An Informational Brief on Polymer Machining

 

Vespel Polyimide (PI) is a high-performance polymer frequently machined for end-use in aerospace, semiconductor and transportation technology. This material thrives in extreme environments with high strength, chemical resistance, high temperatures, and a low coefficient of friction. It also has impressive sealing and wear properties.

Our latest machining guide discusses what goes into machining Vespel and how its considerations differ from other manufacturing options such as metal machining, injection molding, and 3D printing.

How does AIP approach Vespel and its machining process? To start, we’ll explain the difference between machining PI, a thermoplastic, and machining thermosets.

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that Vespel is a thermoplastic, but what does that mean exactly?

All polymers can more or less be divided into two categories: thermoplastics and thermosets. The main difference between them is how they react to heat. Thermoplastics like Vespel, for example, melt in heat, while thermosets remain “set” once they’re formed. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

What type of thermoplastic is Vespel in particular? PI is a semi-crystalline engineering thermoplastic, meaning its molecular structure is highly ordered.

 

Properties & Grades of Machined Vespel

 

Combining heat resistance, lubricity, dimensional stability, chemical resistance and creep resistance, Vespel works well in hostile and extreme environmental conditions. Vespel is able to overcome severe sealing and wear. As we mentioned before, these properties allow Vespel to be commonly machined for semiconductors and transportation applications.

Unlike most plastics, Vespel doesn’t produce significant outgassing, even at high temperatures. This makes it useful for lightweight heat shields and crucible support. Vespel also performs well in vacuum applications and extremely low cryogenic temperatures. However, it does absorb a small amount of water, which results in a longer pump time while placed in a vacuum.

Although there are polymers that surpass individual properties of this polyimide, the combination of these factors is Vespel’s primary advantage.

We regularly machine various grades of Vespel at AIP Precision Machining, including the Vespel SP and Vespel SCP family of products from DuPont. The former group is known for their durability and exceptional thermal resistance, while the latter is known for its mechanical properties and thermal stability.

 

Machining Vespel

 

Annealing Vespel

The process of annealing and stress-relieving Vespel reduces the likelihood of surface cracks and internal stresses occurring in the material. Post-machining annealing also helps to reduce stresses that could potentially contribute to premature failure.

 

Machining Vespel

 

Vespel offers ease of machining and tight tolerances due to its inherent mechanical strength, stiffness and dimensional stability. Machining Vespel isn’t too different from machining metals as a result of this; pretend you’re machining brass. Unlike metal, though, Vespel (like all thermoplastics) will deform if you hold it too tightly.

We generally recommend Tungsten Carbide Alloy Tooling, although we recommend diamond tooling for large volume runs or work requiring close tolerances. Be wary of overheating Vespel when you machine it. It shouldn’t become so hot that you can’t grasp it with your bare hands.

We also suggest non-aromatic, air-based coolants to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well.

 

Preventing Contamination

 

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace sciences. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

Vespel Machining Guide: Supportive Information

DuPont Machining Vespel Guide

Aerospace Market Materials

Energy Sector Materials

Extreme Performance Materials

 

 

Explore Our Inventory

or request a quote here.

Follow AIP Precision Machining on Linkedin

linkedin logo

An Informational Brief on Polymer Machining

 

Celazole, known as Polybenzimidazole (PBI), is a synthetic fiber characterized by exceptional thermal and chemical stability. PBI is commonly used in electrical insulators and high strength situations, where it shines due to its compressive strength and insulation properties.

Our latest machining guide discusses what goes into machining Celazole and how its considerations differ from other manufacturing options such as metal machining, injection molding, and 3D printing.

How does AIP approach Celazole and its machining process? To start, we’ll explain the difference between machining PBI, a thermoplastic, and machining thermosets.

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that Celazole is a thermoplastic, but what does that mean exactly?

All polymers can more or less be divided into two categories: thermoplastics and thermosets. The main difference between them is how they react to heat. Thermoplastics like Celazole, for example, melt in the heat, while thermosets remain “set” once they’re formed. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

What type of thermoplastic is Celazole in particular? PBI is an amorphous engineering thermoplastic.

