An Informational Brief on Polymer Machining

 

Known for its ease of machining, coloring and adaptability to additives, ABS is a versatile performance thermoplastic.  While it may be used in household toys, it is also used for mission critical applications like electrical insulators and automotive interior and exterior parts.

 

AIP has over 37 years of experience machining complex components from thermoplastics like Acrylonitrile Butadiene Styrene (ABS).  In this insightful technical brief, we will discuss what goes into machining ABS and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of ABS

 

Machinists should keep data on the properties of the thermoplastics they use.  This aids in selecting the right material for a project.  Also, it helps determine if the material is a good candidate for the end-use.  Below are some of the key characteristics of Acrylonitrile Butadiene Styrene (ABS):

 

Key Properties

  • Impact resistance
  • Chemical resistance
  • Ideal electrical insulator with added moisture resistance
  • Good strength and stiffness
  • Platable grades
  • Excellent aesthetic qualities
  • Colorable
  • Various gloss levels (Matte to High Gloss)

 

Description

ABS is one of the most common thermoplastic polymers manufactured. It is relatively cheap compared to other performance thermoplastics, such as, PEEK or VESPEL.

 

It provides good mechanical properties, including, impact resistance, toughness and rigidity compared to other common polymers. It is also easy to modify with additives to improve any of its properties. It is often a polymer of choice where aesthetics and color are concerned, since its natural color is translucent ivory to white. Pigments and additives are often added to this resin to improve the qualities based on the project needs.

 

Two major categories could be ABS for extrusion and ABS for injection molding, then high and medium impact resistance. Generally, ABS would have useful characteristics within a temperature range from −20 to 80 °C (−4 to 176 °F). As an amorphous polymer, it does not have a true melting point.

 

The table below displays an overview of the material properties, units and values for machining ABS:

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%20
Flexural Modulus of Elasticity @ 73 Fpsi340000
Tensile Modulus of Elasticity @ 73 Fpsi346000
Flexural Strength @ 73 Fpsi9300
Specific Gravity @73 FASTM D7921.04
Tensile Strength @73 F, (ult)/(yld)psi5500 (ult)
Notched Izod Impact @73 Fft-lb/in of notch7.0
Heat Deflection Temperature @ 264 psiF220
Flammability RatingUL94HB(6.10mm)
Coefficient of Linear Thermal Expansion @73 Fin/in/F5.2E-05
Dielectric Strength, Short TermVolts/mil450
Water Absorption, Immersion, 24 hours
Water Absorption, Saturation
% by weight
% by weight
0.30
0.70

 

Applications of ABS

 

ABS is mostly found in a wide variety of consumer products. Some of which include – Legos®, recorders and other musical instruments, golf club heads, household vacuums, and so on. ABS is a household staple for many consumer goods.

 

It also finds several end-use applications in the industrial sector. Applications include – automotive trim and components, inhalers, tendon prostheses, drug-delivery system tracheal tubes, enclosures for electrical and electronic assemblies, protective headgear and more.

 

Common Applications

  • Structural components
  • Automotive interior and exterior parts
  • Medical devices
  • Electrical components and assemblies
  • Toys
  • Housings/covers
  • Kitchen appliances

 

AIP Machining Capabilities: Unrivaled Expertise

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. If you are looking for a trademarked material for your project, we have a host of material bases available for expert machining. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Our Suppliers

 

Machining ABS

 

Annealing ABS

As with any CNC machined part, annealing and stress-relieving is crucial to the machining process. Coolants, lubricants and trained procedures prevent cracking and crazing in a precision machined component. We recommend slow heating and cooling during the annealing process of thermoplastics. This reduces the chances of these stresses occurring from the heat generating during machining polymers like ABS. Our AIP machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control. .

 

Machining ABS

PVC can be injection molded, extruded or thermoformed.  At AIP, we CNC machine compounded PVC.  For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating.  We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants also preserve and extend the life of tools.  These guidelines are general and are not a substitute for a conversation with your machinist.  For further information, speak to a CNC machinist at AIP to get specific machining information on PVC and other performance thermoplastics.

 

Although it is often blow molded, ABS can be CNC machined and milled for precision parts. ABS is manufactured in a variety of grades, but for precision machining of ABS structural parts, it is recommended to use Machine Grade ABS. For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

ABS Machining Guide: Supportive Information

 

Quality Assurance Certifications
Miscellaneous Materials

 

How will the heat from your machining project affect your project? Make sure to talk to your machinist about the CLTE of your machined part.

 

Read Our Blog
 

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An Informational Brief on Polymer Machining

 

PVC, or polyvinyl chloride, is a rigid material that exhibits high corrosion resistance, high chemical resistance, low moisture absorption and excellent dielectric strength.  These qualities make it a choice material for a wide range of industries, including:  medical devices, industrial/construction components and everyday household items.  It is the world’s third largest thermoplastic material by volume only after polyethylene and polypropylene.

 

AIP has over 37 years of experience machining complex components from thermoplastics like PVC.  In this insightful technical brief, we will discuss what goes into machining PVC and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of PVC

 

All machine shops should keep data on the properties of the thermoplastics and materials they use.  The data helps in selecting the right material for a project and a material’s suitability for the end-use product.  Below are some of the key characteristics of PVC:

 

Key Properties

  • Good insultation
  • Dielectric strength
  • Durable
  • Flame Retardant
  • Low maintenance and long life span
  • Abrasion resistant
  • Light-weight
  • Chemical resistance

 

Description

Polyvinyl Chloride (PVC or vinyl) is a highly durable thermoplastic material.  It is versatile and economical for applications in medical, construction, industrial and consumer end use markets.

