PBI Fiber (Celazole)
also Celazole
PBI Fiber (Celazole) is a polybenzimidazole organic fiber that chars rather than melts, supplied as staple, filament, felt and pre-blended forms such as the 40/60 PBI/para-aramid Gold yarn.
Reference datasheet — PBI Fiber (Celazole) is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PBI Fiber (Celazole) grades and fills
PBI Fiber (Celazole) is supplied in 6 conditions, soft to hard.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
PBI needle-punched felt / blended filter media | Nonwoven form for hot-gas filtration, aluminium-casting contact rolls and thermal insulation batts above 250 °C. | 12 | 35 | ||
PBI continuous filament yarn | Continuous filament form for woven high-temperature tapes, sewing thread and reinforcement scrims. | 380 | 25 | ||
three-fiber PBI/aramid blend, cost-optimised outer shell | Entry-level PBI-containing turnout shell where budget matters and full PBI Gold performance is not required. | 1,000 | 9 | ||
PBI-rich blend for maximum thermal protective performance | Higher PBI fraction than PBI Gold; pick for the highest char integrity and lowest shrinkage in flashover exposure. | 1,100 | 10 | ||
PBI Gold | Classic firefighter turnout outer-shell blend: PBI supplies char stability and no shrink, para-aramid supplies tear and tensile strength. | 1,300 | 8 | ||
PBI/para-aramid blend with high-tenacity aramid ripstop grid | Choose when a lighter outer shell with much higher tear strength is required for structural firefighting gear. | 1,500 | 7 |
Supply forms, finishes and certifications
Ways PBI Fiber (Celazole) is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PBI-100-STAPLEDefault | 100% PBI staple fiber | Supply form |
What is PBI Fiber (Celazole)?
PBI Fiber (Celazole) is a polybenzimidazole organic fiber that chars rather than melts, supplied as staple, filament, felt and pre-blended forms such as the 40/60 PBI/para-aramid Gold yarn. It is chosen where para-aramid begins to decompose: density 1.43 g/cm³, tensile strength 340 MPa, elongation 28%, elastic modulus 5.6 GPa and a maximum service temperature of 300 °C, with no melt-drip or shrink-open behaviour in flame. Cost is high and the modulus is low, so it serves as a protective textile rather than a structural reinforcement; para-aramid is the lower-cost alternative where 300 °C exposure is not required. PBI Fiber (Celazole) has a density of 1.43 g/cm³ (0.0517 lb/in³), lighter than 63% of composite grades. Its glass-transition temperature is 427°C (801 °F). PBI Fiber (Celazole) has a tensile strength of 340 MPa (49.3 ksi), stronger than 61% of composite grades. Elongation at break is 28% and the elastic modulus is 5.6 GPa (0.812 Msi).
What is PBI Fiber (Celazole) used for?
- firefighter turnout gear
- aerospace fire-blocking layers
- high-temperature protective clothing
Advantages
- Ductile — tolerates forming and impact — 28%, better than 99% of composite grades
Limitations
- Absorbs moisture — dry before molding — 13%, worse than 100% of composite grades
- Low stiffness — 5.6 GPa (0.812 Msi), worse than 79% of composite grades
- High embodied carbon — 28 kg CO₂/kg, worse than 76% of composite grades
PBI Fiber (Celazole) properties
Typical room-temperature values; bars are the position among composite grades.
Physical4
PBI Fiber (Celazole) has a density of 1.43 g/cm³ (0.0517 lb/in³), lighter than 63% of composite grades. Its glass-transition temperature is 427°C (801 °F).
Mechanical3
PBI Fiber (Celazole) has a tensile strength of 340 MPa (49.3 ksi), stronger than 61% of composite grades. Elongation at break is 28% and the elastic modulus is 5.6 GPa (0.812 Msi).
