high heat polymer extrusion presentation

HOW TO CHOOSE THE IDEAL HIGH

HEAT POLYMER FOR YOUR

EXTRUDED MEDICAL APPLICATION

by

Jonathan Jurgaitis

Sr. Extrusion Engineer

Personal Introduction

• Employed at Apollo Medical Extrusion as Sr. Extrusion Engineer.

• In the extrusion industry for 23 years.

• 13 years at industrial custom profile and tubing extruder.

• 9-3/4 years in custom medical extrusion industry.

• Have been extruding high heat polymers for about 7 years, now

exclusively focusing on high heat polymer extrusion.

• Responsible for business development of high heat polymer projects,

materials research, technical assistance, tooling design, process

development and R&D processing.

Introduction

A profound shift is taking place in the medical industry of more minimally

invasive, quicker and more effective procedures. The goal of this shift is to

minimize patient recovery times, reduce access incision sizes and provide

better outcomes. This requires new medical devices that demand more

performance from their components. The greater demands require

components to be made of advanced materials, some of these materials

fall under the description of high heat polymers.

There are a wide range of these high heat polymers but many may be

relatively unknown to device designers and engineers. Unfamiliarity with

high heat polymers can prove challenging in choosing the ideal material

for today’s demanding and cutting edge medical devices and

components.

My aim is to share information about the variety of high heat polymers that

are available for high requirement medical applications so designers and

engineers will have the tools to better choose the ideal high heat polymer

for their devices and components.

Overview

• What is a high heat polymer?

• How is a high heat polymer different than other polymers?

• General medical uses and applications of high heat polymers.

• Types, properties, positives and limitations of major high heat polymer

families.

• Conclusion.

WHAT IS A HIGH HEAT POLYMER?

• High heat polymers fall into the description of engineering polymers but

have properties at the pinnacle of performance.

• Generally, a high heat polymer is categorized as any plastic that is

processed at temperatures at or above 600° F.

• They are sometimes also tagged

with an added descriptor to

differentiate them, such as

“Ultra” polymer.

• High heat polymers account for

a very small percentage, by

volume, of all plastics.

WHAT IS A HIGH HEAT POLYMER?

• Because of their high processing temps, they require specially outfitted

extruders, ideally, tooling made of special alloys and require different

downstream processing techniques.

• High heat polymers bridge the performance gap between standard

engineering materials and metals, composite materials and thermoset

plastics.

• There are semi-crystalline and amorphous high heat polymers.

• Increasingly finding applications in demanding medical devices and

procedures.

• Many high heat polymers are relatively new to the plastics industry and

just gaining interest in the medical industry.

• Customers, processors and end users could benefit from additional

information about high heat polymer properties, types and their uses.

HOW IS A HIGH HEAT POLYMER DIFFERENT

THAN OTHER POLYMERS?

• High heat polymers process at higher temperatures, typically 600° F +, and therefore are more heat resistant and have higher continuous operating temps, most well above 300° F.

• High heat polymers have stronger physical properties than other engineering materials, such as nylon and PC, in the areas of impact resistance, tensile and flexural strength.

• High heat polymers are very chemically resistant and can withstand all but the harshest chemicals and environments.

• The high heat materials listed here are all flame resistant without the need for additives.

• Some high heat polymers are moderately priced but can range up to being rather expensive. Their different processing requirements also tend make them more expensive to process.

• All high heat polymers are considered rigid materials and do not come in varying durometers.

GENERAL MEDICAL USES AND APPLICATIONS

OF HIGH HEAT POLYMERS

• All the high heat materials that will be covered here have ISO 10993

and/or USP Class VI approval, they are suitable for medical applications

and up to permanent implantation with some grades.

• Because of the strength and stiffness of these materials they tend to be

used as structural aspects of a device.

• These materials have excellent pushability and torque properties even at

very small diameters so they may be able to eliminate braid and coil

reinforcement in some instances.

• Orthopedic and dental applications are common because of their

similarity to the density and strength of bone.

• High heat polymers can replace stainless steel because their strength is

approaching that of stainless steel, but can add flexibility, transparency

and easier attachment methods to a device.

• High heat polymers are suitable for one time use applications but also for

durable devices because of their strength and sterilization performance.

