Category: Medical and Life Sciences

The top 3 reasons to consider Torlon® over metal for your advanced engineering application

PolyamideImide (PAI) is a leading thermoplastic engineering plastic that offers extraordinary toughness and strength, even at temperatures up to 275°C (525°F). One of the leading PAI grades on the market is Solvay’s Torlon®. Developed for demanding aerospace and defense applications, Torlon® has also found broad use in automotive, energy, medical and other industries. Its superb performance makes it an excellent replacement for metals in many weight-sensitive applications. With its high strength-to-weight ratio, Torlon® PAI can help reduce component weight and lower manufacturing costs.

In this informational guide, we discuss the top three properties that make Torlon® a leading material pick for mission critical applications.

Top 3 Properties of TORLON® PAI

There is no doubt, this thermoplastic works well under pressure. PAI competes with metals like titanium and steel when it comes to high strength and wear resistance. These properties coupled with good mechanical stability over a broad range of temperatures put Torlon at the top of the material selection list. Let’s take a closer look.

High strength and wear resistance

Wear-resistant grades of Torlon® PAI offer custom combinations of mechanical and tribological properties. For this reason, PAI is often a metal replacement due to its capability to function under a wide range of temperatures, high pressure and velocities (PV). This is the case even when lubrication is marginal or non-existent. PAI can be formulated into specialized grades to suit even the harshest of environments.

High temperature resistance and functionality

When it comes to heat, PAI outperforms many advanced engineering resins, exhibiting great durability at 200 C (400 F). This makes it a leading choice for mission critical components used in repetitive-use, load-bearing operations. Carbon-fiber and glass-filled grades of PAI add stiffness, strength, low creep, and enhanced thermal expansion properties.

Chemical resistance

In critical industries like automotive and aerospace, chemical exposure is common for engineering materials. Performance materials like PAI are unaffected by aliphatic and aromatic hydrocarbons, chlorinated and fluorinated hydrocarbons, and most acids at moderate temperatures. However, this polymer does not respond well to saturated steam, strong bases, and some high-temperature acid systems. This is why it’s important to ensure proper post-cure for PAI parts. Torlon®, like PEEK, does not perform well in moist environments and will absorb water, but the rate is slow and parts can be restored to original dimension and properties by drying.

Industry Applications of Torlon® PAI

Aerospace and defense

Components for aerospace and defense have to maintain functionality under extreme temperatures, withstand high pressures, and resist corrosion and friction. Torlon® PAI is one of the leading thermoplastics on the market that meets these requirements, while also saving aircraft on weight reduction.

Automotive

Thermoplastics like Torlon® PAI have gained popularity as a metal replacement, especially in the automotive industry. PAI has the strength, impact resistance, and high temperature tolerance at a fraction of the weight of metal. It is used for transmission components where there are high levels of heat, pressure and friction.

Oil and gas

Due to its chemical resistance and continuous use under pressure and intense temperatures, PAI is a natural pick for unpredictable, harsh environments like those in the oil and gas industry. Where metal easily corrodes in these environments, PAI is the right material pick for applications like seals, back-up seal rings, bearings and bushings.

Electric / Electrical

Applications of PAI in the electric / electrical sector include insulators and electrical connectors. PAI has excellent dielectric strength, outstanding impact strength, and electrical insulation. These properties make it an ideal material pick for high-performance connectors, relays and switches.

Semiconductors

The semiconductor industry demands high-temperature processing and continuous stability. PAI offers both and more. It keeps components dimensionally stable at variable temperatures, provides pure surfaces, and has a strong resistance to chemicals like acids and solvents. In the semiconductor industry, common applications for PAI include wafer handling, bearing surfaces, IC test equipment sockets and handlers.

Grades of TORLON® PAI machined at AIP

At AIP, we partner with leading polymer suppliers like Solvay to provide the best grades of thermoplastic PAI on the market. We source and machine several grades of Torlon® from general purpose to metal replacements for advanced engineering applications.

Torlon® 4203

Torlon® 4203 is the unfilled or natural grade of Torlon® PAI that outperforms other grades with the best impact resistance and the most elongation. PAI has the highest strength and stiffness of any thermoplastic up to 275°C (525°F). Torlon® 4203 can be used for a variety of applications but due to its excellent electrical properties, it is commonly machined for electronic equipment, connectors, spline liners, thrust washers, valve seals, bearings and temperature test sockets.

