different products can run unattended off-shift,” said Hoklas. “A secondary benefit is that during primary shifts, less experienced machinists gain exposure to new technologies. Additionally, not only does lights-out machining provide flexibility in both low volume, high mix and forecast turbulent environments, it also ensures reliable quality.”
What OEMs Want
As their medical device designs get smaller and more complex, often with multiple features, more delicate components, and tighter tolerances, OEMs seek higher quality standards, lower costs, and faster speed to market.
“Our customers continuously bring us complex components and sub-assemblies that require an open communication log with their design engineers to understand the end-use application,” said Clive James, vice president of global business development for Wytech Industries, a Rahway, N.J.-based designer and manufacturer of specialty core wires and precision wire components for a wide range of advanced guidewires and delivery systems for the medical device market. “The unique custom geometries and requirements of their device designs are often best achieved with laser machining, which offers greater versatility, higher levels of repeatability, and faster process speeds compared to traditional machining methods.”
OEMs also want as little risk as possible. Machinists can minimize risk and maximize quality through various combinations of flexibility, automation, process verification, custom software, and the ability to configure their machines to meet specific product requirements.
“Something seemingly as small as the positioning of a door or the type of chuck on a rotary axis can be a tremendous help and quite advantageous to the customer,” said David Locke, regional sales manager at ACSYS Lasertechnik US, a Lenexa, Kan.-based manufacturer of turn-key high-precision laser-based processing machines. “Software designed to accommodate product flow and user input requirements can reduce the chances of mistakes, thereby increasing the chances of consistently producing good parts.”
Another way to reduce risk is to work with experienced contract manufacturers early in the design stage that are vertically integrated and skilled in multiple services. Their expert advice is often invaluable in coming up with the best machining solution for making the best possible product at the lowest possible cost.
“Manufacturers prefer experienced partners who can provide a wide range of expert capabilities and services, all under one roof—thereby shortening the supply chain, reducing risk, improving decision making, and getting products to market faster,” said Nipper. “For example, we also offer clean room processing and packaging and inventory management and supply chain management—providing a single point of contact for managing downstream vendors, which reduces lead time and costs.”
New Technology Advancements
The reliability of CNC machining and laser processing systems continues to improve, as well as advancements in adjustable beam wavelength and maximum pulse energy. Combining precise tuning and variable defocusing of the beam can be used to produce semi-blind features with an acceptable surface roughness.
“Conventional machining tends to put too much force on the workpiece to make truly delicate features,” said Emilio Mejia, new product introduction manager for platinum group metals and nitinol components for JM Medical Device Components. “EDM fares a little better in terms of both machining force and precision, but the laser is typically faster when they are both viable.”
New grinding technologies utilize new, stronger materials that last longer. For example, in orthopedics, especially grinding femur parts for artificial knee implants, the trend is toward using state-of-the-art super-abrasive grinding wheels, rather than the conventional aluminum oxide grinding wheels which were used in the past. “This makes it possible to decrease grinding cycle times and increase output per wheel,” said Dierigl. “As a result, less frequent tool changing and, therefore, reduced tool changing time is achieved because of longer lifetime of the grinding wheel, which is made from an extremely low density core material that makes them much easier to handle. The same is true for grinding artificial hip cups, where productivity can be raised by nearly 90 percent using super-abrasive tools, reducing cost per parts for the customer.”
Photochemical machining is another process that can be used to make medical device components, including blades, microfluidic sensors, and filter screens. For example, Resonetics has advanced and refined photochemical etching techniques that “enable the sharpening of custom blades via chemical machining instead of mechanical grinding, with tolerances of 10 microns or less,” said Hartke. “The effective sharpness of this process meets and exceeds mechanical sharpening and opens a wider array of custom-shaped geometries.”
Achieving optimal laser processing results is dependent on matching the proper laser pulse width and wavelength with the material to be processed. The material chemistry, thickness, precision, and price considerations all factor into this decision process. Laser processing procedures will continue to advance as medical device manufacturers incorporate more complex designs, materials, and added functionality. “For example, we can drill to controlled depths within a catheter structure to create microscopic features, such as slots or blind holes,” said Nipper.
