Patent ID: 8365506

Claim:
An apparatus ( 1 ) for closing tubular mesh bags of heat-sealable material from a longitudinal portion of constricted mesh ( 5 ) and from a portion of at least one plastic strip ( 4 ), with a width (D) greater than that of the longitudinal portion of constricted mesh and applied in a longitudinal direction on the mentioned longitudinal portion of constricted mesh, such that respective side bands ( 4 a , 4 b ) of the strip project on both sides of the constricted mesh, comprising a die ( 6 ) and a mobile carriage ( 15 ), between which the mesh and the strip can be arranged, the die being provided with a groove ( 6 a ) with a width (d) less than that of the strip and the carriage being movable according to an alternate linear back and forth movement between the extreme positions of start (A) and end (B) of run, towards the die, and vice versa, being assembled on the carriage, such that they automatically and consecutively operate the assembly formed by the mesh and the strip, as the carriage moves from the start position towards the final position of the run thereof, transverse constriction means ( 12 ) for a longitudinal portion of mesh, capable of constricting and applying the mentioned longitudinal portion of mesh against a portion of the plastic strip; introducing means ( 13 ) for compressing and introducing in the die the mentioned portion of constricted mesh and the portion of the strip on which the mesh is applied, causing the bending of the side bands of the strip towards the constricted mesh; and folding means ( 14 ) for folding the bent side bands of the strip over the constricted mesh; the apparatus further comprising: welding means ( 18 ) by the melting of the materials forming the mesh and the strip, suitable for forming one or several attachment sections ( 10 , 11 ) between the folded strip and the constricted mesh along the compressed portions of the mesh and of the strip, wherein the folding means ( 14 ) comprise at least one pushing body ( 14 a , 14 b ), provided with an arched concavity suitable for receiving the side bands ( 4 a , 4 b ) of the strip ( 4 ) and for gradually folding them over the constricted mesh ( 5 ) as said pushing body advances towards the die ( 6 ), when the carriage ( 15 ) moves in the same direction.