Fire Retardant finishing 

protecting the fibre from easy firing is know as Fire retardant finish.
Fire retardant finishing
It is a Chemical and property giving finish.

Purpose 


Cotton and Regenerated rayon’s catch fire and causes fire hazards and fire accidents at home particularly while in cooking

Children's cloth are susceptible to this hazard. The men who are working in Fire service Department should wear only this type of ire retarded fabrics to protect catching of fire when they are working.

 It defense for tents, ropes, baggage, parachutes., in industry for uniforms in ammunition factories fabrics given flame retardant finish are used It is therefore necessary to make the fabric Flame proof for many reasons. This finish is also essential for Curtain hangings, Decorative, Furnishing etc.,

Requirement 

The fabric should not adversely affect the fastness property of the dyed material, shade and tone, feel, handle and should not cause any irritation to the skin.
 The finish should be fast to wash, light and laundering.

Process

 (A) Mechanism of Flame proofing is
Reducing the oxygen content of fibre and /or
 Increasing the moisture content of fibre.
(B) Flame proofing car be done by
Precipitating insoluble metallic compound or
 By depositing soluble metallic salts.

Theory and mechanisms of flame retardancy
 1 Coating theory


Flame retardance is due to formation of a layer of a fusible substance which melts and forms a coating thus excluding the air necessary for the propagation of flame. Carbonates and ammonium salts liberates gases like CO2 Nh3 and exclude air

2 Gas theory

The flame retardant decomposes at burning Temperature and evolves non combustible gases which obstruct and dilute the combustible gases. E.g. Mixtures of titanium and antimony oxides.

3 Thermal theory

 Heat supplied from the source is conducted from the fibres very rapidly that the fabric never reaches the temperature of combustion.

4. Chemical theory


 The flame retardants react with cellulose on burning and forms chemicals such as phosphoric and sulphuric acid which are dehydrating agents, these bring about catalytic dehydration of cellulose which on combustion produces mainly carbon and water.




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