Torlon® 4301

Torlon® 4301 is a general purpose, wear-resistant grade of PAI containing PTFE and graphite. It offers high compressive and flexural strength with a low coefficient of friction along with good mechanical properties. Where high temperature and strength are a necessity, Torlon® 4301 is a good material choice. Common applications include thrust washers, bearings, and wear rings.

Torlon® 4XG

As a 30% glass-reinforced extruded grade of PAI, Torlon® 4XG is well suited to higher load structural or electronic applications. For applications that require a high degree of dimensional stability, 4XG offers high-performance. Several uses of 4XG include burn-in sockets, gears, valve plates, impellers, rotors, terminal strips and insulators.

Torlon® 4XCF

Torlon® 4XCF is a 30% carbon-reinforced extruded grade of PAI that has the lowest coefficient of thermal expansion and the most impressive fatigue resistance of all thermoplastics. This durable PAI grade is a common metal replacement  for mission-critical aerospace components, in addition to impellers, shrouds and pistons.

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Precision PPSU Takes Flight in Mission-Critical Aerospace Applications

Safety and engineering finesse come together in every aircraft on the market. It’s not just about ensuring a good flight experience for consumers; it’s the law. The Federal Aviation Administration (FAA) has regulations in place that dictate the material choices for commercial aircraft. For instance, fireproof materials are an essential part of aircraft interiors.

In the late 1980s, FAA statistics showed that about 40% of survivors from impact-related aircraft crashes died from post-crash fire and smoke exposure. At the time, most aircraft interiors were made of combustible plastics. In 1987 the FAA mandated the use of fire-resistant plastics in all passenger planes.

Performance plastics like Solvay’s RADEL®, polyphenylsulfone (PPSU), offer not only high impact resistance but also high heat resistance. RADEL® is a key material in mission-critical performance within the cabin of an aircraft. In this article, we discuss the advantages of RADEL® for aerospace applications.

Demands of Aircraft Interiors – Beyond Comfort

Passengers might think about leg space and seat comfort, but there is a lot of thought put into the safety of cabin space. Fireproofing an aircraft is a crucial part of construction and engineering. Yet, engineers also look for a material that meets the industry’s lightweight and durability requisites.

Performance plastics in aerospace design have played a major role for several decades. Prior to the 1987 FAA mandate for fire-resistant plastics, most cabin interior composites were epoxy-based. These highly-flammable plastics, while providing the aesthetics and durability needed for aircraft interiors, were also highly dangerous in the event of a fire.

Since then, aircraft interior material selection has evolved to meet the standards of aesthetics, durability, AND flame resistance. Flame-resistant polymers for aircraft interiors have physical and chemical properties in terms of their effect on the heat release rate of burning material. Those qualities include: fuel replacement, flame inhibition, intumescence, and heat resistance.

These fire resistance mechanisms, acting simultaneously or collaboratively, are effective at reducing the heat release rate of a new generation of transparent plastics suitable for aircraft cabin interiors.

Properties of RADEL® PPSU for Aerospace

Solvay’s RADEL® PPSU meets all of the stringent requirements of the aerospace sector as well as the FAA regulations on flame retardance. With high heat and high impact performance, RADEL® delivers better impact resistance and chemical resistance than other sulfone-based polymers, such as PSU and PEI. It also performs under repeated chemical and hydrolytic exposure.

Furthermore, RADEL® PPSU meets the aircraft flammability requirements of 14 CFR Part 25, enabling engineers a material choice that is lightweight, safe and, aesthetically pleasing. It comes in a variety of colors to avoid painting and is FDA and NSF-approved for food and beverage contact.

Performance Properties

• Excellent toughness and impact strength
• Meets OSU 65/65 and FAR 25.853 (a & d)
• Color grades eliminate painting
• Lower-cost paintable grades
• Flame retardant – Inherently UL-94 V0
• Exceptional long-term hydrolytic stability

Setting the Standard for Aerospace Precision Plastic Machining

Standards in the Aerospace and Defense sector are rigorous and non-negotiable. Aviation contractors put the greatest pressure on finding manufacturers who exceed the standards of the industry.

At AIP, we make it our priority to set the standard for aerospace precision plastic machining. For over three decades, we have worked with top aviation and defense contractors to deliver cutting-edge plastic components.

