Patent ID: 6619947
Filing Date: 2003-09-16
Classification: D01D,D01F,D04H,Y10S,Y10T

Abstract:
A spinneret design for producing a crimped homofilament fiber comprising:a) an extruder for forcing a liquid polymer through spinneret capillaries; b) a fiber forming portion consisting of: i) a counterbore connected to a polymer supply channel, the counterbore longitudinal axis defining a polymer flow axis, the counterbore having a first channel connected to a polymer supply channel and a second channel narrower than the first channel, the second channel connected to the first channel by a first conical feed chamber, the second channel ending in a second conical feed chamber; ii) a first capillary connected to the first conical feed chamber and having an exit hole out of the die head, the first capillary having a length to diameter ratio of between about 6:1 to about 10:1, the first capillary longitudinal axis being parallel to the flow axis; (iii) a second capillary connected between the first capillary at a point prior to the exit hole and the second feed chamber, the second capillary having a length to diameter ratio of about 1.5:1 to achieve a desired crystallinity percentage within the fiber; and whereby liquid polymer extrusions from the first capillary and the second capillary commingle to form a single filament having sections of different induced shear thereby causing the filament to crimp.