Apparatus and method for monitoring the transfer of a material web

Abstract

A machine, for at least one of producing and treating a web of fibrous material in which the web is guided along a web guide path by at least one web guide device from one of a web production section and a web input section to pass at least one web treatment device, includes a first apparatus configured for forming a transfer strip of the web and for transferring the transfer strip through the machine, the machine being configured for transferring the web along the web guide path in that the first apparatus is configured for forming the transfer strip which is a leading transfer strip of the web, for guiding the transfer strip through the machine, and for increasing the transfer strip to a full width of the web and thereby performing tail widening; and a second apparatus configured for detecting a break in the web, the second apparatus being configured for responding to a break in one of the transfer strip and the web during a transfer of the web and during an increase in a width of the transfer strip.

1 . A machine for at least one of producing and treating a web of fibrous material in which the web is guided along a web guide path by at least one web guide device from one of a web production section and a web input section to pass at least one web treatment device, said machine comprising:
 a first apparatus configured for forming a transfer strip of the web and for transferring the transfer strip through the machine, the machine being configured for transferring the web along the web guide path in that said first apparatus is configured for forming said transfer strip which is a leading transfer strip of the web, for guiding said transfer strip through the machine, and for increasing said transfer strip to a full width of the web and thereby performing tail widening; and   a second apparatus configured for detecting a break in the web, said second apparatus being configured for responding to a break in one of said transfer strip and the web during a transfer of the web and during an increase in a width of said transfer strip.   
   
   
       2 . The machine as claimed in  claim 1 , wherein said second apparatus is configured for responding to a break in one of said transfer strip and the web on a basis of at least one detection variable representing said width of said transfer strip, one of directly and indirectly. 
   
   
       3 . The machine as claimed in  claim 2 , wherein said at least one detection variable representing said width of said transfer strip is pressure. 
   
   
       4 . The machine as claimed in  claim 2 , wherein said second apparatus has at least one of an optical detection arrangement and a temperature detection arrangement in order one of to detect said break in the web and to provide said at least one detection variable. 
   
   
       5 . The machine as claimed in  claim 2 , wherein said second apparatus has at least one of a pressure detection arrangement and a pressure change detection arrangement in order at least one of to detect said break in the web and to provide a plurality of pressure values as said at least one detection variable. 
   
   
       6 . The machine as claimed in  claim 5 , wherein said second apparatus includes at least one of a vacuum device and a positive pressure device acting on one of the web and said transfer strip, wherein said at least one of said pressure detection arrangement and said pressure change detection arrangement is configured for detecting at least one instantaneous operating pressure of said at least one of said vacuum device and said positive pressure device acting on one of the web and said transfer strip. 
   
   
       7 . The machine as claimed in  claim 6 , wherein said at least one of said vacuum device and said positive pressure device is configured for at least participating in guiding one of the web and said transfer strip as part of the web guide device. 
   
   
       8 . The machine as claimed in  claim 6 , wherein said vacuum device includes at least one of a suction roll, a suction box, and a vacuum transport belt. 
   
   
       9 . The machine as claimed in  claim 8 , wherein said at least one of said pressure detection arrangement and said pressure change detection arrangement includes at least one pressure sensor which is arranged in one of said suction box and said blower box. 
   
   
       10 . The machine as claimed in  claim 9 , wherein said suction box includes a transfer suction zone and an operating suction zone, said transfer suction zone being assigned to said transfer strip, said operating suction zone being, together with said transfer suction zone, assigned to said full width of the web, said operating suction zone being one of connected and configured for being connected via said transfer suction zone to a vacuum source, said pressure sensor being arranged in said operating suction zone. 
   
   
       11 . The machine as claimed in  claim 6 , wherein said positive pressure device includes at least one of a blower roll, a blower box, and an air turn. 
   
   
       12 . The machine according to  claim 6 , further including an evaluation unit configured for (a) comparing one of a plurality of detected said pressure values and a plurality of consequential values dependent on said plurality of detected pressure values at least one of with one another and with at least one predefined reference value, and (b) outputting a break signal when at least one break condition is fulfilled. 
   
