The Evaluation Method of FR Fabric
2015-07-30 17:01 | writer: admin
In people’s life, there are all kinds of fire hidden danger. In order to reduce the fire accident caused by textile flammable, reduce the harm to people life and property safety, textile flame test get the high attention of the world. The textile treated by FR finishing can be reduce the speed of flaming, or can be stop burning after leave the fire, so the fire retardant is a relative concept.
Most of the textile is flammable, even through treated with flame retardant technology is still difficult to stop the fiber burning in the fire. Aim at the all kinds of usage of textile, the FR laws and regulations setted out by countries in the world have from the plane decoration textile, carpet, building decoration materials expanded to sleepwear, furniture sofa cover, mattress and decoration textile and so on. UK, the United States, Japan and other countries request in law that the clothing of women, children, the aged, the disabled and sleepwear must have FR function, and indicate the function on the products.
To evaluate the flame retardant performance of textile usually takes two standard:
One is determined by the LOI of textile. The burning need oxygen, LOI is the indication of Oxygen volume needed by burning, so by measuring LOI index can judge the FR feature of fabric. The higher of Oxygen index, the higher oxygen concentration needed by burning, which mean it’s very difficult to burn. The index can be indicated by the min volume percentage of oxygen that keep candle shape burning in the nitrogen and oxygen mixed air. Theoretically, as long as the LOI of the textile is more than 21%( The volume of oxygen concentration in natural air ), it can be self-extinguishing, According to the LOI, the textile usually divide into 4 grades, highly flammable (LOI<20%), flammable (LOI＝20%～26%), difficult to flammable(LOI＝26%～34%), non-flammable(LOI>35%). In fact, almost all of common textile material (fiber) are belong to highly flammable or flammable.
The second is evaluated by the burning speed rate of textile. It’s mean that the FR treated fabric contact with the flame in a certain time follow to the specified method, then leave the fire, then test the after burn time and after glow time, and the damage length. the shorter after burn time and after glow time, the less the char length, it mean that the FR performance of the fabric is better. otherwise, the FR performance of the fabric is not good.