The burning test is a traditional method of identifying different types of textile fibers based on their behavior when exposed to a flame. Each fiber type exhibits distinct characteristics during combustion, such as the color of the flame, odor, residue, and whether it melts or continues to burn after the flame is removed. In this guide, we’ll explore how to identify common textile fibers using the burning test.
1. Cotton
- Odor: Smells like burning paper or leaves.
- Flame Color: Yellow.
- Smoke: White.
- Residue: Dark gray ash that is fluffy and easily crushed.
- Burning Speed: Rapid burning with a steady, round flame.
- Melting: Does not melt.
- Additional Notes: Cotton is highly flammable and ignites easily. Once ignited, it burns rapidly and continues to burn even after the flame source is removed.
2. Viscose (Rayon)
- Odor: Smells similar to burning paper or leaves.
- Flame Color: Yellow.
- Smoke: White or light gray smoke.
- Residue: Light gray ash.
- Burning Speed: Rapid burning with a steady, round flame.
- Melting: Does not melt.
- Additional Notes: Viscose catches fire quickly and burns faster than cotton. This rapid burning quality makes it easy to distinguish from fibers that burn more slowly.
3. Wool
- Odor: Smells like burning hair or feathers.
- Flame Color: Orange.
- Smoke: Dark smoke.
- Residue: Coarse, dark ash that is easily crushed.
- Burning Speed: Burns slowly.
- Melting: Does not melt.
- Additional Notes: Wool is naturally flame-resistant and curls away from the flame before igniting. When removed from the fire source, wool stops burning almost immediately. This slow ignition and self-extinguishing behavior make wool distinct among textile fibers.
4. Linen
- Odor: Smells like burning paper or wood.
- Flame Color: Yellow to orange.
- Residue: Similar to cotton.
- Burning Speed: Burns slowly.
- Additional Notes: Linen fibers take longer to ignite than cotton but otherwise exhibit similar characteristics, such as a yellow-to-orange flame and paper-like odor.
5. Silk
- Odor: Smells like burning hair or feathers.
- Flame: Mostly smolders and sizzles, with little visible flame.
- Smoke: Black.
- Residue: Small, dark beads that are soft and easily crushed.
- Burning Speed: Burns slowly, mostly smoldering.
- Melting: Does not melt.
- Additional Notes: Silk does not burn easily. When exposed to a flame, it tends to curl away and is difficult to ignite. Its slow smoldering and hair-like odor make it recognizable.
6. Acetate
- Odor: Smells like vinegar or acetic acid.
- Smoke: Produces dark black smoke.
- Residue: Hard, black beads that cannot be crushed.
- Burning Speed: Burns quickly.
- Melting: Melts and continues melting even after the flame goes out.
- Additional Notes: Acetate burns with a quick, sizzly flame and continues to melt after removal from the flame source, producing hard black beads. Its distinct vinegar-like smell is a key identifying feature.
7. Nylon
- Odor: Smells like celery or has a fishy odor.
- Flame Color: Yellow with a blue base.
- Smoke: Black.
- Residue: Hard, round, grayish or brownish beads.
- Burning Speed: Burns slowly and melts.
- Melting: Melts and forms small bubbles while burning.
- Additional Notes: Nylon shrinks rapidly when exposed to heat, burning slowly with a characteristic blue base and yellow tip in the flame.
8. Polyester
- Odor: Chemical or sweet smell.
- Flame Color: Orange.
- Smoke: Black.
- Residue: Hard, round, black beads.
- Burning Speed: Burns slowly and shrinks.
- Melting: Melts and burns slowly.
- Additional Notes: Polyester emits a chemical odor and forms hard beads upon burning. It shrinks rapidly and burns slowly without producing sparks.
9. Acrylic
- Odor: Acrid, sometimes compared to burning meat or fish.
- Flame Color: White to orange.
- Smoke: Black.
- Residue: Yellow-brown hard crust with an irregular shape.
- Burning Speed: Burns slowly and shrinks.
- Melting: Melts and sputters while burning.
- Additional Notes: Acrylic burns with a whitish-orange flame and tends to sputter, creating a distinctive and unpleasant odor. The hard crusty residue is another clue to its identity.
10. Polypropylene (Olefin)
- Odor: Odor of burning Polypropylene fibres When polypropylene fibers burn, they typically produce a faintly sweet, paraffin-like odor
- Residue: Hard, round bead that may be light brown.
- Burning Speed: Burns and shrinks quickly.
- Melting: Melts.
- Additional Notes: Polypropylene burns and melts quickly, forming hard beads upon cooling. Its lack of a distinct odor and quick shrinkage help differentiate it from other synthetic fibers.
Conclusion
The burning test provides a quick and practical way to identify textile fibers based on their unique combustion characteristics. By observing the flame color, odor, smoke, residue, and melting behavior, you can differentiate between natural, semi-synthetic, and synthetic fibers. This method is particularly useful in scenarios where fiber labeling is absent or ambiguous, allowing for a straightforward approach to textile identification.