Patent Publication Number: US-2018030619-A1

Title: Down-like fiber

Description:
FIELD OF THE INVENTION 
     The present invention relates to a down-like fiber, particularly, to a down-like fiber with a hollow stem and a plurality of shaped lobes. 
     BACKGROUND OF THE INVENTION 
     Natural feathers consist of vaned feathers and down feathers; the former has hollow stems, and the latter does not. The arrangement of both vaned feathers and down feathers forms irregular spaces, thereby trapping air to reduce heat dissipation and thus can provide warm effect. However, the warm effect of natural feathers is extremely decreased due to absorption of water. 
     In the prior art, fibers with different shaped lobes such as cross-shaped, Y-shaped and W-shaped lobes have been disclosed. For example, U.S. Pat. No. 5,057,368 discloses a fiber comprising 3 or 4 T-shaped lobes. Although the above fibers have capability of absorbing moisture and relieving sweat, the warm effect thereof is not good enough. Contrarily, polyester fibers sold in the market have a hollow structure and thus possess the warm effect, but the effects of absorbing moisture, relieving sweat and a soft touch feeling are poor. 
     Therefore, it is highly desired to have a fiber that not only has good effect of keeping warm but also possesses excellent effects of drainage and fast-drying, and a lightened weight and a soft tough feeling can be achieved as well. 
     SUMMARY OF THE INVENTION 
     To solve the above problems, the present invention provides a down-like fiber which possesses an effect of keeping warm just like feathers, and presents an outstanding fast drying effect as well. 
     The present invention provides a down-like fiber which comprises a hollow stem and a plurality of shaped lobes arranged radially from the hollow stem as a center, wherein each of the shaped lobes comprises a bottom end and a head end opposite the bottom end. The bottom end connects to a surface of the hollow stem, and the head ends of two adjacent shaped lobes do not connect with one another to form an opening. 
     According to one aspect of the present invention, the shaped lobes can be T-shaped, cross-shaped, Y-shaped, ↑-shaped, ♀-shaped, W-shaped, H-shaped, V-shaped or rectangular-shaped and the number of the shaped lobes can range from 2 to 6. 
     According to one aspect of the present invention, the down-like fiber stated above can be a filament or a staple. 
     The present invention also provides a spinneret for manufacturing the down-like fiber stated above. The spinneret comprises a plurality of slits of spinning nozzles. Each of the slits of spinning nozzles comprises an inner ring portion and an outer lobe portion which has a bottom end and a head end opposite the bottom end wherein the bottom end connects to the inner ring portion. The inner ring portions of the plurality of slits of spinning nozzles are arranged in a circle at a regular interval, and the head ends of two adjacent outer lobe portions do not connect with one another to form an opening. 
     According to one aspect of the present invention, the outer lobe portion can be T-shaped, cross-shaped, Y-shaped, ↑-shaped, ♀-shaped, W-shaped, H-shaped, V-shaped or rectangular-shaped. The number of the slits of spinning nozzles can range from 2 to 6. 
     The present invention also provides a method for manufacturing the above down-like fiber, which comprises extruding a polyester polymer in melting form through the spinneret stated above. 
     The down-like fiber provided by the present invention has a hollow stem and shaped lobes which imitates the structure of feathers, and thus can not only conserve heat dissipated from body but also lighten the weight of fiber, thereby providing a soft touch feeling. Moreover, since the head ends of adjacent shaped lobes do not connect with each other, the ditches formed therefrom can improve drainage functions. Accordingly, the effects of keeping warm and fast-drying can be achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee. 
         FIG. 1  schematically shows the cross section of the down-like fiber having T-shaped lobes according to one embodiment of the present invention; 
