Spun-dyed, crimped polylactic acid fiber, method for manufacture thereof, and carpet

Abstract

A spun-dyed textured polylacted filament yarn according to the present invention comprises a textured polylacted filament yarn, wherein the textured polylacted filament yarn includes a filament having an approximately circular or circular cross-section and has a relative viscosity of 2.5 to 3.8, wherein the textured polylacted filament yarn contains a coloring agent in an amount of 0.01 to 3 mass %, and wherein the textured polylacted filament yarn is 1.75 to 3.5 cN/dtex in tenacity, 35 to 60% in elongation, 500 to 3,500 dtex in total fineness, 2.5 to 25 dtex in a filament fineness, 2 to 8% in hot water shrinkage ratio, and 5 to 25% in dry heat crimp ratio. By employing the above structure, a spun-dyed textured polylacted filament yarn excellent in loftiness, toughness and abrasion resistance can be obtained. It is preferable that the cross-section of the filament has a degree of deformation less than 1.5, the degree of deformation being expressed by a ratio (B/A) of a diameter B of an circumscribed circle of the filament cross-section to a diameter A of a inscribed circle of the filament cross-section.

1 . A spun-dyed textured polylacted filament yarn, comprising a textured polylacted filament yarn,
 wherein the textured polylacted filament yarn comprises a filament having an approximately circular or circular cross-section and has a relative viscosity of 2.5 to 3.8,   wherein the textured polylacted filament yarn contains a coloring agent in an amount of 0.01 to 3 mass %, and   wherein the textured polylacted filament yarn is 1.75 to 3.5 cN/dtex in tenacity, 35 to 60% in elongation, 500 to 3,500 dtex in total fineness, 2.5 to 25 dtex in a filament fineness, 2 to 8% in hot water shrinkage ratio, and 5 to 25% in dry heat crimp ratio.   
   
   
       2 . The spun-dyed textured polylacted filament yarn as recited in  claim 1 , wherein the filament has an approximately circular or circular cross-section having a degree of deformation less than 1.5. 
   
   
       3 . The spun-dyed textured polylacted filament yarn as recited in  claim 1 , wherein the coloring agent is at least one pigment selected from the group consisting of an inorganic pigment and an organic pigment. 
   
   
       4 . A carpet in which the spun-dyed textured polylacted filament yarn as recited in  claim 1  is used as at least a part of constituent yarn. 
   
   
       5 . (canceled) 
   
   
       6 . A method for manufacturing a spun-dyed textured polylacted filament yarn, comprising the steps of:
 obtaining spun filaments by extruding a polylacted resin composition containing a coloring agent and a polylacted resin and having a coloring agent content of 0.01 to 3 mass % and a relative viscosity of 2.5 to 3.8 through a spinning nozzle into filaments each having an approximately circular or circular cross-section and a degree of deformation less than 1.5, cooling the filaments with quench air, and then coating the filaments with lubricant;   drawing the spun filaments at a draw ratio of 3 times to 6 times with a draw roller set to 70 to 125° C.;   heat-setting the drawn spun filaments with a heat-set roller set to 100 to 150° C.;   giving crimps to the heat-set drawn spun filaments by bringing a heated fluid of 90 to 160° C. into contact with the heat-set drawn spun filaments using a texturing device; and   cooling the textured spun filaments after the crimping step to a temperature lower than a glass transition temperature of the polylacted polymer.   
   
   
       7 . The method of manufacturing a spun-dyed textured polylacted filament yarn as recited in  claim 6 , wherein the following relational expression is met:
   30° C.≧S−R≧—10° C.   where “S” is a temperature of the heat-set roller, and “R” is a temperature of the heated fluid in the texturing device.   
   
   
       8 . The method of manufacturing a spun-dyed textured polylacted filament yarn as recited in  claim 6 , wherein the drawn spun filaments are heat-set with a heat-set roller set to a temperature range of 100° C. to a softening point of the polylacted polymer. 
   