PBI is characterized by high strength; it exhibits excellent thermal stability, is hydrolytically stable after exposure to high-pressure steam or water, is broadly resistant to hydrocarbons, alcohols, weak acids, weak bases, hydrogen sulfide, chlorinated solvents, oils, heat transfer fluids and many other organic chemicals.

 

Properties & Grades of Machined Celazole

 

Celazole PBI is one of the highest performing thermoplastics on the market today; it has the lowest coefficient of thermal expansion of all unfilled plastics. At above 400°F (204°C), Celazole possesses the highest mechanical properties of any thermoplastic. By itself, PBI offers a continuous use operating temperature of 1,004°F (540°C). Even after being submerged in hydraulic fluid at 200°F (93°C) for thirty days, Celazole retains 100% tensile strength.

When you combine those exceptional qualities with excellent wear and frictional properties, as well as extreme resistance to chemicals and hydrolysis, it’s no wonder that Celazole excels in industries that require high-performance in hostile environments. For example, semiconductor parts made with Celazole can last twice as long as those made with polyimides.

Other applications that Celazole is commonly machined for include gas plasma equipment, aircraft engine components and other applications for “hot” section areas or environments with harsh chemicals. Whenever dielectric properties are required or high-strength situations arise, Celazole PBI is an ideal material for your application.

We regularly machine various grades of Celazole at AIP Precision Machining, including Celazol U-60 and Duratron PBI.

 

Machining Celazole PBI

 

Annealing Celazole

The process of annealing and stress-relieving Celazole reduces the likelihood of surface cracks and internal stresses occurring in the material. Post-machining annealing also helps to reduce stresses that could potentially contribute to premature failure.

 

Machining Celazole

 

Celazole is known for its extreme hardness, which poses a challenge to HSS machining. Instead, carbide and polycrystalline diamond tools are recommended for machining Celazole PBI.

Keep in mind that Celazole PBI is notch sensitive as well and that high tolerance components machined from this thermoplastic should be stored and sealed to prevent any dimensional changes from moisture absorption.

We also suggest non-aromatic, air-based coolants to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well.

 

Preventing Contamination

 

Contamination is a serious concern when machining polymer components for technically demanding industries such as medical and life sciences. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

Celazole PBI Machining Guide: Supportive Information

 

Extreme Performance Materials

Aerospace Market Materials

Energy Sector Materials

 

 

 

or request a quote here.

Follow AIP Precision Machining on Linkedin

linkedin logo

An Informational Brief on Polymer Machining

 

Polytetrafluoroethylene (PTFE) is a fluorocarbon-based polymer, known more commonly as Dupont’s brand name Teflon®. The enhanced electrical properties, high-temperature capabilities and chemical resistances of this thermoplastic make it a favorite for backup rings, coatings, distribution valves, electrical insulation applications and more.

 

Our latest machining guide discusses what goes into machining Teflon and how its considerations differ from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Read on to learn more about Teflon’s machining, applications and properties in AIP’s informational polymer brief below, starting with the difference between working with a thermoset and a thermoplastic.

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that Teflon is a thermoplastic, but what does that mean exactly?

 

All polymers can more or less be divided into two categories: thermoplastics and thermosets. The main difference between them is how they react to heat. Thermoplastics like Teflon, for example, melt in heat, while thermosets remain “set” once they’re formed. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

 

What type of thermoplastic is Teflon in particular? PTFE is a fluoropolymer, making it a semi-crystalline thermoplastic. As a fluoropolymer, PTFE possesses an inherent high resistance to solvents, acids and bases.

 

Properties & Grades of Machined Teflon

 

Teflon has excellent electric stability in a wide range of conditions and environments, and its coatings are popular in the aerospace sector. Offering excellent chemical resistance and sliding properties, PTFE finds many applications in seals, housings, linings and bearings. Teflon also maintains very good UV resistance, hot water resistance and electrical insulation at higher temperatures.

 

Unfilled PTFE is chemically inert and has the highest physical and electrical insulation properties of any Teflon grade. Mechanical grade PTFE is often made up of reground PTFE and exists as a cost-effective alternative for industries that don’t require high purity materials while providing superior compressive strength and wear resistance to virgin Teflon.

 

There are several different modified PTFE materials available with unique properties. Many of these modified grades offer greatly reduced deformation percentages under load, as well as a lower coefficient of friction. These include glass-filled, nanotube, synthetic mica and carbon-filled grades. Teflon (PTFE) is more commonly used as an additive to numerous other base polymers in order to provide reduced friction and wear properties.

