[rollei_list] Re: looks like ... agfa Sala
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <rollei_list@xxxxxxxxxxxxx>
- Date: Mon, 30 May 2005 19:33:26 -0700
----- Original Message -----
From: "Jerry Lehrer" <jerryleh@xxxxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx>
Sent: Monday, May 30, 2005 7:14 PM
Subject: [rollei_list] Re: looks like ... agfa Sala
> Richard,
>
> Nitrate film is nitrocellulose; an explosive used as part
> of some smokeless powders. The actual amount of
> the nitration of the cellulose determines it's explosive
> powers. The other component of some gunpowder
> is nitroglycerine.
>
> Many organic components can be nitrated, some are more
> unstable than others. (Benzene, chloroform, kerosene,
> ethane etc.) Usually nasty stuff to play with.
>
> As kids, we used to use old nitrate base films to make
> explosives.
>
> Jerry
>
The material used in nitrate film base is not explosive
per se. However it burns very firstly with the evolution of
a lot of gasses. Decomposing nitrate film base emits a toxic
and explosive gas. It also generates enough heat to result
in catching fire. As I pointed out nitrate film fires are
exceptionally difficult to extinguish, the only practical
method being to limit fuel. This was done in the motion
picture industry by storing nitrate film in properly
ventilated explosion proof vaults and not storing too much
in the same place. The old rules for projection rooms also
required that the film be stored away from the projection
room and not more than a limited amount be in the projection
room. Projection rooms were also required to have explosion
proof front walls with very limited port areas and
automatic, heat operated, shutters over the ports. The
projectors were completely enclosed and were
compartmentalized with pinch rollers between each section to
limit the amount of film that could burn to a foot or so at
most. There were some early theater fires that resulted in
extensive loss of life that resulted in the very stringent
regulations applied to theaters in most places.
For film buffs the last Hollywood movie photographed on
Nitrate was "Sunset Boulevard".
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
---
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