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).
Report comparing the properties and test results of various insulating materials like phenols, rubbers, and fibres.
| Identifier | ExFiles\Box 24\2\ Scan194 | |
| Date | 23th May 1922 guessed | |
| -3- Contd. Material. Grade. Test 3(%) Test 8. Remarks. PHENOLS Bakelite. Campbell. 5.0 Surface rotted. Bak-dilecto. Black. 1.8 Unaffected. Bak-micarta. Black. 6.6 Surface rotted. " Brown. 5.6 " None left for test Contl.bak'te. Canvas. .70 Unaffected. (5. " Linen. .925 " None left for test Condensite (5. celeron. Canvas. 2.60 Surface slightly rotted. Ditto. Paper. 1.47 Unaffected. Paxolin. Standard. 6.41 Surface slightly rotted. *Belcalite. Admiralty. 11.5 Ditto. RUBBERS *Ebonite. Brit.Eb.Co. 0 Unaffected. " Carson. .038 " Hightensite. Standard. .016+ " " Heat resis. 3.49 " Vulcanite. 102. .08 " " 110 C " FIBRES Diamond Fib. Red. 40.8 Rotted, split.) Sheets not tested. " Natural. 52.8 " Vulmos " 19.0 " Siluminite. Cured. 5.29 Surface whitened. Solidite. - .0765. Unaffected. Thermoplax. - 1.25 Surface whitened. From what the foregoing tests show the best all round sheet material is condensite celeron with the paper base, being hard heat-resisting, of small absorption and unaffected by oil and acid. It is also has a very smooth finish. This is closely approached by continental bakelite, especially in the canvas base grade, which stands up well to heat and absorbs less water than condensite celeron. Bakelite-dilecto also shows favourably though it is slightly more absorbent. The Admiralty quality of Paxolin is softer and more absorbent than the standard. Amongst the rubber materials, the ebonite made by the Hightensite Co. seems to be generally the best, but if found to be sufficiently hard, vulcanite would be superior. The fibre materials appear to have no point of superiority over the phenol sheet substances, and mostly are very inferior. The special heat resisting grade of hightensite does not resist heat any better than the standard grade, though it is better in some other respects. Some further samples of insulating materials are awaiting tests for machining properties in the expl. shop. FJA. | ||