43
Sample Nos.
1-16
17-20
21-27
28, 29
The results of these tests can be summarized as follows:
Details.
Apparently normal, material taken from various points within several rolls of normal appearance.
"cinema-made" neat splices from
ditto.
From different portions of a roll touching rusty drum lid and sides.
Two ends of film which had become trapped under the flange of drum lids, and had consequently been in intimate contact with iron for a long period.
Heat test at 160°C. Minutes required for puffing.
over 60 mins.
over 60 mins.
over 60 mins.
over 60 mins.
30-33
Light blue coloured spottings found in 2 rolls
over 60 mins.
34-38
Black spots and streaks from 3 rolls.
39-45
over 60 mins.
over 60 mins.
46-47
48-57
58-60
Other stains and discoloured portions, from 4 rolls.
From a roll of crinkle-edged, distorted film.
Roughly made splices, taken from 6 rolls.
Three roughly-made splices, all from one roll of film. The splices were all dark in colour, and two of them had been rein- forced by the use of wire staples.
The following conclusions thus emerge:
over 60 mins.
Difficult to estimate. After 10 minutes, became dark brown and shewed signs of gas evolution.
After 30-35 minutes, most samples shewed a gentle and progressive puffing out with
gas.
Only one sample inflamed during the tests; after 35 minutes heating.
The material is undoubtedly of lower stability than the basic film, but its stability is still fairly good.
These samples all "puffed off" within three minutes heating.
1. The greater part of the material is very stable.
2.
Rust, or contact with iron, alone, appears to have little effect on the stability.
3.
The rough splices in the material have a lower stability than the main mass of film.
4.
Rough splices from one roll of film had a very low stability.
In my opinion, celluloid which lasts for only three minutes in the 160° heating test, is so unstable as to be liable to spontaneous ignition.