Method for producing a spunbond nonwoven

Abstract

The invention relates to a process (100) for the production of spunbonded nonwoven (1) wherein a spinning mass (2) is extruded through the nozzle holes (4) of at least one spinneret (3, 30) to form filaments (5, 50), the filaments (5, 50) are drawn in the extrusion direction and deposited on a first conveying device (9) to form the spunbonded nonwoven (1), and wherein the spunbonded nonwoven (1) is subjected to at least one washing (10). For increasing the throughput of the process without losses of quality, it is suggested that the spunbonded nonwoven (1) is subjected to the washing (10) at least partially on a perforated second conveying device (13) with a lower conveying speed with respect to that of the first conveying device (9), wherein the spunbonded nonwoven (1) is sprayed with washing liquid during the washing (10) and the washing liquid is discharged at least partially through the perforated second conveying device (13).

1 . A process for the production of spunbonded nonwoven ( 1 ) wherein a spinning mass ( 2 ) is extruded through the nozzle holes ( 4 ) of at least one spinneret ( 3 ,  30 ) to form filaments ( 5 ,  50 ), the filaments ( 5 ,  50 ) are drawn in the extrusion direction and deposited on a first conveying device ( 9 ) to form the spunbonded nonwoven ( 1 ), and wherein the spunbonded nonwoven ( 1 ) is subjected to at least one washing ( 10 ), characterized in that the spunbonded nonwoven ( 1 ) is subjected to the washing ( 10 ) at least partially on a perforated second conveying device ( 13 ) with a lower conveying speed with respect to that of the first conveying device ( 9 ), wherein the spunbonded nonwoven ( 1 ) is sprayed with washing liquid during the washing ( 10 ) and the washing liquid is discharged at least partially through the perforated second conveying device ( 13 ). 
     
     
         2 . A process according to  claim 1 , characterized in that the conveying speed of the second conveying device ( 13 ) is reduced by a factor of between 1 and 1000, in particular by a factor of between 1 and 100, particularly preferably by a factor of between 1 and 25, with respect to the first conveying device ( 9 ). 
     
     
         3 . A process according to  claim 1  or  2 , characterized in that the spunbonded nonwoven ( 1 ) is deposited in loops ( 14 ) on the second conveying device ( 13 ). 
     
     
         4 . A process according to any of  claims 1  to  3 , characterized in that, after washing ( 10 ), the spunbonded nonwoven ( 1 ) is subjected to further treatment steps ( 11 ,  12 ) on a third conveying device ( 15 ) at a conveying speed that is higher with respect to that of the second conveying device ( 13 ). 
     
     
         5 . A process according to  claim 4 , characterized in that the conveying speed of the third conveying device ( 15 ) is increased by a factor of between 1 and 1000, in particular by a factor of between 1 and 100, particularly preferably by a factor of between 1 and 25, with respect to the second conveying device ( 13 ). 
     
     
         6 . A process according to  claim 4  or  5 , characterized in that the third conveying device ( 15 ) has essentially the same conveying speed as the first conveying device ( 9 ). 
     
     
         7 . A process according to any of  claims 1  to  6 , characterized in that the spunbonded nonwoven ( 1 ) is subjected to hydroentanglement ( 11 ) and/or drying ( 12 ) after the washing ( 10 ). 
     
     
         8 . A process according to any of  claims 1  to  7 , characterized in that the washing ( 10 ) is a multi-stage countercurrent washing. 
     
     
         9 . A process according to any of  claims 1  to  8 , characterized in that the spunbonded nonwoven ( 1 ) is deposited on the second conveying device ( 13 ) directly after it has been deposited and formed on the first conveying device ( 9 ). 
     
     
         10 . A process according to any of  claims 1  to  9 , characterized in that the spunbonded nonwoven ( 1 ) is deposited on the second conveying device ( 13 ) directly before the washing ( 10 ). 
     
     
         11 . A process according to any of  claims 1  to  10 , characterized in that the spinning mass ( 2 ) is extruded into filaments ( 5 ,  50 ) through at least a first spinneret ( 3 ) and a second spinneret ( 30 ), wherein the filaments ( 5 ) of the first spinneret ( 3 ) are deposited on the first conveying device ( 9 ) to form a first spunbonded nonwoven ( 1 ) and the filaments ( 50 ) of the second spinneret ( 30 ) are deposited on the first conveying device ( 9 ) to form a second spunbonded nonwoven, wherein the filaments ( 50 ) of the second spinneret ( 30 ) are deposited on the first conveying device ( 9 ) to form the second spunbonded nonwoven over the first spunbonded nonwoven ( 1 ) in order to obtain a multi-layered spunbonded nonwoven. 
     
     
         12 . A process according to  claim 11 , characterized in that the multi-layered spunbonded nonwoven is unravelled into at least the first spunbonded nonwoven ( 1 ) and the second spunbonded nonwoven in a subsequent step, particularly after the washing ( 10 ). 
     
     
         13 . A process according to any of  claims 1  to  12 , characterized in that the spunbonded nonwoven ( 1 ) is a cellulosic spunbonded nonwoven ( 1 ) and the spinning mass ( 2 ) is a solution of cellulose in a direct solvent, particularly a tertiary amine oxide. 
     
     
         14 . A process according to any of  claims 1  to  13 , characterized in that the filaments ( 5 ,  50 ) are coagulated at least partly after the extrusion from the spinneret ( 3 ,  30 ), whereby in particular a coagulation air stream ( 7 ) comprising a coagulation liquid is assigned to the spinneret ( 3 ,  30 ) for the at least partial coagulation of the filaments ( 5 ,  50 ). 
     
     
         15 . A process according to any of  claims 1  to  14 , characterized in that the coagulation liquid is a mixture of water and the direct solvent for cellulose, particularly a tertiary amine oxide.