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.

 

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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

 

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Read Our HDPE Machining Guide
 

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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

 

Quality Assurance Certifications
 
 

Looking for more machining guides on performance thermoplastics?

 

Read Our ULTEM Machining Guide

 

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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

 

Chemical Resistant Materials
Quality Assurance Certifications

 

Looking for corrosion and chemical resistant materials like ECTFE for your precision machined part?

 

 

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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.

 

 

Learn More
 

 

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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.

 

Read Our Blog
 

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An Informational Brief on Polymer Machining

 

Since it was first polymerized in 1954 by Karl Rehn and Giulio Natta, polypropylene (PP) has become one of the leading polymer choices for a wide array of applications from automotive to commercial to medical.

 

Polypropylene plays a significant role in medical applications due to its high chemical resistance, lightweight, radiolucency and repeated autoclavability. Furthermore, medical grade PP exhibits good resistance to steam sterilization and moisture resistance. Disposable syringes, instrument or implant caddies and fluid delivery systems are the most common medical application of polypropylene. Other applications include medical vials, diagnostic devices, petri dishes, intravenous bottles, specimen bottles and surgical trays.

 

Want to learn more about the polymers we precision machine for medical applications?

 

Read Our blog

 

AIP has over 35 years of experience machining complex components from thermoplastics like polypropylene. In this insightful technical brief, we will discuss what goes into machining polypropylene and how it differs from other manufacturing options such as metal machining, injection molding, and 3D printing.

 

Homopolymer vs Copolymer – What’s the Difference?

 

The two main types of polypropylene available on the market are homopolymers and copolymers. Although they share many properties, there are some differences that help guide machinists and engineers in choosing the right material for their PP application. For the purposes of this blog, we will briefly review the differences between PP homopolymer and PP copolymer.

 

PP HomopolymerPP Copolymer
  • High strength to weight ratio and stiffer & stronger than copolymer
  • Good chemical resistance and weldability
  • Good processability
  • Good impact resistance
  • Good stiffness
  • Food contact acceptable
  • Suitable for corrosion resistant structures
  • Bit softer but has better impact strength; tougher and more durable than homopolymer
  • Better stress crack resistance and low temperature toughness
  • High processability
  • High impact resistance
  • High toughness
  • Not preferable for food contact applications

 

Properties of Polypropylene

 

Keeping information about the properties of a thermoplastic beforehand is always beneficial. This helps in selecting the right thermoplastic for an application. It also assists in evaluating if the end use requirement would be fulfilled or not. Here are some of the key properties of polypropylene:

 

Polypropylene is characterized by excellent chemical resistance in corrosive environments, resistance to cleaning agents and solvents and by a high heat deflection temperature.

 

It also has great dimensional stability and is fairly easy to machine. As noted above, it is available in heat-stabilized homopolymer and copolymer grades. At AIP, we machine POLYSTONE P, PROPYLUX HS and HS2, PROTEUS LSG HS PP from MCAM, TECAPRO MT and TECAFINE PP from Ensinger. Interesting to note is that both the PROPYLUX and TECAPRO heat stabilized PP grades are available in both standard and custom colors for medical sorting and sizing organization. Whatever your application, our machinists can help you in material selection, sizing and manufacturing techniques from concept to completion.

 

Melting Point of Polypropylene – The melting point of polypropylene occurs at a range.

 

Homopolymer: 160 – 165°C
Copolymer: 135 – 159°C

 

Density of Polypropylene – PP is one of the lightest polymers among all commodity plastics. This feature makes it a suitable option for lightweight\weight saving applications.

 

Homopolymer: 0.904 – 0.908 g/cm3
Random Copolymer: 0.904 – 0.908 g/cm3
Impact Copolymer: 0.898 – 0.900 g/cm3

 

Machining Polyproylene

 

Annealing Polypropylene

Due to its low annealing temperature, PP, like any polymer under heat and pressure, has a tendency to deform during machining. The annealing process at AIP greatly reduces the chances of these stresses occurring from the heat generated during machining PP and other polymers. Our machinists use computer controlled annealing ovens for the highest quality precision machining.

 

Machining Polypropylene

As a part of the polyolefin family, PP is semi-crystalline, which means that it can be machined at tight tolerances. We recommend non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances.

