Frequently asked questions about SCHÜMER SECAN®
Here, we answer the most common and important questions customers ask us about our SCHÜMER SECAN® products. We hope to give you a good impression of these flammable fabrics, and their advantages and possibilities. Transparency is very important to us. For our customers, we are a company that responds to requests and suggestions. If you have any further questions that are not addressed here, please contact us directly.
How does cotton become SCHÜMER SECAN®?
In a multi-stage refining process, a cross-linked polymer is built up inside the cotton fibre from a phosphorus-nitrogen compound. The cotton retains its natural properties such as a high level of comfort, since no chemical reaction takes place with the fibre. A high level of comfort of the protective clothing is therefore ensured. For many workers who need to wear their personal protective equipment for hours on end, this is a real relief
Is post-impregnation after washing required?
Since the polymer fixed in the fibre by the special SCHÜMER SECAN® process is not dissolved in the wash or by dry cleaning, if the washing and care instructions are followed, post-impregnation is not necessary at all. This is one of the user-friendly advantages that distinguishes SCHÜMER SECAN®.
How long does the flame retardant effect last?
The flame-retardant effect is permanent and resistant to washing or cleaning. As part of the SCHÜMER SECAN® control system, 1 metre of each piece of fabric (length max. 120 meters) undergoes 40, 50 or 60 industrial scrubbing sessions before the burn test, depending on customer requirements. This corresponds to the expected life of the clothing. This does not mean that the fabric will burn after the specified number of washing cycles. However, the protective effect may be impaired by extreme contamination with flammable substances or failure to observe the washing and care instructions.
How does SCHÜMER SECAN® work?
When exposed to flames or heat, the fabric decomposes. It produces gases, carbon and water. This thermal decomposition is called pyrolysis. Cotton produces a carbon layer which is skin-friendly, and is neither combustible, shrinking nor melting. This heat-destroying reaction is called dehydration. This used energy is no longer a danger for people.
The forming carbon layer has – like graphite – an excellent insulation effect, which goes far beyond that of the undamaged fabric. The aim of the flame retardant property is that dehydration takes place earlier and faster than pyrolysis.
How does the material affect the wearability of the fabric?
The SCHÜMER SECAN® process is neither an impregnation nor a coating. As a result, the cotton retains its natural physiological properties. It is kind to the skin and creates a pleasant microclimate on the skin. The ability to absorb body sweat in large quantities, store it and release it over time to the environment, increases the comfort. The clothes feel dry and pleasant on the skin for a very long time. This ensures that the protective clothing is actually worn by the end user and not left in the closet due to discomfort.
What does charring and holes in the fabric mean?
Charring is part of the protective function. Carbon withstands the combustion process. It is expressly a conversion product and not a combustion residue. The carbon layer is stable as long as it is warm. Only after cooling does it become brittle. By breaking up, the heat energy that has penetrated can escape to the outside. Subsequent hole formation therefore does not indicate a failure of flame retardancy. In other words: The fabric has just served as protection in the places where holes are later seen. A little strange, but true.
What is charring, what is burning?
Burning: An exothermic reaction (energy/heat output) with flames of the fabric with oxygen. Heating from outside first evaporates the water in the fabric. Thereafter, after further heating, thermal decomposition begins. The external appearance (for example, flames) is referred to as fire.
Charring: Conversion to carbon with the release of water, no flame (SCHÜMER SECAN®).
Glimmer (smouldering fire): Incomplete combustion of material in a solid state without flames at low combustion temperature and insufficient oxygen supply.
Glowing: Visible radiation that emits heated bodies (e.g. incandescent lamps) produced without combustion.
How does the SCHÜMER SECAN® control system work?
The SCHÜMER SECAN® control system is extremely strict and is a guarantee for our success. Every 100 to 120 production metres, we take a sample to send to an independent testing laboratory. They wash the fabric samples at least 40 times at 95°C and subject them to a burn test. Approval and issuance of a test certificate is only valid for fabric that has passed the test. The whole control process goes far beyond EU standards.
What happens during a burn test?
In the burn test, which is a destructive material test, the fabric sample is exposed to gas flames with a heat of up to 1050°C. The norm is about 830°C. In addition, the Schümer burn test uses larger flame heights, shorter burning time, oxygenation and edge burning at the open fabric edge compared to standardised tests, to match authentic conditions that may occur in everyday work situations.
Can I test a fabric sample myself?
Of course. You can request our “burn test” completely free of charge and without obligation. We will send you a fabric sample (SCHÜMER SECAN®), which comes from a protective suit after 50 wear and washing cycles and which was used in the steel industry. You can light this sample carefully as a self-experiment.