15 Jul FRETWORK SMOULDER TRIALS – 3
FRETWORK SMOULDER TRIALS – 3
This time, whilst still searching for a real result, we resorted to a Non CM 23 kgs foam and started with some lightweight cottons with a more common (cheap) construction. We sourced a 150 gsm calico and a 220 gsm cotton canvas that were from the internet re-upholstery market and described as scour only and not FR. The cotton and wool/cotton fillings came from similar sources.
It is worth putting on record that the wool/cotton wadding we sourced has the title “FR” without any test method described. That is a subject for further inquiry!
This time we used some very kindly donated Senior Service cigarettes – the real deal!
The trials composed 2 cottons against standard PES tests and a second set with a generic Polyester velour donated in both with and without FR coating forms.
One final point: testing 3-some with failing smoulder tests is not recommended and certainly not something to try at home!
Well…. we certainly did find some smoulder and alongside it we had a direct comparison of an inherent FR polyester over the same filling. We did have a pass on the Trevira CS sample and as that left the rig virtually unscathed we did an Ignition source 1 on the self-same rig.
It makes a nice picture that may be a shock to those who do not understand these things!
Now that’s what we call smoulder!
The Standard (and thermoplastic) PES meanwhile passes well and the close ups show how the melt back allows air in – so NO SMOULDER.
Obviously we have not waited for Smoke to Flame (StF) transition but that was never our objective. The Tests used in the FFR with the L shaped rig all focus on an examination to detect smoulder or PROGRESSIVE SMOULDER.
It does not recognise that the thermoplastic fabric will NEVER FAIL this test.
It is interesting to compare the IFRM in the standard test polyester with the generic PES velour – both with and without FR.
The amount of smoke produced by FR treated fabrics – when they do not prevent the cigarette from burning (?) is, of course, great. But that must be compared with the open flame ignition that obviously has plenty of air (oxygen), doesn’t produce much smoke but burns at a very high rate.
The comparison of a fail in 12 seconds against a pass in 20 minutes for the Test PES over non CM foam is stark. And not much time to make smoke and toxic fumes (STF) either. the views of the END of smoulder test with the air tinted yellow from the thick smoke (and not even considering that – because it is a low oxygen burn it contains an excess of CO and CN. Smoky fires often are smoky because of the water content (steam) but this one is purely toxic.
We need to not only focus on the need to consider 2 ignition types but also to emphasise the character of those burns and that we we must take full account of BOTH in our risk assessment.
The treated PES velour shows that the cigarette that worked very well in all other cases can be extinguished by the FR present but the open flame examination was very one sided and clearly favours the `FR treated’. And yes, we did notice that the FR PES velour “wiped its feet” before going out but that should be compared to the test PES that reached the top of the rig in 12 seconds – now that would cause ‘Spread of Fire’.