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).
Summary of leakage tests conducted on various grades of Bakelite coil cases, comparing them with standard Redmanol material.
| Identifier | ExFiles\Box 61\1\ scan0119 | |
| Date | 28th May 1930 | |
| X 6011 COPY. PD.52. 28.5.30. X.6011. SUMMARY OF LEAKAGE TESTS ON X.6013. BAKELITE COIL CASES. Below is given a table summarising the results obtained from the leakage tests carried out on coil cases made in various grades of bakelite powder, in comparison with the standard Redmanol material. Details of these powders and the tests made were given in reports PD.46 - 8.3.30, PD.49 - 10.4.30 and PD.50 - 28.4.30. In the table, the values given are, with the exception of those for the XM.1000 grade, for the case coming direct from the mould without any subsequent baking. With the XM.1000 grade, extra baking had to be included as part of the moulding process. From this table it is seen that the Stiff Bakelite compares favourably with both the ordinary bakelite and the Redmanol, as regards leakage, and since it has the additional advantage of not contracting there appears, electrically, to be no reason why it should not be used in preference to any of the others. | Material. | Ratio (volts / amperes) in Megohms. | | | |---|---|---|---| | | 20°C. | 80°C. | 100°C. | | Std. Redmanol. | 118.7 | 12.3 | 7.3 | | Bakelite X.616B. | 630 | 20.9 | 13.2 | | Bakelite X.616B Stiff. | 5970 | 42.2 | 24.4 | | Bakelite XM.1000 | Inf. | 2280 | 462 | | ||