 

Some of the PTFE grades we regularly machine at AIP include FLUOROSINT 207, FLUOROSINT 500, DYNEON, SEMITRON, ESD 500 HR, and SEMITRON PTFE.

 

Machining Teflon

 

Annealing & Stress Relieving Teflon

 

The process of annealing and stress-relieving PTFE reduces the likelihood of surface cracks and internal stresses occurring in the material. Post-machining annealing also helps to reduce stresses that could potentially contribute to premature failure. AIP’s special annealing process for Teflon is designed to take the specific properties of PTFE into account, and we advise anyone working with PTFE to hire a manufacturer that understands its unique demands.

 

Machining Teflon

 

PTFE’s density and softness make it deceptively easy to machine, and in virgin grade, has a temperature range from -450°F to +500°F (-267.7°C to +260°C). Teflon has low strength when compared to materials like Nylon, which has almost two to three times the tensile strength of Teflon. You’ll want to use extremely sharp and narrow tools to work with this material.

 

Teflon’s high coefficient of expansion and stress creep properties can make it difficult to achieve tight machining tolerances. It’s essential to design your application with PTFE’s inherent properties in mind, instead of trying to force the polymer to act against its nature.

 

We also suggest non-aromatic, water-soluble coolants, such as pressurized air and spray mists, to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well.

 

Preventing Contamination

 

Contamination is a serious concern when machining polymer components for technically demanding industries such as medical and life sciences. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

Teflon Machining Guide: Supportive Information

 

Chemical Resistant Materials

 

 

Explore Our Inventory

 

 

Or request a quote here

Follow AIP Precision Machining on Linkedin

linkedin logo

This post was originally published in August 2017 and updated in March 2019.

 

When in need of a custom-machined component for a project, choosing a metallic material may be the instinctive consideration to the design engineer. This article is intended to provide educational insight as to a more sensible alternative for precision-machined, high-strength, durable parts: machined polymers and composites. Let’s explore the benefits of opting for a plastic material versus the more traditional metal materials for precision parts.

 

Benefits Across the Board

 

Machined polymer and composite components are the most cost-effective solution when compared to metal.

 

Machined plastic parts are lighter and therefore provide immense advantages over metals by offering lower lifetime freight costs for equipment that is regularly transported or handled over the product’s lifetime. In bearing and wear applications, polymers provide extensive advantages over metals by allowing for lower power motors for moving parts due to lower frictional properties of polymer wear components compared to metals. The low frictional properties provide for less wear as well. The lower wear rates allow for less maintenance-related downtime. Now your equipment can be online longer producing you more profit. Not only are plastics lighter, but they’re also less expensive than many raw metal materials used for parts. Plastics are produced in faster cycles than metals which helps keep manufacturing costs down as well.

 

Plastics are more resistant to chemicals than their metal counterparts.

 

Without extensive and costly secondary finishes and coatings, metals are easily attacked by many common chemicals. Corrosion due to moisture or even dissimilar metals in close contact is also a major concern with metal components. Polymer and composite materials such as PEEK, Kynar, Teflon, and Polyethylene are impervious to some of the harshest chemicals. This allows for the manufacture and use of precision fluid handling components in the chemical and processing industries which would otherwise dissolve if manufactured from metallic materials. Some polymer materials available for machining can withstand temperatures over 700°F (370°C).

 

Plastic parts do not require post-treatment finishing efforts, unlike metal.


Polymer and composites are both thermally and electrically insulating. Metallic components require special secondary processing and coating in order to achieve any sort of insulating properties. These secondary processes add cost to metallic components without offering the level of insulation offered by polymer materials. Plastic and composite components are also naturally corrosion resistant and experience no galvanic effects in a dissimilar metal scenario that require sheathing. Unlike metals, plastic materials are compounded with color before machining, eliminating the need for post-treatment finishing efforts such as painting.

 

Let’s Break It Down by Industry

 

The benefits and features of plastic materials over metals discussed above span across multiple industries, showcasing the utility and versatility that plastic brings to the table.

