Cirlex all-polyimide laminate Cirlex
Poly(4,4'-oxydiphenylene-pyromellitimide), the Kapton polyimide chemistry
Also known as Cirlex
Cirlex is a thick all-polyimide material made by Fralock from DuPont Kapton adhesiveless polyimide film, joined by Fralock's Adhesiveless Lamination Technology into one monolithic piece.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
High-temperature stiffness
402 kpsi at 200 degC
Electrical insulation
2790 V/mil
Heat flow
0.17 W/m K
Recipe, share of the weight
- PMDA Molar mass 218.120 g/mol, Wikipedia infobox (CAS 89-32-7)Pyromellitic dianhydride
- ODA Molar mass 200.24 g/mol, Wikipedia infobox (CAS 101-80-4); the Kapton article prints the name as oxydiphenylamine4,4'-Oxydianiline
Best for
Thick, dimensionally stable polyimide parts for thermal barriers, sealing shims, stand-offs and electrical isolation, where an adhesive-free laminate is wanted
Weakest at
Outgassing and long-term exposure to strong acids and strong oxidizers. The Fralock data sheet gives a total mass loss of 0.5 % in vacuum, and the Kapton safety sheet lists strong acids and strong oxidizers as incompatible.
Risk at a glance
- People Low. No hazard classification on the family sheet
- If it fails High. Use above the rated temperature
- Corrosion Moderate. The Kapton safety sheet prints "Temperature > 400 °C" as a condition to avoid, while Cirlex is rated to 351 degC.
Quick facts: Cirlex
| Property | Value | Basis |
|---|---|---|
| Density | 1.42 | 1 sourced value |
| Yield strength | 42.1 MPa | 1 sourced value |
| Tensile strength | 224 MPa | 1 sourced value |
| Young's modulus | 2.28 GPa | 1 sourced value |
| Thermal conductivity | 0.17 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 30 to 118 ppm/K | 2 sourced values across conditions |
| Specific heat | 1,090 J/(kg·K) | 1 sourced value |
| Maximum service temperature | 351 °C | 1 sourced value |
What is the density of Cirlex all-polyimide laminate?
Cirlex all-polyimide laminate has a density of 1.42. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Cirlex all-polyimide laminate?
Cirlex all-polyimide laminate has a thermal conductivity of 0.17 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Cirlex all-polyimide laminate?
Cirlex all-polyimide laminate has a coefficient of thermal expansion of 30 to 118 ppm/K. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the yield strength of Cirlex all-polyimide laminate?
Cirlex all-polyimide laminate has a yield strength of 42.1 MPa. The source and test conditions are listed in the properties table on this page.
What is the tensile strength of Cirlex all-polyimide laminate?
Cirlex all-polyimide laminate has a tensile strength of 224 MPa. The source and test conditions are listed in the properties table on this page.
What is Cirlex all-polyimide laminate used for?
Uses recorded in the sources include Thermal barriers and thermal shields; Flex and rigid-flex circuits, electrostatic chucks and flexible multizone heaters; Stand-offs, component stiffeners and washers with adhesive.
Why it exists
Cirlex is a thick all-polyimide laminate made by Fralock from DuPont Kapton film, without adhesive. Its Tg is 351 degC and its thermal conductivity is 0.17 W/m K, which is why Fralock sells it for thermal barriers and shims. Fralock's statement that it is used in aerospace is the only aerospace link in the sources read this run.
Where it's used
Thermal barriers and shields
The Fralock flyer lists thermal barriers and thermal shields as the first applications of Cirlex.
Electrical isolation and flexible electronics
The Fralock web page lists flex circuits, electrostatic chucks and flexible multizone heaters as customer uses, next to electrical insulators.
Recipe
Poly(4,4'-oxydiphenylene-pyromellitimide), the Kapton polyimide chemistry; Fralock prints no formula for Cirlex
Cirlex is made from DuPont Kapton adhesiveless polyimide film, using Fralock's Adhesiveless Lamination Technology to form a monolithic all-polyimide part. The Kapton chemistry is the condensation of pyromellitic dianhydride with an oxydianiline, followed by a thermal ring closure, per the Wikipedia Kapton article.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Pyromellitic dianhydride PMDA | Molar mass 218.120 g/mol, Wikipedia infobox (CAS 89-32-7) | Dianhydride monomer of the Kapton film, per Wikipedia Kapton article. |
| 4,4'-Oxydianiline ODA | Molar mass 200.24 g/mol, Wikipedia infobox (CAS 101-80-4); the Kapton article prints the name as oxydiphenylamine | Diamine monomer of the Kapton film, per Wikipedia Kapton article. |
Weight shares are as printed in the sources.
What it can do
High-temperature stiffness
402 kpsi at 200 degC
Fralock typical tensile modulus at 200 degC is 402 kpsi, with a glass transition temperature of 351 degC.
Electrical insulation
2790 V/mil
Fralock typical dielectric strength is 2790 V/mil, and the dielectric constant is 3.45 at 10 kHz.
Heat flow
0.17 W/m K
Fralock typical thermal conductivity is 0.17 W/m K, which the sheet presents as low.
