Twaron · grade

Twaron PULP

Properties of the PULP condition, compared with the other Twaron grades.

Highly fibrillated, high-surface-area pulp used as an asbestos replacement in friction materials, gaskets, sealants and greases.

High cost $$$$

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What is Twaron PULP?

Twaron PULP is Twaron in the PULP grade — highly fibrillated, high-surface-area pulp used as an asbestos replacement in friction materials, gaskets, sealants and greases. Twaron PULP has a tensile strength of 3,100 MPa (450 ksi), stronger than 82% of composite grades. Elongation at break is 3.6% and the elastic modulus is 70 GPa (10.2 Msi). Twaron PULP has a density of 1.44 g/cm³ (0.052 lb/in³), lighter than 62% of composite grades. Its glass-transition temperature is 340°C (644 °F). 1000 is the default condition FabDigit quotes; PULP is available on request or by drawing note.

Advantages

Ductile — tolerates forming and impact — 3.6%, better than 80% of composite grades

Limitations

Absorbs moisture — dry before molding — 4.5%, worse than 95% of composite grades
Degrades in UV without stabilisers — 20/100, worse than 94% of composite grades
Poor heat conductor — 0.05 W/m·K (0.0289 BTU/hr·ft·°F), worse than 87% of composite grades

Twaron PULP properties

Typical room-temperature values for Twaron PULP — 3 properties are specific to this condition; the rest are grade-level values shared by every Twaron grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.

Physical3

Twaron PULP has a density of 1.44 g/cm³ (0.052 lb/in³), lighter than 62% of composite grades. Its glass-transition temperature is 340°C (644 °F).

Density1.44 g/cm³0.05 lb/in³

Glass Transition (Tg)340°C644 °F

Water Absorption (24 h)4.5%

Mechanical6

Twaron PULP has a tensile strength of 3,100 MPa (450 ksi), stronger than 82% of composite grades. Elongation at break is 3.6% and the elastic modulus is 70 GPa (10.2 Msi).

Elastic (Young's) Modulus70 GPa10.2 Msi

Shear Modulus2.9 GPa0.42 Msi

Poisson's Ratio0.36

Tensile Strength (Ultimate)3,100 MPa450 ksi

Elongation at Break3.6%

Compressive Strength400 MPa58 ksi

Thermal8

Twaron PULP is rated for continuous service to 200°C (392 °F). It conducts heat at 0.05 W/m·K (0.0289 BTU/hr·ft·°F), worse than 87% of composite grades. Thermal expansion is -3.5 µm/m·K (-1.94 µin/in·°F).

Thermal Conductivity0.05 W/m·K0.03 BTU/hr·ft·°F

Specific Heat Capacity1,420 J/kg·K0.34 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)-3.5 µm/m·K-1.9 µin/in·°F

Max Service Temperature (continuous)200°C392 °F

Min Service Temperature-196°C-321 °F

Flammability (UL 94)Self-extinguishing, non-melting and non-dripping; carbonizes rather than melts, LOI ≈ 29 %

Limiting Oxygen Index29%

Max Service Temperature (short-term)250°C482 °F

Electrical3

Twaron PULP has an electrical resistivity of 1×10¹² Ω·m.

Electrical Resistivity1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Constant (1 MHz)4

Volume Resistivity1×10¹⁴ Ω·cm

Chemical & Environmental3

Corrosion resistance is very good (80/100), better than 54% of composite grades. UV resistance is poor.

Corrosion ResistanceVery good80/100

UV / Weathering ResistancePoor20/100

Chemical Resistance SummaryExcellent against hydrocarbons, oils, most organic solvents and neutral salts; attacked by strong mineral acids, concentrated alkalis, hypochlorite bleach and hot steam (hydrolysis); must be shielded from sunlight/UV.

Sustainability4

Producing a kilogram of Twaron PULP takes about 280 MJ of energy and emits 16 kg of CO₂ — more than 62% of composite grades. Typical recycled content is 0%.

