Method and device for the production of a one-layered or multilayered nonwoven fabric

Abstract

The invention relates to a method for the production of a one-layered or multilayered nonwoven fabric, a machine for the production of such a nonwoven fabric, and a correspondingly produced nonwoven fabric. The task of improving such a method and a production apparatus underlies the invention to the effect that projecting loops and fibrils no longer stick out, and thus individual filaments can be prevented from pulling out during the use of the nonwoven fabric. According to the invention, this is achieved in that the nonwoven fabric is smoothed after water needling by the use of a calendar. The machine according to the invention is characterized by the fact that the machine has a spun bonded fabric, at least one subsequent needling device, a dryer connected thereto, and thereafter at least one calendar.

1 . A method for producing a one-layer or a multilayer nonwoven fabric with a plurality of yarn-type fiber groups or endless filaments, which are joined at least in the area of connecting locations, characterized in that following the water needling, the nonwoven fabric is smoothed with the aid of a calender. 
   
   
       2 . The method according to  claim 1 , characterized in that following the water needling, the nonwoven fabric is smoothed with the aid of a calender and that the calender is adjusted in such a way that more than 90% of the tensile strength of the nonwoven fabric is retained in conveying direction. 
   
   
       3 . The method according to  claim 1 , characterized in that relative to the water needling, the nonwoven fabric is reduced in volume by 25% to 15%, or 22 to 18%, or by approximately 20%. 
   
   
       4 . The method according to  claim 1 , characterized in that the area subjected to pressure measures approximately 16% to 25%, or 17% to 22%, or 18% to 20% of the total surface area of the nonwoven fabric. 
   
   
       5 . The method according to  claim 1 , characterized in that the nonwoven fabric is treated with a smoothing roll temperature of between 120° and 155°, or between 125° and 150°, or between 130° and 150°, or between 140° and 150° C. 
   
   
       6 . The method according to  claim 1 , characterized in that the nonwoven fabric is treated with an engraving temperature between 120° and 155°, or between 125° and 150°, or between 130° and 150°, or between 140° and 150° C. 
   
   
       7 . The method according to  claim 1 , characterized in that the nonwoven fabric is treated with an engraving temperature that is approximately between 120° and 155°, or between 125° and 150°, or between 130° and 150°, or between 140° and 150° C., and that a line pressure of between 20 and 30 or between 24 and 28 N/mm is used during the subsequent calendering. 
   
   
       8 . The method according to  claim 1 , characterized in that a drying operation takes place between the water needling and the calendering. 
   
   
       9 . The method according to  claim 1 , characterized in that the nonwoven fabric is perforated (openings  6 . 1 ) as a result of the water needling. 
   
   
       10 . The method according to  claim 1 , characterized in that a nonwoven fabric with a weight per unit area of 7 to 300 g/m 2  is processed. 
   
   
       11 . The method according to  claim 1 , characterized in that the processing speed is at least 100 m/min. 
   
   
       12 . The method according to  claim 1 , characterized in that the nonwoven fabric has a fiber strength (diameter of the filaments) of between 0.4-10 dtex. 
   
   
       13 . An apparatus for realizing the production method according to  claim 1 , characterized in that the apparatus comprises a spun-bonding plant, at least one downstream connected needling device and an adjoining dryer, which is followed by at least one calender. 
   
   
       14 . The apparatus according to  claim 13 , characterized in that the apparatus comprises a spun-bonding plant for depositing the filaments on an endless belt, embodied as a screen belt, as well as at least one downstream connected needling device, an adjoining dryer, and at least one calender that follows the dryer. 
   
   
       15 . The apparatus according to  claim 13 , characterized in that the apparatus comprises the following:
 a spun-bonding plant;   a down-stream arranged pre-needling device that can be admitted with low water pressure;   an adjoining second needling device with thereto assigned at least one structured drum with a suction box;   an adjoining dryer;   and at least one calender that follows the dryer.   
   
   
       16 . The apparatus according to  claim 13 , characterized in that the apparatus comprises a spun-bonding plant, by means of which the filaments are deposited on a drum, as well as a needling device that is directly assigned to the drum, the adjoining dryer, and at least one calender that follows the dryer. 
   
   
       17 . The apparatus according to  claim 16 , characterized in that the drum is embodied as a structured drum. 
   
   
       18 . The apparatus according to  claim 1 , characterized in that at least one conveying drum is assigned to the structured drum, such that the endless belt is guided S-shaped or in the form of two semi-circles across the structured drum and the conveying drum. 
   
   
       19 . The apparatus according to  claim 16 , characterized in that the endless belt is embodied as a conveying belt or as a structured belt. 
   
   
       20 . A nonwoven fabric, characterized in that the nonwoven fabric is produced in accordance to  claim 1 .