Method and a Device for Heat-Sealing a Film/Foil Onto a Peripheral Top Edge of a Packaging and Such a Packaging

Abstract

The invention relates to a method for sealing an opening of a packaging, in which the packaging includes at least a peripheral wall with a peripheral top edge. The peripheral top edge forms the contour of the opening, including the following process steps: positioning a flexible film/foil layer over the peripheral top edge in such a way that the opening is completely covered and the film/foil layer overhangs beyond the peripheral top edge; heat-sealing the film/foil layer to the peripheral top edge of the packaging; folding the part of the film/foil layer overhanging beyond the opening towards the peripheral wall; heat-sealing the folded-over film/foil layer to the peripheral wall at a distance from the peripheral top edge, in which case a contact point of a device for heat-sealing the folded-over film/foil layer to the peripheral wall at a distance from the peripheral top edge does not move with respect to the film/foil layer during the heat-sealing, at least for as long as the contact point is in contact with the film/foil layer. The invention also relates to a device for heat-sealing according to the above method, and to a packaging manufactured in this way.

1 . A method for sealing an opening of a packaging, in which the packaging comprises at least a peripheral wall with a peripheral top edge, which peripheral top edge forms the contour of the opening, comprising the following process steps:
 a. positioning a flexible film/foil layer over the peripheral top edge in such a way that the opening is completely covered and the film/foil layer overhangs beyond the peripheral top edge;   b. heat-sealing the film/foil layer to the peripheral top edge of the packaging;   c. folding the part of the film/foil layer overhanging beyond the opening towards the peripheral wall;   d. heat-sealing the folded-over film/foil layer to the peripheral wall at a distance from the peripheral top edge, wherein a contact point of a device for heat-sealing the folded-over film/foil layer to the peripheral wall at a distance from the peripheral top edge does not move with respect to the film/foil layer during the heat-sealing, at least for as long as the contact point is in contact with the film/foil layer.   
     
     
         2 . The method according to  claim 1 , wherein the contact point approaches the film/foil layer only in a direction towards the peripheral wall and forces the film/foil layer towards the peripheral wall during heat-sealing. 
     
     
         3 . The method according to  claim 1 , wherein the heat-seal locations are uniformly distributed on the peripheral wall of the packaging in a peripheral direction. 
     
     
         4 . The method according to  claim 1 , wherein the part of the film/foil layer overhanging beyond the peripheral top edge is arranged in wave- or zigzag-shaped folds when heat-sealing the film/foil layer against the peripheral wall of the packaging at the at least one heat-seal location. 
     
     
         5 . The method according to  claim 1 , wherein the at least one contact point moves in a substantially circular motion towards the heat-seal location on the peripheral wall of the packaging during folding over in step c, the centre of the circle being situated on the plane of the peripheral top edge. 
     
     
         6 . The method according to  claim 1 , wherein the folding in step c is performed with at least one directional component perpendicular to a plane which is enclosed by the peripheral top edge. 
     
     
         7 . The method according to  claim 1 , wherein the film/foil layer is also punched before and/or during one of the steps a-c. 
     
     
         8 . The method according to  claim 1 , wherein the film/foil layer is heat-sealed to the peripheral top edge so as to be medium-tight with the packaging. 
     
     
         9 . The method according to  claim 1 , wherein the heat-seal on the peripheral top edge and/or the peripheral wall of the packaging is detachable. 
     
     
         10 . A device for sealing an opening of a packaging with a film/foil, wherein the packaging comprises at least a peripheral wall with a peripheral top edge, which peripheral top edge forms the contour of the opening, the device comprising
 a holder for the packaging;   means for positioning a flexible film/foil layer over the peripheral top edge in such a way that the opening is completely covered and the film/foil layer overhangs beyond the peripheral top edge;   a first heat-seal element   which is movable to and from the opening of a packaging placed in the holder and   is configured to heat-seal a film/foil layer onto the peripheral top edge of a packaging placed in the holder;   a bending element for bending the part of the film/foil overhanging beyond the peripheral top edge over the peripheral top edge as far as against the peripheral wall of a packaging;   a second heat-seal element,   which is movable to and from the peripheral wall of a packaging placed in the holder, wherein the second heat-seal element, at least when touching the peripheral wall, is only movable perpendicularly to the plane of the packaging and the film/foil folded against it.   
     
     
         11 . The device according to  claim 10 , wherein the second heat-seal element is at least movable in a direction towards the peripheral wall, and wherein the second heat-seal element is configured to force the film/foil layer towards the peripheral wall during heat-sealing. 
     
     
         12 . The device according to  claim 10 , wherein the device also comprises a punching member configured for punching the film/foil layer. 
     
     
         13 . The device according to  claim 10 , wherein the bending element, the first and the second heat-seal element are formed by one component. 
     
     
         14 . A packaging, comprising a bottom, a peripheral wall which extends from the bottom and has a peripheral top edge on the side facing away from the bottom, which peripheral top edge forms the contour of an opening, a flexible film/foil layer which completely covers the opening and overhangs beyond the peripheral top edge, a first heat-seal which extends on and is substantially limited by the peripheral top edge, and a second heat-seal by means of which the part of the film/foil extending beyond the peripheral top edge is bonded to the peripheral wall, at a distance from the peripheral top edge , wherein the first and second heat-seal are produced by fusing at least the film/foil.