Woven or knitted cloth containing two different yarns from and exhibiting reduction of interstitial rate in becoming wet

Abstract

A woven or knitted fabric, formed from two types of yarns different in self-elongating property upon absorbing water and capable of increasing the opening area (%) when wetted with water compared with that in dry condition, is constituted so that a ratio A/B of a mean length A of yarns (1) having a high self-elongating upon absorbing water to a mean length B of yarns (2) arranged in the same direction as that of the yarn (1) and having a lower self-elongating upon absorbing water than that of the yarn (1) is adjusted to more than 0.9.

1 . A woven or knitted fabric containing two types of yarns different in self-elongating property upon absorbing water, from each other, wherein when a test piece is prepared from the fabric in such a manner that said woven or knitted fabric is stabilized in dimension in the atmosphere having a temperature at 20° C. and a relative humidity at 65% and then cut into pieces of 30 cm long in the warp or wale direction and 30 cm long in the weft or course direction; and yarns (1) having a high water-absorbing and self-elongating property and yarns (2) having a low water-absorbing and self-elongating property and respectively contained in the test pieces satisfy the following requirement:  
         A/B> 0.9  
     wherein A represents a mean length of the yarns (1) having high water-absorbent and self-elongative property and B represents a mean length of said yarns (2) having low water-absorbing and self-elongating property, the yarns (1) and (2) being arranged in the same direction as each other in the test piece and picked up from the test piece; the length of the respective yarn being measured under a load of 1.76 mN/dtex when the yarn is a non-elastic yarn having an elongation at break of 200% or less or under a load of 0.0088 mN/dtex when the yarn is an elastic yarn having an elongation at break higher than 200%, and whereby an opening area percentage of the fabric decreases when wetted with water.  
   
   
       2 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein when the two types of yarns (1) and (2) different in the water-absorbing, self-elongating property are respectively subjected to a measurement of self-elongation upon absorbing water in such a manner that each of the yarns is wound 10 times around a reel for a hank having a circumference of 1.125 m long under a load of 0.88 mN/dtex to form a hank; the hank is removed from the reel and left to stand in the air atmosphere having a temperature at 20° C. and a relative humidity at 65% for 24 hours to dry the hank; then the length (Ld, m) of the dry hank is measured under a load of 1.76 mN/dtex when the yarn is a non-elastic yarn having an elongation at break of 200% or less, or under a load of 0.0088 mN/dtex when the yarn is an elastic yarn having an elongation at break higher than 200%; the hank is immersed in water at a temperature at 20° C. for 5 minutes; then the hank is taken out from water; a length (Lw, m) of the wet hank is measured under the same load as described above in response to the elongation at break of the hank; and the self-elongation of each yarn is calculated in accordance with the following equation:  
       Self-elongation of yarn (%)=[( Lw−Ld )/( Ld )]×100  one (1) of the two type of yarns is a high water-absorbing, self-elongating yarn having a mean self-elongation of +5% or more and the other (2) is a low water-absorbing, self-elongating yarn having a mean self-elongation lower than +5%.    
   
   
       3 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , wherein the difference (E (1) −E (2) ) between the self-elongation (E (1) ) upon absorbing water of the yarn (1) and the self-elongation E (2) ) upon absorbing water of the yarn (2) is in a range of from 5 to 35%.  
   
   
       4 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , having a circular knitting structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form composite yarn loops in the circular knitting structure.  
   
   
       5 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , having a weave structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form at least one of warp and weft of the woven fabric.  
   
   
       6 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein the yarns (1) and the yarns (2) are arranged alternately with every at least one yarn in at least one direction selected from the warp and weft directions of a woven fabric structure or in at least one direction selected from the wale and course directions in a knitted fabric structure.  
   
   
       7 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein at least one of the yarns (1) is combined with at least one of the yarn (2) to form a composite yarn.  
   