 

PVC has excellent dielectric strength which makes it a good insultation material.  It is also resistant to weathering, chemical rotting, corrosion, shock and abrasion – therefore, a preferred material choice for long-life and outdoor products.  PVC is resistant to all inorganic chemicals. It has very good resistance against diluted acids, diluted alkalis and aliphatic hydrocarbons. Attacked by ketones; some grades swollen or attacked by chlorinated and aromatic hydrocarbons, esters, some aromatic ethers and amines, and nitro- compounds.

 

It is available in two forms – rigid and flexible – but it is often mixed with additives to enhance properties and improve machineability.

 

The table below displays an overview of the material properties, units and values for machining PVC Gray Type 1:

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%
Flexural Modulus of Elasticity @ 73 Fpsi455000
Tensile Modulus of Elasticity @ 73 Fpsi392000
Flexural Strength @ 73 Fpsi
Specific Gravity @73 FASTM D7921.43
Tensile Strength @73 F, (ult)/(yld)psi7300 (yld)
Notched Izod Impact @73 Fft-lb/in of notch0.7
Heat Deflection Temperature @ 264 psiF169
Flammability RatingUL94
Coefficient of Linear Thermal Expansion @73 Fin/in/FE-831(TMA)
Dielectric Strength, Short TermVolts/mil
Water Absorption, Immersion, 24
Water Absorption, Saturation
% by weight
% by weight

 

Applications of PVC

 

PVC comes in two general forms – rigid and flexible.  However, it can be combined with several different materials to enhance its qualities for use in a range of applications from medical devices to industrial construction components.  Here is a list of the most common applications:

 

Common Applications

 

ApplicationRigid PVCFlexible PVC
ConstructionWindow Frames, Pipes, House Siding, Ports, RoofingWaterproof Membranes, Cable Insultations, Roof Lining, Greenhouses
DomesticCurtain Rails, Drawer Sides, aminates, Audio and Videotape Cases, RecordsFlooring, Wall Coverings, Shower Curtains, Leather Cloth, Hosepipes
PackagingBottles, Blister Packs, Transparent Packs and PunnetsCling Film
TransportCar Seat BacksUnder Seal, Roof Linings, Leather Cloth Upholstery, Wiring Insultation, Window Seals, Decorative Trim
MedicalOxygen Tents, Bags and Tubing For Blood Transfusions, Drips and Dialysis Liquids
ClothingSafety EquipmentWaterproofs for Fishermen and Emergency Services, Life-Jackets, Shoes, Aprons and Baby Pants
ElectricalInsultation pipes, jacketing, electricity distribution boxes, switches, transparent distributor box housings, plug housings and battery terminalsCable and wire insultation, plugs, cable jackets, sockets, sable heads and distributors
OtherCredit Cards, Traffic SignageConveyor Belts, Inflatables, sports goods, toys, garden hoses

 

AIP Machining Capabilities: Unrivaled Expertise

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures.  If you are looking for a trademarked material for your project, we have a host of material bases available for expert machining.  Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining PVC

 

Annealing PVC

Annealing and stress-relieving prevents cracking and crazing in a precision machined component with lubricants, cooling agents and trained procedures.  We recommend slow heating and cooling during the annealing process of thermoplastics.  This reduces the chances of these stresses occurring from the heat generating during machining polymers like PVC.  Our AIP machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.  If you have a specific question about the annealing process for PVC or other thermoplastics, our machinists at AIP can provide an in-depth consultation.

 

Machining PVC

PVC can be injection molded, extruded or thermoformed.  At AIP, we CNC machine compounded PVC.  For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating.  We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants also preserve and extend the life of tools.  These guidelines are general and are not a substitute for a conversation with your machinist.  For further information, speak to a CNC machinist at AIP to get specific machining information on PVC and other performance thermoplastics.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products.  Past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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.  This allows us to de-risk the process from metallic cross contamination.

 

PVC Machining Guide: Supportive Information

 

Quality Assurance Certifications
Miscellaneous Materials

 

Looking for more plastics machining guides on polymers with chemical resistance?

 

Read Our PCTFE Machining Guide
 

 

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An Informational Brief on Polymer Machining

 

Copolyester elastomers (COPE) are high-performance, high-temperature elastomers that have several properties of thermoset rubber with the processing ease of engineering plastics. One of these thermoplastic elastomers (TPC-ET) is DuPont’s HYTREL®. It is known for toughness, tear resistance and good flex fatigue along with good chemical and temperature resistance. For these reasons, it is an excellent general engineering thermoplastic for everyday to mission critical applications.

 

AIP has over 37 years of experience machining complex components from thermoplastics like HYTREL® thermoplastic elastomer. In this insightful technical brief, we will discuss what goes into machining HYTREL® and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of HYTREL®

 

Machinists should keep data on the properties of the thermoplastics they use. This aids in selecting the right material for a project. Also, it helps determine if the material is a good candidate for the end-use. Below are some of the key characteristics of HYTREL® TPC-ET:

 

Key Properties

  • Excellent Flex Fatigue
  • Excellent Strength
  • Flame Retardant
  • Fluid Resistance
  • Hydrocarbon Resistance
  • Hydrolysis Resistance
  • UV Resistance

 

Description

HYTREL is a brand name for TPC-ET (thermoplastic polyester elastomer). HYTREL comes in several different grades, such as heat stabilized, UV protected, hydrolysis-resistant and flame retardant.

 

Characterized by excellent strength and flex fatigue while being resistant to hydrocarbons and most fluids, HYTREL can be utilized within a wide range of engineering applications.