         FIGS. 2A to 2H  schematically show the cross sections of the down-like fibers having different shaped lobes according to embodiments of the present invention; 
         FIG. 3  shows a photograph of the cross section of physical samples of down-like fibers having T-shaped lobes; 
         FIG. 4  schematically shows the arrangement of several down-like fibers having T-shaped lobes according to one embodiment of the present invention; 
         FIG. 5A  schematically shows a spinneret used for manufacturing down-like fibers having T-shaped lobes according to one embodiment of the present invention; 
         FIG. 5B  schematically shows a spinneret used for manufacturing down-like fibers having cross-shaped lobes according to one embodiment of the present invention; and 
         FIG. 6  shows a bar graph of warm effect tests. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  schematically shows the cross section of the down-like fiber having T-shaped lobes according to one embodiment of the present invention. In  FIG. 1 , the fiber  10  comprises a hollow stem  13  and four T-shaped lobes  11  which arrange radially from the hollow stem  13  as a center. Each of T-shaped lobes  11  comprises a head end  112  and a bottom end  111  wherein the bottom end  111  connects to the surface of the hollow stem  13 , and the head ends  112  of two adjacent T-shaped lobes  11  do not connect with one another to form an opening  12 . The opening  12  can be used as a ditch to drain moisture. 
       FIGS. 2A to 2H  schematically show the cross sections of the down-like fibers having different shaped lobes according to other embodiments of the present invention. As shown in  FIGS. 2A to 2H , the shaped lobes can be cross-shaped, Y-shaped, ̂-shaped, ♀-shaped, W-shaped, H-shaped, V-shaped or rectangular-shaped. The number of the shaped lobes is preferably from 2 to 6. That is because if the number of the shaped lobes is above 6, the design of spinning nozzles will become more complicate and thus lead to increasing the cost; however, if the number of the shaped lobes is too few, the drainage function and warm effect of fibers will be affected. 
       FIG. 3  shows a photograph of the cross section of physical samples of down-like fibers having T-shaped lobes. According to  FIG. 3 , due to the design of T-shaped lobes, those fibers can keep certain spaces to prevent from being tightly packed.  FIG. 4  schematically shows the arrangement of several down-like fibers having T-shaped lobes according to one embodiment of the present invention. In  FIG. 4 , since the head ends  112  of the adjacent T-shaped lobes  11  do not connect to each other, the opening  12  formed therefrom can be used as a ditch. Since water can be drained through the openings  12 , the fabrics woven by the fiber  10  demonstrate an outstanding drying effect after absorbing moisture or sweat. Also, many air rooms formed by the arrangement of the head ends  112  of the T-shaped lobes  11 , in combination with the closed hollow stems  13 , can further conserve heat emitted from a human body, thereby enhancing the warm effect. 
       FIG. 5A  schematically shows a spinneret for manufacturing a down-like fiber having T-shaped lobes according to one embodiment of the present invention. As shown in  FIG. 5A , a spinneret  20  comprises four “ ” shaped slits of spinning nozzles  21 . Each of slits of spinning nozzles  21  comprises an inner ring portion  211  and an outer lobe portion  213 , wherein the outer lobe portion  213  has a bottom end  215  and a head end  217  opposite the bottom end  215 , and the bottom end  215  connects to the inner ring portion  211 . The inner ring portions  211  of the four slits of spinning nozzles  21  are arranged in a circle at a regular interval, and the head ends  217  of two adjacent outer lobe portions  213  do not connect with one another to form an opening  22 . A polymer is extruded from the slits of spinning nozzles  21  which will further swell and connect at the inner ring portions  211  to form a hollow ring, thereby producing the fiber  10  shown in  FIG. 1 . 