How it compares
Cirlex is the thick, adhesive-free form of the Kapton chemistry. Fralock's typical data give a Tg of 351 degC, an in-plane CTE of 30 µm/m °C from 23 to 350 degC, and a through-thickness CTE of 118 µm/m °C, so the material expands much more through its thickness than in its plane. The Kapton film profiles in this database cover thin film, not thick laminate, so their outgassing and erosion numbers do not transfer to Cirlex without a test on the Cirlex grade.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | Cirlex | PI (CP1) | PI (Kapton H) | PI (Kapton HN) | PI (PMR-15) | PI (Upilex-S) |
|---|---|---|---|---|---|---|
| Thermal behavior and safety | ||||||
| Thermal conductivity of Cirlex | 0.17 W/m K21 | no data | no data | 0.12 W/(m K) | no data | 0.29 W/(m.K) |
| Specific heat of Cirlex | 1.09 J/g K23 | no data | no data | 1.09 J/(g K) | no data | 1.13 kJ/(kg.K) |
| Water vapor regain (outgassing), ASTM E595 | 0.42 %28 | no data | no data | no data | no data | no data |
| Temperature behavior | ||||||
| Glass transition temperature of Cirlex | 351 °C22 | 263 °C | no data | no data | 332 °C | no data |
| Other measurements | ||||||
| Ultimate compressive strength at 23 degC | 45.26 kpsi1 | no data | no data | no data | no data | no data |
| Ultimate compressive strength at 100 degC | 42.79 kpsi2 | no data | no data | no data | no data | no data |
| Ultimate compressive strength at 200 degC | 35.61 kpsi3 | no data | no data | no data | no data | no data |
| Ultimate tensile strength at 23 degC | 32.49 kpsi4 | 87 MPa | no data | no data | no data | 520 MPa |
| Ultimate tensile strength at 100 degC | 21.4 kpsi5 | 87 MPa | no data | no data | no data | 520 MPa |
| Ultimate tensile strength at 200 degC | 17.4 kpsi6 | 87 MPa | no data | no data | no data | 520 MPa |
| Ultimate tensile strength at 250 degC | 16.5 kpsi7 | 87 MPa | no data | no data | no data | 520 MPa |
| Tensile modulus at 23 degC | 330 kpsi8 | 2 GPa | no data | no data | no data | 9.1 GPa |
| Tensile modulus at 100 degC | 488 kpsi9 | 2 GPa | no data | no data | no data | 9.1 GPa |
| Tensile modulus at 200 degC | 402 kpsi10 | 2 GPa | no data | no data | no data | 9.1 GPa |
| Tensile modulus at 250 degC | 381 kpsi11 | 2 GPa | no data | no data | no data | 9.1 GPa |
| Tensile yield strength at 3 % elongation, 23 degC | 6.11 kpsi12 | no data | no data | no data | no data | no data |
| Tensile yield strength at 3 % elongation, 200 degC | 5.49 kpsi13 | no data | no data | no data | no data | no data |
| Shear strength at 100 degC | 6.4 kpsi14 | no data | no data | no data | no data | no data |
| Shear strength at 200 degC | 5.4 kpsi15 | no data | no data | no data | no data | no data |
| Poisson's ratio at 23 degC | 0.329 -16 | no data | no data | no data | no data | no data |
| Specific gravity of Cirlex | 1.42 -17 | no data | no data | no data | no data | no data |
| Dielectric strength of Cirlex | 2790 V/mil18 | no data | no data | 303 kV/mm | no data | 6.8 kV |
| Dielectric constant of Cirlex at 10 kHz | 3.45 -19 | 2.4 - | no data | 3.4 (dimensionless) | no data | 3.5 - |
| Dissipation factor of Cirlex | 0.004 -20 | no data | no data | no data | no data | 0.0013 - |
| Coefficient of thermal expansion, in-plane | 30 µm/m °C24 | 51 ppm/°C | no data | 20 ppm/K | no data | 12 ppm/°C |
| Coefficient of thermal expansion, through thickness | 118 µm/m °C25 | 51 ppm/°C | no data | 20 ppm/K | no data | 12 ppm/°C |
| Total mass loss (outgassing TML) | 0.5 %26 | no data | no data | no data | no data | no data |
| Collected volatile condensable material (outgassing CVCM), upper bound | < 0.01 %27 | no data | no data | no data | no data | no data |
| Lowest temperature the laminate keeps its integrity (Fralock claim)Features list, as printed in the Fralock flyer | -269 °C | no data | 4 K | -269 °C | no data | no data |
| Highest temperature the laminate keeps its integrity (Fralock claim)Features list, as printed in the Fralock flyer | 351 °C | no data | 400 °C | 400 °C | 316 °C | no data |
Why choose it, and why not
Good for
- Thermal barriers and thermal shields where an adhesive-free all-polyimide part is wanted (Fralock flyer applications list).
- Electrical isolation and standoffs, with a dielectric strength of 2790 V/mil and a dielectric constant of 3.45 at 10 kHz.
- Parts that must keep their stiffness at high temperature, with a tensile modulus of 402 kpsi at 200 degC.
Watch out for
- Outgassing in vacuum. The total mass loss is 0.5 % under ASTM E595, which the sheet reports without a bake-out procedure.
- Strong acids and strong oxidizers, which the Kapton sheet lists as incompatible.
- The Fralock values are typical averages and are not specification values. The 351 degC upper limit is a Fralock claim, not a rated limit for each part.
- Atomic oxygen, radiation and thermal cycling for Cirlex were not found in any source read this run.