Femtosecond lasers can also compete with traditional machining methods such as turning and can produce edge geometry like chamfering, as well as entrance radii to holes. Lasers can also alter the surface of a material for a variety of applications by adding roughness, increasing surface area, creating hydrophobic or hydrophilic surfaces, or generating custom patterns or micro-geometries such as small dimples or pyramids. When cutting, femtosecond lasers also create less dross and oxide, reducing the need for cleaning and increasing the ability to process more materials.
Resonetics has made great strides using lasers to process nitinol. This material has always presented challenges for machining because of its susceptibility to thermal damage during processing.
Resonetics has developed an in-house high-power femtosecond laser cutting system that is highly effective for nitinol, “eliminating the presence of a heat affected zone for thick-walled [>0.5 mm] nitinol devices,” said Hartke. “Eliminating the HAZ leads to a significant efficiency improvement in downstream processing, including thermal heat setting and electropolishing.”
Another laser system that is hot right now is the hybrid laser cutter, which combines both fiber and femto technologies. “This provides the speed and efficiency of fiber, as well as the precision and fine detail of femto where you need it,” said Dennis Norwich, director of engineering for Wytech Industries. “This breakthrough is similar to the combination of fiber laser and Swiss machining that hit five years ago for complex-cut geometries on hypotubing, non-contact laser knurling, hole popping, and more.”
Motion Dynamics, a Fruitport, Mich.-based manufacturer of medical coils and wire components, is an expert at making assemblies for neurovascular procedures, such as steerable catheter devices, including “pull-wire” assemblies. To maximize process flexibility and ROI, the company uses a Coherent StarCut Tube Hybrid laser cutter for tube-cutting, which has a state-of-the-art femtosecond laser and a long-pulse fiber laser.
“Most of our cutting involves thin tubes where the femtosecond laser gives us a critical edge in terms of surface quality and minimized heat affected zone,” commented Chris Witham, president of Motion Dynamics. “We now have the option of using the fiber laser to cut thicker components in less time, albeit typically with some minor post-processing required. The machine’s software also allows us to explore the benefits of using both lasers to do different cuts on the same component.”
With the COVID-19 epidemic and the new vaccines that are being administered around the world, there is a great need for millions of syringes. One way to speed up manufacturing and delivery of these vaccines is to be sure the latest technologies are being used for needle grinding. For example, TYROLIT offers customized silicon carbide grinding tools in self-sharpening resinoid bond systems that produce fewer burrs at the needle tip and facets, minimizing the need for secondary steps and finishing the product faster. “The long lifetime of the wheels leads to higher productivities for our customers,” said Dierigl.
Industry 4.0-Enabled
Industry 4.0 technologies—especially IoT, automation, and additive manufacturing—are improving quality and efficiency in both machining and laser processing. IoT-enabled machining equipment collect performance data, using algorithms that allow CNC machines to make adjustments in real time, as well as predict when maintenance is needed.
“Standard IoT applications include measuring downtime, temperature, pressure, vibration, cycle times, and similar outputs that can be used for preventive maintenance plans, as well as analyzing tooling life and calculating machine productivity metrics like overall equipment effectiveness (OEE),” said Mejia.
“Using IoT to gather good data helps us with everything from tool failure predictability, viscosity of cutting oil, and solving programming hurdles when faced with dimensional tolerance and run rate challenges,” added Dave Strand, chief operating officer for Precision Plus, an Elkhorn, Wis.-based contract manufacturer of precision machined components and products for the medical device industry.
Even though AM technology continues to make rapid advances, in most cases it cannot compete with the speed and precision of Swiss screw machines. Also, many of the advanced materials or exotic alloys that can be CNC-machined cannot be processed through AM. AM is useful, however, for making numerous tools, fixture holders, and other parts for machining equipment. Most AM-made parts require some degree of post-processing to achieve the necessary tolerances and surface finishes. “Lasers are capable of smoothening or polishing the surface of an additively-made part, and laser cutting of precise holes or contours is possible, regardless of how the part is made,” said Locke.
CNC machining and AM are not mutually exclusive. As AM evolves, hybrid machines are being built that incorporate AM build-up and CNC tolerances, speeds, and surface finishes in both series and parallel operations—for example, feeding in a semi-finished component and then performing both subtractive and additive manufacturing processes.
