Nozzle plate

Abstract

The present invention provides a nozzle plate and the use of the nozzle plate for producing filaments, preferably silica gel fibers.

1 . A nozzle plate comprising at least one nozzle with a nozzle opening, wherein the nozzle opening has a cross-sectional area of size A 1 , wherein a tear-off edge with an angle β in a range from 5° to 90° extends around the nozzle opening, wherein an area which immediately adjoins the nozzle opening outside the nozzle and extends around the nozzle opening has an area of the size A 2 , and wherein a ratio A 2 /A 1  is not more than 20. 
     
     
         2 . The nozzle plate as claimed in  claim 1 , wherein the ratio A 2 /A 1  is not more than 15, optionally not more than 10. 
     
     
         3 . The nozzle plate as claimed in  claim 1 , wherein the angle β of the tear-off edge is in a range from 10° to 90°, optionally in a range from 20° to 90°. 
     
     
         4 . The nozzle plate as claimed in  claim 1 , wherein the nozzle plate has a number of nozzles in a range from 1 to 1000. 
     
     
         5 . The nozzle plate as claimed in  claim 4 , wherein each nozzle comprises a channel which is initially cylindrical, then tapers conically in a flow direction down to a cross-sectional area of size A 1  and again extends cylindrically to the nozzle opening, wherein a cylinder adjoining the nozzle opening has a length L and a diameter D, and wherein the following applies to a ratio L/D: 0.5≦L/D≦10. 
     
     
         6 . The nozzle plate as claimed in  claim 5 , wherein the ratio L/D is in a range 1 to 5, optionally in a range from 1.5 to 3. 
     
     
         7 . The nozzle plate as claimed in  claim 4 , wherein each nozzle take a form of a nozzle insert which is inserted into a corresponding opening in the nozzle plate. 
     
     
         8 . A nozzle plate as claimed in  claim 1  for capable of producing a filament, which optionally comprises silica gel fibers. 
     
     
         9 . A method of producing a filament comprising using a nozzle plate as claimed in  claim 1 . 
     
     
         10 . A method of  claim 9 , wherein said filament comprises a silica gel fiber.