Sample Nos.
1-16
xvii
The results of these tosts can be summarized as follows:
Details.
xvii
Apparently normal, material taken from various points within several rolls of normal appearance
Heat test at 160°c. Minutes required for puffing.
over 60 mins.
17-20
"cinema-made" neat splices from
over 60 mins.
ditto.
21-27
28,29
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 & long period.
over 60 mins.
over 60 mins.
30-33
Light blue coloured spottings
over 60 mins.
found in 2 rolls
34-38
Black spots and streaks from
over 60 mins.
3 rolls
39-45
Other stains and discoloured portions, from 4 rolls.
over 60 mins.
46-47
over 60 mins.
4857
93
58-60
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.
Difficult to estimate, After 10 minutes, became dark brown and shewed signs of gas eve- lution.
After 30-35 minutes, most samples showed 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.
The following conclusions thus emorge :
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 mașs of film.
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