We operate an ITAR facility capable of satisfying all customer DOD, NASA, and FAA quality requirements that flow down from our OEM customers. For your next precision machined PPSU project, call on AIP to exceed the standards for mission-critical aerospace applications.

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What Is Orbital Reconstruction?

Orbital trauma (trauma to the facial bone structure) can happen due to injuries, benign and malignant tumors, or infectious diseases. In the case of tumors where bone extraction may be necessary, replacing the bone in the orbital region does not usually cause deformity. However, in cases where significant bony material is lost or extracted, surgeons have typically used bone grafting to restore facial form and normality.

Yet, bone grafting presents its own issues with misalignment. Medical research has turned to materials such as titanium and precision plastics like PEEK. In this insightful brief, we discuss the advantages of PEEK for maxillofacial surgical procedures.

Challenges of Maxillofacial Surgery

There are issues with bone grafting though, namely imperfect alignment and resorption. The slight variability in the three-dimensional (3D) contour of the orbit with flat or slightly curved bone grafts can have a significant aesthetic effect on the outcome.

For a patient who has suffered trauma, coming out of surgery without the aesthetics of their face is emotionally devastating. For surgeons committed to providing the highest level of medical treatment, bone grafting is not always the best option.

In these cases of orbital reconstruction, it’s common for surgeons to use alloplasty, or inert pieces of metal and plastic for reconstruction. Traditional materials for alloplastic have been titanium plates or mesh. However, challenges associated with these materials include proper fixation and revision surgery complications due to soft tissue ingrowth.

Why PEEK Is Changing the Face of This Industry

With advancements in 3D printing and subtractive manufacturing techniques in precision polymers, patient-specific implants (PSIs) have been successfully reported in facial reconstruction. More recently, polyetheretherketone (PEEK) is a polymer with ideal alloplastic properties: nonconductive, biocompatible, and stable in the setting of long-term exposure to bodily fluids, elasticity is similar to native cortical bone, and light material makes it suitable for even large defects. As medical technologies continue to advance, PEEK has become a popular pick for PSIs.

A Case Study in PEEK Implants

One of the setbacks of titanium and metallic implants is that the manufacturing process takes time. In the case of PEEK implants, subtractive manufacturing offers convenient and quick milling precision at 0.4 mm thickness. The design freedom with PEEK is also much easier to produce than with metallic implants.

In addition, PEEK offers excellent imaging properties without artifact blockage, and it is most comparable to cortical bone. Recent research has shown that PEEK is an optimal choice for patients and surgeons with regard to revision surgery as well.

In a PEEK PSI group, diplopia after surgery was absent in 82.1% of patients versus 70.6% of controls with pre-bent titanium. These results showed that PEEK PSI demonstrated higher clinical efficacy in comparison to pre-bent plates in orbital wall reconstruction, especially in restoring the volume and shape of the damaged orbit.

Comparison to Metallic Surgical Materials

The most commonly used surgical material for orbital reconstruction is titanium. Its strength and flexibility set it apart as a material that lends itself well to meld to complex facial structures. However, Polyetheretherketone (PEEK) presents a major benefit as a material pick for its thermostability and comparability to cortical bone. We’ve mapped out a comparison of these common surgical materials below.

Additive Manufacturing Titanium

3-D manufactured titanium produces surfaces without tools or devices. It also enables options for surface design and intricacies that were previously impossible. In addition, additive manufactured titanium implants are so precise they don’t require reshaping processes.

Advantages
• Wide selection of shapes, structures, and styles
• Precise fitting accuracy
• Exceptionally stability
• Osteoconductive structures are possible
• Complete design freedom for the material and its surface
• Quick operation
• Steam sterilization

Limitations
• Additional material work is required for revision surgeries
• Intraoperative cutting to length is exceptionally difficult

Titanium Mesh

The special microstructure of titanium mesh allows it to be used in three-dimensional deep draw applications. A thermal process helps maintain the closed structure, which means that this material is both stable and intact while still offering excellent biocompatibility with bone apposition potential.

Advantages
• Very good biocompatibility, potential for vascularization
• Good mechanical properties
• Ease of manufacturing and cutting to size
• Bone cell apposition potential
• Relatively low price level
• No other plates required for fixation
• Steam sterilization (autoclavable)

Limitations
• No three-dimensional bone substitute
• Need for tools

Solid Titanium

Solid titanium is a high-strength reconstruction alternative to titanium mesh. Even though it has been widely supplanted by titanium mesh in recent years, it offers several advantages in specific fields of use, such as in relation to the mechanical protective function.

