Burn temperatures

[Thanas]

Hi.

Does anybody know of a list at which temperatures material such as leather, wood (oak) and parchment starts to burn? I need this for research.

Thanks,
Thanas

[TimothyC]

A cursory google search gives me some ignition temperature values.

[madd0ct0r]

link to a (old) pdf giving ignition temps for oak and parchment, it's also worth noting the various factors the scientist explored and which were significant - air flow and rate of temperature increase (and gasification for the wood)- all of which are massively dependent on the current condition of the fire (it's not a simple problem by any means)

oak beam's performance in fire: http://www.forestry.gov.uk/pdf/Greenoak ... uction.pdf
It gives you the charring rate - but again, note the key thing from your point of view is the gasification of oils in the wood - they can cause the fire around the beam to very hot indeed, even if the beam itself is barely burnt afterwards.


There's a lot available on fire retardent leather as used on public transport - but I'm guessing you'd have something more specific in mind. Sheep leather preserved using urea and tannins?

[Thanas]

where are those figures in the document? I could not find them.

[TimothyC]

where are those figures in the document? I could not find them.

Page 34 of the document (35 of the PDF)

When timber is heated, gases are released; mainly incombustible carbon
dioxide and combustible carbon monoxide. It is the gas which first burns,
and not the timber itself. For the vapours to ignite there is normally a source
of ignition. This happens at around 250-300°C. If there is no ignition source,
but the temperature increases, then spontaneous ignition may occur, as
happens when a fire radiates heat onto a remote piece of timber. Once
ignited, the burning vapours heat up adjacent timber and the process
continues. The heat transfer from the flame to unburnt material is mainly by
radiation from the flame, and convection from the burning vapours.
Changing the orientation of a burning match from the horizontal to the
vertical demonstrates the different modes of heat transfer. Because timber is
a good insulant, conduction of heat back into the unburnt material plays a
minor role.
As the gases burn off, the residue, charcoal, is largely pure carbon. The
charcoal intumesces during its formation, expanding in volume and creating
microscopic voids. It is an excellent insulant and the timber a short distance
behind the charring layer is virtually undamaged. This has the effect of
controlling the rate at which combustion occurs, and many tests have
shown an approximately linear relationship between charring depth and
time, which, for a particular temperature, is known as the charring rate. The
charring rate depends upon the density of the timber.
European oak is more dense than the average structural softwood and
structural design codes therefore permit advantage to be taken of a slower
charring rate. For example, BS EN 1995-1-2 (Ref: 21) cites a rate of 0.5 mm/
min for European oak, compared with 0.65 mm/min for European spruce or
redwood.
The design of oak structures in relation to fire regulations is covered in
Section 5.2.5

[Thanas]

I know that but there is no mention of ignition temps for parchment so I wonder if maddoctor forgot to link the first pdf described as follows:

link to a (old) pdf giving ignition temps for oak and parchment, it's also worth noting the various factors the scientist explored and which were significant - air flow and rate of temperature increase (and gasification for the wood)- all of which are massively dependent on the current condition of the fire (it's not a simple problem by any means)

none of that is mentioned in the pdf.

Sheep leather preserved using urea and tannins?

Yeah, that would be helpful.

[madd0ct0r]

feck, yes I forgot to link to the first pdf. gimme a minute.

https://www.google.com/url?sa=t&rct=j&q ... Zc6V3ESG6g

[Thanas]

Thanks. That helped a lot.