Laser-welding components onto AM-made parts is also possible, as long as the AM material is fully dense and there is a tight fit in the weld area. “We can also create consistent welds in thin materials if the parts are joined with a tight fit and held in place during the process either mechanically or via tack welds,” said Locke. “The key is to design the parts up front to be compatible with the laser process. Thermal distortion can be minimized or eliminated altogether by clever delivery of the laser beam.”
Automation and robotic-assisted CNC machining continue to advance and improve efficiency, throughput, quality, and tolerance control. IoT makes it possible to integrate robotic-assisted systems across multiple processes, which reduces variability and allows for greater process control. Handling of parts can also be challenging—automation improves clamping as well as moves parts into and out of the laser cell. In laser welding, for example, a robot can hold the part and vision guidance systems control the weld seam and the final inspection.
“There are fully integrated systems that automate production—from raw material to quality control to shipping with minimal touch—that make it much easier to machine challenging materials that require high standards for fit and finish,” said Strand.
Moving Forward
The challenges of 2020 will still be with us in 2021. To stay agile and competitive, machine partners must invest in technology advancements such as smaller cutting tools for CNC machining, laser improvements, software upgrades, and hybrid machines.
As OEMs continue to design more complex products that challenge the current abilities of conventional machining and laser machining, it is important for them to work closely with proven partners who are skilled problem-solvers and know the limits of these systems, and as early in the design process as possible, to take advantage of their material and machining knowledge.
“For example,” said Hoklas, “we worked with a customer to develop a new orthopedic instrument set, where both weight and cost were a challenge with the existing instruments. We devised a novel method for hybrid materials combining complex CNC machining with overmolding to dramatically lessen the weight of the product at one-fourth the cost of fabricating the instruments by machining.
Success is best achieved when the OEM and contract manufacturer collaborate early in the process and understand what the end goal is for a product—what it’s supposed to do—so they can align on the appropriate processes and tolerances to ensure both optimal cost and reliable quality.”
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.
Whether machining requires a computer numerical control (CNC) machine or a laser depends on the design and feature requirements of the device. To be competitive, machine partners must stay current on the technology advancements in the machining/laser processing world and have the knowledge and expertise to push their processes to the limit.
“The state of machining is quite advanced in the medical industry, due to a willingness to embrace process improvement in all areas and to push the current manufacturing systems to get the quickest and most cost-effective process,” said Florian Dierigl, business development manager for the medical industry for TYROLIT, an Austria-based manufacturer of bonded grinding, cut-off, finishing, drilling, and dressing tools.
CNC machine manufacturers continue to add more capabilities to their equipment, such as better processing control of raw materials, Internet of Things (IoT) connectivity, advanced but easy-to-use interfaces, and improved software and cloud interactions. CNC machines are hard to beat for bulk material removal; lasers tend to be more efficient for profiling and drilling fine features, particularly through thin materials. Steady advances in laser micromachining, especially the use of femtosecond-pulsed laser systems, make them competitive with conventional machining methods, including electrical discharge machining (EDM).
“Lasers are very effective for holes and slots—two-dimensional features that are through features,” said Tim Hoklas, senior director of technical solutions for Viant, a Foxborough, Mass.-based strategic design and manufacturing partner to the medical device industry. “CNC is better for three-dimensional features such as turning, milling, and blind holes/features.”
Latest Trends
“Miniaturization continues to be a driving trend in the medical device industry, especially for medical procedures that require micro-scale components such as ophthalmic, neurovascular, cardiovascular, and structural heart therapies,” said Kevin Hartke, chief technology officer for Resonetics, a Nashua, N.H.-based micromanufacturer of components and assemblies for medical device and diagnostics companies.
Both conventional CNC machining and laser processing are valuable manufacturing methods for these devices. Although standard machining is generally preferred for cutting, lasers can make features as small as 10 µm (0.0004 inches). OEMs often request features with single-micron tolerances, which is difficult to achieve with conventional machining. Although CNC micromachining is becoming competitive for cutting extremely fine features, lasers also have other valuable applications, such as texturing and welding.