     Polymers suitable for manufacturing fibers of the present invention include but not limited to polyester, nylon, polyolefin, polyacrylonitrile or cellulose, wherein polyester can be polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polypropylene terephthalate (PPT); nylon can be nylon 6 (N6) or nylon 66 (N66); and polyolefin can be polypropylene (PP) or polyethylene (PE). Besides, additives can be further added in the fibers of the present invention which include but not limited to antibacterial and antifungal agents, anti-conductive agents, deodorants, anti-ultraviolet agents or far-infrared agent. 
       FIG. 5B  schematically shows a spinneret used for manufacturing down-like fibers of  FIG. 2A  which have cross-shaped lobes according to one embodiment of the present invention. As shown in  FIG. 5B , the spinneret  30  comprises four “ ” shaped slits of spinning nozzles  31 . The outer lobe portion  313  of the slit of spinning nozzle  31  is “cross-shaped”. In other embodiments of the present invention, the outer lobe portion  313  can be Y-shaped, ↑-shaped, ♀-shaped, W-shaped, H-shaped, V-shaped or rectangular-shaped to manufacture down-like fibers having different shaped lobes shown in  FIGS. 2B to 2H . 
     The following further describes manufacturing examples of down-like fibers of the present invention and tests of effects. 
     EXAMPLE 1 
     Manufacture of Down-Like Staples Having T-Shaped Lobes 
     The polyester polymer in melting form is extruded through a spinneret as shown in  FIG. 5A  at spinning temperature of 290° C.; quenched by cooling air at a rate of 1.0 m/s; and spun at a spinning rate of 700 m/min. The filaments are drawn at a total elongation of 2.89 times followed by thermosetting at 160° C., cooling, wrinkling, oiling, drying, cutting, and packaging steps. The down-like staples of 3d*51 mm whose cross section is a hollow stem with four T-shaped lobes are thus obtained. 
     EXAMPLE 2 
     Manufacture of Down-Like Staples Having Cross-Shaped Lobes 
     The polyester polymer in melting form is extruded through a spinneret as shown in  FIG. 5B  at spinning temperature of 290° C.; quenched by cooling air at a rate of 1.0 m/s; and spun at a spinning rate of 700 m/min. The filaments are drawn at a total elongation of 2.89 times followed by being thermosetting at 160° C. , cooling, wrinkling, oiling, drying, cutting, and packaging steps. The down-like staples of 3d*51 mm whose cross section is a hollow stem with four cross-shaped lobes are thus obtained. 
     EXAMPLE 3 
     Manufacture of Down-Like Filament Textured Yarn Having T-Shaped Lobes 
     The polyester polymer in melting form is extruded through a spinneret as shown in  FIG. 5A  at spinning temperature of 290° C.; quenched by cooling air at a rate of 0.6 m/s; and winded at a spinning rate of 2500 m/min to produce 120/36 partially oriented yarns (POY). The yarns are drawn at a total elongation of 1.6 times followed by thermosetting at 160° C. and winding steps. The 75/36 down-like filament textured yarns whose cross section is a hollow stem with four T-shaped lobes are thus obtained. 
     EXAMPLE 4 
     Manufacture of Down-Like Filament Oriented Yarn Having T-Shaped Lobes 
     The polyester polymer in melting form is extruded through a spinneret as shown in  FIG. 5A  at spinning temperature of 290° C.; quenched by cooling air at a rate of 0.6 m/s; and spun at a spinning rate of 4000 m/min. The yarns are drawn at a total elongation of 2.0 times at the drawn temperature of 90° C. followed by thermosetting at 130° C. and winding steps. The 75/36 down-like filament oriented yarns whose cross section is a hollow stem with four T-shaped lobes are thus obtained. 
     Test 1: Evaporation Rate Test 
     The evaporation rate tests of fabrics woven by the down-like fibers having T-shaped lobes of the present invention, conventional hollow round polyester fibers, solid round polyester fibers and solid fibers having other shaped lobes are described below. 
     First, a sample of size 10×10 cm is placed in an environment of constant temperature and humidity (23° C., 65% RH) for 24 hours and then moved onto a scale. A given amount of water (W1, unit: gram) is dripped from 1 centimeter above the fabric by using a volumetric pipet. After 5 minutes, the remaining amount of water (W2, unit: gram) in the fabric is recorded and the evaporation rate is calculated based on the following formula: 
       Evaporation Rate=( W 1 −W 2)/ W 1×100%
 