Advantages
• Best mechanical protective function
• High-strength reconstruction alternative
• No plates required for fixation
• Steam sterilization

Limitations
• Increased thermal conductivity
• Post-operative bending is not possible
• Post-operative cutting to size is not possible

PEEK

PEEK is a high-performing thermostable plastic. Its physical properties are similar to the cortical bone’s in humans, making PEEK the most frequently used in orthopedics. PEEK implants can be manufactured to be completely solid or contain holes.

Advantages
• Highly elastic, yet very strong and impact resistant at the same time
• Optimal protective function for patients
• No increase in thermal sensitivity
• Low weight
• Resistant to gamma radiation and magnetic resonance imaging (MRI)
• Low artifact formation in X-rays
• Three-dimensional bone replacement
• Steam sterilization

Limitations
• Only conditional cell apposition potential
• Intraoperative adjustment or cutting to size is only possible with additional effort
• Requires further plates for fixation

Unrivaled Expertise in Medical-grade PEEK Devices

Machining complex medical parts and devices takes more than precision. It takes unrivaled expertise. The medical industry is fast-paced and cutting-edge with technology challenges. Precision plastics like PEEK implants play a key role in meeting the demands of the industry.

PEEK and other precision plastics are highly sought after for their radiolucency, biocompatibility, and sanitation. Time is of the essence in healthcare, especially with traumas like orbital reconstruction. These types of surgery demand a quick turnaround on design and manufacturing to lessen surgical downtime.

At AIP, we make it our priority to set the highest standards of quality and sanitation for our customers in the healthcare industry. Quality assurance is an integral part of our process and we address it at every step of your project from beginning to end.

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Celazole® U-Series and Duratron® PBI Take the Heat in Any Extreme Application

Every medical innovation begins with design and manufacturing. Before a small spinal implant goes to the patient, it must meet strict universal industry standards for safety, handling, and product consistency. Afterall, a failure in a medical device can have serious repercussions for not only the health and safety of end users, but also loss of credibility and resources for a manufacturer.

That’s why medical device OEMs demand that machining facilities follow the ISO 13485 standard for medical device manufacturing.

In this informative brief, we take a deeper look at the benefits of this essential certification and how a precision machining facility can get certified.

The Benefits of having an ISO 13485 Certification

PBI has the highest mechanical properties of any polymer over 400°F (204°C). Compared to other performance polymers like Torlon® or PEEK®, it has the highest heat deflection temperature (HDT) at 800°F (427°C), with a continuous service capability of 750°F (399°C) in inert environments, or 650°F (343°C) in the air with short term exposure potential to 1,000°F (538°C).

Wear-Resistant Performance

Celazole® U-60 is an unfilled polymer suitable for injection molding or CNC machining into precision parts. When it comes to wear and abrasion, PBI has the highest compressive strength of all plastics. Its compressive strength is 57 kpsi and, its modulus strength reaches 850 kpsi compared to grades of Torlon® that start at 440 kpsi.

Celazole® can handle high loads at any speed and outperforms wear-grade PAI, PI, and PEEK® under similar conditions. Without additional lubrication, it runs 40-50F cooler than the competition.

PBI Grades

PBI comes in grades that can be extruded or melt processed, but in this brief we are covering grades of PBI that are CNC machined.

Duratron® PBI
Duratron® CU60 PBI is the highest-performance engineering thermoplastic available on the market. It has the highest heat resistance and mechanical property retention over 400°F of any unfilled plastic. It also offers better wear resistance and load-carrying capabilities at extreme temperatures than any other reinforced or unreinforced engineering plastic.

Although it is an unreinforced material, Duratron® CU60 PBI is very “clean” in terms of ionic impurity, and it does not outgas (except water vapor). These properties make this material very attractive to semiconductor manufacturers for vacuum chamber applications.

Other properties of Duratron® CU60 PBI include excellent ultrasonic transparency. This makes it a strong choice for delicate parts, like probe tip lenses in ultrasonic measuring equipment.

Duratron® PBI also serves very well as a thermal insulator. Other plastics melt and do not stick to it. For these reasons, it’s an ideal polymer for contact seals and insulator bushings in plastic production and molding equipment.

