Blending modacrylic with rayon fibers results in significant increases in LOI values and on ignition, a char is formed, creating a flame barrier |
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LOI (Limited Oxygen Index) represents the minimum oxygen concentration of an
O2 ÷ N2 gas mixture required to sustain combustion of a given material.
The materials with higher LOI values are more flame retardant. LOI is determined by ASTM D 2863-77 being expressed as:
(O2 ÷ (O2 + N2)) x 100 |