When using Rock Wool or Glass Wool, having a similar appearance, they make such a difference that it resulted in a huge fire in a STENTER machine.

Glass wool is made from a mixture of natural glass whereas Rockwool is made of Volcanic rock. Rockwool can withstand temperatures of up to 1000° C, while fiberglass melts around 600° C.

Both have a good acoustic isolation and are used in silencer's kits in industry.

In this case there are used inside the stenter machine chimney to reduce the noise outside caused by air flow exhausted.

The stenter machine (is a large oven who temperature range is about 200ºC) used on textile industry to make the fabric finishing (thermosetting, drying, crosslink).

In a stage before the oven are applied finishing products as fabric softeners, among others, as well the yarn oil enzymes take a vapor state that is exhausted through the silencers.

Once a year must to be cleaned the oven and the chimney where is accumulate powder soot soaked in oil vapors.

Part of soot is crystalized gas that could ignite violently with high temperatures - causing an explosion.

The local where accumulation is bigger is on silencers (the wool stay drenched in oil and soot).

In one of the changes of the silencers core there was a mistake on acquisition and came glass wool instead of rock wool – the maintenance guys didn’t notice the difference (they are very similar with a little difference in color being the glass less yellowish).

The result about 6 months later was a fire that twisted the chimney and fired part of roof.

After some tests (we imbibed rock wool and glass wool with oil and fire them with a burner):

i)   the glass wool burns continuously and progressively after removing the flame.

ii)  the rock wool turns red while the flame is present but quickly normalize when remove the flame.

In our case the losses were of thousands of euros, but I know that there have been complete losses (thousands of hundreds of euros) in stenters of other companies, namely one close to us.

#textil