Cirlex is a thick, adhesive-free all-polyimide laminate from Fralock, with a glass transition temperature of 351 degC and a thermal conductivity of 0.17 W/m K. It suits thermal barriers, shims and electrical isolation where those numbers matter. For flight use, check outgassing (0.5 % total mass loss) and do not rely on typical values for specification.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | Cirlex |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Ultimate compressive strength at 23 degC | Typical value printed in the Fralock data sheet table (Mechanical Property), averaged | temperature 23 °C (73.4 degF)standard ASTM D695-15basis typical value, Cirlex all-polyimide laminate | — |
| 2 | Ultimate compressive strength at 100 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 100 °C (212 degF)standard ASTM D695-15basis typical value, Cirlex all-polyimide laminate | — |
| 3 | Ultimate compressive strength at 200 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 200 °C (392 degF)standard ASTM D695-15basis typical value, Cirlex all-polyimide laminate | — |
| 4 | Ultimate tensile strength at 23 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 23 °C (73.4 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 5 | Ultimate tensile strength at 100 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 100 °C (212 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 6 | Ultimate tensile strength at 200 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 200 °C (392 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 7 | Ultimate tensile strength at 250 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 250 °C (482 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 8 | Tensile modulus at 23 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 23 °C (73.4 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 9 | Tensile modulus at 100 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 100 °C (212 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 10 | Tensile modulus at 200 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 200 °C (392 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 11 | Tensile modulus at 250 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 250 °C (482 degF)standard ASTM D638basis typical value, Cirlex all-polyimide laminate | — |
| 12 | Tensile yield strength at 3 % elongation, 23 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 23 °C (73.4 degF)standard ASTM D638basis typical value; the sheet prints the yield as the stress at 3 % elongation | — |
| 13 | Tensile yield strength at 3 % elongation, 200 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 200 °C (392 degF)standard ASTM D638basis typical value; the sheet prints the yield as the stress at 3 % elongation | — |
| 14 | Shear strength at 100 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 100 °C (212 degF)standard ASTM D3846basis typical value, Cirlex all-polyimide laminate | — |
| 15 | Shear strength at 200 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 200 °C (392 degF)standard ASTM D3846basis typical value, Cirlex all-polyimide laminate | — |
| 16 | Poisson's ratio at 23 degC | Typical value printed in the Fralock data sheet table (Mechanical Property) | temperature 23 °C (73.4 degF)standard ASTM D3039-17basis typical value, Cirlex all-polyimide laminate | — |
| 17 | Specific gravity of Cirlex | Physical Property table, row Specific Gravity, as printed in the Fralock data sheet | basis typical value; the sheet gives no temperature for this row | — |
| 18 | Dielectric strength of Cirlex | Electrical Property table, row Dielectric Strength, as printed in the Fralock data sheet | basis typical value; the flyer prints the same figure as a lower bound (greater than 2790 volts/mil) | — |
| 19 | Dielectric constant of Cirlex at 10 kHz | Electrical Property table, row Dielectric Constant DC at 10 kHz | frequency 10 kHztemperature 25 °Cstandard ASTM D150basis typical value | — |
| 20 | Dissipation factor of Cirlex | Electrical Property table, row Dielectric Constant Dissipation Factor | standard ASTM D150basis typical value; the table prints no test frequency for this row | — |
| 21 | Thermal conductivity of Cirlex | Thermal Property table, row Thermal Conductivity, as printed in the Fralock data sheet | temperature not printed in the tablebasis typical value, Cirlex all-polyimide laminate | — |
| 22 | Glass transition temperature of Cirlex | Thermal Property table, row Glass Transition, Tg, as printed in the Fralock data sheet | basis typical value, Cirlex all-polyimide laminate | — |
| 23 | Specific heat of Cirlex | Thermal Property table, row Specific Heat, as printed in the Fralock data sheet | temperature not printed in the tablebasis typical value, Cirlex all-polyimide laminate | — |
| 24 | Coefficient of thermal expansion, in-plane | Thermal Property table, row CTE In-plane, as printed in the Fralock data sheet | temperature range 23 to 350 °Cstandard ASTM E831basis typical value, Cirlex all-polyimide laminate | — |
| 25 | Coefficient of thermal expansion, through thickness | Thermal Property table, row CTE Thru-thickness, as printed in the Fralock data sheet | temperature range 23 to 350 °Cstandard ASTM E831basis typical value, Cirlex all-polyimide laminate | — |
| 26 | Total mass loss (outgassing TML) | Thermal Property table, row Outgassing TML, as printed in the Fralock data sheet | standard ASTM E595basis typical value; the table prints 0.5% (the flyer prints 0.50%) | — |
| 27 | Collected volatile condensable material (outgassing CVCM), upper bound | Thermal Property table, row Outgassing CVCM, as printed in the Fralock data sheet | standard ASTM E595basis printed as less than 0.01 %, so 0.01 is an upper bound | — |
| 28 | Water vapor regain (outgassing), ASTM E595 | Thermal Property table, row Outgassing Water Vapor Regain, as printed in the Fralock data sheet | standard ASTM E595basis typical value | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Strong acids and strong oxidizers | not rated | The Kapton safety sheet lists strong acids and strong oxidizers as incompatible with the film, and gives no rate.1 |
| Humid air (water uptake) | low | Cirlex regains 0.42 % water vapor on the outgassing test, a small uptake.2 |
| Heat above the family limit | moderate | The Kapton safety sheet prints "Temperature > 400 °C" as a condition to avoid, while Cirlex is rated to 351 degC.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Strong acids and strong oxidizers | The sheet names strong acids and strong oxidizers as incompatible and gives no test or rate. Fralock describes the laminate as chemically inert but gives no test for it. | basis Kapton FPC, HN and related family sheet, version 2.2 (the H grade is not named on the sheet) |
| 2 | Humid air (water uptake) | The Fralock sheet prints a water vapor regain of 0.42 % under ASTM E595. The sheet does not give a humidity-exposure test, so the rating below is our reading of that single value. | standard ASTM E595, water vapor regain |
| 3 | Heat above the family limit | Two sources give different limits for the film family and for this laminate. The Kapton sheet prints "Temperature > 400 °C" as a condition to avoid. The Fralock flyer gives 351 degC as the upper limit of integrity for Cirlex. The laminate limit is the lower of the two. | basis the sources are printed side by side, not reconciled |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The DuPont family sheet gives no hazard classification for the film. Thick laminate can cut, and unwrapping can build up static.
- The laminate
- The Kapton family sheet lists no hazard classification and says inhalation and ingestion are not considered routes of exposure. Thick films have sharp edges that can cut.
- Fire
- The sheet says the film does not burn in air but will burn in 100% oxygen.
- Static
- Processing and unwrapping can generate static charge, so the sheet advises avoiding static discharge.
If it fails
The failure modes come from the datasheet limits and the incompatibility list, not from tests on finished hardware.
- Temperature
- The Kapton sheet prints "Temperature > 400 °C" as a condition to avoid, and Cirlex is rated to 351 degC in the Fralock flyer.
- Chemicals
- Strong acids and strong oxidizers are listed as incompatible, with no rate of attack given.
- Vacuum
- The laminate loses 0.5 % of its mass in the ASTM E595 test, so it can add volatiles in a sealed vacuum volume.
Handling and storage
- Storage
- Keep the film dry, away from strong acids and strong oxidizers. The Kapton sheet gives the storage temperature as "20 - 30 °C".
- Static
- Avoid static discharge when unwrapping, and avoid breathing dust.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Attack by strong acids and strong oxidizersmoderate severity | Contact with strong acids or strong oxidizersThe film is listed as incompatible with them. No rate of attack is given for the laminate. |
| Use above the rated temperaturehigh severity | Exposure above the Kapton sheet's "Temperature > 400 °C" condition to avoidCirlex is rated to 351 degC in the Fralock flyer, so use above that rating is outside the stated range. |
| Mass loss and condensed volatiles in vacuumlow severity | Use in vacuum, such as a spacecraft interior or a sealed instrumentTotal mass loss of 0.5 % and CVCM below 0.01 % under ASTM E595. Condensable volatiles may deposit on nearby optics. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Surroundings | The Fralock data sheet prints an outgassing water vapor regain of 0.42 % under ASTM E595. The sheet does not say that moisture affects the laminate in use. |
Handling and storage
- The Kapton sheet gives the storage temperature as "20 - 30 °C" and says "Keep in a dry place" for the family. The sheet does not name Cirlex separately.
