Formation of filaments directly from an unconfined source of molten material

Abstract

The invention comprises methods and apparatus for forming filamentary material directly from a pendant drop of molten material, and provides for a significant improvement in the quench rate. A typical method of making filamentary material according to the invention, comprises the steps of: (a) heating a solid material, typically, a metal or metal alloy, so as to form a pendant molten drop of the material which is at a temperature within 25 percent of its equilibrium melting point in .degree.K, said molten material having a surface tension of 10 to 2500 dynes/cm. and a viscosity of 0.001 to 1.0 poise at said temperature; (b) rotating a hollow cylindrical member about its longitudinal axis at a peripheral speed in excess of 3 feet per second, said member having a circumferential, heat-extracting lip projecting from its inner periphery, and said lip having a narrow peripheral edge of arcute cross section; and, (c) bringing the surface of said pendant molten material drop and said peripheral edge of the lip into contact so as to withdraw a solidifying filament from the drop while maintaining the form and stability of the drop. Typically, said lip is located at one end of said cylindrical member. The heat-extracting lip may typically be substantially V-shaped, with the apical region of the V-shape comprising said narrow peripheral edge of the lip; and typically, said edge may possess at least one indentation disposed to attenuate said filamentary material into discontinuous fiber.

Dependencies are inferred from the claim text.