From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Directions for studying paper, including apparatus for measuring porosity and flash testing for conducting particles.
| Identifier | ExFiles\Box 24\2\ Scan245 | |
| Date | 30th January 1923 guessed | |
| 666 DIRECTIONS FOR THE STUDY OF The last three ingredients are mixed together and the zinc chloride added. The insoluble matter is allowed to settle at least overnight and the supernatant liquid decanted off. The stain must be kept in the dark or in a bottle opaque to light. It may be made up in larger quantities provided it is kept from the light and air. After the fibres are properly teased out with the needles, another but thinner glass slide is placed on top of the first slide, and the excess stain is squeezed out and absorbed by blotting-paper. The slide is now ready for the microscope. (A magnification of about 60 diameters is usually found convenient.) Care must be observed to keep the slide away from the light before using it for the estimation, and in any case the estimation should be made at least within one hour from the time the slide was made up. Under the microscope, using the zinc-chloride-iodine stain, the fibres appear coloured as follows:— Cotton and linen rags } Wine red Cooked and bleached manilla Cooked and bleached wood-pulp } Blue to blue violet Cooked and bleached straw and esparto Mechanical or ground wood-pulp } Yellow to lemon yellow Jute, uncooked, and manilla Highly lignified fibres In making the estimation both the distinctive shape and markings of the fibres, as well as the colours as developed by the zinc-chloride-iodine stain, are of importance. Extreme care must be observed to have all beakers, test tubes, needles, and even fingers free from any fibrous material before beginning the preparation of a sample or slide. Reproductions of micro-photographs showing the fibres in papers containing the following materials are given in Fig. 5 (a) to (f) for comparison :— (a) Rag (cotton and linen). (b) Manilla. (c) Jute. (d) Chemical Wood-pulp. (e) Mechanical Wood-pulp. (f) " Paper mulberry " (Broussonetia papyrifera). Image 1 Diagram Labels: Insert strip of paper about 2 1/2" wide between discs Metal discs: upper has 1" dia. hole, lower has 1" dia. recess Ring support Rubber tube Pinch cock Clamp Flash of about 500 c.c. Water Ring support with slot About 22" 100 c.c. burette Ring support for lower position of flask Stand Image 2 Diagram Labels: Direction of motion of paper Paper Image Captions: Fig. 3.—Apparatus for measuring the porosity of paper. Fig. 4.—Apparatus for flash test for conducting particles. | ||