GB1337573A - High speed wet spinning - Google Patents

Abstract

1337573 Wet spinning process ASAHI KASEI KOGYO KK 2 Dec 1970 [2 Dec 1969 (2)] 57368/70 Heading B5B In a continuous wet spinning process filaments are extruded from a spinneret 2 into a first coagulation bath 1 consisting of a concentric inner funnel 4 spaced at a vertical distance A from the spinneret and an outer funnel 5, supplied through pipe 6 with coagulation liquid, and pass through a narrowed tail pipe 4b downwardly to a braking unit 8 which provides a braking effect on the liquid entrained by the extruded and partially coagulated filaments which emerge from the assembly 1. Braking unit 8 (Fig. 3) comprises an inside guide funnel 9 and an outer concentric box-shaped casing member 10 supplied through inlet 11 with a secondary coagulation liquid. The lower portion of the braking unit 8 is designed such that filaments emerging from the guide funnel 9 are contacted with a thin annular liquid jet 23 injected from the annular nozzle 12 of the casing member 10 at an included angle 0, (suitably # = 20 to 150 degrees), such that the entrained primary bath liquid is subjected to a liquid braking action by the jet. From unit 8 the filaments pass through the secondary coagulation bath, comprising a cup-shaped funnel 14 positioned at a substantial distance below the braking unit 8 and provided with bottom outlet 14a, and round stationary guide bar 15 which deflects their passage from the vertical to the horizontal and leads them to stationary saddle guide 16. Saddle guide 16 (Fig. 4) is provided with a thin filament passage groove 16a along its concave portion and a liquid receiving blind hole 16b for receiving a conventional regenerating liquid from a stationary supply nozzle 24. The freshly spun and coagulated filaments are then passed under tension to contra-rotating, partially engaging vaned rollers 17 and 18 which have vanes 17a 18a coated with, consisting of or covered with (Fig. 6, not shown) a resilient material (e.g. rubber or other elastomeric materials) and which convert the filaments from a tensioned state 13 to a tensionless state 13a (Fig. 5), prior to any post-treatment steps in the process. From the vaned rollers 17, 18 the tensionless filaments pass via primary conveyer 19 and liquid injector 26 to secondary conveyer 27 whereon they are passed through post treatment zones 41 and 42 comprising a conventional acid treating section 28, cold water washing section 29, hot water section 30, dewatering section 31, oiling section 32, de-oiling section 33, drying section 34 and humidifier 35 to a winder 40. Figs. 9 to 14 (not shown) illustrate other suitable braking units 8 whilst Figs. 7 and 8 (not shown), relate to the preferable dimensions of the apparatus in the coagulating phase of the process. An Example relates to the wet spinning of cuprammonium cellulose filaments using warm water as the primary and secondary coagulating liquids and H 2 SO 4 as the regenerating liquid used with the saddle guide 16.