Why ASTM E595 Matters
The demand for higher power electronics has never been greater. Artificial Intelligence, advanced communications, satellite constellations, electric aircraft and next-generation defence systems all generate significant heat that must be managed efficiently.
For many applications, however, thermal conductivity is only one part of the equation.
Where electronics operate inside sealed enclosures, high-vacuum environments or alongside sensitive optical systems, engineers must also consider the outgassing behaviour of every material used within the assembly.
Even tiny amounts of some silicone compounds can condense onto precision optics, sensors and electronic components, leading to degradation of performance and reduced reliability over time.
This is why the ASTM E595 standard has become the recognised benchmark for qualifying thermal interface materials used in contamination-sensitive environments.
Whether selecting a compliant thermal pad or a high-performance thermal grease, engineers increasingly require materials that provide excellent heat transfer while minimising the risk of outgassing.
What is ASTM E595?
ASTM E595 is the internationally recognised test method used to determine the outgassing characteristics of materials exposed to high vacuum environments.
ASTM E595 was developed in response to the need to control molecular contamination on spacecraft. During the 1970s, NASA increasingly recognised that spacecraft and satellites had to be designed with outgassing risks in mind, particularly for materials used in high-vacuum environments where even trace contamination could compromise performance.
The E595 standard established a consistent method for evaluating the outgassing characteristics of materials, helping determine whether they were suitable for use in contamination-sensitive applications. Since its introduction, ASTM E595 has become the global de facto standard test for assessing materials where outgassing cannot be tolerated, from the Apollo and Skylab era through to modern spaceflight programmes.
The procedure measures:
- Total Mass Loss (TML)
- Collected Volatile Condensable Material (CVCM)
- Water Vapour Regained (WVR)
These measurements allow engineers to compare materials based on their tendency to release volatile compounds under vacuum conditions.
Materials achieving low TML and CVCM values are preferred for aerospace, satellites and precision instrumentation because they reduce contamination risks throughout the operational lifetime of the equipment.
What Causes Outgassing?
Every polymer contains small quantities of volatile molecules which evaporate harmlessly into the surrounding air under atmospheric pressure but inside a vacuum environment there is nowhere for these molecules to disperse.
Instead they migrate through the enclosure before depositing onto cooler surfaces. These deposits may be invisible to the eye yet still reduce:
- Optical clarity
- Laser efficiency
- Solar cell output
- Infrared sensor sensitivity
- RF performance
- Electrical insulation reliability
The higher the operating temperature, the greater the potential for outgassing.
Industry Applications That Specify ASTM E595 Materials
Low outgassing materials are increasingly specified within:
- Satellite payloads
- Spacecraft electronics
- Military avionics
- Radar systems
- Optical communications
- Semiconductor manufacturing equipment
- Vacuum chambers
- Cryogenic systems
- Medical imaging equipment
- High-end laboratory instruments
Low Outgassing Thermal Pads
Our Low Outgassing Thermal pads are engineered for applications where thermal performance must be combined with exceptional material cleanliness and long-term reliability. Manufactured to meet the stringent NASA requirements for low outgassing, these advanced thermal interface materials these advanced thermal interface materials (TIMs) minimise the release of volatile compounds in enclosed, vacuum, and contamination-sensitive environments while delivering efficient heat transfer between components and heat sinks.
Advantages of using pads over other materials include ease of assembly with clean installation and consistent thickness with electrical insulation and no pump out.
TG-A1780
At 17.8 W/mK TG-A1780 provides exceptional thermal performance for high heat flux applications.
Frequently Asked Questions
Is ASTM E595 only relevant for space applications?
No. Although originally developed for spacecraft, ASTM E595 is now widely used for aerospace, defence, semiconductor manufacturing, laboratory equipment and any vacuum or contamination-sensitive environment.
How important is thermal conductivity?
Thermal conductivity is one element of thermal performance. Material softness, bond line thickness, contact pressure and interface resistance frequently have a greater impact on junction temperature than the W/mK value alone.
Why Choose T-Global Technology?
With more than two decades of thermal management expertise, T-Global Technology develops engineered thermal interface materials for industries where reliability is critical.
Need help selecting the right thermal interface material?
