Visco-Elastic Polyurethane

Sorbothane (PU Vibration Isolation)

Sorbothane is a proprietary visco-elastic polyurethane engineered for vibration damping, shock absorption, and acoustic isolation. It absorbs up to 94.7% of impact energy and over 50% of vibration energy across the 10 Hz – 30 kHz range — outperforming conventional rubber, neoprene, and foam in energy dissipation. We supply Sorbothane sheet stock in five durometer grades for mounting pads, equipment isolation, and sensitive instrument protection.

At a Glance

Temperature Range

-29 °C to +72 °C continuous

Thickness Range

2.5 mm to 38 mm

Hardness Range

Shore OO 30–70 (approximately Shore A 5–25; conversion is non-linear and indicative only)

Available Forms

Plain sheet stockSheet with PSA (pressure-sensitive adhesive)Die-cut shapesWater-jet cut shapesWater-resistant variant (grey)

Colours

Black (standard)Grey (water-resistant variant)

Brands We Stock

Sorbothane
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Technical Properties

Typical values across stocked grades. Specific grade data sheets available on request.

Temperature Range-29 °C to +72 °C continuous (durometer 70 standard); duro 70 extended service to +93 °C with degraded damping; duro 30 ceiling 60 °C, duro 50 ceiling 66 °C
Hardness (Shore OO)30, 40, 50, 60, 70 (five standard grades)
Density (ASTM D792)1.33–1.36 g/cm³ (durometer dependent)
Tensile Strength (ASTM D412)0.18–1.32 MPa (duro 30: 0.18; duro 50: 0.74; duro 70: 1.32, per Sorbothane Datasheet 101)
Elongation at Break (ASTM D412)334–765% (peak ~765% at duro 50; tapers at extremes)
Tear Strength (ASTM D624)2.3–4.9 kN/m (13–28 pli; duro 30 lower bound)
Compression Set (ASTM D395)2–10% (22 h @ 70 °C / 158 °F, 25% deflection per Sorbothane Datasheet 101): 10% / 3% / 2% for duro 30 / 50 / 70
Impact Energy AbsorptionUp to 94.7% (geometry- and loading-dependent — verify against application; published for standardised drop test)
Vibration Energy Absorption>50% across 10 Hz – 30 kHz (over most of operating temperature range; damping degrades approaching glass-transition Tg ~-25 °C)
Glass Transition (Tg)~-25 °C — damping performance degrades approaching the -29 °C lower service limit
Resilience (Lupke Rebound)10–15 (very low by design)
Flammability (UL 94)V-2
Dielectric Strength (BS 903 Part C2, legacy)11.1–13.1 kV/mm
Shelf Life3 years from pour date

Physical Characteristics

Density

1.30 g/cm³

Tensile Strength

0.52–1.07 MPa (ASTM D412)

Elongation at Break

300–500% (ASTM D412)

Compression Set

4.5–9.7% (72 h, 23 °C, 25%)

Tear Strength

3.01–5.08 kN/m (ASTM D624)

Thermal Conductivity

0.37–0.39 W/m·K

Dielectric Strength

11.1–13.1 kV/mm (BS 903 Part C2, legacy)

Chemical Resistance

Resistant To

  • Mineral oils and greases
  • Mild acids
  • Mild alkalis
  • Water (splash or wipe, not immersion)

Limited Resistance

  • Alcohols (brief contact acceptable, not prolonged exposure)

Not Recommended

  • Water immersion (absorbs moisture, degrades performance)
  • Petrol and gasoline
  • Ketones and plastic solvents
  • Strong oxidising agents
  • Solvent-based adhesives

Environmental Ratings

Flame Rating

UL 94 V-2

Weather Resistance

Not documented; assume limited (typical of polyether PU)

Ozone Resistance

Not documented: assume poor (typical of polyether PU)

UV Resistance

Not documented; assume poor (typical of polyether PU)

Standards & Certifications

Standards Compliance

RoHS compliantREACH compliant (no SVHC substances)California Proposition 65 compliantLatex-free (confirmed by manufacturer)

Common Applications

  • Sensitive equipment vibration isolation pads
  • CNC machine and precision instrument mounts
  • Acoustic dampening panels and enclosures
  • Shock absorption pads for drop protection
  • Electronic component isolation in enclosures
  • Motor and pump anti-vibration mounting
  • Data centre and server rack isolation
  • Medical and laboratory instrument mounting
  • Defence and aerospace equipment dampening
  • Conveyor and chute impact cushioning

Not Recommended For

  • Not a sealing or gasket material; no fluid containment capability
  • Narrow temperature range compared to conventional elastomers (-29 °C to +72 °C)
  • Absorbs water — not suited to wet or submerged environments without water-resistant variant
  • Poor solvent resistance: avoid petrol, ketones, and alcohols
  • Very soft (Shore OO scale), not suited to high-compression-load applications
  • Static deflection should be kept to 15–20% for optimal damping performance
  • 3-year shelf life from pour date; stock rotation required
  • Sole-source manufacturer (Sorbothane Inc., USA), so lead times may apply for custom shapes

Available Grades

Brands we stock: Sorbothane

Sorbothane Shore OO 30

Softest standard grade with maximum energy absorption. Best for lightweight, low-frequency vibration isolation. Max service temperature 60 °C.

Sorbothane Shore OO 50

Mid-range durometer balancing load capacity and damping. Suited to general-purpose vibration isolation of medium-weight equipment. Max service temperature 66 °C.

Sorbothane Shore OO 70

Firmest standard grade with the highest load capacity and tear strength. Suited to heavier equipment and higher-temperature applications. Max service temperature 72 °C.

Sorbothane Water-Resistant

Modified formulation (grey) for wet or high-humidity environments. Not for continuous immersion, but tolerates splash and condensation without moisture absorption.

Related Resources

Shore Hardness Guide

Understand durometer scales including the Shore OO range used for Sorbothane.

Sheet Rubber Selection

Compare Sorbothane against conventional rubber compounds.

Related Materials

Neoprene EPDM Silicone

Need Sorbothane (PU Vibration Isolation)?

We supply sorbothane (pu vibration isolation) in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.

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Disclaimer

This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.