Embodied Energy (primary production)280 MJ/kg120,378 BTU/lb

Embodied Carbon (primary production)16 kg CO₂/kg

Embodied Water400 L/kg47.9 gal/lb

Typical Recycled Content0%

Manufacturability1

Twaron PULP's machinability is poor (25/100, worse than 65% of composite grades).

MachinabilityPoor25/100

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other Twaron grades and fills

Twaron is also supplied in 9 other conditions. The full side-by-side table is on the Twaron overview.

1000DefaultGeneral-purpose para-aramid yarn for ropes, cables, protective textiles and rubber reinforcement.3,100 MPa tensile
AFRP-UDStructural AFRP for impact-tolerant, lightweight panels where low compressive strength is acceptable.1,350 MPa tensile
PULPHighly fibrillated, high-surface-area pulp used as an asbestos replacement in friction materials, gaskets, sealants and greases.3 properties

Working with Twaron PULP

Is Twaron easy to machine?

Cuts fuzz badly — use serrated/hot knives, sharp carbide or PCD tools with high rake and backing plate, or abrasive waterjet; expect rapid tool dulling and hairy edges.

Can Twaron be welded?

Not weldable; joints are made by knotting/splicing, RFL adhesive bonding to rubber, or resin bonding in laminates.

Can Twaron be formed, bent or molded?

Processed by weaving, braiding, filament winding, pultrusion and prepreg lay-up; dry fibre must be conditioned (moisture ≤ 1 %) and vacuum-dried before resin infusion to avoid voids.

What surface finishes work on Twaron?

Difficult to dye (usually solution- or pigment-coloured); requires UV-blocking jacket, coating or paint for outdoor service; surface plasma/epoxy sizing improves resin adhesion.

Twaron 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
p-phenylenediamine (PPD) repeat unitone of the two PPTA backbone monomers	≈ 50	50
terephthaloyl (TDC/terephthalic) repeat one of the two PPTA backbone monomers	≈ 50	50
spin finish / surface treatmentspin finish or adhesive-activation treatment, varies by product	0.2 – 1.5	0.6

Twaron PULP — frequently asked

What is Twaron PULP used for?

Twaron PULP is typically used for ballistic protection, ropes and cables, friction/gasket materials and composite reinforcement. In short: direct Kevlar equivalent; broadest aramid form range; widely stocked in Europe.

What is the tensile strength of Twaron PULP?

Twaron PULP has a typical tensile strength of 3,100 MPa (450 ksi) — stronger than 82% of composite grades. Strength varies by condition: see the 10 listed tempers.

Is Twaron PULP easy to machine?

Not especially — machinability is rated poor (25/100, worse than 65% of composite grades). Cuts fuzz badly — use serrated/hot knives, sharp carbide or PCD tools with high rake and backing plate, or abrasive waterjet; expect rapid tool dulling and hairy edges.

Can Twaron PULP be welded?

Not weldable; joints are made by knotting/splicing, RFL adhesive bonding to rubber, or resin bonding in laminates.

What surface finishes work on Twaron PULP?

Difficult to dye (usually solution- or pigment-coloured); requires UV-blocking jacket, coating or paint for outdoor service; surface plasma/epoxy sizing improves resin adhesion.

Can Twaron PULP be formed, bent or molded?

Processed by weaving, braiding, filament winding, pultrusion and prepreg lay-up; dry fibre must be conditioned (moisture ≤ 1 %) and vacuum-dried before resin infusion to avoid voids.

What is the maximum service temperature of Twaron PULP?

Twaron PULP is rated for continuous use to about 200°C (392 °F), and briefly to 250°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

Twaron Product Brochure & Technical Guide (yarn, staple, short-cut, pulp) — Teijin Aramid (2022)
ASM Engineered Materials Handbook Vol. 1: Composites — ASM International (1987)
MMPDS / composite lamina typical property tables (aramid/epoxy) — Battelle (2021)

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.