 

The table below displays an overview of the material properties, units and values for machining HYTREL® 5556:

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%560
Flexural Modulus of Elasticity @ 73 Fpsi30000
Tensile Modulus of Elasticity @ 73 Fpsi
Flexural Strength @ 73 Fpsi
Specific Gravity @73 FASTM D7921.20
Tensile Strength @73 F, (ult)/(yld)psi1000 (5%)
Notched Izod Impact @73 Fft-lb/in of notchNo Break
Heat Deflection Temperature @ 264 psiF120
Flammability RatingUL94HB(3.05mm)
Coefficient of Linear Thermal Expansion @73 Fin/in/F6.5E-05
Dielectric Strength, Short TermVolts/mil410
Water Absorption, Immersion, 24
Water Absorption, Saturation
% by weight
% by weight
0.30

 

Applications of HYTREL®

 

HYTREL’s properties make it a great general purpose engineering thermoplastic. It has qualities similar to thermoset rubber with the machining ease of engineering plastics. For this reason, it can be found on medical devices, electrical cabling insulation, mechanical gears, automotive components. As a performance thermoplastic, it can flex in multiple directions, cycle after cycle, long after rubber would break.

 

Common Applications

  • Cable insulation and jacketing
  • Chassis suspension Systems
  • Food Contact Materials
  • Innovative Furniture Design
  • Mechanical Gears
  • Medical Device Materials
  • Polymers for Oil and Gas
  • Railway Technology for the Long Haul
  • Seals and Gaskets
  • Sustainability in Airbag Systems
  • Thermoplastic Tubing and Elastomeric Hose
  • Mobile Phone Housing & Components
  • Plastics For Sporting Goods

 

AIP Machining Capabilities: Unrivaled Expertise

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. If you are looking for a trademarked material for your project, we have a host of material bases available for expert machining. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Our Suppliers

We machine DuPont’s HYTREL® and HYTREL® resin at AIP Precision Machining. If you have a question about the grade we use or machining specifications for this brand, our machinists are happy to help you.

 

 

Machining HYTREL®

 

Annealing HYTREL®

As with any CNC machined part, annealing and stress-relieving is crucial to the machining process. Coolants, lubricants and trained procedures prevent cracking and crazing in a precision machined component. We recommend slow heating and cooling during the annealing process of thermoplastics. This reduces the chances of these stresses occurring from the heat generating during machining polymers like HYTREL®. Our AIP machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control. If you have a specific question about the annealing process for HYTREL® or other thermoplastics, our machinists at AIP can provide an in-depth consultation.

 

Machining HYTREL®

HYTREL® can be injection molded, extruded or thermoformed. At AIP, we CNC machine HYTREL® and HYTREL® resin. For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well. These are general machining guidelines. For further information, speak to a CNC machinist at AIP to get specific machining information on HYTREL® and other performance thermoplastics.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

HYTREL® Machining Guide: Supportive Information

 

Quality Assurance Certifications
Miscellaneous Materials

 

Looking for more machining guides on thermoplastics from supplier DuPont?

 

Read Our Delrin Machining Guide
 

 

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An Informational Brief on Polymer Machining

 

Hemodialysis bloodline tubes connected to hemodialysis machine. Health care blood purification kidney failure transplantation medical equipment concept.Polychlorotrifluoroethylene (PCTFE) is a thermoplastic chlorofluoropolymer; some of its fluoropolymer cousins include: FEP, Kynar® PVDF, Teflon® PTFE and Halar® ECTFE. Fluoropolymers are known for their excellent chemical and hydro-resistance. This makes them candidates for critical applications, such as medical devices and industrial piping, where fluid exposure and hazardous materials can wear on a machined plastic part.

 

AIP has over 37 years of experience machining complex components from thermoplastics like Polychlorotrifluoroethylene PCTFE. In this insightful technical brief, we will discuss what goes into machining PCTFE and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of PCTFE

 

It is helpful to keep information on the properties of a thermoplastic before machining. This helps in selecting the right material for your project. Also, it helps determine if the material is a candidate for the end-use requirement. Below are some of the key characteristics of PCTFE:

 

Key Properties

  • High Chemical Resistance
  • Extremely Low Moisture Absorption
  • High Compressive Strength
  • Low Deformation
  • Low Gas Permeability
  • Nonflammable

 

PCTFE offers high compressive strength, low deformation, low gas permeability and extremely low moisture absorption. Nonflammable and resistant to most corrosive chemicals, PCTFE additionally has a much lower cold flow characteristic than other fluoropolymers.

 

Able to maintain excellent chemical resistance and ultraviolet stability in a temperature range from -400°F (-230°C) to 393°F (201°C), PCTFE has many applications in food processing, industrial and aerospace applications.

 

The table below displays the material properties for KEL-F®, a trade name for PCTFE.

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%140
Flexural Modulus of Elasticity @ 73 Fpsi190000
Tensile Modulus of Elasticity @ 73 Fpsi220000
Flexural Strength @ 73 Fpsi8500
Densityg/cm3
lb/in3
2.13
0.077
Tensile Strength @73 F, (ult)/(yld)psi5700/(ult)
Notched Izod Impact @73 Fft-lb/in of notch1.5
Heat Deflection Temperature @ 264 psiF167
Flammability RatingUL94V-0
Coefficient of Linear Thermal Expansion @73 Fin/in/F3.5E-05
Dielectric Strength, Short TermVolts/mil500
Water Absorption 24 hours% by weight0.00

 

Applications of PCTFE

 

There are two main qualities that direct PCTFE’s application usage: water resistance and chemical stability. PCTFE films are used as a protective layer against moisture. Some applications include: moisture barriers in pharmaceutical blister packaging, protection of LCD panels, cryogenic seals and components.

When it comes to chemical resistance, PCTFE acts as a protective barrier for coatings and prefabricated liners. It is used for laminating other polymers like PVC, Polypropylene, PETG, APET and more. It can be found in transparent eyeglasses, tubes, valves, chemical tank liners, O-rings, seals and gaskets.