   
       8 . The woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein fibers from which the yarn (1) having a high water-absorbing and self-elongating property is constituted, are selected from polyetherester fibers formed from polyetherester elastomer comprising hard segments comprising polybutylene terephthalate blocks and soft segments comprising polyoxyethylene glycol blocks.  
   
   
       9 . A woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein fibers from which the yarn (2) having a low water-absorbing and self-elongating property is constituted, are selected from polyester fibers.  
   
   
       10 . A woven or knitted fabric containing two different types of yarns as defined by  claim 1 , wherein when the fabric is subjected to a measurement of change in opening area of the fabric in such a manner that a plurality of test pieces of the woven or knitted fabric are left to stand in the air atmosphere having a temperature at 20° C. and a relative humidity at 65% for 24 hours to prepare a plurality of dry test pieces, and separately a plurality of other test pieces of said woven or knitted fabric are immersed in water at a temperature at 20° C. for 5 minutes, then taken out from water, and sandwiched between a pair of filter papers under the pressure of 490 N/m 2  for one minute to remove water existing in the interstices between fibers in the test pieces to prepare a plurality of wet test pieces, surfaces of each of the dry and wet test pieces are observed by an optical microscope at a magnification of 20 and the opening areas of the dry and wetted test pieces are calculated in accordance with the following equation:  
       Opening area (%)=[(total area of openings between yarns)/(observed area)]×100  then, a mean value of the measured opening areas of each of the dry and wetted test piece are calculated and a change between the mean opening area of the wetted test pieces and the mean opening area of the dry test pieces was calculated in accordance with the following equation:      Change in opening area (%)=[(mean opening area of dry test pieces)−(mean opening area of wetted test pieces)]/(mean opening area of dry test pieces)×100, and    the resultant change in the yarn gap area is at least 10%.    
   
   
       11 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , having a circular knitting structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form composite yarn loops in the circular knitting structure.  
   
   
       12 . The woven or knitted fabric containing two different types of yarns as defined by  claim 3 , having a circular knitting structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form composite yarn loops in the circular knitting structure.  
   
   
       13 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , having a weave structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form at least one of warp and weft of the woven fabric.  
   
   
       14 . The woven or knitted fabric containing two different types of yarns as defined by  claim 3 , having a weave structure in which the yarns (1) and (2) are combined in parallel with each other, and the combined yarns form at least one of warp and weft of the woven fabric.  
   
   
       15 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , wherein the yarns (1) and the yarns (2) are arranged alternately with every at least one yarn in at least one direction selected from the warp and weft directions of a woven fabric structure or in at least one direction selected from the wale and course directions in a knitted fabric structure.  
   
   
       16 . The woven or knitted fabric containing two different types of yarns as defined by  claim 3 , wherein the yarns (1) and the yarns (2) are arranged alternately with every at least one yarn in at least one direction selected from the warp and weft directions of a woven fabric structure or in at least one direction selected from the wale and course directions in a knitted fabric structure.  
   
   
       17 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , wherein at least one of the yarns (1) is combined with at least one of the yarn (2) to form a composite yarn.  
   
   
       18 . The woven or knitted fabric containing two different types of yarns as defined by  claim 3 , wherein at least one of the yarns (1) is combined with at least one of the yarn (2) to form a composite yarn.  
   
   
       19 . The woven or knitted fabric containing two different types of yarns as defined by  claim 2 , wherein fibers from which the yarn (1) having a high water-absorbing and self-elongating property is constituted, are selected from polyetherester fibers formed from polyetherester elastomer comprising hard segments comprising polybutylene terephthalate blocks and soft segments comprising polyoxyethylene glycol blocks.  
   
   
       20 . The woven or knitted fabric containing two different types of yarns as defined by  claim 3 , wherein fibers from which the yarn (1) having a high water-absorbing and self-elongating property is constituted, are selected from polyetherester fibers formed from polyetherester elastomer comprising hard segments comprising polybutylene terephthalate blocks and soft segments comprising polyoxyethylene glycol blocks.