- Take action to avoid static discharge when unwrapping and processing. Avoid breathing dust. Thick films have sharp edges which can cause cuts.
Supply and geography
How common the raw materials are and where they come from.
Cirlex all-polyimide laminate
Not read in a fetched page for this product.
- Top producers
- USA (2023), USA, USA (2025)
- Recycling
- Not sourced.
- Substitutes
- Fralock names ceramic and Vespel as materials that Cirlex can replace (Fralock generic data sheet, first page).
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: cirlex-polyimide
spore_version: 0.2
family: polyimides
name: Cirlex all-polyimide laminate
abbreviation: Cirlex
role: thick adhesiveless all-polyimide laminate for thermal barriers, shims and electrical isolation
category: polymers
type: polyimides
summary: |
Cirlex is a thick all-polyimide material made by Fralock from DuPont Kapton adhesiveless polyimide film, joined by Fralock's Adhesiveless Lamination Technology into one monolithic piece. Fralock's typical-value data sheet gives a glass transition temperature of 351 degC and a thermal conductivity of 0.17 W/m K. Its flyer says the material keeps its integrity from -269 degC to 351 degC. The listed typical values are averages that Fralock says should not be used in writing specifications.
best_for: Thick, dimensionally stable polyimide parts for thermal barriers, sealing shims, stand-offs and electrical isolation, where an adhesive-free laminate is wanted
weakest_at: Outgassing and long-term exposure to strong acids and strong oxidizers. The Fralock data sheet gives a total mass loss of 0.5 % in vacuum, and the Kapton safety sheet lists strong acids and strong oxidizers as incompatible.
identity:
formula: Poly(4,4'-oxydiphenylene-pyromellitimide), the Kapton polyimide chemistry; Fralock prints no formula for Cirlex
source: wiki-kapton
where: Chemistry and variants section (the chemical name for Kapton K and HN); Cirlex is made from Kapton film per the Fralock datasheet, and no grade letter is printed for the Kapton film used
designations:
- system: Trade name
code: Cirlex
source: fralock-web
where: Page title and product name on the Cirlex engineered solutions page
tags:
environments: []
stresses:
- extreme-cold
applications:
- thermal-control
- structures
- electronics-and-chips
properties:
- benchmark: ultimate_compressive_strength
label: Ultimate compressive strength at 23 degC
value: 45.26
unit: kpsi
scope: material
conditions:
temperature: 23 degC (73.4 degF)
standard: ASTM D695-15
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property), averaged
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Compressive Strength, 23 degC row
- benchmark: ultimate_compressive_strength
label: Ultimate compressive strength at 100 degC
value: 42.79
unit: kpsi
scope: material
conditions:
temperature: 100 degC (212 degF)
standard: ASTM D695-15
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Compressive Strength, 100 degC row
- benchmark: ultimate_compressive_strength
label: Ultimate compressive strength at 200 degC
value: 35.61
unit: kpsi
scope: material
conditions:
temperature: 200 degC (392 degF)
standard: ASTM D695-15
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Compressive Strength, 200 degC row
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength at 23 degC
value: 32.49
unit: kpsi
scope: material
conditions:
temperature: 23 degC (73.4 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Tensile Strength, 23 degC row
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength at 100 degC
value: 21.4
unit: kpsi
scope: material
conditions:
temperature: 100 degC (212 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Tensile Strength, 100 degC row
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength at 200 degC
value: 17.4
unit: kpsi
scope: material
conditions:
temperature: 200 degC (392 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Tensile Strength, 200 degC row
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength at 250 degC
value: 16.5
unit: kpsi
scope: material
conditions:
temperature: 250 degC (482 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Ultimate Tensile Strength, 250 degC row
- benchmark: elastic_modulus
label: Tensile modulus at 23 degC
value: 330
unit: kpsi
scope: material
conditions:
temperature: 23 degC (73.4 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Modulus, 23 degC row
- benchmark: elastic_modulus
label: Tensile modulus at 100 degC
value: 488
unit: kpsi
scope: material
conditions:
temperature: 100 degC (212 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Modulus, 100 degC row
- benchmark: elastic_modulus
label: Tensile modulus at 200 degC
value: 402
unit: kpsi
scope: material
conditions:
temperature: 200 degC (392 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Modulus, 200 degC row
- benchmark: elastic_modulus
label: Tensile modulus at 250 degC
value: 381
unit: kpsi
scope: material
conditions:
temperature: 250 degC (482 degF)
standard: ASTM D638
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Modulus, 250 degC row
- benchmark: yield_strength
label: Tensile yield strength at 3 % elongation, 23 degC
value: 6.11
unit: kpsi
scope: material
conditions:
temperature: 23 degC (73.4 degF)
standard: ASTM D638
basis: typical value; the sheet prints the yield as the stress at 3 % elongation
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Yield @ 3% Elongation, 23 degC row
- benchmark: yield_strength
label: Tensile yield strength at 3 % elongation, 200 degC
value: 5.49
unit: kpsi
scope: material
conditions:
temperature: 200 degC (392 degF)
standard: ASTM D638
basis: typical value; the sheet prints the yield as the stress at 3 % elongation
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Tensile Yield @ 3% Elongation, 200 degC row
- benchmark: shear_strength
label: Shear strength at 100 degC
value: 6.4
unit: kpsi
scope: material
conditions:
temperature: 100 degC (212 degF)
standard: ASTM D3846
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Shear Strength, 100 degC row
- benchmark: shear_strength
label: Shear strength at 200 degC
value: 5.4
unit: kpsi
scope: material
conditions:
temperature: 200 degC (392 degF)
standard: ASTM D3846
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Shear Strength, 200 degC row
- benchmark: poissons_ratio
label: Poisson's ratio at 23 degC
value: 0.329
unit: '-'
scope: material
conditions:
temperature: 23 degC (73.4 degF)
standard: ASTM D3039-17
basis: typical value, Cirlex all-polyimide laminate