 

Common Applications

  • Aerospace Applications
  • Food Coating Films
  • Instrumentation
  • Seats
  • Valves
  • Films
  • Fluid Handling Systems

 

AIP Machining Capabilities: Unrivaled Expertise

 

We machine various grades and brand name PCTFE, including the following:

  • NEOFLON® / KEL-F®

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining PCTFE

 

Annealing PCTFE

As with any CNC machined part, annealing and stress-relieving is crucial to the machining process. Coolants, lubricants and trained procedures prevent cracking and crazing in a precision machined component. We recommend slow heating and cooling during the annealing process of thermoplastics. This reduces the chances of these stresses occurring from the heat generating during machining polymers like PCTFE. Our AIP machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.

 

Machining PCTFE

PCTFE and other fluoropolymers are known for their dimensional stability – PCTFE has a melting point temperature of 419oF and a continuous use temperature of 250oF. However, once it reaches elevated temperatures, it will start to decompose. For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

 

PCTFE Machining Guide: Supportive Information

 

Quality Assurance Certifications
Chemical Resistant Materials

 

Looking for innovative, high-performance thermoplastics designed to perform in hostile, critical environments? Here’s 7 Thermoplastics We Recommend.

 

Read Our Blog
 

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An Informational Brief on Polymer Machining

 

Polyethylene terephthalate (PET or PET-P) is a general-purpose thermoplastic polymer which belongs to the polyester family. Highlights of this material include: an excellent combination of mechanical, thermal, chemical resistance and dimensional stability. Another notable characteristic of this material is that it is one of the most recycled thermoplastics.

 

AIP has over 37 years of experience machining complex components from thermoplastics like Polyethylene Terephthalate Polyester. In this insightful technical brief, we will discuss what goes into machining PET-P and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of PET-P

 

It is beneficial to keep information on the properties of a thermoplastic before machining. This helps in selecting the right thermoplastic for a project. Furthermore, it assists in evaluating if the material is a candidate for the end-use requirement. Below are some of the key characteristics of Polyethylene Terephthalate Polyester:

 

Key Properties of PET-P

  • Chemical Resistance
  • Enhanced Electrical Properties
  • High Dimensional Stability
  • High Strength
  • Lightweight
  • Low Water Absorption

 

PET-P (Polyethylene Terephthalate Polyester) is a thermoplastic polyester, commonly referred to as just Polyester. With good dimensional stability, electrical properties, high strength, low water absorption, and good chemical resistance (with the exception of alkalis), PET-P offers a greater acidic resistance and stain resistance than Nylon or Acetal.

 

Applying PET-P reduces the need for heavy lubrication, making the material useful for manifolds, distribution valves and pistons. PET-P is also lightweight and is widely used for packaging material, electrical insulation and coatings.

 

While PET-P can be provided in FDA compliant grades, it should not be used for continuous use in hot water.

 

A wide range of extruded and compression molded shapes and sizes are available for machining. Some processing challenges may arise due to the uneven sizing of the rod diameter and plate thickness.

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%20
Flexural Modulus of Elasticity @ 73 Fpsi490000
Tensile Modulus of Elasticity @ 73 Fpsi460000
Flexural Strength @ 73 Fpsi18000
Hardness Shore DD87
Tensile Strength @73 F, (ult)/(yld)psi12400/(ult)
Notched Izod Impact @73 Fft-lb/in of notch0.5
Heat Deflection Temperature @ 264 psiF240
Melting Point, (VS = Vicat Softening Temp)F491
Coefficient of Linear Thermal Expansion @73 Fin/in/F3.3E-05
Dielectric Strength, Short TermVolts/mil385
Water Absorption 24 hours% by weight0.07

 

Applications of PET-P

 

Due to its chemical resistance to solvents, acids and other liquids, PET-P is often used for packaging materials, such as soft drinks, flexible food packaging, even thermal insulation like space blankets. Among its other applications, you can find it as polyester yarn, spun fibers and microfiber towels and cleaning cloths.

 

Polyethylene Terephthalate helps make electrical devices, photovoltaic panels, switches and other critical energy and industrial components stronger and reliable. See the list below for other common PET-P applications.

 

Common Applications

  • Coatings
  • Distribution Valves
  • Electrical Insulation
  • Manifolds
  • Packaging Material
  • Pistons
  • Pharmaceutical Test Equipment

 

Grades of PET-P

 

At AIP, we machine various grades and brand name Polyethylene Terephthalate Polyester (PET-P), including the following:

 

  • ERTALYTE®
  • ERTALYTE® TX
  • RYNITE®
  • SUSUSTADUR® PET
  • TECAPET
  • VALOX™

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining PET-P

 

Annealing PET-P

As with any polymer CNC machined part, annealing and stress-relieving is crucial to the machining process. Without coolants, lubricants and trained procedures, cracking and crazing is inevitable in a machined part. We recommend slow heating and cooling during the annealing process of PET-P. Our process at AIP significantly reduces the chances of these stresses occurring from the heat generating during machining polymers like PET-P. Our machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.

 

Machining PET-P

PET-P is one of the most dimensionally stable plastic materials to machine, especially when trying to maintain tight tolerances or flatness. For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

Polyethylene Terephthalate Polyester Machining Guide: Supportive Information

 

Chemical Resistant Materials
Quality Assurance Certifications

 

Looking for more machining guides on performance thermoplastics?

