GB728233A - Improvements in or relating to processes of and apparatus for melting melt-spinnablesubstances - Google Patents

Abstract

<PICT:0728233/IV (a)/1> Solid particles of a melt-spinnable substance such as a polyamide are continuously fed to a melting space, within which they are retained until completely melted; a stream of the same substance in the molten state is caused to flow between and over the solid particles retained in the melting space so that they are gradually melted; and the stream of molten substance is collected, together with the freshly molten substance so obtained, in a collecting space from which the stream of molten substance required for melting the solid particles is continously withdrawn. As shown, solid polymeric melt-spinnable substance in chips, granules or other comminuted form is fed into the melting apparatus from a feed reservoir or measuring device and falls into a basket 14. The polymer may be preheated before entering the melting apparatus. Molten polymer 11 is collected in the lower part of the melting chamber. A circulation pump 16 draws liquid polymer from the bottom of the chamber and forces it through conduit 17 and tube 18, from the end of which the liquid flows on to the mass of solid particles held in the basket 14. The liquid is maintained at a temperature above the melting point of the polymer, e.g. 20 DEG C. above, so that it melts the solid particles as it passes in contact with them. The liquid polymer, including that portion obtained from the freshly melted particles, passes through the walls of the basket into the lower part of the melting chamber. The whole melting chamber may be surrounded by a jacket 20 through which heating fluid may be circulated, and the temperature may be thermostatically controlled. The conduit 17 may be surrounded by an electric heater 21. The molten polymer is delivered to a spinneret by way of conduit 23. At the beginning of the operation, the collecting space or sump is filled with molten polymer, either by introducing polymer that has been melted in some other apparatus or by introducing solid polymer through an opening, normally closed by lid 24, and melting it by specially provided heating devices or by the heating devices used for maintaining the temperature of the melting chamber at a desired value during normal operation. Specification 728,232 is referred to.