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).
Test report comparing varnished fabric board with continental bakelite.
| Identifier | ExFiles\Box 39\3\ Scan253 | |
| Date | 15th September 1925 | |
| EFC. WB{Mr Brazier/Mr Bell}42. 15th Sept. 1925. X.3513. VARNISHED FABRIC BOARD. We have now tested samples of this material handed to us by EY. comparatively with continental bakelite of the same gauge. The samples were tested as follows :- (a) Absorption of moisture. (b) Compressibility. (c) Leakage on 200 V.{VIENNA} A.C. (d) Machining properties. (a) The hygroscopic quality of this material after immersion in water with a similar sample of bakelite for 120 hours, was observed to be approximately the same as the bakelite. The percentage increase in weight being, in the case of the V.F. board 1.3% and the bakelite 1.01%. (b) This material like the continental bakelite does not shrink appreciably under pressure. (c) After being soaked for about 50 hours in water and dried with a cloth a leakage of 1 1/2 milli-amperes at 200 V.{VIENNA} A.C. could be obtained between two terminals screwed into the material about an inch apart but when thoroughly dried in a dessicator no leakage could be observed. (d) This material machines much the same as the bakelite but does not drill so well. In conclusion it is considered that there is very little difference in the qualities of this varnished fabric board and the continental bakelite. The bakelite appears to be manufactured on a finer linen base than the V.F. board. EFC/HEW. | ||