 

Read Our HDPE Machining Guide
 

Follow AIP Precision Machining on Linkedin

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An Informational Brief on Polymer Machining

 

ARDEL® Polyarylates are a family of aromatic polyesters.  It has inherent UV stability and superior retention of optical and mechanical properties.  These qualities combined make it an excellent choice for applications where weathering and wear are a concern.  To make a comparison, polyaryls have similar mechanical properties to polycarbonates.  Likewise, its impact strength can be compared to medium-impact ABS.

 

AIP has over 37 years of experience machining complex components from thermoplastics like ARDEL® Polyarylate.  In this insightful technical brief, we will discuss what goes into machining ARDEL® Polyarylate and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of ARDEL® Polyarylate

 

It is helpful to keep information on the properties of a thermoplastic before machining. This helps in selecting the right material for your project.  Also, it assists in evaluating if the material is a candidate for the end-use requirement.  Below are some of the key characteristics of ARDEL® Polyarylate:

 

Key Properties

  • Chemical Resistance
  • Dimensional Stability
  • Excellent UV Resistance
  • Optical Characteristics
  • Inherent UV Stability
  • Dielectric Strength

 

ARDEL® Polyarylate is specifically formulated to endure extreme UV light. When exposed to UV, ARDEL® Polyarylate undergoes a molecular rearrangement resulting in the formation of a protective layer (UV stabilizer).

 

This high UV resistance makes ARDEL® Polyarylate the ideal material for any application where weathering effects could pose a problem.  ARDEL provides for long lasting components in automated UV curing equipment.

 

Further, this material also offers good dimensional stability, chemical resistance and optical characteristics.

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%10
Flexural Modulus of Elasticity @ 73 Fpsi310000
Tensile Modulus of Elasticity @ 73 Fpsi300000
Flexural Strength @ 73 Fpsi11000
Densityg/cm3
lb/in3
1.21
0.044
Tensile Strength @73 F, (ult)/(yld)psi10000/(ult)
Notched Izod Impact @73 Fft-lb/in of notch3.8
Heat Deflection Temperature @ 264 psiF345
Flammability RatingUL94V-0
Coefficient of Linear Thermal Expansion @73 Fin/in/F3
Dielectric Strength, Short TermVolts/mil400
Water Absorption 24 hours% by weight0.26

 

Applications of ARDEL® Polyarylate

 

As mentioned previously, arylates are a good choice where weathering effects are an issue.  Since they have excellent mechanical and electrical properties and excellent chemical stability, arylates are used in a variety of applications including automobiles, precision and medical devices, electronic displays and other electrical parts.  Other parts include semiconductor molding compounds, decorative displays and protective coverings.  Finally, with excellent resistance to degradation from ultraviolet radiation, ARDEL® Polyarylate can be found in solar-energy panels.

 

Common Applications

  • Automotive Applications
  • Connectors
  • Electrical Parts
  • Protective Coverings

 

AIP Machining Capabilities:  Unrivaled Expertise

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures.  Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining ARDEL® Polyarylate

 

Annealing ARDEL® Polyarylate

As with any CNC machined part, annealing and stress-relieving is crucial to the machining process.  Coolants, lubricants and trained procedures prevent cracking and crazing in a precision machined part.  We recommend slow heating and cooling during the annealing process of thermoplastics.  Our process at AIP significantly reduces the chances of these stresses occurring from the heat generating during machining ARDEL® Polyarylate.  Our machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.

 

Machining ARDEL® Polyarylate

ARDEL® Polyarylate is one of the most dimensionally stable plastic materials to machine with a score of 3 (1 being easy and 10 being difficult), especially when trying to maintain tight tolerances or flatness.  For the best results, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating.  We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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.  This allows us to de-risk the process from metallic cross contamination.

 

ARDEL® Polyarylate Machining Guide: Supportive Information

 

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An Informational Brief on Polymer Machining

 

One of the high-performance polymers we precision machine is ECTFE (Ethylene Chlorotrifluoroethylene).  It is marketed under the branded name of Halar® ECTFE by Solvay Specialty Polymers.  This material was developed to provide chemical resistance in heavy duty corrosion applications, such as acid handling, mining applications and class 8 hazardous goods transportation.

 

AIP has over 37 years of experience machining complex components from thermoplastics like Ethylene Chlorotrifluoroethylene.  In this insightful technical brief, we will discuss what goes into machining ECTFE and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of ECTFE

 

It is beneficial to keep information on the properties of a thermoplastic pre-machining. This helps in selecting the right thermoplastic for a project. Furthermore, it assists in evaluating if the material is a candidate for the end-use requirement. Below are some of the key characteristics of Ethylene Chlorotrifluoroethylene:

 

Key features of ECTFE

  • Chemical Resistance
  • Corrosion Resistance
  • High Resistivity
  • High Strength
  • Low Dielectric Constant

 

ECTFE (Ethylene Chlorotrifluoroethylene) is a fluorocarbon-based polymer manufactured from Halar® resin. It is an extremely pure polymer. Static soak testing in ultra-pure water and high purity chemicals shows low levels of metallic and organic extractables.

 

Offering high strength, high resistivity, a low dielectric constant and good chemical and corrosion resistance from -105°F (-76°C) to 300°F (150°C), ECTFE is very similar to Teflon (PTFE), the major difference between them being that ECTFE has a slightly lower melting point.

