GB897155A - Strings for musical instruments and processes for making the same - Google Patents

Abstract

897,155. Strings coated with finely-divided material. BAYER, W. May 22, 1959 [July 23, 1958], No. 17570/59. Class 93 [Also in Groups XXV and XXXVIII] A musical instrument string comprises a single or compound metallic or non-metallic core on which is built up an air-resistant coating of metallic or non-metallic material in powder or flake form with the aid of a binding medium which will adhere both to the core and the coating. The material may consist wholly or partly of ferromagnetic material, and may be a metal or metal alloy, a metal oxide, an ore, or graphite. The binder, which may be natural or synthetic resin or a chemically modified natural product, may be used in solution, as an emulsion, in melted form, or as a monomer which may be polymerized during the treatment. The core may be drawn through a solution of the binder, or the solution may be sprayed or painted on to the core. The powder may be dusted on, or the coated core drawn through the agitated powder, and excess powder may be removed by blowing, wiping or shaking. The binder may be set by treatment with hot air, heat radiations or a chemical hardener, or by mere storage at room temperature. The working sequence is repeated, e.g. in a continuous operation, until the desired coating thickness has been built up. The last coatings may be with binder only. The string may be braided with bright iron wire prior to coating. The powder may be a magnetic steel, a silicon-containing iron alloy, "Ferrum Reductum", magnetite, or a ferrite, either of the "ferroxdure" or "ferroxcube" types. With high retentivity materials, the string may be magnetized normally to the direction of the core. Such a magnetized string may be located in an induction coil having a soft iron or ferrite core to produce directly an alternating voltage output. The core may be of synthetic material, e.g. of a polyamide. In Example 1, a steel wire of 0.25 mm. diameter is drawn through an acetone solution of cellulose acetate, through zinc dust, excess being removed by a blower, and through a drying tube, the wire being wound on to a bobbin. The wire is again drawn through the solution and dried to form a guitar 2nd string. In Example 2, a steel wire of 0.28 mm. diameter is drawn through an aqueous dispersion of polyvinyl acetate, slightly dried, drawn through fine iron powder, excess being removed by vibration, dried, and wound on to a bobbin. The process is repeated three times, and the wire is finally drawn through the aqueous dispersion and dried to form a guitar 3rd string. In Example 3, a galvanized steel wire is drawn through an aqueous dispersion of polyvinyl acetate, slightly dried, and drawn through powdered barium sulphate, excess being blown off after drying. The coating is twice repeated without the powder treatment and dried to produce a guitar 2nd string.