Celazole® PBI U-Series (U-60)
Celazole® U-Series has superior polymer strength with thermal stability. By itself, PBI can operate at continuous temperatures up to 1,004°F (540°C). As a resin incorporated into plastics, PBI features high heat and chemical resistance and good fatigue resistance, compressive strength, wear resistance, and electrical insulation.

Components made from Celazole® U-Series polymer perform well under conditions too severe for most plastics and outperform other materials like polyamide-imide (PAI) and polyetheretherketone (PEEK®) in many extreme environments.

Celazole® U-60 is an unfilled PBI polymer suitable for compression molding. It is often molded and machined into precision parts for industrial, chemical and petrochemical industries; aerospace, glass making, and liquid crystal display (LCD) panel manufacture.

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A Universal Standard of Safety and Quality

Every medical innovation begins with design and manufacturing. Before a small spinal implant goes to the patient, it must meet strict universal industry standards for safety, handling, and product consistency. Afterall, a failure in a medical device can have serious repercussions for not only the health and safety of end users, but also loss of credibility and resources for a manufacturer.

That’s why medical device OEMs demand that machining facilities follow the ISO 13485 standard for medical device manufacturing.

In this informative brief, we take a deeper look at the benefits of this essential certification and how a precision machining facility can get certified.

The Benefits of having an ISO 13485 Certification

Global Standard

The ISO 13485 international standard is the world’s most widely used means of measuring the effectiveness of a medical device manufacturer’s quality management system (QMS). While different countries may have different standards for measuring quality and effectiveness, ISO 13485 provides a globally harmonized model of QMS requirements for international markets.

Quality Assurance

When it comes to machining for the Medical, Healthcare, and Life Sciences sector, true culture of quality and consistency in manufacturing techniques are paramount. An ISO 13485 certification ensures that machining processes, product handling, storage, and shipping are all accounted for in a facility’s processes. 

Requirement for Business 

Most medical device OEMs require compliance with ISO 13485, including all European Union members, Canada, Japan, Australia, and more (165 member countries in total). Therefore, precision manufacturers that want to serve the Medical sector must show proof of and adherence to ISO 13485 guidance. 

Works at the Federal & Civil Enterprise Level

The FDA recently proposed aligning current Quality management system regulations with ISO 13485. This means that at the federal and civil enterprise level, ISO 13485 would satisfy standards for quality, consistency, risk management, and in medical device manufacturing.

How to get ISO 13485 certified

The International Standardization Organization establishes and maintains standards, but it is not an enforcement agency. Certification for ISO 13485 is evaluated by third party agencies. The first step is establishing a QMS that is in alignment with the guidance. Then, an independent certification body audits the performance of the QMS against the latest version of the ISO 13485 requirements. The agency must be part of the International Accreditation Forum (IAF) and employ the relevant certification standards established by ISO’s Committee on Conformity Assessment (CASCO). Once an organization passes the ISO 13485 audit, they are issued a certificate that is valid for three years. Manufacturers must undergo a yearly surveillance audit and be recertified every three years. 

Here’s what the ISO 13485 certification will assess: 

• Promotion and awareness of regulatory requirements as a management responsibility.
• Controls in the work environment to ensure product safety
• Focus on risk management activities and design control activities during product development
• Specific requirements for inspection and traceability for implantable devices
• Specific requirements for documentation and validation of processes for sterile medical devices
• Specific requirements for verification of the effectiveness of corrective and preventive actions
• Specific requirements for cleanliness of products

Unrivaled Expertise in Precision Medical Plastics

Performance plastics play a huge role in medical device composition. Whether it’s hip replacement or a PEEK spinal implant, these life-saving technologies require durability, cleanliness, and high temperature and moisture resistance. This is no simple process…it’s precise. 

That’s where AIP, global leader in Precision Plastics Machining, provides unrivaled expertise in medical machining practices. For over three decades, we’ve served the medical community providing custom designed thermoplastic components for surgical devices, orthopedic equipment, and performance PEEK implants. 

We take quality management seriously because we know that performance is only half the equation for medical device manufacturing. For these reasons, we are an ISO 13485 certified facility and FDA compliant. We have been successfully audited by some of the most stringent OEMs in the orthopedic and medical device industries. Our plastics are processed with strict hygienic procedures to ensure innovative medical advancements continue striding forward. Let our team go to work for you! 

Find out more by visiting https://aipprecision.com or call us at +1 386.274.5335.

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