 

Material PropertyUnitsValue
Tensile Elongation at Break @73 F%250
Flexural Modulus of Elasticity @ 73 Fpsi245000
Tensile Modulus of Elasticity @ 73 Fpsi240000
Flexural Strength @ 73 Fpsi6800
Hardness Shore DD75
Tensile Strength @73 F, (ult)/(yld)psi4300(yld)
Notched Izod Impact @73 Fft-lb/in of notchNo Break
Heat Deflection Temperature @ 264 psiF145(yld)
Melting Point, (VS = Vicat Softening Temp)F437
Coefficient of Linear Thermal Expansion @73 Fin/in/F5.6E-05
Dielectric Strength, Short TermVolts/mil350
Water Absorption 24 hours% by weight0.1

 

Applications of ECTFE

 

ECTFE is widely used in anti-corrosion applications across a wide range of markets. This includes coatings for self-supporting constructions (pipes) and architectural films. Due to its excellent fire-resistance and chemical resistance, it is a prime product for wire and cable, communication cable and specialty cable applications. As a fluoropolymer with good UV resistance, it is often used for outdoor applications. ECTFE films can be transparent and provide UV protection for underlying layers.

 

It comes in several forms, such as monofilament fibers in the chemical process industry, powders over metal, films, sheets and various molded precision parts.

 

Other common applications include:

 

  • Chemical Storage
  • Containers
  • Fire Safe Componentry
  • Fluid Handling
  • Housing Parts
  • Housings
  • Pipes
  • Pump Parts
  • Seals
  • Semiconductor Process Equipment
  • Sleeves

 

Grades of ECTFE

 

At AIP, we machine various grades and brand name Ethylene Chlorotrifluoroethylene (ECTFE), including the following:

 

  • HALAR®
  • HALAR® RESIN
  • SUSTA ECTFE
  • SYMALIT ECTFE

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures.  Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining ECTFE

 

Annealing ECTFE

Annealing and stress-relieving plastics is critical to the machining process. Cracking and crazing can happen if ECTFE is not machined with coolants, lubricants and trained procedures. Due to the low thermal conductivity of Halar® ECTFE, slow heating and cooling is required for this step. The annealing process at AIP greatly reduces the chances of these stresses occurring from the heat generated during machining polymers like ECTFE. Our machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.

 

Machining ECTFE

Machining ECTFE is similar to machining Nylon Polyamide. As a general rule of thumb, use sharp tools, avoid excessive clamping and cutting forces and use coolants to prevent overheating. With a relatively low melting point at 242 C (468 F), ECTFE may soften quickly. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

Ethylene Chlorotrifluoroethylene Machining Guide: Supportive Information

 

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An Informational Brief on Polymer Machining

 

Polybutylene Terephthalate, also known as PBT, is a crystalline polyester thermoplastic that is a household name in everyday applications. You can find it under the hood in automotive applications, such as brake cable liners or sockets due to its ability to endure harsh environments and resist chemicals. In food processing and electrical applications, it is chosen for its resistance to staining and low moisture absorption. As industries continue to expand and populations grow, the demand for this thermoplastic “miracle worker” only continues to increase.

 

AIP has over 37 years of experience machining complex components from thermoplastics like Polybutylene Terephthalate. In this insightful technical brief, we will discuss what goes into machining PBT and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of PBT

 

It is beneficial to keep information on the properties of a thermoplastic pre-machining. This helps in selecting the right thermoplastic for a project. Furthermore, it assists in evaluating if the end use requirement would be fulfilled or not. Below are some of the key characteristics of Polybutylene Terephthalate:

 

PBT (Polybutylene Terephthalate) is a thermoplastic polyester that is very similar to PET (Polyethylene Terephthalate) but has a slightly better impact resistance. As a semi-crystalline engineering thermoplastic, it has outstanding processing properties for molding, thermoforming and machining. It is often a prime candidate for injection molding as the material crystallizes rapidly, so mold cycles are short and temperatures can be lower than for many thermoplastics.

 

PBT is produced by polycondensation of terephthalic acid or dimethyl terephthalate with 1,4-butanediol using special catalysts.

 

PBT Scientific Breakdown Infographic

Molecular Structure of PBT

Chemical Formula: (C12H12O4)n


 
Key features of Polybutylene Terephthalate

PBT displays excellent mechanical and electrical properties like good chemical resistance, impact resistance, low moisture absorption, rigidity, low co-efficient of friction and staining resistance. It is often reinforced with glass-fibers or minerals to improve its tensile, flexural and compressive strengths and moduli.

 

Material PropertyValue
Elongation at Break5-300%
Elongation at Yield3.5-9%
Flexibility & Stiffness (Flexural Modulus)2-4 GPa
Hardness Rockwell M70-90
Hardness Shore D90-95
Tensile Strength40-50 MPa
Notched Izod Impact at Room Temperature27-999 J/m
Notched Izod Impact at Low Temperature27-120 J/m
Young Modulus2-3 GPa
Coefficient of Linear Thermal Expansion6-10 x 10-5/oC
Shrinkage0.5-2.2%
Water Absorption 24 hours0.1-0.2%

 

Applications of PBT

 

PBT finds many applications in the electrical and automotive industries. It is particularly common in food processing applications as it offers very low moisture absorption, resistance to staining and resistance to cleaning chemicals.

 

At room temperature, PBT is resistant to the following chemicals: aliphatic hydrocarbons, gasoline, carbon tetrachloride, perchloroethylene, oils, fats, alcohols, glycols, esters, ethers and dilute acids and bases. However, they are attacked by strong bases.

 

For this reason, PBT can endure extreme and harsh environments such as automotive under-hood applications, outdoor electrical applications where fire is a concern, and valves or insulation in food processing or autoclave components.

 

Other common applications include:

  • Cams
  • Food Piston Pumps
  • Fuel Pump Components
  • Gears
  • Wear Strips
  • Housing Components

 

The broad use of PBT is also shown by the numerous regulatory approvals held by various grades. These include VDE or UL-approvals for the electrical and electronics market or FDA approval for the nutrition and medical market.

