Fiberglass Ducting - Fire Resistant Phenolic Resin

Schauenburg fiberglass ducting is manufactured using phenolic resins. One of the main attractions of phenolic materials is its fire performance. The table below shows some typical fire test results for phenolic/glass composites and compares these to polyurethane and polyester.

 

Fire Properties of Phenolic/Glass Composites Compared with Polyurethane and Polyester

Property	Phenolic	Polyester	Rigid Polyurethane
ASTM D229 - Oxygen Index	45-55*	40	20-25
ASTM D229 - Rate of burning	Does not ignite	-	-
BS 476 PT.7 - Spread of Flame	Class 1 (Zero Spread)	Class 1	Class 1 – Class 4
Toxicity of combustion products	Very low	Toxic	Toxic
Smoke	Virtually NIL	Very high	Very high
* Catalyst Dependent

When phenolic resin fiberglass ducting is exposed to fire they char on the surface which further protects the underlying layers from the heat source. In extreme conditions when fire does destroy the product only gasses of Carbon, Hydrogen and Oxygen are produced. This in essence means that the phenolic will and can only finally break down to form Carbon Dioxide, Water and Carbon Monoxide. These gasses will result from any form of combustion. A most significant factor is also the very low levels of visible smoke produced. See test results.


Phenolam Laminate Test Results

Test – Flammability	ASTM Test	Results
NBS Smoke Chamber	E-622
D16		>5 min.
Dmax		42
Radiant Panel Test	E-162	6.7
Tunnel Test	E-84
FS1		19
Smoke		12
Limiting Oxygen Index	D2863	67
Thermal
Heat Deflection @ 264 psi	D-648	>570°F
Linear Thermal Expansion		2.93 x 10.5 m/in. °F
Specific Heat @ 50°C		0.3 cal/ g°F

The physical properties of phenolic fiber reinforced composites are retained to at least 200°C at which temperature other matrix resins have generally degraded substantially. The inherent fire properties of phenolic resins composites are excellent having the highest fire rating in all test methods, extremely low smoke emission and virtually no toxic combustion products. E.M.R. Flame Certificate Number 395.


Fire Retardency and Flammability Video