method: Typical value printed in the Fralock data sheet table (Mechanical Property)
status: ground
source: fralock-ds
where: Mechanical Property table, row Poisson's Ratio
- benchmark: specific_gravity
label: Specific gravity of Cirlex
value: 1.42
unit: '-'
scope: material
conditions:
basis: typical value; the sheet gives no temperature for this row
method: Physical Property table, row Specific Gravity, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Physical Property table, row Specific Gravity
- benchmark: dielectric_strength
label: Dielectric strength of Cirlex
value: 2790
unit: V/mil
scope: material
conditions:
basis: typical value; the flyer prints the same figure as a lower bound (greater than 2790 volts/mil)
method: Electrical Property table, row Dielectric Strength, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Electrical Property table, row Dielectric Strength
- benchmark: dielectric_constant
label: Dielectric constant of Cirlex at 10 kHz
value: 3.45
unit: '-'
scope: material
conditions:
frequency: 10 kHz
temperature: 25 degC
standard: ASTM D150
basis: typical value
method: Electrical Property table, row Dielectric Constant DC at 10 kHz
status: ground
source: fralock-ds
where: Electrical Property table, row Dielectric Constant DC @ 10KHz
- benchmark: dissipation_factor
label: Dissipation factor of Cirlex
value: 0.004
unit: '-'
scope: material
conditions:
standard: ASTM D150
basis: typical value; the table prints no test frequency for this row
method: Electrical Property table, row Dielectric Constant Dissipation Factor
status: ground
source: fralock-ds
where: Electrical Property table, row Dielectric Constant Dissipation Factor
- benchmark: thermal_conductivity
label: Thermal conductivity of Cirlex
value: 0.17
unit: W/m K
scope: material
conditions:
temperature: not printed in the table
basis: typical value, Cirlex all-polyimide laminate
method: Thermal Property table, row Thermal Conductivity, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Thermal Conductivity
- benchmark: glass_transition_temperature
label: Glass transition temperature of Cirlex
value: 351
unit: degC
scope: material
conditions:
basis: typical value, Cirlex all-polyimide laminate
method: Thermal Property table, row Glass Transition, Tg, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Glass Transition, Tg
- benchmark: specific_heat
label: Specific heat of Cirlex
value: 1.09
unit: J/g K
scope: material
conditions:
temperature: not printed in the table
basis: typical value, Cirlex all-polyimide laminate
method: Thermal Property table, row Specific Heat, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Specific Heat
- benchmark: cte
label: Coefficient of thermal expansion, in-plane
value: 30
unit: µm/m °C
scope: material
conditions:
temperature_range: 23 to 350 degC
standard: ASTM E831
basis: typical value, Cirlex all-polyimide laminate
method: Thermal Property table, row CTE In-plane, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row CTE In-plane (23 to 350 degC)
- benchmark: cte
label: Coefficient of thermal expansion, through thickness
value: 118
unit: µm/m °C
scope: material
conditions:
temperature_range: 23 to 350 degC
standard: ASTM E831
basis: typical value, Cirlex all-polyimide laminate
method: Thermal Property table, row CTE Thru-thickness, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row CTE Thru-thickness (23 to 350 degC)
- benchmark: total_mass_loss
label: Total mass loss (outgassing TML)
value: 0.5
unit: '%'
scope: material
conditions:
standard: ASTM E595
basis: typical value; the table prints 0.5% (the flyer prints 0.50%)
method: Thermal Property table, row Outgassing TML, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Outgassing TML
- benchmark: collected_volatile_condensable_material
label: Collected volatile condensable material (outgassing CVCM), upper bound
value: 0.01
bound: upper
unit: '%'
scope: material
conditions:
standard: ASTM E595
basis: printed as less than 0.01 %, so 0.01 is an upper bound
method: Thermal Property table, row Outgassing CVCM, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Outgassing CVCM
- benchmark: water_vapor_regain
label: Water vapor regain (outgassing), ASTM E595
value: 0.42
unit: '%'
scope: material
conditions:
standard: ASTM E595
basis: typical value
method: Thermal Property table, row Outgassing Water Vapor Regain, as printed in the Fralock data sheet
status: ground
source: fralock-ds
where: Thermal Property table, row Outgassing Water Vapor Regain
- benchmark: min_service_temp
label: Lowest temperature the laminate keeps its integrity (Fralock claim)
value: -269
unit: degC
scope: material
conditions:
basis: Fralock statement of integrity over the range, not a tested rating of one part
method: Features list, as printed in the Fralock flyer
status: ground
source: fralock-flyer
where: Features list, first bullet ("from -269 C (-452 F)")
- benchmark: max_service_temp
label: Highest temperature the laminate keeps its integrity (Fralock claim)
value: 351
unit: degC
scope: material
conditions:
basis: Fralock statement of integrity over the range, not a tested rating of one part; the same figure is the glass transition
method: Features list, as printed in the Fralock flyer
status: ground
source: fralock-flyer
where: Features list, first bullet ("to 351 C (664 F)")
corrosion:
- environment: Strong acids and strong oxidizers
headline: The Kapton safety sheet lists strong acids and strong oxidizers as incompatible with the film, and gives no rate.
effect: The sheet names strong acids and strong oxidizers as incompatible and gives no test or rate. Fralock describes the laminate as chemically inert but gives no test for it.
rating: unknown
conditions:
basis: Kapton FPC, HN and related family sheet, version 2.2 (the H grade is not named on the sheet)
source: dupont-ais
where: Incompatibility line, Stability and reactivity section
- environment: Humid air (water uptake)
headline: Cirlex regains 0.42 % water vapor on the outgassing test, a small uptake.
effect: The Fralock sheet prints a water vapor regain of 0.42 % under ASTM E595. The sheet does not give a humidity-exposure test, so the rating below is our reading of that single value.
rating: low
conditions:
standard: ASTM E595, water vapor regain
source: fralock-ds
where: Thermal Property table, row Outgassing Water Vapor Regain
- environment: Heat above the family limit
headline: The Kapton safety sheet prints "Temperature > 400 °C" as a condition to avoid, while Cirlex is rated to 351 degC.