 

Bear in mind that polypropylene has variable levels of thermal expansion and will move a great deal with slight temperature changes. Some examples are 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 clients. Many past experiences have shown parts going to customer without cracks, only to develop cracks 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.

 

Polypropylene Machining Guide: Supportive Information

 

ISO 13485:2016 Certification
ISO 9001:2015 Certification

 

Need a machined part from medical grade polypropylene?

Talk to our team of expert engineers and machinists about your project needs and specifications.

 

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Learn about AIP’s precision machining capabilities for mission-critical components.

 

High-performance precision plastics require high-performance precision CNC machining.  CNC machines, or computer numerically controlled machines, are electro-mechanical devices that use tools at varying axes (usually 3-5) to produce a physical part from a computer design file.

 

Our modern society runs on CNC machined plastic components – from everyday household piping to critical spinal implants.  The breadth of materials, shapes and industries served is endless.

At AIP, we precision machine parts for industries such as the aerospace & defense, medical & life sciences and power & energy.  Each part that is CNC machined comes with design specifications and dimensional tolerances.  Our machinists are capable of crafting parts at .002 mm tolerance, which can make a whole lot of a difference in the performance of a mission-critical part.

 

Let’s back up a moment though.  What are dimensional tolerances? And how do you know if your project should demand a tighter tolerance?  Read on in this month’s blog to find out.

 

Let’s Talk About Tolerance

 

What are machining tolerances?

In CNC machining terms, tolerance, or dimensional accuracy, is the amount of deviation in a specific dimension of a part caused by the manufacturing process.  No machine can perfectly match specified dimensions.  The designer provides these specifications to the machinists based on the form, fit and function of a part.

 

How are tolerances measured?   

CNC machines are precise and measured in thousandths of an inch, referred to as “thou” among machinists.  Any system is usually expressed as “+/-”; this means that a CNC machine with a tolerance of +/- .02 mm can either deviate an extra .02 mm from the standard value or less .02 mm by the standard value.

 

A precision machining tolerance scale
 

Why are tolerances critical?

Tolerances keep the integrity and functionality of the machined part.  If the component is manufactured outside of the defined dimensions, it is unusable, since the crucial features are not fulfilling the intent of the design.

 

How close can a tolerance get?

Tolerance depends on the material that you use and the desired purpose of the design.  In plastics machining, the tolerances can be from +/- 0.10 mm to +/- 0.002 mm.  Tighter tolerances should only be used when it is necessary to meet the design criteria for the part.

 

When .002 mm Matters

 

What is the .002 mm difference?  In many industries, such as the medical industry, it is crucial to machine parts with extreme precision so that they can interact with human tissue or other medical devices.  In fact, when it comes to manufacturing medical applications, subtractive manufacturing (CNC machining) provides tighter tolerances than additive manufacturing (3-D printing).

 

 

Color Pencil compared to precision machining
(AIP PEEK Eye Implant)
 

Tight tolerances like the .002 mm are important because plastics are machined to interact with other parts.  In particular, CNC milled or turned plastics are unique designs for limited quantities, such as custom-made brackets and fasteners, or components for prototyping purposes.

 

One of the most critical considerations when applying tolerances is to take into account fits. This refers to how shafts will fit into bushings or bearings, motors into pilot holes, and so on. Depending on the application, the part may require a clearance fit to allow for thermal expansion, a sliding fit for better positioning, or an interference fit for holding capability.

 

As with anything that is precision machined, tighter tolerances demand time and skill.  Make sure to work with a certified company like AIP that has the infrastructure and expertise to complete your project with unmatched precision and unrivaled experience.

 

Let our team go to work for you

 

With 36+ years of experience in the industry, our dedicated craftsmen and ties to leading plastic manufacturers allow us to provide you with unrivaled knowledge and consulting in material selection, sizing, manufacturing techniques and beyond to best meet your project needs.

 

AIP offers a unique combination of CNC machining, raw material distribution, and consultancy as a reliable source for engineering information for materials such as PEEK, TORLON, ULTEM and more.

 

We are AS 9100D compliant; certified and registered with ISO 13485 and ISO 9001 and standards in our commitment to machining quality custom plastic components for specialized industrial sectors. Quality assurance is included as an integral part of our process and is addressed at every step of your project, from concept to completion.