Thermal8
PBI Fiber (Celazole) is rated for continuous service to 300°C (572 °F). It conducts heat at 0.41 W/m·K (0.237 BTU/hr·ft·°F), better than 55% of composite grades. Thermal expansion is 23 µm/m·K (12.8 µin/in·°F).
Electrical3
PBI Fiber (Celazole) has an electrical resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
UV resistance is poor.
Sustainability3
Producing a kilogram of PBI Fiber (Celazole) takes about 450 MJ of energy and emits 28 kg of CO₂ — more than 79% of composite grades. Typical recycled content is 0%.
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. PBI Fiber (Celazole) is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PBI Fiber (Celazole)
Is PBI Fiber (Celazole) easy to machine?
Not machined as a fiber; cut with hot knife or ultrasonic cutter, dry-cut felts blunt steel blades quickly.
Can PBI Fiber (Celazole) be welded?
Not weldable — PBI does not melt; joins are sewn (PBI or aramid thread) or mechanically clamped.
Can PBI Fiber (Celazole) be formed, bent or molded?
Processed on conventional cotton/aramid staple spinning and needle-punch lines; blend with para-aramid to raise yarn strength and reduce cost.
PBI Fiber (Celazole) 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 |
|---|---|---|
| spin finish / processing lubricantremovable surface finish on staple and filament | 0.2 – 1 | 0.5 |
| poly[2,2'-(m-phenylene)-5,5'-bibenzimidacondensation product of 3,3'-diaminobenzidine and diphenyl isophthalate; fiber is sulfonation-stabilised | ≥ 99 (balance) |
What surface finishes work on PBI Fiber (Celazole)?
Natural gold colour is inherent and essentially undyeable by conventional means; scour to remove spin finish and pre-shrink at 250–300 °C before laminating or coating.
Equivalent designations
Standards and trade names that resolve to PBI Fiber (Celazole) in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Celazole
- Also called
- PBI
How much does PBI Fiber (Celazole) cost?
PBI Fiber (Celazole) is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PBI Fiber (Celazole) — frequently asked
What is PBI Fiber (Celazole) used for?
PBI Fiber (Celazole) is typically used for firefighter turnout gear, aerospace fire-blocking layers and high-temperature protective clothing. In short: highest-temperature organic fiber; non-melting, char-forming; blended with para-aramid.
What is the tensile strength of PBI Fiber (Celazole)?
PBI Fiber (Celazole) has a typical tensile strength of 340 MPa (49.3 ksi) — stronger than 61% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is PBI Fiber (Celazole) easy to machine?
Not machined as a fiber; cut with hot knife or ultrasonic cutter, dry-cut felts blunt steel blades quickly.
Can PBI Fiber (Celazole) be welded?
Not weldable — PBI does not melt; joins are sewn (PBI or aramid thread) or mechanically clamped.
What surface finishes work on PBI Fiber (Celazole)?
Natural gold colour is inherent and essentially undyeable by conventional means; scour to remove spin finish and pre-shrink at 250–300 °C before laminating or coating.
Can PBI Fiber (Celazole) be formed, bent or molded?
Processed on conventional cotton/aramid staple spinning and needle-punch lines; blend with para-aramid to raise yarn strength and reduce cost.
What is the maximum service temperature of PBI Fiber (Celazole)?
PBI Fiber (Celazole) is rated for continuous use to about 300°C (572 °F), and briefly to 500°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PBI Fiber (Celazole) cost?
PBI Fiber (Celazole) is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- PBI Fiber and PBI Gold Fabric Technical Data — PBI Performance Products, Inc. (2023)
- Celazole PBI Polymer Property Data — Celanese / PBI Performance Products (2022)
- Handbook of Fiber Chemistry — High-Performance Fibers — CRC Press (2007)
- Engineered Materials Handbook Vol.2: Engineering Plastics — ASM International (1988)
- NFPA 1971 Standard on Protective Ensembles for Structural Fire Fighting — NFPA (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.