effect: Two sources give different limits for the film family and for this laminate. The Kapton sheet prints "Temperature > 400 °C" as a condition to avoid. The Fralock flyer gives 351 degC as the upper limit of integrity for Cirlex. The laminate limit is the lower of the two.
rating: moderate
conditions:
basis: the sources are printed side by side, not reconciled
source: dupont-ais
where: Stability and reactivity section, Conditions to avoid line; also fralock-flyer features
risks:
hazards:
- text: 'DuPont Kapton article information sheet (family sheet, which covers the film family and does not name Cirlex or the H grade): gives no hazard classification and no hazard statements. It says inhalation and ingestion are not considered potential routes of exposure. It advises washing skin with soap and water. The film is insoluble in water.'
ghs: []
source: dupont-ais
where: Hazards identification, First aid measures, Physical and chemical properties sections
- text: 'Fire: the sheet reports the film as self-extinguishing and says it does not burn in air, but the sheet states "Kapton will burn in an atmosphere of 100% oxygen" and that it will char. Processing and unwrapping can generate static charge.'
ghs: []
source: dupont-ais
where: Firefighting measures, Specific hazards during firefighting
- text: 'GHS for the monomer pyromellitic dianhydride (PMDA), harmonised EU CLP entry 607-098-00-X, not for Cirlex or Kapton itself: H317 May cause an allergic skin reaction; H318 Causes serious eye damage; H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled. Signal word Danger.'
ghs:
- H317
- H318
- H334
source: pubchem-ghs
where: GHS Classification, harmonised entry from Regulation (EC) No 1272/2008 (SourceID 607-098-00-X)
failure_risks:
- mode: Attack by strong acids and strong oxidizers
trigger: Contact with strong acids or strong oxidizers
consequence: The film is listed as incompatible with them. No rate of attack is given for the laminate.
severity: moderate
source: dupont-ais
where: Stability and reactivity, Incompatibility line
- mode: Use above the rated temperature
trigger: Exposure above the Kapton sheet's "Temperature > 400 °C" condition to avoid
consequence: Cirlex is rated to 351 degC in the Fralock flyer, so use above that rating is outside the stated range.
severity: high
source: fralock-flyer
where: Features list (upper temperature of integrity 351 degC); the Kapton sheet condition is in dupont-ais, Stability and reactivity
- mode: Mass loss and condensed volatiles in vacuum
trigger: Use in vacuum, such as a spacecraft interior or a sealed instrument
consequence: Total mass loss of 0.5 % and CVCM below 0.01 % under ASTM E595. Condensable volatiles may deposit on nearby optics.
severity: low
source: fralock-ds
where: Thermal Property table, rows Outgassing TML and Outgassing CVCM
side_effects:
- text: The Fralock data sheet prints an outgassing water vapor regain of 0.42 % under ASTM E595. The sheet does not say that moisture affects the laminate in use.
source: fralock-ds
where: Thermal Property table, row Outgassing Water Vapor Regain
handling:
- text: The Kapton sheet gives the storage temperature as "20 - 30 °C" and says "Keep in a dry place" for the family. The sheet does not name Cirlex separately.
source: dupont-ais
where: Handling and storage, Requirements for storage areas and containers; Storage temperature
- text: Take action to avoid static discharge when unwrapping and processing. Avoid breathing dust. Thick films have sharp edges which can cause cuts.
source: dupont-ais
where: Handling and storage, Precautions for safe handling
uses:
- application: thermal-control
device: Thermal barriers and thermal shields
example: The Fralock flyer lists thermal barriers and thermal shields as Cirlex applications, along with sealing shims, lid rings, gasket rings, stand-offs and electrical isolation.
source: fralock-flyer
where: Applications list on page 1
- application: electronics-and-chips
device: Flex and rigid-flex circuits, electrostatic chucks and flexible multizone heaters
example: The Fralock web page lists flex and rigid-flex circuits, electrostatic chucks and flexible multizone heaters among customer uses of Cirlex, next to encapsulated shims and electrical insulators.
source: fralock-web
where: Customer uses list on the Cirlex engineered solutions page
- application: structures
device: Stand-offs, component stiffeners and washers with adhesive
example: The Fralock flyer lists stand-offs, component stiffeners, washers with adhesive and gasket rings as Cirlex applications. The flyer does not name a spacecraft or a mission.
source: fralock-flyer
where: Applications list on page 1
documents:
- title: Cirlex Polyimide Technical Data Sheet, generic, Rev_042420 (Fralock)
type: datasheet
url: https://www.fralock.com/wp-content/uploads/2021/07/Cirlex-DataSheet_Generic-042520.pdf
year: 2020
- title: Cirlex Engineered Thick All-Polyimide Material, Technical Data Sheet, REV051923 (Fralock)
type: datasheet
url: https://www.fralock.com/wp-content/uploads/2023/05/Cirlex-Flyer-Data-Sheet_051923.pdf
year: 2023
- title: DuPont Kapton FPC; HN; HPP-ST; PST; VN; V; GS (0.3 - 2 mil) Article Information Sheet, version 2.2
type: sds
url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/Kapton-Film-Dupont-Safety-Data-Sheet-SDS-11-30-2016.PDF
year: 2016
- title: PubChem GHS Classification, pyromellitic dianhydride (CID 6966)
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/6966
year: 2026
gaps:
- 'Grade of the Kapton film: the Fralock sheets say Cirlex is made from "100% DuPont Kapton adhesiveless polyimide film" and print no grade letter, so the Kapton grade is not known and the properties cannot be assigned to H, HN or any other grade.'
- Atomic oxygen erosion of Cirlex was not read in any source this run. The H-grade film result is in profile pi-kapton-h and is not a Cirlex result.
- Radiation (proton, electron, UV) tolerance for Cirlex was not found in any source this run.
- Thermal cycling endurance and cryogenic mechanical results beyond the -269 degC integrity claim were not found in any source this run.
- 'Spacecraft flight heritage: the lane brief names spacecraft thermal breaks, shims and isolators, but the Fralock pages read this run name aerospace, not a spacecraft or mission. No flight use of Cirlex was found.'
