1897 __ Durinoid — thermoplastic shellac
‣ Comment : Gramophone discs begin to be made of a thermoplastic shellac compound called Durinoid. — When it appeared commercially in the United States in 1894, the single-sided disc cost sixty cents and held two minutes of material, an improvement over the ninety- second capacity of the cylinder at that moment. Discs were first made from a form of vulcanized rubber, ebonite, which did not wear out as quickly as wax, nor was it as subject to chemically induced deterioration as wax. Partly because of the high durability of this material, these discs were difficult to press. Berliner then discovered an alternative substance used in making buttons, called Durinoid. Durinoid was an amalgamation of shellac and other substances that was both durable and easy to press. The machine upon which discs were played was also more cost-effective than that for cylinders, costing a mere $12. (Joshua A. Neumann) — The first recordings made by Edison in 1878 were made on tinfoil or copper sheets. When Emile Berliner developed his disc record player around 1895, he used hard “vulcanite” rubber discs. Edison cylinders made between 1901 and about 1912 used a soft material that was like a hard soap. — it has been described as “metallic soap” because of its chemical composition. An improvement introduced for 78-rpm discs after 1896 was an early form of plastic called Durinoid, which was first used by a company in Newark, New Jersey to make buttons. The most successful 78 RPM record material was called shellac. It was made from excretions of the Lac bug, which was native to India. To save money, the shellac was sometimes mixed with cotton fibers called flock, or some other fillers, and it was colored by the addition of lampblack, (or other colouring agents) which was a fine carbon powder. It is believed that the shellac disc was invented by the Victor Record Company, and nearly every other record company around the world used it (or something quite like it) from about 1896 to the end of the 78-rpm disc era in the mid-1950s. Here are some other formulations used by various manufacturers: A) Shellac13.5% White filler (powdered Indiana limestone) 37.5% Red filler (powdered red Pennsylvania slate) 37.5% Vinsol (type of plastic with a low melting point) 8.5% Congo Gum (flexible binder) 1.0% Carbon Black (colorant for appearance) 1.5% Zinc stearate (lubricant for mold release) 0.5%. — B) Flake Shellac 15.63% Congo Gum 6.51% Vinsol Resin 5.86% Carbon Black (low oil content) 2.61% Zinc Sterate 0.32% Whiting (CaCO3)52.13% Aluminum Silicate 13.03% Flock (long fibre) 3.91%. — C) Wood flour 58% Modified ethyl alcohol (AKA ethynol) 26% Phenol formaldehyde (AKA Bakelite) 15% Lampblack (the pigment) 1% Edison condensite varnish (modified ethyl alcohol) 55% Phenol formaldehyde (63% phenol + 37% formaldehyde) 38% Other, including "Shino", used to promote a gloss finish 7%. (Compiled from various sources)
‣ Source : Neumann, Joshua A. (2008), “Performance Practices in Four Puccini Arias: Tempo Choices and Choosers”, Music, School of Student Research, Creative Activity, and Performance - School of Music , University of Nebraska - Lincoln.
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