 

Grades of PBT

 

At AIP, we machine various grades and brand name Polybutylene Terephthalate, including Hydex PBT. Branded names include the following:

 

  • CELANEX
  • DURANEX
  • HYDEX 4101
  • HYDEX 4101L**
  • SUSTADUR PBT
  • TECADUR
  • VALOX
  • TECADUR PBT GF30

 

**PBT is also available as Hydex 4101L in a bearing grade.

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining PBT

 

Annealing PBT

Annealing and stress-relieving plastics is crucial to the machining process. If not machined with coolants, lubricants and trained procedures, this material is subject to cracking and crazing. The annealing process at AIP greatly reduces the chances of these stresses occurring from the heat generated during machining polymers like PBT. Our machinists use computer controlled annealing ovens for the highest quality precision temperatures and time control.

 

Machining PBT

We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

PBT is a semi-aromatic thermoplastic that is easily molded and thermoformed. Since it crystallizes rapidly, mold cycles are short and molding temperatures can be lower compared to other engineering plastics.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

Polybutylene Terephthalate Machining Guide: Supportive Information

 

General Engineering Materials
Quality Assurance Certifications

 

Providing unrivaled expertise and unparalleled results is at the heart of our mission at AIP Precision Machining.

 

Tell us about your project’s specifications and we will help you solve your plastics puzzle.

 

 

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An Informational Brief on Polymer Machining

 

Polyphenylene Oxide (PPO), also known by its trade name NORYL™, is an amorphous engineering thermoplastic.  It is generally used commercially for electrical components, automotive parts and in medical grade sterilizable medical instruments that require high heat resistance, dimensional stability and accuracy.  Some of its benefits include being low cost, light-weight with very low moisture absorption.

 

AIP has over 37 years of experience machining complex components from thermoplastics like polyphenylene oxide.  In this insightful technical brief, we will discuss what goes into machining PPO and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

PPO Product Image

 

Properties of PPO

 

Keeping information about the properties of a thermoplastic beforehand is always beneficial. This helps in selecting the right thermoplastic for a project.  Furthermore, it assists in evaluating if the end use requirement would be fulfilled or not.  Here are some of the key properties of polyphenylene oxide:  

 

PPO (Polyphenylene Oxide) is characterized by an extremely low moisture absorption rate and low thermal expansion.  As a dimensionally stable thermoplastic, PPO also has high dielectric strength and a flammability rating of UL94 V-1 at .058” thickness.  For machined parts, it is available in black, natural or a 30% glass filled gray version.  

 

Although it has many attractive properties, PPO is susceptible to thermal oxidation in relation to its high glass transition temperature, which poses a problem for melt processing.  To offset this, commercial resins are often blended with high-impact polystyrene (HIPS) or polyamide (PA).

 

PropertiesValueUnitsMethod
Resistance to WeatheringGood
Tensile Strength at Break9200psiASTM D638
Elongation at Break25.0%ASTM D638
Thermal Expansion3.3 x 10-5in/in/oFASTM D696
Impact Strength, Notched @ -40 oF2.5ft-lb/inASTM D256
Impact Strength, Notched @ 73 oF3.5ft-lb/inASTM D256
Dielectric Strength500V/milD149
Heat Deflection Temperature, @264psi254FD648
Flammability, @ .058”V-1UL94
Flammability, @ .236”V-0UL94

 

Key features of polyphenylene oxide:

  • Flame Resistance
  • Flexural Strength
  • High Dielectric Strength
  • Insulated
  • Low Moisture Absorption Rate
  • Low Thermal Expansion

 

Applications of PPO

 

Polyphenylene Oxide blends are used for structural parts, electronics, household and automotive items that depend on high heat resistance, dimensional stability and accuracy. They are also used in medicine for sterilizable instruments made of plastic.  Common applications include the following:

 

  • Manifolds
  • Pump, valve and fitting applications
  • Scientific and analytical instrument components
  • Housings
  • Covers
  • Electrical components

 

Grades of PPO

 

At AIP, we machine various grades and brand name polyphenylene oxide.  Branded names include the following:  NORYL™, NORYL™ EN 265, NORYL™ PPO, NORYL™ RESIN, NORYL™ SE-1 GFN3, NORYLUX™, SUSTAPPO™, TECANYL™.

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures.  Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion

 

Machining PPO

 

Annealing PPO

If machined with coolants, lubricants and untrained procedures, this material is subject to cracking and crazing.  Therefore, annealing is necessary for a quality, precision machined part out of the stock shape.  The annealing process at AIP greatly reduces the chances of these stresses occurring from the heat generated during machining PPO and other polymers.  Our machinists use computer controlled annealing ovens for the highest quality precision machining.  

 

Machining PPO

We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

This plastic is processed by injection molding or extrusion; depending on the material, the processing temperature is 260-300 °C. The surface can be printed, hot-stamped, painted or metallized.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination

Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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.  This allows us to de-risk the process from metallic cross contamination

 

Polyphenylene Oxide Machining Guide: Supportive Information

 

General Engineering Materials

Quality Assurance Certifications

 

 

We machine critical components from PPO, ULTEM, PEEK and more to endure harsh environments in power and energy applications.

 

 

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Celanese Ball Socket Product Image

Source: Plastics Today

Ultra-high molecular weight polyethylene (UHMWPE) is part of the umbrella of polyethylene thermoplastics. Other peers include low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Although UHMWPE embodies many similar qualities as HDPE, it is much stronger and carries a significantly higher resistance to chemicals, wet environments and withstands abrasion 15 times greater than carbon steel. This is why, among its many applications, it is the most common material for total joint replacements.