TYPES, PROPERTIES, POSITIVES & LIMITATIONS OF

MAJOR HIGH HEAT POLYMERS

We will be covering the more common types of high heat polymers, PEEK,

PPSU, PSU, PESU* and PEI**, their main properties, costs and their positive

and limiting factors.

Each of these materials have different grades designed for different

processing methods and end uses but all have grades suitable for

extrusion.

*PEEK, PPSU, PSU and PESU information will be based on Solvay Specialty

Polymers’ versions of these materials.

**PEI information will be based on Ultem, manufactured by SABIC.

PEEK (POLYETHERETHERKETONE)

• PEEK is currently the high heat polymer “buzz” material in medical

applications.

• PEEK is a semi-crystalline polymer. This means that a portion of the

molecules align during proper processing and form crystals. This

crystallinity is partly what gives PEEK superior properties.

• Extreme continuous use temperature of 465° F +.

• Excellent chemical resistance to all hospital disinfectants.

• Highest stiffness of these materials.

• Highest tensile and flexural strength and lowest elongation of these

materials.

• High purity, very bio-stable.

• Smooth, glossy, low energy surface finish.

• Permanent implant grade available. Must go through extensive

approval process per application.

MEDICAL DEVICE APPLICATIONS, EXTRUSION

• PEEK is finding an increase in new device applications. Currently, PEEK is

being used in many orthopedic applications for long-term implants

primarily for spine and bone-screw applications. While most of these

applications are molded components bone-screws can be machined

from PEEK extrusions.

• Developing markets for PEEK extrusions include

• Cardiovascular applications

• Neurovascular applications

• Atrial Fibrillation (due to PEEK’s insulating properties & heat resistance)

• Artherectomey devices (due to PEEK’s insulating properties & heat resistance)

PEEK POSITIVES & LIMITATIONS

• Positives

• Can be extruded into large diameter and micro tubing, thin walls, multi-

lumens, rods, mandrels and filament.

• Can be compounded to custom colors, with additives and reinforcements.

• Easier to cut, can be heat formed & RF welded.

• Can withstand 40 kGy of Gamma, greater than 1000 steam sterilization

cycles, and 100 or more cycles of all other sterilization methods.

• Limitations

• High raw material costs. Compounded costs can be well over $100/lb.

• Opaque beige color that may not be aesthetically pleasing, can cause

limitations for some colors. Some colors and additive types can be limited

because of high process temps.

• Not as “tough” as other high heat polymers.

• Needs special surface preparation prior to printing.

• Special tooling required for some configurations.

PEEK ALTERNATIVE PAEK (POLYARYLETHERKETONE)

• PAEK has very similar properties to PEEK with only slightly better or worse

performance in various areas. (See comparison chart below)

• Still semi-crystalline.

• Approximately 20% to 30% lower raw material costs.

• Many of the same positives & limitations as PEEK.

AMORPHOUS HIGH HEAT POLYMERS

The remainder of the high heat polymers to be discussed are all

amorphous and transparent. Amorphous materials do not have a distinct

melting temperature and no crystalline structure. (See comparison chart

below)

PPSU (POLYPHENYLSULFONE)

• PPSU is the highest performing sulfone polymer.

• PPSU has the highest heat resistance of all the sulfones.

• Continuous use temperature of about 400° F.

• Excellent chemical resistance to all hospital disinfectants.

• Hydrolytically stable for high heat and humidity environments.

• Excellent ductility and toughness.

• Potential applications: steerable catheters, fluid transfer of aggressive

chemicals and drugs.



• Permanent applications such as wire lead coatings and orthopedics.

PPSU POSITIVES & LIMITATIONS

• Positives

• Can be extruded into large and micro tubing, thin walls, multi-lumen, rods, and filament.


• Transparent. Can be made with transparent color tints.

• Can be heat formed, RF welded and reflowed.

• Can be printed on without significant surface preparation.

• Can withstand 40 kGy of Gamma, greater than 1000 steam sterilization cycles, and 100 or more cycles of all other sterilization methods.

• Limitations

• Highest raw material cost of all the sulfones and Ultem, but less than PEEK.

• Transparent amber color that may affect some colors. Some colors and additive types can be limited because of high process temps.

• Lower tensile and flexural strengths than other sulfones and Ultem.


PSU (POLYSULFONE)

• PSU is a high strength sulfone polymer.


• Good chemical resistance to many hospital disinfectants.


• Better ductility and toughness.

• High clarity.

• Potential applications: dental tools and components.