   
       13 . The machine as claimed in  claim 12 , wherein said evaluation unit is configured for comparing a magnitude of one of said plurality of detected pressure values and said plurality of consequential values corresponding to said plurality of detected pressure values recorded successively in order to check said break condition, said break condition being fulfilled when one of said plurality of detected pressure values and said plurality of consequential values deviates from a predefined reference curve. 
   
   
       14 . The machine as claimed in  claim 13 , wherein said break condition is fulfilled when one of (a) in a case of said vacuum device, a pressure value that is assigned to a later time is one of greater than and equal to a pressure value that is assigned to an earlier time, and (b) in a case of said positive pressure value device, a pressure value that is assigned to a later time is one of less than and equal to a pressure value that is assigned to an earlier time. 
   
   
       15 . The machine as claimed in  claim 13 , wherein said break condition is fulfilled when one of (a) in a case of said vacuum device, a pressure value assigned to a later time exceeds a pressure value assigned to an earlier time by a predefined threshold value, and (b) in a case of said positive pressure device, a pressure value assigned to a later time falls below a pressure value assigned to an earlier time by a predefined threshold value. 
   
   
       16 . The machine as claimed in  claim 13 , wherein said evaluation unit is configured for comparing one of said plurality of detected pressure values and said plurality of consequential values dependent on said plurality of detected pressure values with one said predefined reference value in order to test a tail-widening finished condition which is fulfilled when said pressure value reaches a threshold value corresponding to said predefined reference value. 
   
   
       17 . The machine as claimed in  claim 16 , wherein said second apparatus is configured for being changed over to a normal operation monitoring mode when said tail-widening finished condition is fulfilled. 
   
   
       18 . The machine as claimed in  claim 1 , wherein the machine is configured for initiating at least one reactive measure automatically in response to detecting said break in one of said transfer strip and the web in order at least one of to avoid damage to the machine as a result of said break and to prepare for a renewed transfer of the web. 
   
   
       19 . The machine as claimed in  claim 18 , wherein said at least one reactive measure is at least one of triggering a web knock-off, setting components of the machine into one of a waiting and a safe state, activating one of said positive pressure device and said vacuum device for said renewed transfer of the web, and activating said first apparatus for said renewed transfer of the web. 
   
   
       20 . A machine for at least one of producing and treating a web of fibrous material in which the web is guided along a web guide path by at least one web guide device from one of a web production section and a web input section to pass at least one web treatment device, said machine comprising:
 an apparatus including a vacuum device and at least one pressure sensor, said vacuum device including a suction box, said at least one pressure sensor arranged in said suction box and being configured for detecting an operating pressure of said vacuum device, said apparatus being configured for detecting a break in the web on a basis of a detected said operating pressure of said vacuum device.   
   
   
       21 . The machine as claimed in  claim 20 , wherein the machine is configured for forming a transfer strip of the web, said suction box including a transfer suction zone and an operating suction zone, said transfer suction zone being assigned to said transfer strip, said operating suction zone being, together with said transfer suction zone, assigned to a full width of the web, said operating suction zone being one of connected and configured for being connected via said transfer suction zone to a vacuum source, said pressure sensor being arranged in said operating suction zone. 
   
   
       22 . An apparatus, comprising:
 structure configured for monitoring a transfer of a web of fibrous material along a web guide path of a machine for at least one of producing and treating said web such that said transfer of said web is carried out in that a leading transfer strip of said web is guided through said machine and a width of said transfer strip is increased to a full width of said web such that tail widening is thereby performed, said structure being configured for monitoring, during said transfer of said web, for a break in one of said transfer strip and said web.   
   
   
       23 . The apparatus as claimed in  claim 22 , wherein said structure is configured for monitoring, during said transfer of said web, for said break in said transfer strip on a basis of at least one detection variable representing said width of said transfer strip.