Strength band
varies widely by micron; fine merino is not a rope fibre
Darker cells mean a higher score for this topic on that metric.
Strength32
Heat resistance38
Fire performance48
Insulation72
Workability70
Circularity58
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Quick answers
Is Wool non-combustible?
Declared reaction class in this atlas: better than commodity synthetics in many apparel tests. Assemblies still need resistance tests.
Does Wool insulate?
Thermal mark 72/100 versus the atlas. Conductivity note: low when lofted.
What is the density band?
~1.31 g/cm³
How is it made?
Origin story: Neolithic sheep; merino Spain; industrial Yorkshire (Near East → Spain → Australia).
Can it be recycled?
Circularity mark 58/100 — editorial, route-specific.
Typical melting or failure heat?
chars; does not melt-drip like PE
heat 38 · fire 48
Numbers below are bands used by working engineers, not live quotes. Tensile note: varies widely by micron; fine merino is not a rope fibre.
Fire performance in this atlas is editorial. Real projects need the assembly report.
Mechanical
Stiffness
Modulus follows chemistry and orientation — not the marketing nickname.
Toughness
Crack growth, not peak stress, retires most real parts.
Fatigue / creep
Cyclic and time-dependent damage dominate certificates issued on static coupons.
Hardness / hand
Indentation, drape or compressive class — whichever the trade actually measures.
Thermal
Conductivity
low when lofted — Wool is used as insulation.
Service temperature
Melting / softening / decomposition band: chars; does not melt-drip like PE.
Expansion
Joints and clearances must follow the expansion class of Wool, not of steel-by-habit.
Thermal mass
Density ~1.31 g/cm³ sets how fast a section changes temperature.
Ageing of λ
Foams, VIPs and moist batts drift; quote aged values.
Electrical
Conductor or dielectric
Wool is generally a dielectric or semiconductor film, not building wire.
Static / EMI
Fillers and moisture change resistivity more than brochures admit.
Standards language
IACS, volume resistivity or dielectric strength — pick the quantity the job uses.
Fire
Reaction to fire
Typical declared class: better than commodity synthetics in many apparel tests. This is not a universal passport.
Resistance vs reaction
Euroclass is reaction. EI/R ratings are assemblies — boards, coats, cavities.
Melt-drip / char
Wool can burn or drip; do not treat it as A1 without a system test.
Smoke / toxicity
CO, HCN, HF or fibres — the species depend on chemistry. Name the test (ISO 5659, EN 45545, NFPA 1971).
If a salesperson quotes a single “safety score”, ask which standard, which thickness, which year.
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