Cork Composite Core CR (Cold rolled)
Supply condition
also Corecork
Denser rubber-bonded cork for gaskets, anti-vibration pads and machinery mounts rather than lightweight sandwich cores.
Values for the CR condition
Other Cork Composite Core grades and fills
Cork Composite Core is listed in 5 conditions; see the grade overview at Cork Composite Core.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Low-density cork core | Lightest grade for weight-critical, lightly loaded sandwich skins and damping layers. | — | 0.45 | 12 | 25 Shore A |
Fire-retardant treated core for rail/marine interiors | Binder/additive package tuned for EN 45545-2 HL2–HL3 and IMO low smoke/toxicity interior panels. | — | 0.75 | 9 | 38 Shore A |
NL20Default Standard-density cork core | General-purpose marine/rail sandwich core balancing damping, strength and resin uptake. | — | 0.8 | — | — |
High-density cork core | Choose where higher core shear/compression is needed, e.g. hardpoints, decks and fastener zones. | — | 1 | 9 | 45 Shore A |
CRThis page Cold rolled | Denser rubber-bonded cork for gaskets, anti-vibration pads and machinery mounts rather than lightweight sandwich cores. | — | 2 | 18 | 22 Shore D |
What is Cork Composite Core CR?
Cork Composite Core CR is Cork Composite Core supplied in the CR condition — denser rubber-bonded cork for gaskets, anti-vibration pads and machinery mounts rather than lightweight sandwich cores. Cork Composite Core CR has a tensile strength of 2 MPa (0.29 ksi), weaker than 92% of composite grades. Elongation at break is 18% and the elastic modulus is 0.02 GPa (0.0022 Msi). Cork Composite Core CR has a density of 0.75 g/cm³ (0.0271 lb/in³), lighter than 82% of composite grades. NL20 is the default condition FabDigit quotes; CR is available on request or by drawing note.
Advantages
- Low embodied carbon — 0.5 kg CO₂/kg, better than 100% of composite grades
- Ductile — tolerates forming and impact — 18%, better than 95% of composite grades
- Easy to machine — 85/100, better than 90% of composite grades
- Lightweight — 0.75 g/cm³ (0.0271 lb/in³), better than 82% of composite grades
Limitations
- Low stiffness — 0.02 GPa (0.0022 Msi), worse than 97% of composite grades
- Absorbs moisture — dry before molding — 6%, worse than 97% of composite grades
- Limited service temperature — 110°C (230 °F), worse than 87% of composite grades
- Poor heat conductor — 0.09 W/m·K (0.052 BTU/hr·ft·°F), worse than 81% of composite grades
Cork Composite Core CR properties
Typical room-temperature values for Cork Composite Core CR; 16 are specific to this condition. Other listed values are Cork Composite Core reference data and may not represent this condition. Bars are the position among composite grades.
Physical3
Cork Composite Core CR has a density of 0.75 g/cm³ (0.0271 lb/in³), lighter than 82% of composite grades.
Mechanical9
Cork Composite Core CR has a tensile strength of 2 MPa (0.29 ksi), weaker than 92% of composite grades. Elongation at break is 18% and the elastic modulus is 0.02 GPa (0.0022 Msi).
Thermal8
Cork Composite Core CR is rated for continuous service to 110°C (230 °F). It conducts heat at 0.09 W/m·K (0.052 BTU/hr·ft·°F), worse than 81% of composite grades. Thermal expansion is 50 µm/m·K (27.8 µin/in·°F).
Chemical & Environmental2
UV resistance is fair.
Sustainability3
Producing a kilogram of Cork Composite Core CR takes about 6 MJ of energy and emits 0.5 kg of CO₂ — less than 100% of composite grades. Typical recycled content is 90%.
Manufacturability1
Cork Composite Core CR's machinability is excellent (85/100, better than 90% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Cork Composite Core CR
Is Cork Composite Core easy to machine?
Cuts easily with sharp knives, band saw, router or CNC; use vacuum extraction for dust and avoid crushing edges with dull tools.
Can Cork Composite Core be welded?
Not weldable — panels are joined by adhesive bonding, scarf joints or resin fillets between core blocks.
Can Cork Composite Core be formed, bent or molded?
Flexible enough to conform to single- and mild double-curvature molds cold; hot-forming above ~90 °C improves drape, and perforated/grooved sheets are used for vacuum infusion.
What surface finishes work on Cork Composite Core?
Skins bond directly with epoxy, vinylester or polyester; seal or prime exposed faces since untreated cork absorbs resin/moisture and darkens under UV.
Cork Composite Core 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 |
|---|---|---|
| cork granulate (Quercus suber)expanded/agglomerated granules, by-product of cork stopper production | 82 – 95 | 90 |
| polyurethane binderMDI-based PU; rubber (NBR/SBR) binder in cork–rubber grades | 5 – 18 | 10 |
Cork Composite Core CR — frequently asked
What is Cork Composite Core CR used for?
Cork Composite Core CR is typically used for boat deck cores, acoustic/vibration-damping panels and rail interior panels. In short: best-damping natural core; drapes cold to curvature; low stiffness versus foam cores.
What is the tensile strength of Cork Composite Core CR?
Cork Composite Core CR has a typical tensile strength of 2 MPa (0.29 ksi) — weaker than 92% of composite grades. Strength varies by condition: see the 5 listed tempers.
Is Cork Composite Core CR easy to machine?
Yes — machinability is rated excellent (85/100, better than 90% of composite grades). Cuts easily with sharp knives, band saw, router or CNC; use vacuum extraction for dust and avoid crushing edges with dull tools.
Can Cork Composite Core CR be welded?
Not weldable — panels are joined by adhesive bonding, scarf joints or resin fillets between core blocks.
What surface finishes work on Cork Composite Core CR?
Skins bond directly with epoxy, vinylester or polyester; seal or prime exposed faces since untreated cork absorbs resin/moisture and darkens under UV.
Can Cork Composite Core CR be formed, bent or molded?
Flexible enough to conform to single- and mild double-curvature molds cold; hot-forming above ~90 °C improves drape, and perforated/grooved sheets are used for vacuum infusion.
What is the maximum service temperature of Cork Composite Core CR?
Cork Composite Core CR is rated for continuous use to about 110°C (230 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- CoreCork NL series technical datasheet — Amorim Cork Composites (2023)
- ASTM C273 Shear Properties of Sandwich Core Materials — ASTM (2020)
- ASTM D1621 Compressive Properties of Rigid Cellular Plastics — ASTM (2016)
- EN 45545-2 Railway applications — Fire behaviour of materials — CEN (2020)
- Cellular Solids: Structure and Properties (cork chapter) — Cambridge University Press (1997)
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.