Plastic Bag, in Particular FFS Bag, and Method and Device for Producing and Filling a Bag

Abstract

The invention relates to a plastic bag, in particular an FFS bag, comprising a first wall and a second wall, which are joined to each other by means of side edges or side folds and by means of bottoms and which bound a bag interior, wherein at least one bottom comprises a weld seam, which extends between the side edges and touches the side edges, and venting openings in the first and/or in the second wall for venting the bag interior, characterized in that at least one channel is provided on the outside of at least one wall, which channel covers the venting openings and is formed by at least two parallel fastening strips and by a cover strip, wherein the cover strip likewise comprises venting openings and wherein the shortest path between the parallel fastening strips along the cover strip is longer than the shortest path along the at least one wall between the parallel fastening strips or the cover strip and/or the parallel fastening strips consist of stretchable material.

1 . A plastic bag, in particular an FFS bag, comprising a first wall and a second wall which are connected to one another by side edges or side folds and by bottoms and bound a bag interior,
 wherein at least one bottom comprises a weld seam which runs between the side edges and contacts them,   and comprising vent openings in the first and/or in the second wall for venting the bag interior,   characterized in that   at least one channel is provided on the outside of at least one wall which channel covers the vent openings and which is formed at least by two parallel fastening strips and a cover strip, wherein the cover strip also comprises openings and wherein the shortest path between the parallel fastening strips along the cover strip is longer than the shortest path along the at least one wall between the parallel fastening strips or the cover strips and/or the parallel fastening strips consist of stretchable material.   
     
     
         2 . The plastic bag according to  claim 1 ,
 characterized in that   the shortest path between the parallel fastening strips along the cover strip is at least 3% longer than the shortest path along the at least one wall.   
     
     
         3 . The plastic bag according to  claim 1 ,
 characterized in that   a layer of a filter material is provided inside the channel.   
     
     
         4 . The plastic bag according to  claim 1 ,
 characterized in that   a layer consisting of a filter material is provided in the bag interior, wherein the filter material covers the venting openings.   
     
     
         5 . The plastic bag according to  claim 1 ,
 characterized in that   the air permeability of the venting openings in the at least one wall is greater than the air permeability of the cover strip.   
     
     
         6 . The plastic bag according to  claim 1 ,
 characterized in that   the venting openings of the cover strip are at a distance from at least one bottom by a maximum of one half a bag length, in particular by a maximum of one third of the bag length.   
     
     
         7 . The plastic bag according to  claim 1 ,
 characterized in that   the plastic bag comprises side folds and in that the venting openings of the covering strip have at least one distance to the closest welding seam, which distance corresponds to the side fold depth.   
     
     
         8 . The plastic bag according to  claim 1 ,
 characterized in that   the plastic bag comprises side folds and in that the channel extends over at least one outer corner or inner corner of the side fold.   
     
     
         9 . A method for manufacturing and filling a bag, in particular a bag according to  claim 1 , wherein
 a roller with a hose web is made available,   the hose web is wound off from the roller in a winding-off device,   the hose web is provided with a bottom on its front end in a bag forming device, preferably by producing a cross wielding seam,   a hose piece is separated from the hose web in the bag forming device,   the hose piece is transported by moving holding elements to a filling device,   the bag is filled with a filling material, wherein the air entering with the filling material into the interior of the bag is at least partially conducted outward via venting openings in at least one outer wall of the bag, and   wherein the air is conducted into a channel located on the outer side of a wall,   
       characterized in that 
       the volume of the channel is enlarged 
       by the conducting of air into the channel which covers the venting openings and which is formed at least by two parallel fastening strips and by one covering strip, wherein the covering strip also comprises venting openings, and wherein the shortest path between the parallel fastening strips is longer along the covering strip than the shortest path along the at least one wall between the parallel fastening strips or the covering strips, and/or the parallel covering strips consist of stretchable material. 
     
     
         10 . The method according to the previous claim,
 characterized in that after the filling, the bag is transported at least by other movable holding elements to a closing device in which the bag is closed at its second end.   
     
     
         11 . The method according to the previous claim, characterized in that the bag is placed on a transport device after the closing at its second end so that the cover strip faces the upper side and/or one of the side surfaces. 
     
     
         12 . A device for producing and filling a bag, in particular for carrying out a method according to  claim 1 , comprising:
 a winding-off device in which a hose web can be wound off from a roller,   a bag forming device in which the hose web can be provided on its front end with a bottom, wherein a welding device for producing a transverse welding seal is preferably provided and in which a hose piece can be separated from the hose web,   movable holding elements with which the hose piece can be transported to a filling device, and   a filling device in which the bag can be filled with a filling material, wherein the air entering with the filling material into the bag interior at least partially via venting openings in at least one outer wall of the bag, can be conducted outwards,   wherein the air can be guided into a channel located on the outer side of a bag wall,   
       characterized in that 
       at least one device for facilitating the venting is provided with which the conducting of the air into the channel can be facilitated, 
       which channel covers the venting openings and which is formed at least by two parallel fastening strips and one covering strip, wherein the covering strip also comprises venting openings, and wherein the shortest path between the parallel fastening strips along the covering strip is longer than the shortest path along the at least one wall between the parallel fastening strips or the covering strips and/or the parallel fastening strips consist of stretchable material, wherein the volume of the channel is increased. 
     
     
         13 . The device according to the previous claim, characterized in that the device for facilitating the venting comprises at least one welding beam which is adapted to the contour of the bag in the area of the covering strip. 
     
     
         14 . The device according to  claim 12 ,
 characterized in that that the device for facilitating the venting comprises at least one transport and/or guide roller the diameter of which, viewed in the axial direction, varies.   
     
     
         15 . The device according to  claim 12 ,
 characterized in that the device for facilitating the venting comprises at least one web guide device with which the hose web can be guided, wherein the hose piece produced from the web comprises a cover strip facing in the filling station in the direction of the bag forming device.   
     
     
         16 . The device according to  claim 13 ,
 characterized in that the device for facilitating the venting comprises at least one placing device with which the bag can be placed with its head facing in a transport direction onto a transport device so that the cover strip faces the upper side and/or one of the side surfaces.   
     
     
         17 . The device according to  claim 13 ,
 characterized in that the device for facilitating the venting comprises at least one agitation device with which the filling material can be set in vibrations.