Kevlar · matrix · default condition
Kevlar Epoxy Matrix
Properties of the Epoxy Matrix condition, compared with the other Kevlar grades.
Default structural aramid composite: best stiffness/strength and adhesion, for aerospace panels, filament-wound vessels and marine hulls up to ~120 °C.
What is Kevlar Epoxy Matrix?
Kevlar Epoxy Matrix is Kevlar in the Epoxy Matrix condition — default structural aramid composite: best stiffness/strength and adhesion, for aerospace panels, filament-wound vessels and marine hulls up to ~120 °C. Kevlar Epoxy Matrix has a tensile strength of 1,350 MPa (196 ksi), stronger than 72% of composite grades. Elongation at break is 1.8% and the elastic modulus is 76 GPa (11 Msi). Kevlar Epoxy Matrix has a density of 1.38 g/cm³ (0.0499 lb/in³), lighter than 68% of composite grades. Its glass-transition temperature is 135°C (275 °F).
Advantages
- Tough — resists crack growth — 35 MPa·√m (31.9 ksi·√in), better than 93% of composite grades
Limitations
- Degrades in UV without stabilisers — 25/100, worse than 86% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 79% of composite grades
- Difficult to machine — 20/100, worse than 77% of composite grades
Kevlar Epoxy Matrix properties
Typical room-temperature values for Kevlar Epoxy Matrix — 11 properties are specific to this condition; the rest are grade-level values shared by every Kevlar grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.
Physical4
Kevlar Epoxy Matrix has a density of 1.38 g/cm³ (0.0499 lb/in³), lighter than 68% of composite grades. Its glass-transition temperature is 135°C (275 °F).
Mechanical12
Kevlar Epoxy Matrix has a tensile strength of 1,350 MPa (196 ksi), stronger than 72% of composite grades. Elongation at break is 1.8% and the elastic modulus is 76 GPa (11 Msi).
Thermal9
Kevlar Epoxy Matrix is rated for continuous service to 120°C (248 °F). It conducts heat at 0.5 W/m·K (0.289 BTU/hr·ft·°F), better than 54% of composite grades. Thermal expansion is -2 µm/m·K (-1.11 µin/in·°F).
Electrical5
Kevlar Epoxy Matrix is an electrical insulator with a dielectric strength of 18 kV/mm (457.2 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 54% of composite grades. UV resistance is poor.
Sustainability3
Producing a kilogram of Kevlar Epoxy Matrix takes about 250 MJ of energy and emits 14 kg of CO₂ — more than 53% of composite grades. Typical recycled content is 0%.
Manufacturability2
Kevlar Epoxy Matrix's machinability is poor (20/100, worse than 77% of composite grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Kevlar grades and fills
Kevlar is also supplied in 7 other conditions. The full side-by-side table is on the Kevlar overview.
- Epoxy MatrixDefaultDefault structural aramid composite: best stiffness/strength and adhesion, for aerospace panels, filament-wound vessels and marine hulls up to ~120 °C.1,350 MPa tensile
- Vinyl Ester MatrixMarine and corrosion service: cheaper wet-layup/infusion than epoxy, better hydrolysis resistance than polyester, slightly weaker bond to aramid.1,150 MPa tensile
- Woven FabricChoose for balanced 0/90 in-plane properties, drapeable complex shapes, canoe/helmet/panel skins; lower strength than UD due to crimp.520 MPa tensile
- Phenolic MatrixAircraft interiors, ducting and Nomex-type honeycomb faces where FAR 25.853 fire/smoke/toxicity and V-0 rating dominate over strength.450 MPa tensile
- TP MatrixStampable, weldable and re-formable aramid composite for high-rate parts and impact liners; lower stiffness and creep resistance than epoxy.450 MPa tensile
Working with Kevlar Epoxy Matrix
Is Kevlar easy to machine?
Fibers do not cut cleanly — use sharp carbide/PCD shear-angle or serrated 'Kevlar' router bits, back-up plates, or waterjet/laser trimming to avoid fuzzing and delamination.
Can Kevlar be welded?
Thermoset epoxy laminates cannot be welded; join by secondary bonding with film/paste adhesive or bolted joints with bushed holes (thermoplastic-matrix variants can be resistance or ultrasonic welded).
Can Kevlar be formed, bent or molded?
Processed as prepreg autoclave/oven cure (120–180 °C), resin infusion/RTM, wet layup or filament winding; aramid fabric drapes well but must be dried before cure to avoid moisture-induced porosity.
What surface finishes work on Kevlar?
Cut edges must be sealed with resin or edge tape; paint or gel-coat with UV-blocking pigment is essentially mandatory for outdoor service, and surfacing film gives a smooth paintable skin.
Kevlar 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 |
|---|---|---|
| para-aramid fiber (PPTA, poly-p-phenylenfiber volume fraction ≈ 55–62 % for prepreg laminates | 50 – 65 | 60 |
| sizing / finishfiber surface treatment for adhesion | 0.1 – 1 | 0.5 |
| epoxy resin (DGEBA / amine or dicyandiammatrix; substituted by vinyl ester, phenolic or thermoplastic in other variants | ≥ 35 (balance) | — |
Kevlar Epoxy Matrix — frequently asked
What is Kevlar Epoxy Matrix used for?
Kevlar Epoxy Matrix is typically used for body armor, ballistic panels, aerospace interior and secondary structure panels, filament-wound pressure vessel overwraps, boat hulls and impact skins and sports equipment shells. In short: aramid impact laminate.
What is the tensile strength of Kevlar Epoxy Matrix?
Kevlar Epoxy Matrix has a typical tensile strength of 1,350 MPa (196 ksi) — stronger than 72% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is Kevlar Epoxy Matrix easy to machine?
Not especially — machinability is rated poor (20/100, worse than 77% of composite grades). Fibers do not cut cleanly — use sharp carbide/PCD shear-angle or serrated 'Kevlar' router bits, back-up plates, or waterjet/laser trimming to avoid fuzzing and delamination.
Can Kevlar Epoxy Matrix be welded?
Thermoset epoxy laminates cannot be welded; join by secondary bonding with film/paste adhesive or bolted joints with bushed holes (thermoplastic-matrix variants can be resistance or ultrasonic welded).
What surface finishes work on Kevlar Epoxy Matrix?
Cut edges must be sealed with resin or edge tape; paint or gel-coat with UV-blocking pigment is essentially mandatory for outdoor service, and surfacing film gives a smooth paintable skin.
Can Kevlar Epoxy Matrix be formed, bent or molded?
Processed as prepreg autoclave/oven cure (120–180 °C), resin infusion/RTM, wet layup or filament winding; aramid fabric drapes well but must be dried before cure to avoid moisture-induced porosity.
What is the maximum service temperature of Kevlar Epoxy Matrix?
Kevlar Epoxy Matrix is rated for continuous use to about 120°C (248 °F), and briefly to 200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in Kevlar Epoxy Matrix?
Yes — Kevlar Epoxy Matrix is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Kevlar Aramid Fiber Technical Guide — 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)
- Aramid fabric prepreg datasheets — Hexcel / Toray Advanced Composites (2022)
- CES EduPack material data — aramid fiber reinforced epoxy — Granta/Ansys (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.