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).
The manufacture and application of synthetic resin-based insulating materials.
| Identifier | ExFiles\Box 39\3\ Scan257 | |
| Date | 7th June 1926 guessed | |
| Contd. -3- [strikethrough]Other issues[/strikethrough] A variant of the processes of manufacture of synthetic material is to treat paper or fabrics with the gum from which the powder is made, under pressure, so as to form sheets of insulating material of great strength and possessing most of the properties of moulded articles. The thickness is simply controlled by varying the number of layers of paper or fabric used. This product is of a brown or black colour and is non-shrinking. It is a good substitute for mica, etc. in electrical machines. Both this material and the moulded forms are employed for many non-electrical purposes. They are easy to machine (ebonite requires a diamond tool for satisfactory fine cuts) and the resulting surfaces have all the properties of the unmachined surfaces. Aeroplane propellers of fabric based material moulded direct to shape are standard in the U.S.A. Navy. Silent pinions are made from similar material. Oilless bushings impregnated with graphite are made with paper base, and commutators for small electrical machines are sometimes made without steel retaining rings, but moulded together with the powder material. The resinous gum may be dissolved in alcohol to form a varnish. This may be used for armatures, etc. and makes a very solid job. Banding wires can be dispensed with, although the armature cannot be unwound, once stoved, without destruction. It seems likely that there would be a market for blocks of insulating material moulded to various dimensions from the powder form of synthetic resin, for applications where it is not practicable, owing to their small number, to make moulds for the articles required. These could be machined to the desired shapes, thus providing synthetic materials where now only rubbers & etc. can be used. | ||