GB1336294A - Low viscosity melt spinning process - Google Patents

Abstract

1336294 Continuous casting MONSANTO CO 5 Oct 1970 47239/70 Heading B3F [Also in Division C1] Inorganic materials which when molten have a viscosity/surface-tension ratio (in poise and dynes/em.) equal to or less than unity, such as ceramics, metals or alloys (e.g. Al, Cu or steel, containing 1% Al, or Pb-Sn) or intermetallic compounds or metalloids such as B or Si, are spun to produce staple fibres, by extruding the molten material as a free stream at a velocity V such that the Rayleigh parameter, lies between 1 and 50, and exposing the stream to a gaseous atmosphere (such as a mixture of He or N with a small volume of O or a mixture of He with CO) which reacts to form a film about the stream to prevent its disruption until it solidifies, then decelerating the stream at a point intermediate a point upstream of which deceleration gives a non-fibrous mass but below which deceleration results in staple fibres and a point upstream of which deceleration results in staple fibres but below which deceleration results in a continuous filament. The apparatus used is that described in Specification 1,219,418 and the deceleration of the stream may be by passage through a denser or counterflowing spin atmosphere or by applying an electrostatic field or by a collection surface (36) moved up and down to attain a level giving a desired fibre length. Reference has been directed by the Comptroller to Specifications 1,153,577, 1,197,972 and 1,210,920.