 

Aerospace & Defense

 

  • Lightweight: Polymer and composite materials are up to ten times lighter than typical metals. A reduction in the weight of parts can have a huge impact on an aerospace company’s bottom line. For every pound of weight reduced on a plane, the airline can realize up to $15k per year in fuel cost reduction.

 

  • Corrosion-Resistant: Plastic materials handle far better than metals in chemically harsh environments. This increases the lifespan of the aircraft and avoids costly repairs brought about by corroding metal components an in-turn reducing MRO downtime provides for more operational time per aircraft per year.

 

  • Insulating and Radar Absorbent: Polymers are naturally radar absorbent as well as thermally and electrically insulating.

 

  • Flame & Smoke Resistances: High-performance thermoplastics meet the stringent flame and smoke resistances required for aerospace applications.

 

Learn More

 

Medical & Life Sciences

 

  • Sterility: In the medical industry, cleanliness is vital when it comes to equipment. Infection is the greatest threat facing hospital patients. Polymer and composite materials are easier to clean and sterilize than metal.

 

  • Radiolucency: Radiolucency is the quality of permitting the passage of radiant energy, such as x-rays, while still offering some resistance to it. Surgical instruments and components manufactured from polymer materials allow the surgeon a clear unobstructed view under fluoroscopy. This allows for safer, more precise surgeon outcomes in the OR. Metal instruments impede the surgeon’s view.

 

  • Lightweight: Plastic and composite surgical components allow orthopedic OEMs to meet ergonomic weight limits for surgical trays. Each metallic instrument adds weight and strain to the surgical team carrying and using metal instruments.

 

  • Reduced Stress-Shielding: Stress shielding occurs when metal implants and bone don’t become one nor work in unison. In medical-grade polymers like PEEK, however, its similar modulus to bone “fuses” with the bone into a single construct.

 

Learn More

 

Specialized Industrial

 

  • High Tensile Strength: Several lightweight thermoplastics can match the strength of metals, making them perfect for industrial equipment metal part replacement.

 

  • Chemical & Corrosion Resistances: Semiconductor equipment and electronics require survival in extreme, high-pressure environments.

 

  • Flexibility & Impact Resistance: Polymers are resistant to impact damage, making them less prone to denting or cracking the way that metals do.

 

  • Excellent Bearing & Wear Properties: Bearing-grade plastics can withstand repeated friction and wear for your high-load solutions.

 

Learn More

 

Power & Energy

 

  • Weight, corrosion, and sealing: Plastic materials allow the oil and gas industry to explore deeper depths than ever before by offering tool weight reduction without a loss of strength as well as materials which offer superior sealing attributes.

 

  • Superior Insulation: Naturally insulating plastics provide for superior thermal and electrical insulation over metals, which is a must for power generation equipment that deals with electrical currents.

 

  • Chemical, Wear & Corrosion Resistances: Plastic components with a strong chemical, wear and corrosion resistances reduce downtime and yield long-lasting performance and reliability.

 

  • Extreme Water & Earth Depth Capabilities: These qualities are necessary for high pressure and temperature applications that involve surviving extreme environments.

 

Learn More

 

As you can see, plastics have a variety of unique attributes which place them above metals in terms of utility, cost-effectiveness and flexibility for precision-machined components. Search specific plastic materials and their applications per industry with our useful material search function.

 

Download Our Plastics Over Metals Infographic

Take Our Material Expertise with You.

Download Now

Follow AIP Precision Machining on Linkedin

linkedin logo

An Informational Brief on Polymer Machining

 

Delrin®, also commonly known as an acetal (polyoxymethylene) homopolymer, is an impact and wear resistant semi-crystalline thermoplastic popular for a broad range of machining applications. To list just a few of its impressive qualities, Delrin offers great stiffness, flexural modulus, and high tensile and impact strength.

Our latest machining guide discusses what goes into machining Delrin and how its considerations differ from other manufacturing options such as metal machining, injection molding, and 3D printing.

How does AIP approach Delrin and its machining process? To start, we’ll explain the difference between machining Delrin, a thermoplastic, and machining thermosets.

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that Delrin is a thermoplastic, but what does that mean exactly?

All polymers can more or less be divided into two categories: thermoplastics and thermosets. The main difference between them is how they react to heat. Thermoplastics like Delrin, for example, melt in the heat, while thermosets remain “set” once they’re formed. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

What type of thermoplastic is Delrin in particular? Acetal homopolymer is a semicrystalline, engineering thermoplastic.

