[rollei_list] Re: looks like ... agfa Sala

----- 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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