“For the range of feature sizes and the soft polymer materials we specialize in, the laser is often the only manufacturing solution for the features our clients desire,” said Matthew Nipper, director of engineering at Laser Light Technologies, a Hermann, Mo.-based full-service laser solutions provider to the medical device, life science, and microelectronics industries. “Laser machining does not necessarily displace conventional machining, but it is absolutely critical for achieving designs with a continuously shrinking form factor.”
“Laser machining is being used more frequently as medical devices get smaller and more complex,” agreed Mike Chmura, operations manager medical for the Litron Division of Hermetic Solutions Group, an Agawam, Mass.-based provider of laser services and package fabrication to the medical device industry. “This can create new challenges, such as with work holding. Being able to hold the pieces together with high precision for laser machining or welding means tighter tolerances and higher accuracies.”
Femtosecond lasers are increasingly popular because of their speed, precision, and ability to cut small features with no heat alteration zones (HAZ). The shorter the pulse width, the greater the effectiveness of the cut, with fewer burrs or thermal defects. Ultrafast lasers—those defined as having pulse widths equal to or less than 10E-12 (10 picoseconds)—strip electrons from the atoms in the material, ionizing the atoms and forcing them to explode out of the bulk material, with virtually no heat transfer. “Femtosecond lasers—with a pulse width of 10 femtoseconds (10E-15s)—produce the least amount of heat damage and are critical for the high-precision manufacturing of medical devices,” said Nipper.
Femtosecond laser processing is trending toward higher power and pulse energy. “This allows for faster material removal rates and makes shorter wavelength options, such as green and UV, more viable for industrial applications,” said Zane Wyatt, new product introduction engineer for laser applications for JM Medical Device Components, a San Diego, Calif.-based provider of custom-machined parts for the medical device industry.
Machine tool suppliers have started integrating lasers and traditional machining methods into a single “hybrid” machine. For example, by combining laser cutting and welding with traditional Swiss turning, laser-Swiss machines can perform multiple processes in a single set-up, improving efficiency, reducing costs, and streamlining validation. A CNC/laser welding platform can be equipped with multiple lasers and even a plastic printer to help with model and fixture construction.
Automation also helps CNC machines and lasers stay competitive with additive manufacturing (AM). The integration of automation across multiple processes, including CNC machining and laser processing, results in higher quality, performance, and efficiency. Automation and IoT enable lights-out machining, which helps to counteract the lack of qualified workers and keep overall costs down.
“With lights-out machining, which combines several operations in one, multiple different products can run unattended off-shift,” said Hoklas. “A secondary benefit is that during primary shifts, less experienced machinists gain exposure to new technologies. Additionally, not only does lights-out machining provide flexibility in both low volume, high mix and forecast turbulent environments, it also ensures reliable quality.”
What OEMs Want
As their medical device designs get smaller and more complex, often with multiple features, more delicate components, and tighter tolerances, OEMs seek higher quality standards, lower costs, and faster speed to market.
“Our customers continuously bring us complex components and sub-assemblies that require an open communication log with their design engineers to understand the end-use application,” said Clive James, vice president of global business development for Wytech Industries, a Rahway, N.J.-based designer and manufacturer of specialty core wires and precision wire components for a wide range of advanced guidewires and delivery systems for the medical device market. “The unique custom geometries and requirements of their device designs are often best achieved with laser machining, which offers greater versatility, higher levels of repeatability, and faster process speeds compared to traditional machining methods.”
OEMs also want as little risk as possible. Machinists can minimize risk and maximize quality through various combinations of flexibility, automation, process verification, custom software, and the ability to configure their machines to meet specific product requirements.
“Something seemingly as small as the positioning of a door or the type of chuck on a rotary axis can be a tremendous help and quite advantageous to the customer,” said David Locke, regional sales manager at ACSYS Lasertechnik US, a Lenexa, Kan.-based manufacturer of turn-key high-precision laser-based processing machines. “Software designed to accommodate product flow and user input requirements can reduce the chances of mistakes, thereby increasing the chances of consistently producing good parts.”
Another way to reduce risk is to work with experienced contract manufacturers early in the design stage that are vertically integrated and skilled in multiple services. Their expert advice is often invaluable in coming up with the best machining solution for making the best possible product at the lowest possible cost.