 

Properties & Grades of Machined Delrin

 

This strong, stiff and hard acetal homopolymer is easy to machine and exhibits dimensional stability and good creep resistance, among several other desirable qualities. Delrin is also known for its superior friction resistance, high tensile strength, and its fatigue, abrasion, solvent and moisture resistance.

The latter quality allows Delrin to significantly outperform other thermoplastics like Nylon in high moisture or submerged environments without losing high-performance in the process. In other words, Delrin can retain its low coefficient of friction and good wear properties in wet environments.

One of the main reasons for Delrin’s popularity is its sheer versatility. The above blend of unique qualities makes Delrin broadly applicable to various industries in the medical, aerospace and energy sectors. For example, you can machine Delrin for medical implants and instruments, or for industrial bearings, rollers, gears, and scraper blades. It is ideal for smaller applications at temperatures below 250 °F (121°C) and can have centerline porosity.

Some of the Delrin grades we regularly machine at AIP include:

 

PTFE-Filled Acetals

 

PTFE (polytetrafluoroethylene) filled grades of Delrin is ideal where impact strength and wear capability are of the highest importance.

 

Glass-Reinforced Acetals

 

Acetals that are reinforced with glass have a much higher strength and greater heat resistance than other grades of Delrin.

 

FDA-Compliant Acetals

 

There are FDA-compliant grades of Delrin available for use in medical and food-related applications.

 

Machining Delrin

 

Machining Delrin

 

It’s true that Delrin is an easy material to work with in terms of machining. It is a very stable material, which makes precise, tight tolerances easier to achieve for this thermoplastic.

While machining, keep in mind that Delrin is sensitive to heat at or above 250 °F (121°C).

Balance the material removal as best as you can to keep your dimensions stable.

We also suggest non-aromatic, air-based coolants to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well.

 

Preventing Contamination

 

Contamination is a serious concern when machining polymer components for technically demanding industries such as medical and life sciences. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats, and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

Delrin Machining Guide: Supportive Information

 

General Engineering Materials

Want to learn more about AIP’s polymer and composite materials?

or request a quote here.

Follow AIP Precision Machining on Linkedin

linkedin logo

AIP explains the advantages of using plastics over metals in our infographic below, with special emphasis on how each industry benefits from using polymers. Read on to learn all about it from the plastics professionals.

 

Follow AIP Precision Machining on Linkedin

linkedin logo

An Informational Brief on Polymer Machining

 

Nylatron® is Quadrant’s trademark name for a whole family of wear resistant and low friction Nylon polymers, most of which are filled with molybdenum disulphide (MoS2) powder. What makes this material popular for industrial and bearing applications is its mechanical properties and impressive wear-resistance.

 

In our latest machining guide, we discuss what goes into machining Nylatron, and how its considerations differ from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Machining Nylatron: A Plastics Guide shows you how AIP Precision Machining approaches this material and its machining process. To start, we’ll explain the difference between machining Nylatron, a thermoplastic, and machining thermosets.

 

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that Nylatron is a thermoplastic, but what does that mean exactly?

 

All polymers can more or less be divided into two categories: thermoplastics and thermosets.  The main difference between them is how they react to heat. Thermoplastics like Nylatron, for example, melt as heat is increased to the material’s melt point, while thermosets remain “set” once they’re formed regardless of heat; rather, they simply char or burn. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

 

What type of thermoplastic is Nylatron in particular? As part of the Nylon family, it is a semi-crystalline, engineering thermoplastic polyamide.

 

 

 

Properties & Grades of Machined Nylatron

 

Nylatron’s main characteristics include a high mechanical strength, stiffness, hardness and toughness. As a semi-crystalline thermoplastic, Nylatron has good fatigue resistance as well. With excellent wear resistance and good electrical insulating properties, it’s not surprising that this material is often used for specialized industrial applications. One feature that’s of special interest to us at AIP is Nylatron’s ease of machinability with high precision. However, it’s also easy to extrude and fabricate.

 

Like Nylon, Nylatron is resistant to chemicals and hydrocarbons; the latter characteristic is especially useful in the oil and gas sector. Add in abrasion resistance, low coefficient of friction and outstanding corrosion resistance and you have a long-wearing material that can serve as a cost-effective replacement for metals and rubber.