 

AIP has over 37 years of experience machining complex components from thermoplastics like ultra-high molecular weight polyethylene. In this insightful technical brief, we will discuss what goes into machining UHMWPE and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Properties of UHMWPE

 

Keeping information about the properties of a thermoplastic beforehand is always beneficial. This helps in selecting the right thermoplastic for a project. Furthermore, it assists in evaluating if the end use requirement would be fulfilled or not. Here are some of the key properties of ultra-high molecular polyethylene:

 

UHMWPE is a part of the family of polyethylene thermoplastics. One of its defining characteristics is its toughness and high impact strength; this is due to long polymer chains with a molecular mass between 3.5 and 7.5 million amu. With a long chain, it has great bearing load which strengthens the intermolecular interactions. The result is a tough material that withstands incredible impacts and extreme temperature fluctuations.

 

PropertiesValueUnitsMethod
Resistance to WeatheringExcellent
Tensile Strength at Break24MPAASTM D638
Elongation at Break300%Elongation at Break
Thermal Expansion2010-4KASTM D696
Coefficient of Friction P = 0.05 N/m2, v = 0.6m/s0.29
Impact StrengthNo breakkJ/m2ASTM D256
Compressive Stress at 10% Deformation3,000 psiPSIASTM 695
Dielectric Strength44kV.mmISO 60243-1
Melting Point130 – 136
266 – 277
C
F
Service TemperatureShort term.120
Long term. 90
C
FlammabilityHBUL94

 

*This information represents typical figures intended for reference and comparison purposes only.
Key features of ultra-high molecular weight polyethylene:

 

  • Low moisture absorption
  • Chemical resistant
  • High thermal conductivity
  • Low dielectric constant
  • FDA compliant
  • Low coefficient of friction
  • Self-lubricating
  • Resistant to UV radiation

 

Applications of UHMWPE

 

Common applications for UHMWPE include: food processing equipment, water treatment, conveyor lines, wear strips, bearings, gears, pistons, valves, marine equipment and wet environments that require harsh cleaning. Let us take a closer look at some of the major applications of this mighty material.

 

Fiber
UHMWPE as a fiber is branded under the name Dyneema and Spectra. They have yield strengths as high as 2.4 GPa (2.4 kN/mm2 or 350,000 psi) and density as low as 0.97 g/cm3. High-strength steels have comparable yield strengths, and low-carbon steels have yield strengths much lower (around 0.5 GPa). Dyneema and Spectra have a strength-to-weight ratio eight times that of high-strength steels.

 

This fact makes UHMWPE a top-pick for industries requiring heavy-duty protection and strength from a fiber. Applications include personal armor and vehicle armor for military and defense industries.

 

Civil applications containing UHMWPE fibers are cut-resistant gloves, bow strings, climbing equipment, automotive winching, fishing line, spear lines for spearguns, high-performance sails, suspension lines on sport parachutes and paragliders and yacht rigging.

 

Medical
Since the 1960s, UHMWPE has also been the biomaterial of choice for total joint arthroplasty in orthopedic and spine implants. Clinical studies continue to work to improve its effectiveness for hip, knee and spine implants.

 

In 1998 one advancement introduced highly cross-linked UHMWPE. These new materials are cross-linked with gamma or electron beam radiation (50-105 kGy) and then thermally processed to improve their oxidation resistance. They have since become the standard of care for total hip replacements.

 

As of 2007, clinicians started incorporating anti-oxidants into UHMWPE for hip and knee arthroplasty bearing surfaces. The anti-oxidant improves oxidation resistance to the UHMWPE without the need for thermal treatment.

 

Marine
UHMWPE is a polymer that retains its properties in extreme environments, such as the marine industry. It is often used in marine structures and vessels for the mooring. UHMWPE forms the contact surface between the floating vessel and the fixed one. UHMWPE is chosen as the facing of fender systems for berthing structures because of the following properties: wear resistance, impact resistance and low friction (wet and dry conditions).

 

Grades of UHMWPE

 

At AIP, we machine various grades and brand name ultra-high molecular weight polyethylene. Branded names include the following: TIVAR®, POLYSTONE® M, LENNITE®, HOSTALEN GUR®, UHMW-PE, CERAM P, ULTRAPOLY CL6, ULTRAPOLY W1.

 

Our close ties with the industry’s leading plastics manufacturers give us even further insight and access to technical help in material selection, sizing and manufacturing procedures. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Machining UHMWPE

 

Annealing UHMWPE

Thermoplastics are prone to stress cracking and premature part failure when placed under high heat and tensile load. Therefore, annealing is crucial if you want a quality, precision machined part out of the stock shape. The annealing process at AIP greatly reduces the chances of these stresses occurring from the heat generated during machining UHMWPE and other polymers. Our machinists use computer controlled annealing ovens for the highest quality precision machining.

Generally, UHMWPE should be heated between 135 C to 138 C in an oven or liquid bath of silicone oil or glycerine. It is then cooled down at a rate of 5 C/hour to at least 65 C. Afterwards, it should be wrapped in an insulating blanket for 24 hours to bring to room temperature.

Machining UHMWPE
We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. These include pressurized air and spray mists. Coolants have the additional benefit of extending tool life as well.

 

Some companies machine both metals and plastics, which has detrimental outcomes for machined polymer products. Many past experiences have shown parts going to customer without cracks, only to develop surface cracks and warping over time due to exposure to metal machine shop fluids. Be sure to use a facility like AIP that only machines polymers.

 

Preventing Contamination
Contamination is a serious concern when machining polymer components for technically demanding industries such as aerospace and medical 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. This allows us to de-risk the process from metallic cross contamination.

 

Ultra-high Molecular Weight Polyethylene Machining Guide: Supportive Information

 

Medical Sector Biomaterials

 

Miscellaneous Materials

 

Quality Assurance Certifications

 

UHMWPE is one of several thermoplastics we machine for the medical and life sciences sector.

 

Learn about 8 other common thermoplastics and their medical applications.

 

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