Method and apparatus for producing a composite nonwoven

Abstract

A method for producing a composite nonwoven in a continuous process sequence, and an apparatus for carrying out the method are provided. A fibrous web is formed by a carding device from a fiber strand, on the surface of which fibrous web subsequently a nonwoven layer of synthetic fibers is laid. To this end, the fibrous web is guided within a suction zone on a laydown belt to a melt-blowing device, in which the synthetic fibers are laid on the surface of the fibrous web by melt-blowing. The fibrous web which is covered with the nonwoven layer is subsequently laid by a nonwoven laying device in a plurality of layers to form the composite nonwoven.

1 . A method for producing a composite nonwoven in a continuous process sequence the method comprising the steps of:
 feeding a continuous fiber strand formed of fibers or fiber blends to a carding device;   carding and doffing of the fibers to form at least one fibrous web;   guiding of the fibrous web to a holding zone and holding the fibrous web at a running conveying means within the holding zone;   melt blowing a plurality of synthetic fibers extruded from a polymer melt and laying of the synthetic fibers to form a nonwoven layer on the fibrous web in the area of the holding zone;   leading the fibrous web with nonwoven layer out of the holding zone to a further processing device.   
     
     
         2 . A method in accordance with  claim 1 , wherein the fibrous web is sucked onto the conveying means in a holding zone designed as a suction zone. 
     
     
         3 . A method in accordance with  claim 1 , wherein the fibrous web passes through a plurality of suction areas located one after another with separately adjustable suction capacities within a suction zone. 
     
     
         4 . A method in accordance with  claim 1 , wherein the fibrous web with nonwoven layer is laid in a nonwoven laying device in a plurality of layers to form a composite nonwoven. 
     
     
         5 . A method in accordance with  claim 1 , wherein the fibers or fiber blends for forming the fibrous web are formed from synthetic fibers at a weight percentage in the range of 10% to 100%. 
     
     
         6 . A method in accordance with  claim 1 , wherein the fiber material of the synthetic fibers and the polymer melt for extruding the synthetic fibers are formed from an identical basic material. 
     
     
         7 . A method in accordance with  claim 1 , wherein the synthetic fibers are laid on the fibrous web with a fine fiber cross section in the range of 0.2μ to 3μ to form the nonwoven layer during melt blowing. 
     
     
         8 . A method in accordance with  claim 1 , wherein the fibrous web is led continuously at a belt speed in the range of 50 m/minute to 200 m/minute after doffing until laying. 
     
     
         9 . A method in accordance with  claim 1 , wherein a plurality of fibrous webs are doffed from the carding device one on top of another and put together in a sandwich pattern after melt blowing and laying of the synthetic fibers, the nonwoven layer forming an intermediate layer between the fibrous webs. 
     
     
         10 . A method in accordance with  claim 1 , wherein a plurality of fibrous webs are covered with a nonwoven layer each and the fibrous webs are brought together with the nonwoven layers before the further processing device comprising a nonwoven laying device, to form a multilayered nonwoven. 
     
     
         11 . A method in accordance with  claim 1 , wherein a composite nonwoven laid by a nonwoven laying device is fed continuously to a bonding device and bonded. 
     
     
         12 . A method in accordance with  claim 1 , wherein a composite nonwoven is bonded by heat treatment in a belt type drier, wherein the composite nonwoven is passed, during bonding, through a calibration zone, in which a calibrating belt, that is adjustable relative to a guide belt, acts on a free surface of the composite nonwoven. 
     
     
         13 . A method in accordance with  claim 1 , wherein a composite nonwoven is fed to a storage device and stored as a roll or as a stack. 
     
     
         14 . A device for producing a composite nonwoven, the device comprising:
 a carding device;   a doffer device;   a conveying device;   a further processing device   a station, for producing a nonwoven layer, provided between the doffer device and the further processing device, wherein the station comprises a melt-blowing device; and   a holding device arranged at the conveying device, the holding device being associated with the melt-blowing device.   
     
     
         15 . A device in accordance with  claim 14 , wherein the holding device comprises a suction device. 
     
     
         16 . A device in accordance with  claim 15 , wherein the suction device is arranged under a laydown belt, of the conveying device. 
     
     
         17 . A device in accordance with  claim 16 , wherein the suction device has a plurality of suction chambers for applying suction to the laydown belt and further comprising a separate control means associated with the suction chambers for setting a vacuum. 
     
     
         18 . A device in accordance with  claim 16 , wherein the melt-blowing device has a movable spinning head, which can be guided between an operating position above the laydown belt, and an inoperative position on a side next to the laydown belt. 
     
     
         19 . A device in accordance with  claim 14 , wherein the doffer device has two separate doffing sites, which cooperate with two belt arrangements of the conveying device for picking up and doffing a plurality of fibrous webs. 
     
     
         20 . A device in accordance with  claim 19 , wherein:
 the conveying device comprises a laydown belt; and   one of the belt arrangements cooperates with the laydown belt and that a second belt arrangement is arranged with a conveying section above the spinning head in parallel to the laydown belt.   
     
     
         21 . A device in accordance with  claim 20 , wherein the second belt arrangement has a second laydown belt and that a second spinning head of the melt-blowing device is associated with the second laydown belt. 
     
     
         22 . A device in accordance with  claim 14 , wherein the further processing device comprises a nonwoven laying device that cooperates with a conveyor belt device, a bonding device and a storage device, wherein the composite nonwoven laid by the nonwoven laying device is led to a roll or a stack in a storage station. 
     
     
         23 . A device in accordance with  claim 22 , wherein the bonding device has a belt type drier with a guide belt and with a calibrating belt arranged above the guide belt and that the calibrating belt is designed as a height-adjustable belt relative to the guide belt. 
     
     
         24 . A soundproofing nonwoven element, wherein the nonwoven element has a composite nonwoven and is manufactured by a method comprising the steps of:
 feeding a continuous fiber strand formed of fibers or fiber blends to a carding device;   carding and doffing of the fibers to form at least one fibrous web;   guiding of the fibrous web to a holding zone and holding the fibrous web at a running conveying means within the holding zone;   melt blowing a plurality of synthetic fibers extruded from a polymer melt and laying of the synthetic fibers to form a nonwoven layer on the fibrous web in the area of the holding zone;   leading the fibrous web with nonwoven layer out of the holding zone to a further processing device.