- 'Dissipation factor: the Fralock table prints 0.0040 with ASTM D150 but no test frequency, so the frequency is not stated.'
- Specific gravity is recorded as specific_gravity with unit "-" because the sheet prints no density in g/cm3. specific_gravity and ultimate_compressive_strength are not in spores/property-canon.yaml, so they are short snake_case names.
- 'Typical values only: the Fralock data sheet says "The above values are averaged values and should not be used in writing specifications." No minimum or specification values were found.'
- 'Flammability: the Fralock web page and flyer state "UL94V-0" with a UL file number. This is a pass listing, not a numeric property, so it is not recorded as a property.'
- Surface roughness "Ra 32 µin" is in the Fralock sheet but is not recorded as a property.
- 'Supply: no producer share by country, production volume, feedstock abundance or critical-mineral list was found for Cirlex or its monomers. The Fralock pages name Valencia, California as the head office. Wikipedia names Qnity Electronics as the current maker of Kapton, and this is not confirmed on a Cirlex page.'
- 'Name of the diamine: the Wikipedia Kapton article prints "4,4''-oxydiphenylamine (ODA)", while the ODA infobox names the compound 4,4''-Oxydianiline. The recipe uses the infobox name.'
sources:
fralock-ds:
title: Cirlex Polyimide Technical Data Sheet, generic, Rev_042420
id: Fralock, Valencia CA, file Cirlex-DataSheet_Generic-042520.pdf (uploaded 2021-07)
url: https://www.fralock.com/wp-content/uploads/2021/07/Cirlex-DataSheet_Generic-042520.pdf
year: 2020
kind: datasheet
license: manufacturer document, linked not reproduced
note: Typical values for mechanical, thermal, electrical and outgassing properties; the Electrical and Thermal tables are read from this sheet
fralock-flyer:
title: Cirlex Engineered Thick All-Polyimide Material, Technical Data Sheet, REV051923
id: Fralock, file Cirlex-Flyer-Data-Sheet_051923.pdf
url: https://www.fralock.com/wp-content/uploads/2023/05/Cirlex-Flyer-Data-Sheet_051923.pdf
year: 2023
kind: datasheet
license: manufacturer document, linked not reproduced
note: Applications list, features (temperature range, thermal conductivity, dielectric strength, NASA outgassing and UL94V-0 claims), and thickness range
fralock-web:
title: Cirlex Engineered Solutions, Polyimide Lamination Manufacturer (Fralock)
url: https://www.fralock.com/engineered-solutions/cirlex/index.html
kind: web
license: manufacturer web page, linked not reproduced
note: Licensee and manufacturer statement, temperature range, customer uses list, product name
dupont-ais:
title: 'DuPont Article Information Sheet: Kapton FPC; HN; HPP-ST; PST; VN; V; GS (0.3 - 2 mil), version 2.2'
id: Ref. 150000003827, revision date 11/30/2016
url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/Kapton-Film-Dupont-Safety-Data-Sheet-SDS-11-30-2016.PDF
year: 2016
kind: datasheet
license: manufacturer document, linked not reproduced
note: Family sheet; covers the Kapton film family and does not name Cirlex or the H grade. Used for handling, the incompatibility list, the 400 degC condition to avoid and the flammability note.
wiki-kapton:
title: Wikipedia, Kapton
url: https://en.wikipedia.org/wiki/Kapton
kind: web
license: CC BY-SA (Wikipedia)
note: Used for the Kapton chemistry, the ring-closure range, the Kapton service range and the maker history; the family statements are not Cirlex data
wiki-pmda:
title: Wikipedia, Pyromellitic dianhydride (infobox)
url: https://en.wikipedia.org/wiki/Pyromellitic_dianhydride
kind: web
license: CC BY-SA (Wikipedia)
note: Molar mass 218.120 g/mol, density 1.68 g/cm3, CAS 89-32-7
wiki-oda:
title: Wikipedia, 4,4'-Oxydianiline (infobox)
url: https://en.wikipedia.org/wiki/4,4%27-Oxydianiline
kind: web
license: CC BY-SA (Wikipedia)
note: Molar mass 200.24 g/mol, density 1.417 g/cm3, CAS 101-80-4
pubchem-ghs:
title: PubChem GHS Classification, pyromellitic dianhydride (CID 6966), harmonised EU CLP entry 607-098-00-X
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/6966/JSON
year: 2026
kind: database
license: PubChem (NCBI, public domain); the CLP entry is EU law, CC BY 4.0
note: Monomer hazard data only; no GHS record for Cirlex was read
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 30
unreachable: 0
caveats: 3
note: Written by an AI assistant on 2026-11-01. Values were read in this run from the Fralock generic data sheet (Rev_042420), the Fralock flyer (REV051923), the Fralock product page, the DuPont Kapton article information sheet, and Wikipedia and PubChem pages. The Fralock figures are typical averages, not specification values.
story:
risk_groups:
- title: For people
level: 1
verdict: No hazard classification on the family sheet
lead: The DuPont family sheet gives no hazard classification for the film. Thick laminate can cut, and unwrapping can build up static.
points:
- label: The laminate
line: The Kapton family sheet lists no hazard classification and says inhalation and ingestion are not considered routes of exposure. Thick films have sharp edges that can cut.
- label: Fire
line: The sheet says the film does not burn in air but will burn in 100% oxygen.
- label: Static
line: Processing and unwrapping can generate static charge, so the sheet advises avoiding static discharge.
- title: If it fails
lead: The failure modes come from the datasheet limits and the incompatibility list, not from tests on finished hardware.
points:
- label: Temperature
line: The Kapton sheet prints "Temperature > 400 °C" as a condition to avoid, and Cirlex is rated to 351 degC in the Fralock flyer.
- label: Chemicals
line: Strong acids and strong oxidizers are listed as incompatible, with no rate of attack given.
- label: Vacuum
line: The laminate loses 0.5 % of its mass in the ASTM E595 test, so it can add volatiles in a sealed vacuum volume.
- title: Handling and storage
points:
- label: Storage
line: Keep the film dry, away from strong acids and strong oxidizers. The Kapton sheet gives the storage temperature as "20 - 30 °C".
