Spunbond tower having electrostatic device

Abstract

The invention relates to a spunbond tower that includes a die ( 103 ), a device ( 106 ) for cooling the filaments formed by the die, a device ( 107 ) for stretching the cooled filaments, a system ( 108 ) for forming a non-woven web ( 110 ) on a mat, said system including an electrostatic device ( 117 ) and a dehumidifier mounted at least on a formation air inlet between the bottom of the stretching device and the top of the formation system.

1 . Spunbond tower successively comprising in a downward direction:
 a die forming filaments from plastics material,   a device for cooling the filaments formed by the die,   a device for drawing the filaments cooled by the cooling device and having a bottom, and   a system for forming, on a conveyor belt, a non-woven web from the filaments drawn by the drawing device, that system comprising a top and an electrostatic device and a forming air inlet being provided between the bottom of the drawing device and the top of the forming system, comprising a first dehumidifier for the forming air.   
     
     
         2 . Spunbond tower according to  claim 1 , comprising an air inlet into the drawing device and a second dehumidifier which is mounted on the drawing air inlet. 
     
     
         3 . Spunbond tower according to  claim 1 , in which the cooling device has a cooling air inlet, comprising a third dehumidifier which is mounted on the cooling air inlet. 
     
     
         4 . Spunbond tower according to  claim 2 , in which the cooling device has a cooling air inlet, comprising a third dehumidifier which is mounted on the cooling air inlet. 
     
     
         5 . Spunbond tower according to  claim 1 , in which an air inlet aperture is provided in the forming system, comprising a fourth dehumidifier for the air which is introduced via the aperture. 
     
     
         6 . Spunbond tower according to  claim 2 , in which an air inlet aperture is provided in the forming system, comprising a second dehumidifier for the air which is introduced via the aperture. 
     
     
         7 . Spunbond tower according to  claim 3 , in which an air inlet aperture is provided in the forming system, comprising a third dehumidifier for the air which is introduced via the aperture. 
     
     
         8 . Spunbond tower according to  claim 1 , wherein the first dehumidifier comprises, in a downstream direction in the direction in which the air is introduced into the tower, an air/water exchanger for cooling the air in order to condense the humidity therein to form water droplets, a droplet separator and a reheater in order to bring the relative humidity of the air to a value between 20% and 30%. 
     
     
         9 . Spunbond tower according to  claim 1 , which has an intake device below the conveyor belt, wherein the first dehumidifier is constituted by a device for recycling at least a portion of the forming air being introduced via the air inlet aperture the drawing air which is drawn in by the intake device at the forming air inlet. 
     
     
         10 . Spunbond tower according to  claim 3 , which has an intake device below the conveyor belt, wherein the third dehumidifier is constituted by a device for recycling at least a portion of the cooling air being introduced via the air inlet aperture the drawing air which is drawn in by the intake device at the cooling air inlet. 
     
     
         11 . Spunbond tower according to  claim 5 , which has an intake device below the conveyor belt, wherein the fourth dehumidifier is constituted by a device for recycling at least a portion of the air being introduced via the air inlet aperture the drawing air which is drawn in by the intake device at the inlet aperture of the forming system. 
     
     
         12 . Spunbond tower according to  claim 2 , which has an intake device below the conveyor belt, wherein the second dehumidifier is constituted by a device for recycling at least a portion of the air being introduced via the air inlet aperture the drawing air which is drawn in by the intake device at the drawing air inlet. 
     
     
         13 . Spunbond tower according to  claim 9 , comprising a humidity sensor at an air inlet in the tower, controlling, by means of a control device, an adjustment register of the air flow drawn in by the intake device. 
     
     
         14 . Spunbond tower according to  claim 9 , comprising a humidity sensor for air which is introduced into the tower, controlling, by means of a control device, a register adjusting the flow of air recycled. 
     
     
         15 . Spunbond tower according to  claim 9 , comprising below the conveyor two separate intake devices, one called a formation chamber intake device below the forming system and the other called a maintenance chamber intake device downstream of the formation chamber. 
     
     
         16 . Spunbond tower according to  claim 15 , characterised by a device for recycling the air of the maintenance chamber at the spunbond tower.