Contact the T-Global Technology technical sales team to discuss your thermal management requirements or request samples for evaluation by clicking the button below.
Why ASTM E595 Matters
The demand for higher power electronics has never been greater. Artificial Intelligence, advanced communications, satellite constellations, electric aircraft and next-generation defence systems all generate significant heat that must be managed efficiently.
For many applications, however, thermal conductivity is only one part of the equation.
Where electronics operate inside sealed enclosures, high-vacuum environments or alongside sensitive optical systems, engineers must also consider the outgassing behaviour of every material used within the assembly.
Even tiny amounts of some silicone compounds can condense onto precision optics, sensors and electronic components, leading to degradation of performance and reduced reliability over time.
This is why the ASTM E595 standard has become the recognised benchmark for qualifying thermal interface materials used in contamination-sensitive environments.
Whether selecting a compliant thermal pad or a high-performance thermal grease, engineers increasingly require materials that provide excellent heat transfer while minimising the risk of outgassing.
What is ASTM E595?
ASTM E595 is the internationally recognised test method used to determine the outgassing characteristics of materials exposed to high vacuum environments.
ASTM E595 was developed in response to the need to control molecular contamination on spacecraft. During the 1970s, NASA increasingly recognised that spacecraft and satellites had to be designed with outgassing risks in mind, particularly for materials used in high-vacuum environments where even trace contamination could compromise performance.
The E595 standard established a consistent method for evaluating the outgassing characteristics of materials, helping determine whether they were suitable for use in contamination-sensitive applications. Since its introduction, ASTM E595 has become the global de facto standard test for assessing materials where outgassing cannot be tolerated, from the Apollo and Skylab era through to modern spaceflight programmes.
The procedure measures:
- Total Mass Loss (TML)
- Collected Volatile Condensable Material (CVCM)
- Water Vapour Regained (WVR)
These measurements allow engineers to compare materials based on their tendency to release volatile compounds under vacuum conditions.
Materials achieving low TML and CVCM values are preferred for aerospace, satellites and precision instrumentation because they reduce contamination risks throughout the operational lifetime of the equipment.
What Causes Outgassing?
Every polymer contains small quantities of volatile molecules which evaporate harmlessly into the surrounding air under atmospheric pressure but inside a vacuum environment there is nowhere for these molecules to disperse.
Instead they migrate through the enclosure before depositing onto cooler surfaces. These deposits may be invisible to the eye yet still reduce:
- Optical clarity
- Laser efficiency
- Solar cell output
- Infrared sensor sensitivity
- RF performance
- Electrical insulation reliability
The higher the operating temperature, the greater the potential for outgassing.
Industry Applications That Specify ASTM E595 Materials
Low outgassing materials are increasingly specified within:
- Satellite payloads
- Spacecraft electronics
- Military avionics
- Radar systems
- Optical communications
- Semiconductor manufacturing equipment
- Vacuum chambers
- Cryogenic systems
- Medical imaging equipment
- High-end laboratory instruments
Low Outgassing Thermal Pads
Our Low Outgassing Thermal pads are engineered for applications where thermal performance must be combined with exceptional material cleanliness and long-term reliability. Manufactured to meet the stringent NASA requirements for low outgassing, these advanced thermal interface materials these advanced thermal interface materials (TIMs) minimise the release of volatile compounds in enclosed, vacuum, and contamination-sensitive environments while delivering efficient heat transfer between components and heat sinks.
Advantages of using pads over other materials include ease of assembly with clean installation and consistent thickness with electrical insulation and no pump out.
Frequently Asked Questions
Is ASTM E595 only relevant for space applications?
No. Although originally developed for spacecraft, ASTM E595 is now widely used for defence, semiconductor manufacturing, laboratory equipment and any vacuum or contamination-sensitive environment.
How important is thermal conductivity?
Thermal conductivity is one element of thermal performance. Material softness, bond line thickness, contact pressure and interface resistance frequently have a greater impact on junction temperature than the W/mK value alone.
Why Choose T-Global Technology?
With more than two decades of thermal management expertise, T-Global Technology develops engineered thermal interface materials for industries where reliability is critical.
Need help selecting the right thermal interface material?
Contact the T-Global Technology technical sales team to discuss your thermal management requirements or request samples for evaluation by clicking the button below.