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PI Foam FLEX-10

Grade · default condition

FLEX-10 = flexible open-cell general-purpose grade, ~9.6 kg/m³

Default balance of insulation value, resilience and handling strength for thermal/acoustic blanket work to 300 °C.

High cost $$$$

Values for the FLEX-10 condition

Other PI Foam grades and fills

PI Foam is listed in 7 conditions; see the grade overview at PI Foam.

Compare all 7 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
Flexible open-cell acoustic grade, ~6.4 kg/m³
Lightest practical grade — pick it when weight and acoustic absorption dominate and mechanical loading is negligible (aircraft fuselage blankets).—0.0412—
FLEX-10DefaultThis page
Flexible open-cell general-purpose grade, ~9.6 kg/m³
Default balance of insulation value, resilience and handling strength for thermal/acoustic blanket work to 300 °C.—0.0615—
Hydrophobic / water-repellent treated flexible foam
Silicone- or fluoro-treated open-cell foam for marine, bilge and condensation-prone insulation where liquid-water pickup must be suppressed.—0.0712—
High-temperature / higher-strength flexible grade, ~16 kg/m³
Choose when the blanket must resist handling abuse, vibration and sustained 300–315 °C exposure (engine nacelle, exhaust duct lagging).—0.1212—
Semi-firm flexible grade, ~32 kg/m³
Denser resilient grade for high-temperature gaskets, seals and vibration pads where a measurable sealing load is required.—0.310—
Rigid polyimide foam, ~32 kg/m³
Rigid low-density board for high-temperature sandwich cores and cryogenic tank insulation where dimensional stability matters more than resilience.—0.35——
High-density rigid polyimide foam, ~100 kg/m³
Load-bearing rigid grade for hot sandwich panels, tooling blocks and machined high-temperature insulation parts.—1——

What is PI Foam FLEX-10?

PI Foam FLEX-10 is PI Foam in the FLEX-10 grade — default balance of insulation value, resilience and handling strength for thermal/acoustic blanket work to 300 °C. PI Foam FLEX-10 has a tensile strength of 0.06 MPa (0.0087 ksi), weaker than 100% of polymer grades. Elongation at break is 15% and the elastic modulus is 3×10⁻⁴ GPa (4.35×10⁻⁵ Msi). Its glass-transition temperature is 300°C (572 °F).

Advantages

  • High service temperature — 300°C (572 °F), better than 99% of polymer grades
  • Good UV / weathering resistance — 70/100, better than 83% of polymer grades
  • Forms and bends easily — 85/100, better than 81% of polymer grades

Limitations

  • Low stiffness — 3×10⁻⁴ GPa (4.35×10⁻⁵ Msi), worse than 99% of polymer grades
  • High embodied carbon — 15 kg CO₂/kg, worse than 96% of polymer grades
  • Poor heat conductor — 0.04 W/m·K (0.0208 BTU/hr·ft·°F), worse than 92% of polymer grades
  • Difficult to weld — 5/100, worse than 89% of polymer grades

PI Foam FLEX-10 properties

Typical room-temperature values for PI Foam FLEX-10; 15 are specific to this condition. Other listed values are PI Foam reference data and may not represent this condition. Bars are the position among polymer grades.

Physical1

Its glass-transition temperature is 300°C (572 °F).

Glass Transition (Tg)300°C572 °F

Mechanical7

PI Foam FLEX-10 has a tensile strength of 0.06 MPa (0.0087 ksi), weaker than 100% of polymer grades. Elongation at break is 15% and the elastic modulus is 3×10⁻⁴ GPa (4.35×10⁻⁵ Msi).

Elastic (Young's) Modulus3×10⁻⁴ GPa4.35×10⁻⁵ Msi
Tensile Strength (Ultimate)0.06 MPa0.01 ksi
Elongation at Break15%
Compressive Strength0.01 MPa0 ksi
Compressive Modulus2×10⁻⁴ GPa2.9×10⁻⁵ Msi
Tear Strength0.2 kN/m1.1 lbf/in
Compression Set (22 h, 70 °C)8%

Thermal7

PI Foam FLEX-10 is rated for continuous service to 300°C (572 °F). It conducts heat at 0.04 W/m·K (0.0208 BTU/hr·ft·°F), worse than 92% of polymer grades.

Thermal Conductivity0.04 W/m·K0.02 BTU/hr·ft·°F
Specific Heat Capacity1,150 J/kg·K0.27 BTU/lb·°F
Max Service Temperature (continuous)300°C572 °F
Min Service Temperature-196°C-321 °F
Flammability (UL 94)V-0 typical; low smoke and toxicity
Limiting Oxygen Index45%
Max Service Temperature (short-term)400°C752 °F

Electrical4

PI Foam FLEX-10 is an electrical insulator with a dielectric strength of 2 kV/mm (50.8 V/mil) and a resistivity of 1×10¹³ Ω·m.

