Kevlar 49 PREPREG-EP
Matrix
Pick for autoclave/oven-cured aerospace and sporting-goods laminates needing repeatable fiber volume and resin content.
Values for the PREPREG-EP condition
Other Kevlar 49 grades and fills
Kevlar 49 is listed in 5 conditions; see the grade overview at Kevlar 49.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Woven fabric / epoxy laminate, Vf ≈ 50 % | Design values for quasi-isotropic hand-layup or infused panels (hulls, radomes, impact skins). | — | 480 | 1.9 | — |
Kevlar 49 / carbon hybrid fabric laminate | Pick when carbon stiffness/compression must be combined with aramid impact and splinter containment. | — | 620 | 1.4 | 88 Shore D |
PREPREG-EPThis page Epoxy prepreg (UD or woven, 120–180 °C cure) | Pick for autoclave/oven-cured aerospace and sporting-goods laminates needing repeatable fiber volume and resin content. | — | 1,350 | 1.8 | 86 Shore D |
Unidirectional Kevlar 49 / epoxy laminate, Vf ≈ 60 % | Design values for 0° dominated tension-critical structures (pressure vessels, tension members). | — | 1,380 | 1.8 | — |
Chopped fiber (3–12 mm) for compounds and friction materials | Pick for thermoplastic/thermoset compounding, brake and gasket materials, and asbestos replacement. | — | 3,000 | 2.4 | — |
What is Kevlar 49 PREPREG-EP?
Kevlar 49 PREPREG-EP is Kevlar 49 in the PREPREG-EP condition — pick for autoclave/oven-cured aerospace and sporting-goods laminates needing repeatable fiber volume and resin content. Kevlar 49 PREPREG-EP has a tensile strength of 1,350 MPa (196 ksi), stronger than 73% of composite grades. Elongation at break is 1.8% and the elastic modulus is 75 GPa (10.9 Msi). Kevlar 49 PREPREG-EP has a density of 1.37 g/cm³ (0.0495 lb/in³), lighter than 67% of composite grades. Its glass-transition temperature is 360°C (680 °F).
Limitations
- Degrades in UV without stabilisers — 20/100, worse than 94% of composite grades
- Poor heat conductor — 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 79% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
- Difficult to machine — 20/100, worse than 77% of composite grades
Kevlar 49 PREPREG-EP properties
Typical room-temperature values for Kevlar 49 PREPREG-EP; 18 are specific to this condition. Other listed values are Kevlar 49 reference data and may not represent this condition. Bars are the position among composite grades.
Physical3
Kevlar 49 PREPREG-EP has a density of 1.37 g/cm³ (0.0495 lb/in³), lighter than 67% of composite grades. Its glass-transition temperature is 360°C (680 °F).
Mechanical5
Kevlar 49 PREPREG-EP has a tensile strength of 1,350 MPa (196 ksi), stronger than 73% of composite grades. Elongation at break is 1.8% and the elastic modulus is 75 GPa (10.9 Msi).
Thermal8
Kevlar 49 PREPREG-EP is rated for continuous service to 120°C (248 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 79% of composite grades. Thermal expansion is -2 µm/m·K (-1.11 µin/in·°F).
Electrical4
Kevlar 49 PREPREG-EP has an electrical resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (75/100), worse than 55% of composite grades. UV resistance is poor.
Sustainability3
Producing a kilogram of Kevlar 49 PREPREG-EP takes about 280 MJ of energy and emits 17 kg of CO₂ — more than 63% of composite grades. Typical recycled content is 0%.
Manufacturability1
Kevlar 49 PREPREG-EP's machinability is poor (20/100, worse than 77% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Kevlar 49 PREPREG-EP
Is Kevlar 49 easy to machine?
Cut with serrated/shear scissors, hot knife or abrasive waterjet; drilling needs brad-point or dagger drills with backing to stop fuzzing and delamination — carbide tools dull quickly.
Can Kevlar 49 be welded?
Not weldable; join by adhesive bonding, co-cured resin joints or mechanical fasteners with bushings to avoid fiber crushing.
Can Kevlar 49 be formed, bent or molded?
Excellent drape for hand layup, RTM/infusion, braiding and filament winding; dry the fiber (~4 h at 100–120 °C) before impregnation and use low-viscosity resin plus vacuum to fully wet the yarns.
What surface finishes work on Kevlar 49?
Seal all cut edges with resin to block moisture wicking; sanding leaves fuzz, so use peel-ply for bond surfaces and pigmented/UV-blocking topcoats or gelcoat for outdoor exposure.
Kevlar 49 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) monomer unitas-polymerized mole basis | ≈ 45 | 45 |
| terephthaloyl chloride (TCl) monomer unias-polymerized mole basis | ≈ 55 | 55 |
| surface finish / sizingform-dependent (weaving, epoxy-compatible or none) | 0 – 1 | 0.3 |
| poly(p-phenylene terephthalamide) (PPTA)condensation polymer of p-phenylenediamine and terephthaloyl chloride; ~0.1–1 % surface finish/sizing depending on form | balance | — |
Kevlar 49 PREPREG-EP — frequently asked
What is Kevlar 49 PREPREG-EP used for?
Kevlar 49 PREPREG-EP is typically used for aerospace composite panels, boat hulls, pressure vessels, sporting goods and armor laminates. In short: standard structural aramid fiber; best impact-to-weight laminate; poor compressive strength.
What is the tensile strength of Kevlar 49 PREPREG-EP?
Kevlar 49 PREPREG-EP has a typical tensile strength of 1,350 MPa (196 ksi) — stronger than 73% of composite grades. Strength varies by condition: see the 5 listed tempers.
Is Kevlar 49 PREPREG-EP easy to machine?
Not especially — machinability is rated poor (20/100, worse than 77% of composite grades). Cut with serrated/shear scissors, hot knife or abrasive waterjet; drilling needs brad-point or dagger drills with backing to stop fuzzing and delamination — carbide tools dull quickly.
Can Kevlar 49 PREPREG-EP be welded?
Not weldable; join by adhesive bonding, co-cured resin joints or mechanical fasteners with bushings to avoid fiber crushing.
What surface finishes work on Kevlar 49 PREPREG-EP?
Seal all cut edges with resin to block moisture wicking; sanding leaves fuzz, so use peel-ply for bond surfaces and pigmented/UV-blocking topcoats or gelcoat for outdoor exposure.
Can Kevlar 49 PREPREG-EP be formed, bent or molded?
Excellent drape for hand layup, RTM/infusion, braiding and filament winding; dry the fiber (~4 h at 100–120 °C) before impregnation and use low-viscosity resin plus vacuum to fully wet the yarns.
What is the maximum service temperature of Kevlar 49 PREPREG-EP?
Kevlar 49 PREPREG-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 (Kevlar 49 properties) — DuPont (2017)
- ASM Handbook Vol. 21: Composites — ASM International (2001)
- CMH-17 (MIL-HDBK-17) Composite Materials Handbook, Vol. 3 Polymer Matrix Composites — SAE International / CMH-17 (2012)
- ASTM D7269 – Tensile Testing of Aramid Yarns — ASTM (2017)
- CES/Granta EduPack eco and mechanical data, aramid fiber & KFRP 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.