Stage 1 — Raw material
Burn Test — Cotton (CO)
What you see in the film
A cotton thread is held into the flame. It catches fire immediately and burns away quickly.
What you learn from it
Cotton does not melt. It burns like paper, smells like burning paper and leaves soft grey ash.
What you can say to a customer
“If it burns to ash, it is a natural fibre. Cotton is soft and easy to sew, but it has less strength than polyester.”
Burn Test — Polyester (PES)
What you see in the film
The thread pulls back from the flame, melts, burns with dark smoke and forms a hard bead at the end.
What you learn from it
Polyester melts before it burns. The hard, round, dark bead is its clearest sign.
What you can say to a customer
“Polyester melts. That is why needle heat matters at high speed – and why it gives you the best mix of strength, UV resistance and price.”
Burn Test — Polyamide (PA)
What you see in the film
The thread shrinks away, melts and burns with a small bluish flame. A hard, light-coloured bead remains.
What you learn from it
Polyamide also melts. Flame colour, smell and the lighter bead separate it from polyester.
What you can say to a customer
“Polyamide stretches more and takes more abrasion than polyester. That is why it is the classic choice for shoes and leather goods.”
Burn Test — Polypropylene (PP)
What you see in the film
The thread melts very fast and burns with an almost colourless flame. The smell is waxy.
What you learn from it
Polypropylene is the lightest of all common fibres – it even floats on water.
What you can say to a customer
“PP is the lightest material. The same weight of thread gives you more metres on the machine.”
Burn Test — Polyethylene (PE)
What you see in the film
The thread melts and drips like a candle. The smell is clearly waxy, the residue hard and light.
What you learn from it
Polyethylene has the lowest melting point in this group. It softens earlier than PES and PA.
What you can say to a customer
“Before we choose PE, let us check your washing, ironing and process temperatures. That is where its limit is.”
Burn Test — Para-Aramid (Kevlar)
What you see in the film
The thread does not melt. It turns black in the flame and stops burning as soon as the flame is taken away.
What you learn from it
Para-aramid chars instead of melting and is self-extinguishing. It also has very high tensile strength.
What you can say to a customer
“This thread does not melt and does not drip. That is exactly what you need where heat and high load come together.”
Burn Test — Meta-Aramid (Nomex)
What you see in the film
The thread chars and swells slightly. It does not melt and goes out by itself.
What you learn from it
Meta-aramid is the softer, more flexible aramid. Its strength is lower than para-aramid, its wearing comfort higher.
What you can say to a customer
“Same fibre family, different job: Nomex for flame protection and comfort, Kevlar for maximum strength.”
Burn Test — PTFE
What you see in the film
The thread does not burn. Nothing melts, nothing drips, the thread stays as it is.
What you learn from it
PTFE is chemically almost inert and highly resistant to UV, weather and aggressive media.
What you can say to a customer
“PTFE costs more, but the seam outlasts the fabric – outdoors, under UV and in contact with chemicals.”
Burn Test — PEEK
What you see in the film
The thread hardly reacts. It chars in the flame and stops burning by itself.
What you learn from it
PEEK is a high-performance plastic with a very high melting point, high strength and high chemical resistance.
What you can say to a customer
“PEEK is the answer when high strength and high temperature come together in one technical application.”
Burn Test — Basalt
What you see in the film
Nothing happens. The thread stays intact in the flame – no bead, no ash, no smoke.
What you learn from it
Basalt is a mineral fibre made from rock. It is non-combustible by nature.
What you can say to a customer
“If nothing at all happens in the flame, you are holding a mineral fibre. That is the reference for real non-combustibility.”
Solubility Test — The Second Method
What you see in the film
A thread sample is put into a solvent in a petri dish. Some fibres dissolve, some swell, some stay unchanged.
What you learn from it
The solubility test is a second, independent way to identify a fibre. It confirms what the burn test suggested.
What you can say to a customer
“The burn test narrows it down, the solubility test confirms it. Two results that agree are something you can put in writing.”