Process of making viscose staple fibers
AssigneeCourtaulds Limited
InventorsAndrew G. Wilkes, Alan J. Bartholomew
Life of this patent
Estimating the term…
Abstract
Viscose filaments, preferably in staple fibre form, which have a decitex of less than 5.0 and a multi-limbed cross-section, the limbs having a length-to-width aspect ratio of at least 2:1. Examples of multi-limbed cross-sectional shapes are Y-, X-, H- and T-shapes. The fibre can be formed into woven, non-woven or knitted fabrics, and is especially useful for absorbent products.
Claims28
A method of manufacturing solid cellulosic regenerated viscose staple fibre having a decitex in the range 0.5 to 5.0, said staple fibre having a multi-limbed cross-sectional shape comprising at least three limbs, each said limb having a length-to-width aspect ratio in the range 2:1 to 10:1, said method including the steps in sequential order of:
- (a) extruding viscose through a spinnerette defining a plurality of multi-limbed extrusion holes into a spin bath comprising 6 to 20 percent by weight sulphuric acid, 0 to 3 percent by weight zinc sulphate and 10 to 28 percent by weight sodium sulphate thereby forming a tow of solid cellulosic regenerated viscose filaments, each said extrusion hole having a cross-sectional shape which is similar to said multi-limbed cross-sectional shape of said staple fibre;
- (b) stretching said tow of filaments;
- (c) cutting said tow of filaments to form staple fibre;
- (d) washing said staple fibre;
- and
- (e) drying said staple fibre.
A method of manufacturing regenerated viscose staple fibre, said staple fibre consisting of a plurality of three-limbed individual fibres having a decitex in the range 0.5 to 5.0, including the steps in sequential order of:
- (a) extruding a standard viscose composition through a spinnerette into a standard viscose spin bath composition under standard viscose spinning conditions to form a tow of regenerated viscose filaments, said spinnerette defining a plurality of extrusion holes, each said extrusion hole being of three-limbed cross-section;
- (b) stretching said tow of filaments;
- (c) cutting said tow of filaments to form staple fibre;
- (d) washing said staple fibre;
- and
- (e) drying said staple fibre,
- whereby essentially all of said three-limbed individual fibres have essentially the same cross-sectional shape wherein the length-to-width aspect ratio of essentially all of said limbs of said three-limbed individual fibres is in the range 2:1 to 10:1.
Dependencies are inferred from the claim text.