Process and an apparatus for producing coarse count and tridimensional crimped multifilament bcf yarns, yarns thus obtained and applications thereof

Abstract

The coarse count and tridimensional crimped multifilament BCF yarns having controlled chemical-physical and mechanical properties according to the present invention are suitable for non-textile applications and are preferably and advantageously employed in the manufacture of carpets for large surfaces.

1 - 12 . (canceled) 
     
     
         13 . A process for producing coarse count and tridimensional crimped multifilament BCF yarns, comprising the following steps:
 arranging polyamide 6.6 as starting material (step  100 );   drying said polyamide 6.6 with nitrogen (step  101 );   extruding said polyamide 6.6, thus obtaining filaments ( 6   a ) (step  102 );   immediately downstream the extrusion, cooling in water the filaments ( 6   a ) obtained in the previous step  102  at a predetermined temperature ranging between 17° C. and 50° C. and for a predetermined time ranging between 0.5 seconds and 0.8 seconds, thus obtaining coarse count multifilament BCF yarns ( 6   b ) (step  103 );   subjecting to a non-mechanical treatment with a mixture of air and steam said coarse count multifilament BCF yarns ( 6   b ) obtained in the previous step  103 , wherein the amounts of air and steam are in a predetermined ratio between them ranging between 30:70 by volume and 60:40 by volume, thus obtaining coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) (step  104 ).   
     
     
         14 . A process according to  claim 13 , wherein the cooling in water takes place in a tank placed at a distance equal to or lower than 5 mm from the exit from an extruder, at a speed ranging between 5,800 mm/second and 8,300 mm/second, wherein the temperature of the cooling water is equal to 35° C., and wherein the cooling time is equal to 0.6 seconds. 
     
     
         15 . A process according to  claim 14 , wherein the cooling in water takes place at a speed equal to 6,000 mm/second. 
     
     
         16 . A process according to  claim 15 , wherein the amounts of air and steam are in a ratio 45:55 by volume. 
     
     
         17 . A process according to  claim 16 , wherein the obtained coarse count multifilament BCF yarns have a total count equal to or higher than 4,000 decitex and wherein each filament has a count up to 420 decitex. 
     
     
         18 . A process according to  claim 17 , further comprising the following step:
 between step  101  and step  102 , adding coloring substances.   
     
     
         19 . An apparatus ( 1 ) for producing coarse count and tridimensional crimped multifilament BCF yarns using polyamide 6.6 as starting material, comprising:
 a feed hopper ( 2 ) for feeding said polyamide 6.6;   a drying tower ( 3 ) for drying said polyamide 6.6 with nitrogen;   an extruder ( 4 ) for extruding said polyamide 6.6, thus obtaining filaments ( 6   a );   immediately downstream the extruder ( 4 ), at a distance equal to or lower than 5 mm from the exit from the extruder ( 4 ), a tank ( 5 ) for cooling in water said filaments ( 6   a ), thus obtaining coarse count multifilament BCF yarns ( 6   b );   a device ( 7 ) comprising a compartment ( 8 ) and a tube ( 9 ) placed inside said compartment ( 8 ), said compartment ( 8 ) being suitable to house a mixture of air and steam and said tube ( 9 ) being suitable to host said coarse count multifilament BCF yarns ( 6   b ) previously obtained, thus obtaining coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ).   
     
     
         20 . An apparatus ( 1 ) according to  claim 19 , further comprising:
 means ( 10 ) for winding said coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ).   
     
     
         21 . An apparatus ( 1 ) according to  claim 19 , further comprising:
 means ( 20 ) for cutting said coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ).   
     
     
         22 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) using polyamide 6.6 as starting material and obtained through the process according to  claim 13 , having total count in the range 4,000 decitex to 8,000 decitex, with each filament having a count in the range 44.44 decitex to 420 decitex, and having controlled chemical-physical and mechanical properties, i.e. the amorphicity/crystallinity degree that ranges between 70/30% and 50/50%, the basicity that ranges between 4 French degrees and 10 French degrees, the dyeing affinity that ranges between 80% and 95%, the elasticity that ranges between 30% and 100% and the tenacity that ranges between 15 cNW/tex and 50 cNW/tex. 
     
     
         23 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) according to  claim 22  having the amorphicity/crystallinity degree equal to 60/40%, the basicity equal to 7 French degrees, the dyeing affinity higher than 90%, the elasticity in the range between 40% and 70% and the tenacity equal to 30 cNW/tex. 
     
     
         24 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) according to  claim 23 , having the elasticity equal to 60%. 
     
     
         25 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) according to  claim 24 , which are in a wound form. 
     
     
         26 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) according to  claim 24 , which are in a cut form. 
     
     
         27 . A carpet ( 50 ) made with coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) according to  claim 25  having stain-resistant properties and wear resistance. 
     
     
         28 . Coarse count and tridimensional crimped multifilament BCF yarns ( 6   c ) using polyamide 6.6 as starting material and obtained through the apparatus according to  claim 19 , having total count in the range 4,000 decitex to 8,000 decitex, with each filament having a count in the range 44.44 decitex to 420 decitex, and having controlled chemical-physical and mechanical properties, i.e. the amorphicity/crystallinity degree that ranges between 70/30% and 50/50%, the basicity that ranges between 4 French degrees and 10 French degrees, the dyeing affinity that ranges between 80% and 95%, the elasticity that ranges between 30% and 100% and the tenacity that ranges between 15 cNW/tex and 50 cNW/tex.