- label: Static
line: Avoid static discharge when unwrapping, and avoid breathing dust.
why: Cirlex is a thick all-polyimide laminate made by Fralock from DuPont Kapton film, without adhesive. Its Tg is 351 degC and its thermal conductivity is 0.17 W/m K, which is why Fralock sells it for thermal barriers and shims. Fralock's statement that it is used in aerospace is the only aerospace link in the sources read this run.
uses:
- where: Thermal barriers and shields
line: The Fralock flyer lists thermal barriers and thermal shields as the first applications of Cirlex.
- where: Electrical isolation and flexible electronics
line: The Fralock web page lists flex circuits, electrostatic chucks and flexible multizone heaters as customer uses, next to electrical insulators.
can_do:
- label: High-temperature stiffness
value: 402 kpsi at 200 degC
line: Fralock typical tensile modulus at 200 degC is 402 kpsi, with a glass transition temperature of 351 degC.
- label: Electrical insulation
value: 2790 V/mil
line: Fralock typical dielectric strength is 2790 V/mil, and the dielectric constant is 3.45 at 10 kHz.
- label: Heat flow
value: 0.17 W/m K
line: Fralock typical thermal conductivity is 0.17 W/m K, which the sheet presents as low.
compare: Cirlex is the thick, adhesive-free form of the Kapton chemistry. Fralock's typical data give a Tg of 351 degC, an in-plane CTE of 30 µm/m °C from 23 to 350 degC, and a through-thickness CTE of 118 µm/m °C, so the material expands much more through its thickness than in its plane. The Kapton film profiles in this database cover thin film, not thick laminate, so their outgassing and erosion numbers do not transfer to Cirlex without a test on the Cirlex grade.
compare_rows:
- scope: material
label: Glass transition temperature
benchmark: glass_transition_temperature
- scope: material
label: Thermal conductivity
benchmark: thermal_conductivity
- scope: material
label: Total mass loss (outgassing TML)
benchmark: total_mass_loss
recipe:
line: Cirlex is made from DuPont Kapton adhesiveless polyimide film, using Fralock's Adhesiveless Lamination Technology to form a monolithic all-polyimide part. The Kapton chemistry is the condensation of pyromellitic dianhydride with an oxydianiline, followed by a thermal ring closure, per the Wikipedia Kapton article.
parts:
- name: Pyromellitic dianhydride
symbol: PMDA
molar_mass: 218.12
share_note: Molar mass 218.120 g/mol, Wikipedia infobox (CAS 89-32-7)
role: Dianhydride monomer of the Kapton film, per Wikipedia Kapton article.
- name: 4,4'-Oxydianiline
symbol: ODA
molar_mass: 200.24
share_note: Molar mass 200.24 g/mol, Wikipedia infobox (CAS 101-80-4); the Kapton article prints the name as oxydiphenylamine
role: Diamine monomer of the Kapton film, per Wikipedia Kapton article.
handling:
- Keep the film dry, away from strong acids and strong oxidizers, at the storage temperature the Kapton sheet gives as "20 - 30 °C".
- Avoid static discharge when unwrapping and processing, and avoid breathing dust.
- Thick films have sharp edges which can cause cuts (DuPont Kapton sheet, handling section).
good_for:
- Thermal barriers and thermal shields where an adhesive-free all-polyimide part is wanted (Fralock flyer applications list).
- Electrical isolation and standoffs, with a dielectric strength of 2790 V/mil and a dielectric constant of 3.45 at 10 kHz.
- Parts that must keep their stiffness at high temperature, with a tensile modulus of 402 kpsi at 200 degC.
watch_out:
- Outgassing in vacuum. The total mass loss is 0.5 % under ASTM E595, which the sheet reports without a bake-out procedure.
- Strong acids and strong oxidizers, which the Kapton sheet lists as incompatible.
- The Fralock values are typical averages and are not specification values. The 351 degC upper limit is a Fralock claim, not a rated limit for each part.
- Atomic oxygen, radiation and thermal cycling for Cirlex were not found in any source read this run.
verdict: Cirlex is a thick, adhesive-free all-polyimide laminate from Fralock, with a glass transition temperature of 351 degC and a thermal conductivity of 0.17 W/m K. It suits thermal barriers, shims and electrical isolation where those numbers matter. For flight use, check outgassing (0.5 % total mass loss) and do not rely on typical values for specification.
supply:
- subject: Cirlex all-polyimide laminate
abundance: Not read in a fetched page for this product.
producers:
- name: Fralock
note: Worldwide licensee and manufacturer of Cirlex, and the only maker named on the Cirlex flyer; head office in Valencia, California (Fralock web page and flyer)
country: USA
year: 2023
- name: DuPont
note: Wikipedia, Kapton, prints "Kapton was invented by DuPont in the 1960s"; Fralock is DuPont's sole licensee for Cirlex per the Fralock generic data sheet
country: USA
- name: Qnity Electronics
note: DuPont spinoff; manufactures Kapton as of November 2025 (Wikipedia, Kapton); grade not stated
country: USA
year: 2025
critical_lists: []
recycling: Not sourced.
substitutes:
- Fralock names ceramic and Vespel as materials that Cirlex can replace (Fralock generic data sheet, first page).
source: fralock-ds
where: Fralock first page, Material description; Fralock web page for the licensee wording; Wikipedia Kapton for the history and maker
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Cirlex Polyimide Technical Data Sheet, generic, Rev_042420 | datasheet | 2020 | 32 values | |
| Cirlex Engineered Thick All-Polyimide Material, Technical Data Sheet, REV051923 | datasheet | 2023 | 5 values | |
| Cirlex Engineered Solutions, Polyimide Lamination Manufacturer (Fralock) | web | 1 value | ||
| DuPont Article Information Sheet: Kapton FPC; HN; HPP-ST; PST; VN; V; GS (0.3 - 2 mil), version 2.2 | datasheet | 2016 | 7 values | |
| Wikipedia, Kapton | web | 1 value | ||
| Wikipedia, Pyromellitic dianhydride (infobox) | web | 0 values | ||
| Wikipedia, 4,4'-Oxydianiline (infobox) | web | 0 values | ||
| PubChem GHS Classification, pyromellitic dianhydride (CID 6966), harmonised EU CLP entry 607-098-00-X | database | 2026 | 1 value |
Updated