1) wool or high-grade wool carpet burns no flame, smoke and sparkling, have to burn the smell of the hair, ash, black brittle block after burn, the pressure is broken.

(2) nylon burning, no flame, celery smell, slightly fused into a jelly, a cold namely cold setting, not easy to crush.

(3) acrylic ignited combustion slower, into brittle black ball after burning.

(4) polypropylene is burned, but issued a yellow flame, and quickly curled, melting, almost no ash.