     The test results are shown in Table 1. Sample 1 to 5 are double knit bird eye fabrics with a width of 36 inches*26 needles, which are respectively woven by staples having T-shaped lobes of the present invention, solid staples having 4T cross section, solid staples having cross cross section, solid round polyester fibers and hollow round polyester fibers (the above products are obtained from Shinkong Synthetic Fibers Corporation, in which the solid staples having 4T cross section have been issued Taiwan Patent no. 1374952). 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 sample 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 1 
                   
                   
                   
                   
               
               
                   
                 (the present 
                   
                   
                   
                 5 
               
               
                   
                 invention) 
                 2 
                 3 
                 4 
                 (comparative 
               
               
                   
                 down-like 
                 (comparative 
                 (comparative 
                 (comparative 
                 example) 
               
               
                   
                 staples 
                 example) 
                 example) 
                 example) 
                 hollow 
               
               
                   
                 having 
                 solid staples 
                 solid staples 
                 solid round 
                 round 
               
               
                   
                 T-shaped 
                 having 4T 
                 having cross 
                 polyester 
                 polyester 
               
               
                   
                 lobes 
                 cross section 
                 cross section 
                 fiber 
                 fiber 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 evaporation 
                 76.8 
                 73.5 
                 69.2 
                 50.1 
                 49.6 
               
               
                 rate (%) 
               
               
                   
               
            
           
         
       
     
     According to Table 1, the evaporation rate of the down-like fiber having T-shaped lobes provided by the present invention is around 76.8%, which is much better than 50.1% achieved by the solid round polyester fiber and 49.6% achieved by the hollow round polyester fiber. The test result demonstrates that since fibers of the present invention possess lobe structures as ditches, the fabric woven by fibers of the present invention can keep larger spaces between fibers, and thus facilitate drainage. The fibers of the present invention exhibit a fast drying effect compared with conventional hollow or solid round polyester fibers. Furthermore, the evaporation rate of fibers of the present invention is also higher than solid fibers having other cross sections (i.e. samples 2 and 3). This shows that compared with conventional solid fibers having 4T cross section or cross cross section, fibers of the present invention possess excellent drainage effect, and thus fabrics woven thereby can achieve fast drying effect without a muggy feeling. 
     Test 2: Warm-Keeping Test 
     The warm-keeping test of fabrics woven by down-like fibers having T-shaped lobes of the present invention is described below. The test is performed by AGEMA Thermal vision 900 thermal conductivity meter. A 500W halogen lamp is used as a heat source to irradiate a sample for 10 minutes at a distance of 100 centimeters. The temperature of the sample is measured before and after exposure to the light. Samples 1 to 4 represent double knit bird eye fabrics with a width of 36 inches*26 needles which are respectively woven by four different fibers, including down-like fibers having T-shaped lobes of the present invention, conventional solid fibers having 4T cross section, solid round polyester fibers and hollow round polyester fibers 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Before 
                 After 
                   
               
               
                   
                 Irradiation 
                 Irradiation 
                 Differences of 
               
               
                 Sample 
                 (° C.) 
                 (° C.) 
                 Temperatures 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 down-like fiber having 
                 23.1 
                 29.5 
                 +6.4 
               
               
                   
                 T-shaped lobes 
               
               
                   
                 (the present invention) 
               
               
                 2 
                 solid fibers having 4T 
                 23.2 
                 27.8 
                 +4.6 
               
               
                   
                 cross section 
               
               
                   
                 (comparative example) 
               
               
                 3 
                 solid round polyester 
                 23.1 
                 25.6 
                 +2.5 
               
               
                   
                 fiber 
               
               
                   
                 (comparative example) 
               
               
                 4 
                 hollow round 
                 23.2 
                 26.3 
                 +3.1 
               
               
                   
                 polyester fiber 
               
               
                   
                 (comparative example) 
               
               
                   
               
            
           
         
       
     
       FIG. 6  shows a bar graph based on the results of warm-keeping test. According to Table 2 and  FIG. 6 , the temperature of the fabric woven by fibers of the present invention is obviously raised after irradiation with a light source. The increase of temperature is much greater than those of round polyester fibers (i.e. sample 3 and sample 4), and a better warm effect is also presented compared with conventional solid fibers having 4T cross section (i.e. sample 2). 
     According to the above, the hollow stem of the down-like fiber provided by the present invention, which is like a feather stem, not only reduces the weight of fiber but also provides effect of keeping warm. Moreover, the shaped lobes around the main stem provide several air rooms due to disconnection of adjacent head ends. The ditch structures formed therefrom can further enhance the effects of heat conservation, and improve the effects of drainage and fast-drying. Accordingly, the down-like fibers provided by the present invention can overcome disadvantages of bird feathers, i.e. decrease in the effect of keeping warm as a result of moisture absorption, and of conventional fibers having shaped lobes which has a drainage function but a poor effect of keeping warm. Meanwhile, since the weight of fiber of the present invention has been reduced, a down-like touch feeling is reserved. 
     Exemplary embodiments have been described herein, but do not intend to limit the scope of the present invention. It will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and the scope encompassed by the appended claims. Therefore, the scope of the present invention is determined by the claims that follow.