“Manufacturers prefer experienced partners who can provide a wide range of expert capabilities and services, all under one roof—thereby shortening the supply chain, reducing risk, improving decision making, and getting products to market faster,” said Nipper. “For example, we also offer clean room processing and packaging and inventory management and supply chain management—providing a single point of contact for managing downstream vendors, which reduces lead time and costs.”
New Technology Advancements
The reliability of CNC machining and laser processing systems continues to improve, as well as advancements in adjustable beam wavelength and maximum pulse energy. Combining precise tuning and variable defocusing of the beam can be used to produce semi-blind features with an acceptable surface roughness.
“Conventional machining tends to put too much force on the workpiece to make truly delicate features,” said Emilio Mejia, new product introduction manager for platinum group metals and nitinol components for JM Medical Device Components. “EDM fares a little better in terms of both machining force and precision, but the laser is typically faster when they are both viable.”
New grinding technologies utilize new, stronger materials that last longer. For example, in orthopedics, especially grinding femur parts for artificial knee implants, the trend is toward using state-of-the-art super-abrasive grinding wheels, rather than the conventional aluminum oxide grinding wheels which were used in the past. “This makes it possible to decrease grinding cycle times and increase output per wheel,” said Dierigl. “As a result, less frequent tool changing and, therefore, reduced tool changing time is achieved because of longer lifetime of the grinding wheel, which is made from an extremely low density core material that makes them much easier to handle. The same is true for grinding artificial hip cups, where productivity can be raised by nearly 90 percent using super-abrasive tools, reducing cost per parts for the customer.”
Photochemical machining is another process that can be used to make medical device components, including blades, microfluidic sensors, and filter screens. For example, Resonetics has advanced and refined photochemical etching techniques that “enable the sharpening of custom blades via chemical machining instead of mechanical grinding, with tolerances of 10 microns or less,” said Hartke. “The effective sharpness of this process meets and exceeds mechanical sharpening and opens a wider array of custom-shaped geometries.”
Achieving optimal laser processing results is dependent on matching the proper laser pulse width and wavelength with the material to be processed. The material chemistry, thickness, precision, and price considerations all factor into this decision process. Laser processing procedures will continue to advance as medical device manufacturers incorporate more complex designs, materials, and added functionality. “For example, we can drill to controlled depths within a catheter structure to create microscopic features, such as slots or blind holes,” said Nipper.
Femtosecond lasers can also compete with traditional machining methods such as turning and can produce edge geometry like chamfering, as well as entrance radii to holes. Lasers can also alter the surface of a material for a variety of applications by adding roughness, increasing surface area, creating hydrophobic or hydrophilic surfaces, or generating custom patterns or micro-geometries such as small dimples or pyramids. When cutting, femtosecond lasers also create less dross and oxide, reducing the need for cleaning and increasing the ability to process more materials.
Resonetics has made great strides using lasers to process nitinol. This material has always presented challenges for machining because of its susceptibility to thermal damage during processing.
Resonetics has developed an in-house high-power femtosecond laser cutting system that is highly effective for nitinol, “eliminating the presence of a heat affected zone for thick-walled [>0.5 mm] nitinol devices,” said Hartke. “Eliminating the HAZ leads to a significant efficiency improvement in downstream processing, including thermal heat setting and electropolishing.”
Another laser system that is hot right now is the hybrid laser cutter, which combines both fiber and femto technologies. “This provides the speed and efficiency of fiber, as well as the precision and fine detail of femto where you need it,” said Dennis Norwich, director of engineering for Wytech Industries. “This breakthrough is similar to the combination of fiber laser and Swiss machining that hit five years ago for complex-cut geometries on hypotubing, non-contact laser knurling, hole popping, and more.”
Motion Dynamics, a Fruitport, Mich.-based manufacturer of medical coils and wire components, is an expert at making assemblies for neurovascular procedures, such as steerable catheter devices, including “pull-wire” assemblies. To maximize process flexibility and ROI, the company uses a Coherent StarCut Tube Hybrid laser cutter for tube-cutting, which has a state-of-the-art femtosecond laser and a long-pulse fiber laser.
“Most of our cutting involves thin tubes where the femtosecond laser gives us a critical edge in terms of surface quality and minimized heat affected zone,” commented Chris Witham, president of Motion Dynamics. “We now have the option of using the fiber laser to cut thicker components in less time, albeit typically with some minor post-processing required. The machine’s software also allows us to explore the benefits of using both lasers to do different cuts on the same component.”
