Method and machines for filling flexible tubular-bag packages

Abstract

The invention relates to a tubular-bag machine and to a method for continuous or intermittent production of tubular-bag packages ( 02 ) which are filled with a product ( 03 ) in a tubular-bag machine ( 01 ) of this kind, the tubular-bag machine ( 01 ) comprising a screw-type metering device ( 10 ) in which a metering screw (OS) can be driven to rotate relative to a metering tube ( 06 ) for metering the product ( 03 ), and a compactor ( 07 ) by means of which the product ( 03 ) can be compacted by applying a vacuum and sucking out gas being provided ahead of, behind or within the metering tube ( 06 ), the compactor ( 07 ) comprising a suction bushing which is permeable to gas through fine pores and which extends coaxially with the metering tube ( 06 ), and at least part of the die suction bushing being surrounded by a vacuum chamber. By applying a vacuum, the pores of the suction bushing can be cleaned.

1 . A method for continuous or intermittent production of tubular-bag packages ( 02 ) which are filled with a product ( 03 ) in a tubular-bag machine ( 01 ), the tubular-bag machine ( 01 ) comprising a screw-type metering device ( 10 ) in which a metering screw ( 05 ) can be driven to rotate relative to a metering tube ( 06 ) for metering the product ( 03 ), and a compactor ( 07 ) by means of which the product ( 03 ) can be compacted by applying a vacuum and by sucking out gas being disposed ahead of, behind or within the metering tube ( 06 ), the compactor ( 07 ) comprising a suction bushing ( 17 ) which is preamble to gas through fine pores and which extends coaxially with the metering tube ( 06 ), and at least part of the suction bushing ( 17 ) being surrounded by a vacuum chamber ( 20 ), 
       the method comprising the following method steps, which are to be executed during a tubular-bag production process including multiple cyclically repeating work cycles:
 establishing a vacuum in the vacuum chamber ( 20 ) in a suctioning phase ( 27 ,  29 ,  30 ) during at least one work cycle in order to compact the product ( 03 ) by sucking out gas, 
 establishing pressure in the vacuum chamber ( 20 ) in a blowing phase ( 26 ,  28 ,  33 ) during at least one work cycle in order to clean the pores of the suction bushing ( 17 ) by blowing out product particles that adhere to the inside of the pores during the tubular-bag production process. 
 
     
     
         2 . The method according to  claim 1 ,
 characterized in that   the blowing phases ( 28 ,  33 ) are each executed after a regular number of work cycles, in particular during each work cycle.   
     
     
         3 . The method according to  claim 1 ,
 characterized in that   the blowing phases are each executed after lapse of a predefined process time.   
     
     
         4 . The method according to  claim 1 ,
 characterized in that   the effective vacuum during the suctioning phases ( 27 ,  29 ,  30 ) is measured using a pressure sensor ( 15 ).   
     
     
         5 . The method according to  claim 4 ,
 characterized in that   the process parameters during blowing of the suction bushing ( 17 ) are changed during the blowing phases ( 26 ,  28 ,  33 ) as a function of vacuum values measured using the pressure sensor ( 15 ).   
     
     
         6 . The method according to  claim 5 ,
 characterized in that   the duration of the blowing phases ( 26 ,  28 ) is changed as a function of the vacuum values measured using the pressure sensor ( 15 ).   
     
     
         7 . The method according to  claim 5 ,
 characterized in that   the pressure level in the blowing phases is changed as a function of the vacuum values measured using the pressure sensor ( 15 ).   
     
     
         8 . The method according to  claim 5 ,
 characterized in that   the blowing phases ( 26 ) are triggered as a function of a vacuum value ( 25 ) measured using the pressure sensor ( 15 ).   
     
     
         9 . The method according to  claim 8 ,
 characterized in that   the effective vacuum during a suctioning phase executed using a cleaned suction bushing is measured using a pressure sensor and is stored as an initial vacuum value ( 22 ), a limit value ( 23 ) for triggering the blowing phases being determined as a function of the initial vacuum value.   
     
     
         10 . The method according to  claim 1 ,
 characterized in that   the tubular-bag production process is interrupted or an error is reported if the vacuum pressure during the suctioning phases ( 27 ,  29 ,  30 ) measured using the pressure sensor ( 15 ) exceeds a predefined limit value ( 30 ).   
     
     
         11 . A tubular-bag machine ( 01 ) for continuous or intermittent production of tubular-bag packages ( 02 ) which are filled with a product ( 03 ), comprising a metering device ( 10 ) in which a metering screw ( 05 ) can be driven to rotate relative to a metering tube ( 06 ) for metering the product ( 03 ), a compactor ( 07 ) by means of which the product ( 03 ) can be compacted by applying a vacuum and by sucking out gas being provided ahead of, behind or within the metering tube ( 06 ), and the compactor ( 07 ) comprising a suction bushing ( 17 ) which is permeable to gas through fine pores and which extends coaxially with the metering tube ( 06 ), and at least part of the suction bushing ( 17 ) being surrounded by a vacuum chamber ( 20 ), and the vacuum chamber ( 20 ) being connectable to a vacuum source ( 12 ), and the compactor ( 07 ) being controlled by a controller ( 14 ) as a function of the tubular-bag production process ( 14 ) so as to establish a vacuum in the vacuum chamber ( 20 ) in suctioning phases ( 27 ,  29 ,  30 ) as a function of the process and to compact the product ( 03 ) by sucking out gas,
 characterized in that   the vacuum chamber ( 20 ) can selectively also be connected to a pressure source ( 11 ), the compactor ( 07 ) being controlled by the controller ( 14 ) as a function of the tubular-bag production process so as to establish a vacuum in the vacuum chamber ( 20 ) in blowing phases ( 26 ,  28 ,  33 ) as a function of the process, the pores of the suction bushing ( 17 ) being cleanable during the blowing phases ( 26 ,  28 ,  33 ) by blowing out product particles that adhere to the inside of the pores during the tubular-bag production process.   
     
     
         12 . The tubular-bag machine according to  claim 11 ,
 characterized in that   the effective vacuum in the vacuum chamber ( 20 ) and/or in the vacuum lines ( 16 ) can be measured using a pressure sensor ( 15 ).   
     
     
         13 . The tubular-bag machine according to  claim 11 ,
 characterized in that   the metering device ( 10 ) comprises a metering screw ( 05 ) with an associated metering tube ( 06 ) which are disposed immediately above the sealing jaws ( 08 ) for sealing the tubular-bag packages ( 03 ).   
     
     
         14 . The tubular-bag machine according to  claim 11 ,
 characterized in that   the screw-type metering device is configured in the manner of a feeding screw which is disposed in front of a storage tank ( 04 ) for intermediate storage of the product.