SOUFA was brushed on newspaper, and after drying, it was ignited with an alcohol lamp.
SOUFA gives high flame resistance to cellulose, so it is easy to stop burning. However, SOUFA does burn.
The mechanism of flame retardancy is that SOUFA settles on the cellulose of the pulp and reacts to heat to form a thin glass film on the cotton surface. At the same time, it combines with the carbon of the cotton to form an oxygen-blocking film.
Therefore, once burnt, it does not spread further. The texture of newspaper will be close to crispy. However, it won’t be so crispy that it can be cracked if it’s just a brush coating. In this case, we used 16% density product, but it is thought that even a thinner density product is enough if it is newspaper.
However, if the amount of application is too much, the paper may become hard. This is because boric acid has a property of hardening cellulose a little.