[ST] Tyvek (was: Re: Stairwells)

[Carsten Turner]

Absolutely.
One of the big dangers in firefighting is flashover. Take a room with 
firefighters in it, introduce heat (say, another adjacent burning room) 
and allow that heat to rise to, say, a thousand degrees or so. All of a 
sudden, *woof*, the room the firefighters are in suddenly hits its 
autoignition temperature and lots of fire ensues. I once saw a helmet 
worn by a firefighter who was caught in a flashover. "Charred beyond 
belief" is an apt descriptor. How he survived is beyond me.
Note: this is in contrast to a backdraft-- when you have an enclosed 
space that was actively burning, consumed all its oxygen, and then 
smoldered (remaining in a very hot state) until someone kicks in a door 
and introduces fresh oxygen to the smoldering embers: at which point, 
the embers burst into flame *very* rapidly.

Your Evil Overlord,
-=>Carsten:-)

On Dec 6, 2007, at 9:49 PM, Benjamin Cline wrote:

> On Thu, 6 Dec 2007, Carsten Turner wrote:
>> Benji-- "pre-heating" means that you need to hold a match to it first.
>> It won't spontaneously combust. Flammability rating 1 means "flash
>> point over 200F." Tyvek burns at 660F. (330C)
>> http://www.dhfcs.co.kr/up_file/data/
>> Cat_14_040716_Dupont%20Safety%20Data%20Sheet.pdf
>>
>
> My concern was not that any Tyvek used for signs was going to
> spontaneously burst into flames in the stairwells but that it was
> incorrectly being represented as a fireproof material, which it is not.
>
> But since you bring it up, I see no indication that a flame MUST be
> applied for Tyvek to burn, simply increasing the temperature to the
> autoignition point should be sufficient. Both the MSDS you mentioned 
> and
> the MSDS I quoted list an "Autoignition" temperature. The NFPA 
> Glossary of
> Terms[1] defines Autoignition as "Initiation of combustion by heat but
> without a spark or flame" and Autoignition Temperature as "The lowest
> temperature at which a combustible material ignites in air without a 
> spark
> or flame".
>
> I mentioned ignition temperatures in my previous message about Tyvek
> largely as a nod to the title of a well known novel concerned with the
> burning of paper.
>
> 	Benji
>
> [1] http://www.nfpa.org/assets/files/pdf/definitions.pdf
>
> -- 
> Benjamin R. Cline
> brc at peppermint dot org
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