Process for producing a highly oriented polyester undrawn yarn
AssigneeToray Industries, Inc.
InventorsMasatoshi Mineo, Ken-ichiro Oka, Kiyoshi Nakagawa, Hiyoshi Matsuda, Shigeo Ohno, Yasuo Takagi
Life of this patent
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Abstract
A process for producing a highly oriented polyester undrawn yarn comprising melt-spinning a polyester from a spinneret, solidifying the melt-spun yarn and taking up a solidified yarn at a take-up velocity from 2,500 to 4,500 m/min, wherein the spinning length is set within a specific range in accordance with the take-up velocity, yarn denier and maximum allowable tension of the yarn.
Claims3
In a process for producing a highly oriented polyester undrawn yarn, in which said yarn is spun from a spinneret to a first take-up, the steps which comprise:
- melt-spinning a polyester from a spinneret,
- solidifying the melt-spun yarn and taking up the solidified yarn at a take-up velocity from about 2,500 to 4,500 m/min,
- wherein the spinning length defined by the distance from said spinneret to said first take-up is within the range from about (d + 2)/4 (in meters) to about (A/1.2)/(Faero/x) (in meters),
- wherein d is the filament denier of the undrawn yarn, A is the tension (in grams) of the filament in an elongation range under constant tension of a stress-strain curve, Faero/x is the rate of increase of the yarn tension per meter following the yarn solidification point by an air resistance which is equal to 0.229 .times. 10.sup.-4.D.sup.0.39 .multidot.V.sup.1.39, wherein D is the solidified filament diameter (in cm) and V is the velocity of the solidified filament (in cm/sec),
- wherein the filament denier of the undrawn yarn is within the range from about 2 to 6.
In a process for producing a highly oriented polyester undrawn yarn having a filament denier of about 2 to 6, in which said yarn is spun from a spinneret to a first take-up roller, the steps which comprise
- melt-spinning a polyester from a spinneret,
- solidifying the melt-spun yarn,
- passing the solidified yarn through a guide arranged to cause the yarn to bend through an angle of at least about 5.degree., and
- taking up the solidified yarn at a take-up velocity from about 2,500 to 4,500 m/min,
- wherein the spinning length defined by the distance from said spinneret to said first take-up roller is within the range from about (d + 2)/4 (in meters) to the lower value of either (A/1.2)/(Faero/x) (in meters) or B/(Faero/x) in meters),
- wherein d is the filament denier of the undrawn yarn, A is the tension (in grams) of the filament in the elongation range under a constant tension of a stress-strain curve, B is the maximum allowable tension (in grams) of the undrawn filament when a maximum allowable tension at said guide is 0.3 g/d, and Faero/x is the rate of increase of yarn tension per meter following the yarn solidifying point by an air resistance which is equal to 0.229 .times. 10.sup.-4 .multidot.D.sup.0.39 .multidot.V.sup.1.39,
- wherein D is the diameter of the solidified filament (in cm) and V is the velocity of the solidified filament (in cm/sec).
Dependencies are inferred from the claim text.