PBO

ZYLON® HM 545 321

Toyobo ? High Modulus

Manufacturer page / TDS

Description

PBO fiber with exceptionally high tensile properties. Protection from prolonged UV and humid/thermal exposure is required.

Comparative overview

PBO fiber — High-modulus PBO

Strengths: Among the highest tensile strength/modulus organic fibers, with excellent flame resistance and low creep.

When to use: Select for premium ballistic systems, heat-resistant reinforcement, high-load cables and weight-critical structures when maximum organic-fiber performance is justified.

Key tradeoffs: Very high cost and demanding durability management: UV, moisture and handling can reduce long-term performance.

Qualitative ratings (1–10 scale)

Relative cost10/10 — Very high — very high-cost specialty polymer, limited suppliers and demanding spinning/post-treatment.
EM transparency9/10 — Excellent — organic dielectric fiber with good EM transparency.
Temperature / fire resistance8/10 — Very high — decomposition around 650°C and very high LOI; among the best organic fibers for heat/flame.
Impact / penetration resistance8/10 — Very high — exceptional strength but HM grade's lower elongation reduces energy absorption versus high-strength PBO/aramid/UHMWPE. Stored TDS elongation: 2.5%.
Electrical / thermal conductivity1/10 — Very low — electrically insulating with low thermal transport.
Specific tensile strength10/10 — 10/10 | 3717.9 kN·m/kg | Product TDS
Atmospheric durability3/10 — Low — excellent dry mechanical properties but significant sensitivity to UV and moisture/hydrolytic ageing; strict environmental protection is required.
Sustainability (CO₂e)5/10 — 15.00 kg CO₂e/kg fiber — High emissions — data quality: Low

Technical properties

Tensile strength5800.0 MPa
Tensile modulus270.0 GPa
Density1.56 g/cm³

Applications and processing

Ballisticsheat-resistant reinforcementhigh-load cables and specialty compositesheat-resistant textiles and compositesHigh-performance ropesprotective products

Other grades from Toyobo