 

Some of the Nylatron grades we regularly machine at AIP include:

 

Nylatron GSM PA6

Also known as MoS2-Filled Type 6 Nylon, this filled Nylatron grade has improved strength and rigidity over other Nylon variants, including a lower coefficient of linear thermal expansion. This is because the MoS2 (molybdenum disulphide) enhances the bearing and wear of the material without compromising its impact and fatigue resistance. This grade is often used to replace cast iron industrial applications, as lightweight Nylatron can both reduce weight and eliminate corrosion. As a result, it’s commonly used for gears, bearings, sprockets and sheaves.

 

Nylatron GF30 PA66

This extruded grade of Nylon 6/6 is 30% glass fiber reinforced and heat stabilized to provide improved creep resistance and dimensional stability as well as enhanced strength, stiffness and abrasion resistance. It has almost double the tensile strength of unmodified Nylon 6/6, with an elongation rate of about 1/6th that of unmodified Nylon 6/6. It has good resistance to high energy radiation (such as X-rays or gamma- rays) and allows for higher maximum service temperatures when compared to other grades.

 

Nylatron LIG PA6

Nylatron LIG PA6 is an internally lubricated Nylon grade that can perform up to ten times longer than its unmodified counterpart thanks to its lubricated additives. It strikes an optimal balance of strength and toughness. This makes it work well for industrial and consumable applications including gears, industrial bearings and wear pads.

 

Nylatron NSM

Nylatron NSM is the highest wear resistant thermoplastic available. As a self-lubricating grade of Nylon 6, it’s designed to outperform other wear grade materials and give long-lasting part life for applications that otherwise experience continuous wear and damage, such as bearings and wear pads. Other benefits of Nylatron NSM are its ease of machining, corrosion-resistance and noise reduction.

 

Nylatron GSM Blue PA6

Named for its dark blue color, Nylatron GSM Blue PA6 is the first cast Nylon to combine MoS and oil for the load capacity of Nylatron GSM PA6. This material performs exceptionally in higher pressures and at low speeds of up to 40 fpm. It’s preferred over Nylatron GSM PA6 for slide pads, thrust washers and trunnion bearings due to its 20% lower coefficient of friction, 50% greater limiting PV and its lower “k” factor.

 

Nylatron 703XL

High precision applications machined from Nylatron 703XL benefit from its near-zero level of “stick-slip,” which eliminates chatter to allow for an incredible level of control. Nylatron 703XL possesses a good balance of strength and toughness, as well as good mechanical and electrical properties. This grade works well in critical bearing applications for construction and production equipment industries.

 

Nylatron MC901

Nylatron MC901 is a heat-stabilized Nylon 6 grade that offers long-term thermal stability to 260 °F. This material has high toughness, flexibility and fatigue resistance. It is used in many bearing and structural applications, its most popular being gear wheels, racks and pinions.

 

 

Machining Nylatron

 

Annealing Nylatron
The process of annealing and stress-relieving Nylatron reduces the likelihood of surface cracks and internal stresses occurring in the material. Post-machining annealing also helps to reduce stresses that could potentially contribute to premature failure. We recommend stress relieving Nylons in a nitrogen environment.

 

Machining Nylatron

As stated earlier, Nylatron precision machines easily. This makes it a popular choice for machined industrial components that require precise, tight tolerances. We advise using HSS cutters instead of carbide on Nylatron for its surface finish. Stringer or chip removal during machining of Nyaltron is critical in order to maintain tolerances and surface finish.

 

When under high humidity, or while submerged in water, Nylons can absorb up to 7% by weight of water. This is important to keep in mind for machining Nylatron and designing applications of the material, as this effect can result in dimensional changes and a reduction of physical properties. There are proper design techniques that can compensate for this, so be sure you’re working with a Nylatron expert.

 

We also suggest non-aromatic, air-based coolants to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

 

Nylatron Machining Guide: Supportive Information

Nylon Variants Guide

Chemical Resistant Materials Guide

Energy Sector Materials Guide

Follow AIP Precision Machining on Linkedin

linkedin logo

Where Does This Part Go?

