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).
Letter discussing the supply and properties of insulating materials like Bakelite, Condensite, and Redmanol.
| Identifier | ExFiles\Box 39\3\ Scan094 | |
| Date | 24th May 1921 | |
| COPY. Oy13-G 24521 May 24, 1921. Mr.Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention. Mr. F.H.Royce & Works Committee. Dear Sir, Re Insulating Materials. I wrote Mr.Royce on May 19th. giving prices of our insulation parts in molded Bakelite. The other particulars as to the general molding of Bakelite, Condensite and Redmanol are as follows: (1) SUPPLY. The three compounds are of the same chemical composition, namely formaldehyde and carbolic acid, when in the crude state, which on heating makes a hard gum or horn-like substance, which is chemically inert, of high dielectric strength, low coefficient of expansion, unaffected by water or climatic changes and unaffected by heat up to temperatures of about 250° to 300°F.{Mr Friese} The Condensite Company pays a royalty to the General Bakelite Company, while the manufacturers of Redmanol are in litigation with the Bakelite Co. at this time, to determine the question of royalty. The molded material in all cases consists of a mixture of crude Bakelite (Condensite etc.) with wood flour, except in cases where high fire resistance is desired when asbestos wool is used, also in cases where very high mechanical strength is required, when the base is a fibrous material preformed to the desired shape (e.g. canvas forms used in aeroplane propellers.) The proportion, grain size etc. of the wood flour is changed to suit the type of piece molded, the mechanical strength desired etc. the proportion of wood and grain size being generally increased for greater strength. These mixtures of raw material and wood flour are graded by all the makers and supplied by them ready mixed. It is a matter of experimental adjustment between the molder and the Bakelite or Condensite companies to determine the exact grade of mixture which will give best results on any particular job. The mixtures with a higher proportion of Bakelite, etc. will flow better in the molds than those with a lower proportion, and are therefore more desirable for intricate moldings or those which have | ||