With the COVID-19 epidemic and the new vaccines that are being administered around the world, there is a great need for millions of syringes. One way to speed up manufacturing and delivery of these vaccines is to be sure the latest technologies are being used for needle grinding. For example, TYROLIT offers customized silicon carbide grinding tools in self-sharpening resinoid bond systems that produce fewer burrs at the needle tip and facets, minimizing the need for secondary steps and finishing the product faster. “The long lifetime of the wheels leads to higher productivities for our customers,” said Dierigl.
Industry 4.0-Enabled
Industry 4.0 technologies—especially IoT, automation, and additive manufacturing—are improving quality and efficiency in both machining and laser processing. IoT-enabled machining equipment collect performance data, using algorithms that allow CNC machines to make adjustments in real time, as well as predict when maintenance is needed.
“Standard IoT applications include measuring downtime, temperature, pressure, vibration, cycle times, and similar outputs that can be used for preventive maintenance plans, as well as analyzing tooling life and calculating machine productivity metrics like overall equipment effectiveness (OEE),” said Mejia.
“Using IoT to gather good data helps us with everything from tool failure predictability, viscosity of cutting oil, and solving programming hurdles when faced with dimensional tolerance and run rate challenges,” added Dave Strand, chief operating officer for Precision Plus, an Elkhorn, Wis.-based contract manufacturer of precision machined components and products for the medical device industry.
Even though AM technology continues to make rapid advances, in most cases it cannot compete with the speed and precision of Swiss screw machines. Also, many of the advanced materials or exotic alloys that can be CNC-machined cannot be processed through AM. AM is useful, however, for making numerous tools, fixture holders, and other parts for machining equipment. Most AM-made parts require some degree of post-processing to achieve the necessary tolerances and surface finishes. “Lasers are capable of smoothening or polishing the surface of an additively-made part, and laser cutting of precise holes or contours is possible, regardless of how the part is made,” said Locke.
CNC machining and AM are not mutually exclusive. As AM evolves, hybrid machines are being built that incorporate AM build-up and CNC tolerances, speeds, and surface finishes in both series and parallel operations—for example, feeding in a semi-finished component and then performing both subtractive and additive manufacturing processes.
Laser-welding components onto AM-made parts is also possible, as long as the AM material is fully dense and there is a tight fit in the weld area. “We can also create consistent welds in thin materials if the parts are joined with a tight fit and held in place during the process either mechanically or via tack welds,” said Locke. “The key is to design the parts up front to be compatible with the laser process. Thermal distortion can be minimized or eliminated altogether by clever delivery of the laser beam.”
Automation and robotic-assisted CNC machining continue to advance and improve efficiency, throughput, quality, and tolerance control. IoT makes it possible to integrate robotic-assisted systems across multiple processes, which reduces variability and allows for greater process control. Handling of parts can also be challenging—automation improves clamping as well as moves parts into and out of the laser cell. In laser welding, for example, a robot can hold the part and vision guidance systems control the weld seam and the final inspection.
“There are fully integrated systems that automate production—from raw material to quality control to shipping with minimal touch—that make it much easier to machine challenging materials that require high standards for fit and finish,” said Strand.
Moving Forward
The challenges of 2020 will still be with us in 2021. To stay agile and competitive, machine partners must invest in technology advancements such as smaller cutting tools for CNC machining, laser improvements, software upgrades, and hybrid machines.
As OEMs continue to design more complex products that challenge the current abilities of conventional machining and laser machining, it is important for them to work closely with proven partners who are skilled problem-solvers and know the limits of these systems, and as early in the design process as possible, to take advantage of their material and machining knowledge.
“For example,” said Hoklas, “we worked with a customer to develop a new orthopedic instrument set, where both weight and cost were a challenge with the existing instruments. We devised a novel method for hybrid materials combining complex CNC machining with overmolding to dramatically lessen the weight of the product at one-fourth the cost of fabricating the instruments by machining.
Success is best achieved when the OEM and contract manufacturer collaborate early in the process and understand what the end goal is for a product—what it’s supposed to do—so they can align on the appropriate processes and tolerances to ensure both optimal cost and reliable quality.”
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.
