Thick and thin polyester multifilament yarn

• US 20030066281A1
• Filed: 05/08/2002
• Published: 04/10/2003
• Est. Priority Date: 09/13/2000
• Status: Active Grant

• Current Assignee: Teijin Frontier Co., Ltd. (Teijin Limited)
• Original Assignee: Teijin Limited
• Inventors: Mizumura, Tomoo, Miyasaka, Nobuyoshi
• Granted Patent: US 6,620,504 B2
• Time in Patent Office: Days
• US Class Current: 57/248
• CPC Class Codes: D01D 5/20 with varying denier along their length
• CPC Class Codes: D01F 6/62 from polyesters
• CPC Class Codes: D02G 3/34 Yarns or threads having slubs, knops, spirals, loops, tufts, or other irregular or decorative effects, i.e. effect yarns carding machines for producing decorative or fancy effects in products D01G; drafting machines with varying draft according to a pre-arranged pattern D01H5/36
• CPC Class Codes: D02J 1/08 Interlacing constituent filaments without breakage thereof, e.g. by use of turbulent air streams
• CPC Class Codes: D02J 1/22 Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch stretch spinning D01D5/12
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2969 Polyamide, polyimide or polyester

Abstract

A thick and thin polyester multifilament yarn having an excellent natural fiber yarn-like hand, a dry touch and spun yarn-like appearance includes a plurality of individual thick and thin polyester multifilaments varying in thickness along the longitudinal direction thereof and exhibits a spectrum having a first peak (Pmax1) of a coefficient of variation in yarn thickness of 4 to 10 cm, a second peak (Pmax2) of the yarn thickness variation coefficient of 50 to 150 cm and a ratio (Pmax1/Pmax2) of 1.5 to 4.0, measured by the normal mode test method using the Uster evenness tester.

Claims

1. A thick and thin polyester multifilament yarn comprising a plurality of thick and thin polyester individual filaments the thickness of which periodically varies along the longitudinal direction thereof, wherein when the thick and thin multifilament yarn is subjected to a yarn thickness variation measurement, in the normal mode test method using the Uster evenness tester, the resultant spectrogram of the thick and thin multifilament yarn exhibits a first peak (P_max1) of the coefficient of variation in yarn thickness at a thickness variation period of 4 to 10 cm and a second peak (P_max2) of the coefficient of variation in yarn thickness at a thickness variation period of 50 to 150 cm, and the ratio (P_max1/P_max2) of the first peak coefficient of variation in the yarn thickness (P_max1) to the second peak coefficient of variation in the yarn thickness (P_max2) is in the range of from 1.5 to 4.0.

2. The thick and thin polyester multifilament yarn as claimed in claim 1 wherein, in the spectrogram of the thick and thin multifilament yarn, a ratio (P_max1/P₂₀) of the first peak coefficient of variation in the yarn thickness (P_max1) to a coefficient of variation in the yarn thickness, at a thickness variation period of 20 cm (P₂₀), is in the range of 1.5 to 4.0.

3. The thick and thin polyester multifilament yarn as claimed in claim 1, wherein the individual thick and thin multifilaments have thick portions having a length in the range of 1 to 15 mm, and the thick and thin multifilament yarn has a Uster normal mode U %, which is a mean yarn thickness unevenness represented by a ratio in % of the mean deviation to the mean value of the yarn thickness, of 3.5% or more, determined by the normal mode test method using the Uster evenness tester at a yarn speed of 400 m/min at a twist number of 5500 turns/min for one minute.

4. The thick and thin polyester multifilament yarn as claimed in claim 1, having a shrinkage in boiling water of 10% or less.

5. The thick and thin polyester multifilament yarn as claimed in claim 1, wherein the individual thick and thin multifilaments each have a triangular cross-sectional profile.

6. The thick and thin polyester multifilament yarn as claimed in claim 1, wherein the individual thick and thin multifilaments contain a fine pore-forming agent mixed into a matrix consisting of a polyester resin.

7. The thick and thin polyester multifilament yarn as claimed in claim 6, wherein the fine pore-forming agent comprises a metal salt compound represented by the general formula (I):