Combustion Characteristics Of Webbing

Nylon Webbing: Melts and shrinks near the flame; melts, burns, drips, and bubbles; does not continue to burn directly; smells like celery; residue is hard, round, lightweight, and ranges from brown to gray (bead-like).

Polyester Webbing: Melts and shrinks near the flame; melts, burns, drips, and bubbles; continues to burn (with occasional smoke); faint sweet odor; residue is hard, round, and black or light brown.

Polyester (polyethylene terephthalate fiber) is easily ignited and melts/shrinks near the flame. During combustion, it melts while emitting black smoke and a yellow flame, releasing an aromatic odor; the residue forms hard, black-brown lumps that can be crushed between the fingers.

Polypropylene fiber melts and shrinks near the flame and is highly flammable. After removal from the flame, it burns slowly, emitting black smoke; the flame is yellow at the top and blue at the base, releasing a petroleum-like odor; the residue consists of hard, round, light yellowish-brown granules that are easily crushed by hand.

PVC fiber (polyvinyl chloride) is difficult to ignite and self-extinguishes upon removal from the flame. The flame is yellow with a green base and emits white smoke; it releases a pungent, acrid, acidic odor; the residue forms hard, irregular black-brown lumps that cannot be easily crushed between the fingers.

The burning test is a simple and convenient method for fiber identification, though it is difficult to assess blended products. To identify them, one must extract a yarn from each of the warp and weft directions (i.e., the longitudinal and transverse directions) and burn them separately.