Twaron · matrix
Twaron UD-LFT
Properties of the UD-LFT condition, compared with the other Twaron grades.
0/90 cross-plied unidirectional aramid in a thermoplastic/rubber-modified matrix for hard armour panels and helmets.
What is Twaron UD-LFT?
Twaron UD-LFT is Twaron in the UD-LFT condition — 0/90 cross-plied unidirectional aramid in a thermoplastic/rubber-modified matrix for hard armour panels and helmets. Twaron UD-LFT has a tensile strength of 900 MPa (131 ksi), stronger than 70% of composite grades. Elongation at break is 3% and the elastic modulus is 35 GPa (5.08 Msi). Twaron UD-LFT has a density of 1.28 g/cm³ (0.0462 lb/in³), lighter than 79% of composite grades. Its glass-transition temperature is 340°C (644 °F). 1000 is the default condition FabDigit quotes; UD-LFT is available on request or by drawing note.
Advantages
- Lightweight — 1.28 g/cm³ (0.0462 lb/in³), better than 79% of composite grades
- Ductile — tolerates forming and impact — 3%, better than 75% 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
- Limited service temperature — 90°C (194 °F), worse than 93% of composite grades
- Poor heat conductor — 0.05 W/m·K (0.0289 BTU/hr·ft·°F), worse than 87% of composite grades
Twaron UD-LFT properties
Typical room-temperature values for Twaron UD-LFT — 5 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 UD-LFT has a density of 1.28 g/cm³ (0.0462 lb/in³), lighter than 79% of composite grades. Its glass-transition temperature is 340°C (644 °F).
Mechanical6
Twaron UD-LFT has a tensile strength of 900 MPa (131 ksi), stronger than 70% of composite grades. Elongation at break is 3% and the elastic modulus is 35 GPa (5.08 Msi).
Thermal8
Twaron UD-LFT is rated for continuous service to 90°C (194 °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).
Electrical3
Twaron UD-LFT has an electrical 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.
Sustainability4
Producing a kilogram of Twaron UD-LFT takes about 280 MJ of energy and emits 16 kg of CO₂ — more than 62% of composite grades. Typical recycled content is 0%.
Manufacturability1
Twaron UD-LFT's machinability is poor (25/100, worse than 65% of composite grades).
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
- UD-LFT0/90 cross-plied unidirectional aramid in a thermoplastic/rubber-modified matrix for hard armour panels and helmets.900 MPa tensile
Working with Twaron UD-LFT
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 UD-LFT — frequently asked
What is Twaron UD-LFT used for?
Twaron UD-LFT 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 UD-LFT?
Twaron UD-LFT has a typical tensile strength of 900 MPa (131 ksi) — stronger than 70% of composite grades. Strength varies by condition: see the 10 listed tempers.
Is Twaron UD-LFT 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 UD-LFT 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 UD-LFT?
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 UD-LFT 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 UD-LFT?
Twaron UD-LFT is rated for continuous use to about 90°C (194 °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.