• Higher performance alternative to polycarbonate. Does not require

tinting to compensate for Gamma sterilization effects like

polycarbonate.



PSU POSITIVES & LIMITATIONS

• Positives



• High clarity. Can be made with transparent color tints.



• Can withstand 40 kGy of Gamma and up to 100 cycles of all other sterilization methods.

• Moderate raw material costs similar to PESU and Ultem.

• Limitations

• Decreased sterilization resistance compared to PPSU

• Can limit some colors and additive types because of high process temps.

• Lower tensile and flexural strengths than PESU and Ultem.


PESU (POLYETHER SULFONE)

• PESU is a very high strength sulfone polymer.


• Better chemical resistance to many hospital disinfectants.


• Highest stiffness of the sulfones, can eliminate braiding and

reinforcement in some applications.

• High hardness.

• High clarity.

• Good alternative to Ultem with higher clarity.

• Highest performance alternative to polycarbonate. Does not require

tinting to compensate for Gamma sterilization effects like

polycarbonate.

• Potential applications: sight windows and clear patient access devices.

PESU POSITIVES & LIMITATIONS

• Positives

• Can be extruded into large and micro tubing, thin walls, multi-lumen, rods,

and filament.


• High clarity. Can be made with transparent color tints.



• Can withstand 4 megarads of Gamma, greater than 1000 steam sterilization

cycles and 100 or more cycles of all other sterilization methods.

• Moderate raw material costs similar to PSU and Ultem.

• Limitations

• Can limit some colors and additive types because of high process temps.

• Slightly lower tensile and flexural strengths than Ultem.


PEI (POLYETHERIMIDE)

• PEI is a very high strength amorphous polymer.

• A thermoplastic variation of PI.


• Better chemical resistance to many hospital disinfectants.


• Higher stiffness, strength and tensile properties than the sulfones.

• Excellent color stability through many sterilization cycles.

• Potential applications: device sheaths, access devices, sterilization tray

dividers and supports, dental tool parts and fixtures.

• Ultem is a well known brand name among high heat polymers.

PEI POSITIVES & LIMITATIONS

• Positives



• Transparent. Can be made with transparent color tints.



• Can withstand greater than 1000 steam sterilization cycles, and is suitable for Gamma, EtO and vaporized hydrogen peroxide sterilization processes.

• Moderate raw material costs, similar to PSU and PESU.

• Limitations

• Transparent amber color that can affect some colors. Can limit some colors and additive types because of high process temps.

• Potentially long lead times for raw material.


OTHER HIGH HEAT POLYMERS

There are a variety of other high heat polymer families that fall into similar

performance property ranges as those discussed here.

Many other high heat polymer types have extrusion grades but may have

notable restrictions that could limit the types of extrudable parts.

Other high heat polymer types beyond those listed here, tend to be

formulated for more targeted applications and/or specific physical,

chemical or thermal properties.

The high heat materials previously discussed here are more common, have

good medical application support and mostly have a reliable supply

channel. That is not to say that materials not covered in this presentation

should be avoided.

CONCLUSION

Extrusion of medical components out of high heat polymers is a relatively

new type of application area in the medical industry. High heat materials

have added a level of performance that was relatively unknown until

somewhat recently.

Navigating the properties and differences between high heat polymers

requires those in development and specification roles to gain a new

knowledge set. The goal of this presentation was to provide a high-level

overview of these materials to quickly help designers and engineers gain

awareness of the many high heat material options that are available.

Knowledge of and familiarity with these high heat materials will enable

designers and engineers to specify the ideal high heat polymer for their

application and open up a brave new world of medical devices.

Thank you for your time and attention.

CREDITS

• All material properties and descriptions for Solvay Specialty Polymers

brand materials were compiled from technical data sheets, processing

guides and other material literature generated by Solvay Specialty

Polymers.

• All material comparison charts used herein were copied from

corresponding Solvay Specialty Polymers webpages.

• All comparison information between Solvay Specialty Polymers brand

materials and Ultem were taken from literature generated by Solvay

Specialty Polymers.

• All Ultem material properties and descriptions were taken from technical

data sheets and material literature generated by SABIC. Ultem is

manufactured by SABIC.

• All PEEK extrusion medical application information provided by Joe

Stephens, Apollo Medical Extrusion VP of Sales and Marketing.

high heat polymer extrusion presentation

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