Device and Method for Transporting Material Webs and for Fixing Said Webs on a Counter Bearing

Abstract

The aim of the invention is to improve devices ( 3 ) for transporting material webs ( 1 ) and for fixing said webs ( 1 ) on a counter bearing ( 4 ). Said devices ( 3 ) have the following characteristics: at least one transport roller ( 2, 2 a, 2 b ) for transporting the material webs ( 1 ) and means for applying an electrostatic charge (q) to at least parts ( 8 ) of the material web ( 1 ), wherein the electrostatic forces of said charge (q) aid in the fixing of said parts on a counter bearing. The novelty and inventive step of the invention is that at least one transport roller ( 2, 2 a , 2 b ) comprises means for applying an electrostatic charge (q) to at least parts ( 8 ) of the material web ( 1 ). The invention also claims a method for operating a device of this type.

1 . Device for transporting material webs ( 1 ) and for fixing said webs ( 1 ) on a counter bearing ( 4 ), which device ( 3 ) has the following characteristics:
 at least one transport roller ( 2 ,  2   a ,  2   b ) for transporting the material webs ( 1 ) and   means for applying an electrostatic charge ( 25 ) to at least parts ( 8 ) of the material web ( 1 ), wherein the electrostatic forces of said charge ( 25 ) aid in the fixing of said parts on a counter bearing,   
     characterized in that 
     at least one transport roller ( 2 ,  2   a ,  2   b ) comprises means for applying an electrostatic charge ( 25 ) to at least parts ( 8 ) of the material web ( 1 ). 
   
   
       2 . Device according to  claim 1 ,
 characterized in
 that the device comprises a winding device ( 3 ), using which the material web ( 1 ) can be fixed and wound up on a winding core ( 4 ), and 
 that the at least one transport roller ( 2 ,  2   a ,  2   b ), which has means for applying an electrostatic charge ( 25 ) to at least parts of the material web ( 1 ), is the last roller ( 2 ,  2   a ,  2   b ) before the winding core ( 4 ) in the transport direction (z) of the material web ( 1 ). 
   
   
   
       3 . Device according to one of the preceding claims,
 characterized in that   the means for applying an electrostatic charge ( 25 ) to at least parts ( 8 ) of the material web ( 1 ) are contained inside or on the peripheral surface of the transport roller ( 2 ,  2   a ,  2   b ).   
   
   
       4 . Device according to one of the preceding claims,
 characterized in that   the means for applying an electrostatic charge ( 25 ) to at least parts ( 8 ) of the material web ( 1 ) comprise electrically conductive plastic material ( 27 ).   
   
   
       5 . Device according to one of the preceding claims,
 characterized in that   the at least one transport roller ( 2 ,  2   a ,  2   b ), which comprises means for applying an electrostatic charge ( 25 ) to at least parts of the material web ( 1 ), has a plurality of electrodes ( 15 ,  27 ,  31 ) in the region of its peripheral surface.   
   
   
       6 . Device according to the preceding claim,
 characterized in that   at least one part of the electrodes ( 15 ,  27 ,  31 ) is shaped in a needle-like manner, wherein the tip of the needle points in the radial direction (r) away from the rotation axis of the transport roller ( 2 ,  2   a ,  2   b ).   
   
   
       7 . Device according to one of the two preceding claims,
 characterized in that   at least one part of the electrodes ( 15 ,  27 ,  31 ) is located in the radial direction (r) of the transport roller ( 2 ,  2   a ,  2   b ) inside the outer peripheral surface of said roller ( 2 ,  2   a ,  2   b ).   
   
   
       8 . Device according to one of the three preceding claims,
 characterized in that   a voltage is applied to at least one part of the electrodes ( 15 ,  27 ,  31 ) by a common line ( 31 ).   
   
   
       9 . Device according to the preceding claim,
 characterized in that   the common line ( 31 ) is formed from a metal film or a metal wire, preferably of copper.   
   
   
       10 . Device according to one of the preceding claims,
 characterized in that   at least one part of the electrodes ( 15 ,  27 ,  31 ) is connected to their voltage source ( 34 ) by means of a resistor ( 27 ).   
   
   
       11 . Device according to the preceding claim,
 characterized in that   at least one part of the resistors ( 27 ) consists of a conductive plastic material ( 14 ).   
   
   
       12 . Device according to the preceding claim
 characterized in that   the electrodes ( 15 ,  27 ,  31 ) are embedded at least partially in the conductive plastic material ( 14 ).   
   
   
       13 . Method for transporting material webs ( 1 ) and for fixing said webs ( 1 ) on a counter bearing ( 4 ),
 wherein the material webs ( 1 ) are conveyed by at least one transport roller ( 2 ,  2   a ,  2   b ), and   wherein an electrostatic charge ( 25 ) is applied to at least one part of the material web,   wherein the electrostatic forces coming from this charge ( 25 ) aid in fixing said parts on the counter bearing ( 4 ),   and is characterized in that   the application of the electrostatic charge ( 25 ) to at least parts of the material web ( 1 ) is carried out with the help of devices ( 14 ,  15 ,  27 ,  31 ) integrated in at least one transport roller ( 2 ,  2   a ,  2   b ).   
   
   
       14 . Method according to the preceding claims
 characterized in that   several material webs ( 1 ) or material tubes are transported one upon the other and that the charge transferred by the transport roller ( 2 ,  2   a ,  2   b ) to the material web ( 1 ) aids in fixing different material webs on top of each other or in fixing the upper side of tubes on the lower side thereof.   
   
   
       15 . Method according to the preceding claim, characterized in
 that electrostatic charge ( 25 ) is transferred from parts of at least two transport rollers ( 2 ,  2   a ,  2   b ) to the material webs ( 1 ) or material tubes, and   that electrostatic charge ( 25 ) is transferred from parts of at least one first transport roller ( 2 ,  2   a ,  2   b ) to the upper material web or the upper side of the material tube and   that electrostatic charge ( 25 ) is transferred from parts of at least one second transport roller ( 2 ,  2   a ,  2   b ) to the lower material web or the lower side of the film tube.   
   
   
       16 . Method according to one of the preceding claims,
 characterized in that   the charge transferred from parts of at least one transport roller ( 2 ,  2   a ,  2   b ) aid in fixing one end ( 8 ) of the material web ( 1 ) on a winding core ( 4 ), and   that when fixing the material web ( 1 ) on the winding core ( 4 ), the position of the winding core ( 4 ) and of the transport roller ( 2 ,  2   a ,  2   b ) is adjusted in such a way relative to one another that an air gap ( 9 ) exists between the winding core ( 2 ) [sic;  4 ] and this transport roller ( 2 ,  2   a ,  2   b ).   
   
   
       17 . Method according to the preceding claim,
 characterized in that   the width of the air gap ( 9 ) is adjusted to at least 1 millimeter.   
   
   
       18 . Method according to the preceding claim,
 characterized in that   the width of the air gap ( 9 ) is adjusted to at least 2 millimeters.