Polyester nonwoven fabric with suppressed reduction in physical properties by tufting process, method for manufacturing same, and backing fabric for carpet comprising same

Abstract

The present invention relates to a polyester nonwoven fabric with suppressed reduction in physical properties by a tufting process, a method for manufacturing same, and a backing fabric for a carpet, comprising same and, in particular, to: a polyester nonwoven fabric in which, by controlling the physical properties of fibers of a first component filament and a second filament, a reduction in physical properties is remarkably suppressed before/after a tufting process, thus enabling the manufacture of a carpet backing fabric with excellent mechanical properties; a method for manufacturing same; and a backing fabric for a carpet, manufactured thereby.

1 . A polyester-based nonwoven fabric comprising:
 a first component filament containing a first polyester having a melting point of 250° C. to 300° C.; and   a second component filament containing a second polyester having a melting point of 160° C. to 220° C.,   wherein the stiffness before tufting process measured by the measurement method specified in ASTM D 6125-97 is 100 mg to 300 mg in both the machine direction (MD) and the cross direction (CD).   
     
     
         2 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the machine direction stiffness(S MD ) and the cross direction stiffness(S CD ) of the polyester-based nonwoven fabric before tufting process satisfy the following conditional expression 1).   
       
         
           
             
               
                 
                   
                     0.95 
                     ≤ 
                     
                       
                         S 
                         MD 
                       
                       / 
                       
                         S 
                         CD 
                       
                     
                     ≤ 
                     1.05 
                   
                 
                 
                   
                     1 
                     ) 
                   
                 
               
             
           
         
       
     
     
         3 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the first polyester has an intrinsic viscosity of 0.65 dl/g to 0.80 dl/g.   
     
     
         4 . The polyester-based nonwoven fabric according to  claim 1 , which is formed by fusing the second component filament. 
     
     
         5 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the second polyester is a copolyester formed by the copolymerization of at least one acid component selected from terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate, and at least one diol component selected from 1,4-butanediol(BD), ethylene glycol(EG), and neopentyl glycol(NPG).   
     
     
         6 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the polyester-based nonwoven fabric has a deviation between the machine direction (MD) tensile strength (T MD,0 ) and the cross direction (CD) tensile strength (T CD,0 ) before the tufting process of T CD,0 ×0.05 or less, and   has a reduction rate of tensile strength after the tufting process in both the machine direction and the cross direction of less than 60%.   
     
     
         7 . The polyester-based nonwoven fabric according to  claim 6 , wherein:
 the polyester-based nonwoven fabric has both T MD,0  and T CD,0  5 cm before the tufting process of 25 kgf/5 cm to 35 kgf/5 cm.   
     
     
         8 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the polyester-based nonwoven fabric includes the first component filament and the second component filament in a weight ratio of 85:15 to 90:10.   
     
     
         9 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the polyester-based nonwoven fabric has a heat shrinkage rate in the machine direction of 1.5% or less and a heat shrinkage rate in the cross direction of 1.0% or less, as measured according to the following measurement method.   [Measurement Method]   A pattern with a size of 20 cm×20 cm is drawn on a nonwoven fabric sample with a size 25 cm×25 cm in both the machine direction and the cross direction, this is preheated and then removed on a preheating plate at 180° C. for 3 minutes using a Mathis oven, and the shrunken length is measured to calculate the shrinkage rate.   
     
     
         10 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the polyester-based nonwoven fabric has a tearing strength before the tufting process of in both the machine direction and the cross direction of 7 kgf to 13 kgf.   
     
     
         11 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the polyester-based nonwoven fabric satisfies the following conditional expressions 2) and 3).   
       
         
           
             
               
                 
                   
                     
                       I 
                       . 
                       V 
                       
                         . 
                         2 
                       
                     
                     > 
                     
                       I 
                       . 
                       V 
                       
                         . 
                         1 
                       
                     
                   
                 
                 
                   
                     2 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     0.05 
                     ≤ 
                     
                       
                         ( 
                         
                           I 
                           . 
                           V 
                           
                             . 
                             2 
                           
                           
                             - 
                             
                               I 
                               . 
                               V 
                               
                                 . 
                                 1 
                               
                             
                           
                         
                         ) 
                       
                       / 
                       
                         I 
                         . 
                         V 
                         
                           . 
                           1 
                         
                       
                     
                     ≤ 
                     0.5 
                   
                 
                 
                   
                     3 
                     ) 
                   
                 
               
             
           
         
         in the conditional expressions 2) and 3), I.V. 1  and I.V. 2  respectively represent the intrinsic viscosity of the first polyester and the intrinsic viscosity of the second polyester. 
       
     
     
         12 . The polyester-based nonwoven fabric according to  claim 1 , wherein:
 the first component filament has a fineness of 7 denier to 10 denier, and the second component filament has a fineness of 2 denier to 4 denier, and   the number of filaments of the first component filament is included by a factor in the range of two to five times the number of filaments of the second component filament.   
     
     
         13 . A backing fabric for a carpet comprising the polyester-based nonwoven fabric according to  claim 1 . 
     
     
         14 . A method for manufacturing a polyester-based nonwoven fabric, the method comprising the steps of:
 1) blend-spinning a first polyester with a melting point of 250° C. to 300° C. and a second polyester with a melting point of 160° C. to 220° C. and laminating the web to form a blended web; and   2) heat-bonding the blended web with hot air having a temperature of 0° C. to 10° C. or higher than the melting point of the second polyester; thereby manufacturing a nonwoven fabric in which both a bending strength in the machine direction and a stiffness in the cross direction before the tufting process are 100 mg to 300 mg.   
     
     
         15 . The method for manufacturing a polyester-based nonwoven fabric according to  claim 14 , wherein:
 in step 1), the first polyester and the second polyester are stretched at a speed of 4,500 m/min to 5,200 m/min to form the first component filament and the second component filament, respectively.