GB540967A - Improvements in or relating to the production of artificial filaments, foils, films and like materials - Google Patents

Abstract

540,967. Artificial filaments, films &c. DREYFUS, H. Feb. 3, 1940, No. 2142. [Class 2 (ii)] Artificial filaments, bristles, foils, films, and like materials are obtained by bringing a thermoplastic composition (other than a cellulose acetate composition), which is substantially free from volatile solvents to a substantially uniformly fused condition by feeding it through a heated narrow tube which communicates directly with an extrusion orifice, and extruding and setting the resulting fused composition. The tube may be made of or lined with tin, silver, tantalum, aluminium, copper, chromium, or stainless steel. The process is applicable to the production of filaments or films having a basis of a polyamide formed by self-condensation of an amino-carboxylic acid or by condensation of a diamine with a dicarboxylic acid, or having a basis of other superpolymers, or of cellulose derivatives (other than cellulose acetate) such as the butyrate, or acetobutyrate, or methyl, ethyl, or benzyl cellulose ether, or of polyvinyl esters or ethers, or polyacrylic or polymethacrylic acid esters. The filament or film-forming compositions may contain solvents, softening agents, pigments, or dyes. The heating tube may be provided with an electrical heating coil or a fluid heating bath. The heating fluid may be gaseous, vaporous, or liquid, and it may be a paraffin, arylated paraffin, acenaphthene, anthracene, benzene, diphenyl, toluene, dibenzyl, naphthalene, dinaphthyl, phenanthrene, tetraline, isoamyl ether, dimethyl ether of ethylene glycol, anisole, ethyl benzyl ether, dinaphthyl ether, diphenyl ether, halogenated substitution derivative of a hydrocarbon or ether, or nitrogen, hydrogen, or carbon dioxide. The thermoplastic composition may be fed to the narrow tube as powdered material through a hopper or it may be fed or drawn in partially fused or semi-plastic condition from a heated vessel into a hopper connected with the tube or directly into the tube. The hopper or vessel feeding the tube may be employed as the chamber in which part or the whole of the re-action for producing the thermo-plastic substance is carried out. The extrusion may take place under gravity or pressure may be applied by means of an inert gas or liquid. The extruded materials may be drawn at a speed many times that of extrusion. Specification 529,510 is referred to.