 

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An Informational Brief on Polymer Machining

 

HDPE Product ImageAmong the many polymer materials we machine at AIP, High Density Polyethylene (HDPE) is a common material choice for commercial polymer applications.  HDPE is part of the Polyethylene (PE) family of thermoplastic polymers with variable crystalline structure.

 

First developed in the 1950s by German and Italian scientists Karl Ziegler and Giulio Natta, PE has become one of the most widely produced plastics in the world.  Polyethylene comes in several compounds each with various applications: Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE) and Ultrahigh Molecular Weight Polyethylene (UHMW) are some of the most well-known.

 

For example, you will find LDPE most likely in the grocery store as plastic wrap or grocery bags.  In contrast, HDPE, due to its high density, is much better suited for construction components like a drain pipe.  And UHMW can be machined into high performance applications for medical devices, bulletproof vests and industrial wear components.

 

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

 

A Brief History of Plastic CNC Machining

 

How does AIP approach HDPE and its machining process? To start, let’s explore what plastic machining is, specifically CNC machining.

 

CNC (Computer Numerical Control) machining is a process in the manufacturing sector that involves the use of computers to control machine tools. In the case of plastic machining, this involves the precise removal of layers from a plastic sheet, rod, tube or near net molded blank.

 

Shortly after World War II, the earliest version of CNC technology was developed as a dependable, repeatable way to manufacture more accurate and complex parts for the aircraft industry.  John Parsons is credited with developing numerical control – a method of producing integrally stiffened aircraft skins.

 

While working at the family-owned, Michigan-based business – Parsons Corp., John collaborated on the development of a system for producing helicopter rotor blade templates.  Using an IBM 602A multiplier to calculate airfoil coordinates, and inputting this data to a Swiss jig borer, it was possible to produce templates from data on punched cards.

 

In 1949 Parson’s templates were applied to Air Force research projects at MIT.  Following extensive research and development, an experimental milling machine was constructed at MIT’s Servomechanisms Laboratory.

 

Machining polymers and composites is a precise science that requires strong technical expertise.  For instance, some plastics are brittle, while others melt at a specific temperature.  These diverse mechanical and thermal properties result in varying behaviors when CNC machined.  Thus, it is imperative to understand the polymer structure and qualities of HDPE if you’re machining it.

 

Ever wonder about the differences in cost and process among 3D Printing, Injection Molding or Plastic Machining?

 

Check out our blog:
“Settling the Debate”

 

 

Properties of HDPE

 

HDPE is a high impact, high density crystalline thermoplastic.  It also has a low moisture absorption rate and good chemical and corrosion resistance.  Compared to its sister polymer LDPE, HDPE offers much greater impact resistance and tensile strength.  This polymer has a melt temperature of 266 F (130 C).  Its tensile strength is 20 MPa (2,900 PSI); to put this number into perspective, a slab of concrete may be able to withstand 3,000 PSI.

 

Oftentimes, people use HDPE in everyday home appliances and commercial containers.  Due to its strength and corrosion resistance, it’s a common candidate for garbage bins, laundry detergent cartons and cutting boards.  It is also safe to use for food contact such as milk cartons.

 

PE is available in sheet stock, rods, and even specialty shapes in a multitude of variants (LDPE, HDPE etc.), making it a good candidate for subtractive machining processes on a mill or lathe. However, colors are usually limited to white and black.

 

Machining HDPE

 

Annealing HDPE

Annealing greatly reduces the chance that surface cracks and deformation due to internal stresses will occur from the heat generated during machining HDPE. AIP uses computer controlled annealing ovens for the highest quality precision machining of all thermoplastics.  Talk to our engineers about any questions you have about the annealing of a specific polymer.

 

Machining HDPE

As a crystalline thermoplastic, HDPE can be machined at tight tolerances; remember dimensional stability and strength!  AIP recommends non-aromatic, water-soluble coolants because they are most suitable for ideal surface finishes and close tolerances. Keep in mind however that HDPE has a very low CTLE and therefore will move quite a bit with slight temperature changes.  Some examples are 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 clients. Many past experiences have shown parts going to customer without cracks, only to develop cracks 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 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.

 

HDPE (High Density Polyethylene) Machining Guide: Supportive Information

 

Miscellaneous Materials Guide

ISO 13485:2016 Certification

ISO 9001:2015 Certification

Learn more about HDPE and its applications in other industries

 

Discover what HDPE can do

 

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