PI Foam HYDRO
Additive grade
HYDRO = 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.
Values for the HYDRO 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 datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | 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). | — | 0.04 | 12 | — |
FLEX-10Default 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. | — | 0.06 | 15 | — |
HYDROThis page 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. | — | 0.07 | 12 | — |
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). | — | 0.12 | 12 | — |
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. | — | 0.3 | 10 | — |
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 HYDRO?
PI Foam HYDRO is PI Foam in the HYDRO grade — silicone- or fluoro-treated open-cell foam for marine, bilge and condensation-prone insulation where liquid-water pickup must be suppressed. PI Foam HYDRO has a tensile strength of 0.07 MPa (0.0102 ksi), weaker than 100% of polymer grades. Elongation at break is 12% and the elastic modulus is 3×10⁻⁴ GPa (4.35×10⁻⁵ Msi). Its glass-transition temperature is 300°C (572 °F). FLEX-10 is the default condition FabDigit quotes; HYDRO is available on request or by drawing note.
Advantages
- High service temperature — 260°C (500 °F), better than 97% 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 (0.0214 BTU/hr·ft·°F), worse than 91% of polymer grades
- Difficult to weld — 5/100, worse than 89% of polymer grades
PI Foam HYDRO properties
Typical room-temperature values for PI Foam HYDRO; 16 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).
Mechanical7
PI Foam HYDRO has a tensile strength of 0.07 MPa (0.0102 ksi), weaker than 100% of polymer grades. Elongation at break is 12% and the elastic modulus is 3×10⁻⁴ GPa (4.35×10⁻⁵ Msi).
Thermal7
PI Foam HYDRO is rated for continuous service to 260°C (500 °F). It conducts heat at 0.04 W/m·K (0.0214 BTU/hr·ft·°F), worse than 91% of polymer grades.
Electrical4
PI Foam HYDRO is an electrical insulator with a dielectric strength of 2 kV/mm (50.8 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 74% of polymer grades. UV resistance is very good.
Sustainability3
Producing a kilogram of PI Foam HYDRO takes about 300 MJ of energy and emits 15 kg of CO₂ — more than 97% of polymer grades. Typical recycled content is 0%.
Manufacturability3
PI Foam HYDRO's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (5/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PI Foam HYDRO
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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| surfactant / cell-control additive | 0.1 – 1 | 0.5 |
| residual water / alcohol blowing volatildriven off during cure | 0 – 0.5 | 0.2 |
| aromatic polyimide (dianhydride + diaminformed by in-situ foaming and thermal imidization of a polyamic-acid ester precursor | balance | — |
PI Foam HYDRO — frequently asked
What is PI Foam HYDRO used for?
PI Foam HYDRO 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 HYDRO?
PI Foam HYDRO has a typical tensile strength of 0.07 MPa (0.0102 ksi) — weaker than 100% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is PI Foam HYDRO 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 HYDRO 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 HYDRO?
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 HYDRO 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 HYDRO?
PI Foam HYDRO is rated for continuous use to about 260°C (500 °F), and briefly to 400°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Flexible polyimide foam (Solimide-type) product data — Boyd / Evonik (2023)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (polyimides) — ASM International (1988)
- ASTM D3574 — Flexible Cellular Materials, Slab, Bonded and Molded Urethane Foams (test methods used for PI foam) — ASTM (2017)
- ASTM C177 / C518 — Steady-state thermal transmission — ASTM (2019)
- 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.