Kevlar 29 FAB-EP
Matrix
FAB-EP = woven Kevlar 29 fabric / epoxy laminate, Vf ≈ 50 %
Balanced quasi-isotropic panels — canoe hulls, protective shells, drone and motorsport bodywork with damage tolerance.
Values for the FAB-EP condition
Other Kevlar 29 grades and fills
Kevlar 29 is listed in 5 conditions; see the grade overview at Kevlar 29.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
FAB-EPThis page Woven Kevlar 29 fabric / epoxy laminate, Vf ≈ 50 % | Balanced quasi-isotropic panels — canoe hulls, protective shells, drone and motorsport bodywork with damage tolerance. | — | 500 | 2.2 | — |
Unidirectional Kevlar 29 / epoxy laminate, Vf ≈ 60 % | Use where axial tensile stiffness and impact/energy absorption matter and compressive load is low (pressure-vessel overwrap, panels, radomes). | — | 1,350 | 2 | — |
Braided/twisted K29 rope and sling cordage | Pick for low-stretch, non-conductive lifting slings, mooring and tow lines where creep and UV exposure are controlled. | — | 1,800 | 3 | — |
Highly fibrillated aramid pulp | Asbestos-replacement thickener/reinforcement for brake pads, clutch facings, gaskets, sealants and drilling fluids. | — | 2,900 | 3.6 | — |
Kevlar 29 AP | Pick when ~15 % more break strength per denier is needed in the same K29 modulus class (ropes, slings, thinner ballistic packs). | — | 3,400 | 3.6 | — |
What is Kevlar 29 FAB-EP?
Kevlar 29 FAB-EP is Kevlar 29 in the FAB-EP condition — balanced quasi-isotropic panels — canoe hulls, protective shells, drone and motorsport bodywork with damage tolerance. Kevlar 29 FAB-EP has a tensile strength of 500 MPa (72.5 ksi), stronger than 66% of composite grades. Elongation at break is 2.2% and the elastic modulus is 28 GPa (4.06 Msi). Kevlar 29 FAB-EP has a density of 1.35 g/cm³ (0.0488 lb/in³), lighter than 75% of composite grades. Its glass-transition temperature is 360°C (680 °F).
Advantages
- Lightweight — 1.35 g/cm³ (0.0488 lb/in³), better than 75% of composite grades
Limitations
- Degrades in UV without stabilisers — 20/100, worse than 94% of composite grades
- Absorbs moisture — dry before molding — 4%, worse than 93% of composite grades
- Poor heat conductor — 0.04 W/m·K (0.0231 BTU/hr·ft·°F), worse than 91% of composite grades
- Hard to polish — 20/100, worse than 90% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
Kevlar 29 FAB-EP properties
Typical room-temperature values for Kevlar 29 FAB-EP; 10 are specific to this condition. Other listed values are Kevlar 29 reference data and may not represent this condition. Bars are the position among composite grades.
Physical4
Kevlar 29 FAB-EP has a density of 1.35 g/cm³ (0.0488 lb/in³), lighter than 75% of composite grades. Its glass-transition temperature is 360°C (680 °F).
Mechanical6
Kevlar 29 FAB-EP has a tensile strength of 500 MPa (72.5 ksi), stronger than 66% of composite grades. Elongation at break is 2.2% and the elastic modulus is 28 GPa (4.06 Msi).
Thermal8
Kevlar 29 FAB-EP is rated for continuous service to 120°C (248 °F). It conducts heat at 0.04 W/m·K (0.0231 BTU/hr·ft·°F), worse than 91% of composite grades. Thermal expansion is -2 µm/m·K (-1.11 µin/in·°F).
Electrical4
Kevlar 29 FAB-EP has an electrical resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (65/100), worse than 72% of composite grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Kevlar 29 FAB-EP takes about 270 MJ of energy and emits 13 kg of CO₂ — more than 60% of composite grades. Typical recycled content is 0%.
Manufacturability2
Kevlar 29 FAB-EP's machinability is poor (25/100, worse than 65% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Kevlar 29 FAB-EP
Is Kevlar 29 easy to machine?
Cut with sharp serrated/shear scissors, hot knife or waterjet; drilling and routing of laminates need special aramid (C-type/brad-point) tooling, backing plates and high rake angles to avoid fuzzing and delamination.
Can Kevlar 29 be welded?
Not weldable or fusible — the fibre decomposes near 500 °C without melting; joints are made by stitching, braiding, splicing or adhesive/resin bonding.
Can Kevlar 29 be formed, bent or molded?
Processed as textile (weaving, braiding, filament winding) or as prepreg/RTM laminate; dry the fibre before impregnation (moisture regain ~4–7 %) and keep cure below ~180 °C for standard epoxies.
What surface finishes work on Kevlar 29?
Edges should be resin-sealed or bound to stop fraying; laminates must be painted, gel-coated or fabric-covered because unprotected aramid loses strength rapidly in sunlight.
Kevlar 29 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) unitmonomer share of the repeat unit (mol basis) | ≈ 45 | 45 |
| terephthaloyl chloride (TCl) unitmonomer share of the repeat unit (mol basis) | ≈ 55 | 55 |
| spin finish / sizingtextile or RFL-compatible finish depending on end use | 0.1 – 0.8 | 0.4 |
| poly(p-phenylene terephthalamide) (PPTA)condensation polymer of p-phenylenediamine + terephthaloyl chloride, liquid-crystal spun from sulfuric acid | balance | — |
Kevlar 29 FAB-EP — frequently asked
What is Kevlar 29 FAB-EP used for?
Kevlar 29 FAB-EP is typically used for ballistic vests, ropes and cables, protective fabrics, tire reinforcement and friction materials. In short: baseline industrial para-aramid; highest-toughness aramid grade; rope and ballistic workhorse.
What is the tensile strength of Kevlar 29 FAB-EP?
Kevlar 29 FAB-EP has a typical tensile strength of 500 MPa (72.5 ksi) — stronger than 66% of composite grades. Strength varies by condition: see the 5 listed tempers.
Is Kevlar 29 FAB-EP easy to machine?
Not especially — machinability is rated poor (25/100, worse than 65% of composite grades). Cut with sharp serrated/shear scissors, hot knife or waterjet; drilling and routing of laminates need special aramid (C-type/brad-point) tooling, backing plates and high rake angles to avoid fuzzing and delamination.
Can Kevlar 29 FAB-EP be welded?
Not weldable or fusible — the fibre decomposes near 500 °C without melting; joints are made by stitching, braiding, splicing or adhesive/resin bonding.
What surface finishes work on Kevlar 29 FAB-EP?
Edges should be resin-sealed or bound to stop fraying; laminates must be painted, gel-coated or fabric-covered because unprotected aramid loses strength rapidly in sunlight.
Can Kevlar 29 FAB-EP be formed, bent or molded?
Processed as textile (weaving, braiding, filament winding) or as prepreg/RTM laminate; dry the fibre before impregnation (moisture regain ~4–7 %) and keep cure below ~180 °C for standard epoxies.
What is the maximum service temperature of Kevlar 29 FAB-EP?
Kevlar 29 FAB-EP is rated for continuous use to about 120°C (248 °F), and briefly to 250°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Kevlar Aramid Fiber Technical Guide (H-77848) — DuPont (2017)
- ASM Handbook Vol. 21 — Composites — ASM International (2001)
- ASTM D7269 — Tensile Testing of Aramid Yarns — ASTM International (2020)
- Granta/CES EduPack — Aramid fibre and aramid/epoxy composite records — Ansys Granta (2023)
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.