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 a meeting discussing developments in rubber technology, its properties, and applications.
| Identifier | ExFiles\Box 178\2\ img055 | |
| Date | 25th March 1940 | |
| Serial No 42 EV{Ivan Evernden - coachwork} OY 3/D/Mar.25.40 Mar 25,1940 Rolls-Royce, Ltd. Derby, England Rubber S.M.Cadwell of U.S.Rubber Co.,Detroit A.S.T.M. Meeting,March 6,1940. Re. At the same meeting of the A.S.T.M. on the morning of March 6, when Heron gave his paper on valve steels (already sent you) and Boegehold on hardenability,etc.,S.M. Cadwell delivered the attached on rubber. 1) The outstanding thing is,of course,in the fatigue testing.I do not know when the printed copies will be available,so enclose a typical memorized chart of the fatigue life of rubber plotted against extension or compression at mid-stroke. When used in tension,a mean extension of 200% increases the life from 100 to 750 times as compared with the use of the material under plus and minus loading.Similar effects occur in compression. In other words it responds well only to rough treatment. The application of this to building aircraft engines is not immediately evident.But on motor car engine mounts the results are important.Also,in the increasingly necessary business of rubber noise insulation between body and wheels. 2) Sponge rubber,originally made by Dunlop with baking soda I understand,is now made directly from whipped latex. 3) Cellular rubber,demonstrated at the meeting,is quite different in being a permanently resilient material and having no air passages thru it.Produced originally by subjecting ordinary rubber to 3000 lbs. pressure of nitrogen,and after allowing time for the gas to penetrate, suddenly releasing the pressure. Now produced by other methods - not disclosed. Proposed uses: Trench helmets Life preservers All noise insulation,such as getting softness into large area engine and body mounts. Heat insulation. 4) Neoprene lining of gasoline tanks. 5) Continued development on rayon tyres (But R.D.Evans of Goodyear who introduced rayon tyres,says that rayon competition has led to great improvements in the tensile strength of cotton at temperatures around 275° and that the original difference between the 2 materials no longer exists. OY | ||