Electrical Resistivity1×10¹³ Ω·m3.94×10²⁰ µΩ·in
Dielectric Strength2 kV/mm50.8 V/mil
Dielectric Constant (1 MHz)1.06
Volume Resistivity1×10¹⁵ Ω·cm

Chemical & Environmental3

Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is very good.

Corrosion ResistanceExcellent85/100
UV / Weathering ResistanceVery good70/100
Chemical Resistance SummaryVery good against hydrocarbons, fuels, lubricants, ketones and dilute acids; attacked by hot strong alkali and concentrated acids (imide hydrolysis); open cells wick water and require hydrophobic treatment or a facing in wet service

Sustainability3

Producing a kilogram of PI Foam FLEX-10 takes about 300 MJ of energy and emits 15 kg of CO₂ — more than 97% of polymer grades. Typical recycled content is 0%.

Embodied Energy (primary production)300 MJ/kg128,977 BTU/lb
Embodied Carbon (primary production)15 kg CO₂/kg
Typical Recycled Content0%

Manufacturability3

PI Foam FLEX-10's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (5/100); formability excellent (85/100).

MachinabilityGood55/100
WeldabilityNot recommended5/100
Formability (cold)Excellent85/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with PI Foam FLEX-10

Is PI Foam easy to machine?

Flexible grades are die-cut, band-knife or hot-wire cut; rigid boards machine easily with sharp carbide tools at high speed and low feed, with vacuum dust collection.

Can PI Foam be welded?

Not weldable — join by high-temperature adhesives (silicone, polyimide or ceramic-filled), sewing with glass thread, or mechanical clamping in metal frames.

Can PI Foam be formed, bent or molded?

Supplied as bun stock, sheet or foamed-in-place; the flexible foam drapes and compresses onto complex curvature without heat, while rigid grades must be cut and bonded to shape.

What surface finishes work on PI Foam?

Encapsulate with PI/PTFE film, aluminized facing or glass scrim for abrasion and moisture protection; no painting or plating — surface treatments are limited to hydrophobic sprays.

PI Foam chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
surfactant / cell-control additive0.1 – 10.5
residual water / alcohol blowing volatildriven off during cure0 – 0.50.2
aromatic polyimide (dianhydride + diaminformed by in-situ foaming and thermal imidization of a polyamic-acid ester precursorbalance—

PI Foam FLEX-10 — frequently asked

What is PI Foam FLEX-10 used for?

PI Foam FLEX-10 is typically used for aircraft cabin thermal/acoustic insulation, fire-blocking insulation layers, cryogenic tank insulation and aerospace duct wrap. In short: highest-temperature polymer foam; inherently flame resistant; non-structural insulation only.

What is the tensile strength of PI Foam FLEX-10?

PI Foam FLEX-10 has a typical tensile strength of 0.06 MPa (0.0087 ksi) — weaker than 100% of polymer grades. Strength varies by condition: see the 7 listed tempers.

Is PI Foam FLEX-10 easy to machine?

Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Flexible grades are die-cut, band-knife or hot-wire cut; rigid boards machine easily with sharp carbide tools at high speed and low feed, with vacuum dust collection.

Can PI Foam FLEX-10 be welded?

Not readily — weldability is rated not recommended (5/100). Not weldable — join by high-temperature adhesives (silicone, polyimide or ceramic-filled), sewing with glass thread, or mechanical clamping in metal frames.

What surface finishes work on PI Foam FLEX-10?

Encapsulate with PI/PTFE film, aluminized facing or glass scrim for abrasion and moisture protection; no painting or plating — surface treatments are limited to hydrophobic sprays.

Can PI Foam FLEX-10 be formed, bent or molded?

Supplied as bun stock, sheet or foamed-in-place; the flexible foam drapes and compresses onto complex curvature without heat, while rigid grades must be cut and bonded to shape.

What is the maximum service temperature of PI Foam FLEX-10?

PI Foam FLEX-10 is rated for continuous use to about 300°C (572 °F), and briefly to 400°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. Flexible polyimide foam (Solimide-type) product data — Boyd / Evonik (2023)
  2. Engineered Materials Handbook Vol. 2: Engineering Plastics (polyimides) — ASM International (1988)
  3. ASTM D3574 — Flexible Cellular Materials, Slab, Bonded and Molded Urethane Foams (test methods used for PI foam) — ASTM (2017)
  4. ASTM C177 / C518 — Steady-state thermal transmission — ASTM (2019)
  5. ASTM D2863 — Limiting Oxygen Index — ASTM (2019)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.