PPS Wheel Bushing | AIP Precision Machining

 

If you’ve been to a popular Florida amusement park, then it’s possible you’ve encountered the latest part starring in our “Where Does This Part Go?” series.

Find out why this part really makes a “splash” in the section below…

Follow AIP Precision Machining on Linkedin

linkedin logo

An Informational Brief on Polymer Machining

 

Did you know that PPS (or Polyphenylene sulfide) products offer the broadest resistance to chemicals of any high-performance thermoplastic? It’s no surprise that this makes them a popular choice for industrial applications such as wheel bushings, chemical pumps, and compound clamp rings for semiconductor wafers.

 

What goes into machining this thermoplastic, however, and how does it differ from metal machining, injection molding, or 3D printing?

 

With Machining PPS: A Plastics Guides, AIP provides you with a guide to this material and its machining process. First, let’s start with the basics: thermoplastics vs thermosets.

 

 

Machining Thermoplastics vs Thermosets

 

We’ve already said that PPS is a thermoplastic, but what does that mean exactly?

 

All polymers can more or less be divided into two categories: thermoplastics and thermosets. The main difference between them is how they react to heat. Thermoplastics like PPS, for example, melt in heat, while thermosets remain “set” once they’re formed. Understanding the technical distinction between these types of materials is essential to CNC machining them properly.

 

What type of thermoplastic is PPS in particular? It’s a semi-crystalline, high-performance thermoplastic that has an extremely stable molecular structure. The chemical resistance of PPS is often compared to PEEK  and fluoropolymers.

 

 

Properties & Grades of Machined PPS

 

There’s a lot to like about PPS’s material properties. As we mentioned before, PPS has exceptional chemical resistance that makes its bearing grades especially favorable for the chemical industry or caustic environments. In particular, its resistance to acids, alkalis, ketones, and hydrocarbons lend PPS stellar structural performance in harsh chemicals.

 

Additionally, PPS materials are inert to steam as well as strong bases, fuels and acids. Combine that with a low coefficient of thermal expansion and zero moisture absorption, and you get a material that is ideal for continuous use in corrosive or hostile environments. PPS has replaced stainless steel for a lot of industrial applications for this reason.

 

Most impressively, PPS will not dissolve at temperatures below approximately 200 °C, no matter what solvent is used. In fact, all grades of PPS share UL94 V-0 flammability ratings, without requiring flame retardant additives, resulting in an excellent material for aircraft where flame resistance is paramount.

 

Some grades of PPS that we regularly machine at AIP Precision Machining include Ryton®, Fortron®, TECHTRON®, TECTRON® HPV, TECATRON PVX and TECATRON CMP.

 

 

Machining PPS

 

Annealing PPS

The process of annealing and stress-relieving PPS reduces the likelihood of surface cracks and internal stresses occurring in the material. Post-machining annealing also helps to reduce stresses that could potentially contribute to premature failure. AIP’s special annealing process for PPS is designed to take the specific properties of PPS into account, and we advise anyone working with PPS to hire a manufacturer that understands its unique demands.

 

Machining PPS

PPS is a fantastic material for machining. Its low shrinkage and stable dimensional properties make it easy to machine to incredibly tight, precise tolerances. A unique characteristic of PPS is that when dropped, it sounds just like a piece of metal hitting the floor.

 

PPS, like many other thermoplastics, is notch sensitive, so take care to avoid sharp corners in design. We recommend carbide tipped cutting tools for working with PPS as they provide an ideal speed and surface finish.

 

We also suggest non-aromatic, water-soluble coolants, such as pressurized air and spray mists, to achieve optimum surface finishes and close tolerances. Coolants have the additional benefit of extending tool life as well. No known coolants attack nor degrade PPS.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace. To ensure the highest level of sanitation down to the sub-molecular level, AIP Precision Machining designs, heat-treats, and machines only plastics, with any sub-manufactured metalwork processed outside our facility.

 

To learn more, read our article “Three Ways to Ensure Sterilization in Your Plastic Machined Medical Applications.”

 

 

PPS Machining Guide: Supportive Information

Chemical Resistant Materials Guide

Energy Sector Materials Guide

Aerospace Sector Materials Guide

 

Explore Our Inventory

Follow AIP Precision Machining on Linkedin

linkedin logo