   
       9 . The method of manufacturing a spun-dyed textured polylacted filament yarn as recited in  claim 6 , wherein crimps are given to the heat-set drawn spun filaments by bringing the heated fluid set to a temperature range of 90° C. to a softening point of the polylacted polymer into contact with the filaments using the texturing device. 
   
   
       10 . The method of manufacturing a spun-dyed textured polylacted filament yarn as recited in  claim 6 , further comprising a step of subjecting the textured spun filaments went through the cooling step to an entangle process using a entangle processing device. 
   
   
       11 . A spun-dyed textured polylacted filament yarn manufactured by the manufacturing method as recited in  claim 6 . 
   
   
       12 . A carpet in which at least a part of constituent yarns of the carpet is constituted by the spun-dyed textured polylacted filament yarn as recited in  claim 11 . 
   
   
       13 . A carpet using a spun-dyed textured polylacted filament yarn comprising a filament having an approximately circular or circular cross-section as a pile yarn. 
   
   
       14 . The carpet as recited in  claim 13 , wherein the spun-dyed textured polylacted filament yarn meets all of the following characteristics (1) to (7):
 (1) a filament has an approximately circular or circular cross-section having a degree of deformation less than 1.5, wherein the degree of deformation is expressed by a ratio (B/A) of a diameter B of an circumscribed circle of the filament cross-section to a diameter A of a inscribed circle of the filament cross-section;   (2) relative viscosity (RV) is 2.5 to 3.8;   (3) tenacity is 1.75 to 3.5 cN/dtex;   (4) elongation is 35 to 60%;   (5) a filament fineness is 2.5 to 25 dtex;   (6) hot water shrinkage ratio is 2 to 8%; and   (7) dry heat crimp ratio is 5 to 25%.   
   
   
       15 . The carpet as recited in  claim 13 , wherein the pile yarn comprises a single yarn and/or two or more doubled and twisted yarns made of a non-twisted and/or twisted spun-dyed textured polylacted filament yarn. 
   
   
       16 . The carpet as recited in  claim 13 , wherein an average length of piles forming a carpet is 5 to 15 mm, and a weight per unit area of the piles is 500 to 3,000 g/m 2 . 
   
   
       17 . The carpet as recited in  claim 13 , wherein an abrasion amount of pile yarns forming a carpet measured by a TABER abrasion test (abrasion ring: H-18, abrasion number: 2,500 times) is 5 to 30 mass %. 
   
   
       18 . A carpet according to  claim 13  further comprising a spun-dyed textured synthetic filament yarn as a pile yarn, wherein an abrasion amount of the pile yarn forming a carpet measured by a TABER abrasion test (abrasion ring: H-18, abrasion number: 5,000 times) is 5 to 30 mass %. 
   
   
       19 . The carpet as recited in  claim 18 , wherein the spun-dyed textured synthetic filament yarn is at least one of spun-dyed textured synthetic filament yarn selected from the group consisting of a spun-dyed textured polyester filament yarn, a spun-dyed textured nylon filament yarn, and a spun-dyed textured polypropylene filament yarn. 
   
   
       20 . The carpet as recited in  claim 18 , wherein the spun-dyed textured polylacted filament yarn meets all of the following characteristics (1) to (7):
 (1) a filament has an approximately circular or circular cross-section having a degree of deformation less than 1.5, wherein the degree of deformation is expressed by a ratio (B/A) of a diameter B of an circumscribed circle of the filament cross-section to a diameter A of a inscribed circle of the filament cross-section;   (2) relative viscosity (RV) is 2.5 to 3.8;   (3) tenacity is 1.75 to 3.5 cN/dtex;   (4) elongation is 35 to 60%;   (5) a filament fineness is 2.5 to 25 dtex;   (6) hot water shrinkage ratio is 2 to 8%; and   (7) dry heat crimp ratio is 5 to 25%.   
   
   
       21 . (canceled) 
   
   
       22 . The carpet as recited in  claim 18 , wherein the spun-dyed textured polylacted filament yarn is made of plant-derived material, and the spun-dryed textured synthetic filament yarn is made of petroleum-derived material.