Process for bonding several layers of plastic film

A process for bonding a plurality of plastic films or a plurality of plastic bags into a block from which each plastic film or plastic bag is removable individually, said process comprising:

• arranging the plastic films or plastic bags in a stack and bonding the plastic films or plastic bags together in an edge zone of the stack by means of ultrasonic welding;
• providing said block with at least one securing hole;
• wherein the welds are separated from the removable plastic film or plastic bag by a perforation line;
• wherein every weld is surrounded by and disposed within a curve formed by an individual perforation line, said perforation line beginning at one outer edge of the plastic film or plastic bag and ends at the same outer edge;
• and
• said securing hole being distanced from each weld and disposed exterior to each perforation line.

Process for bonding a plurality of plastic films or a plurality of plastic bags into a block from which each plastic film or plastic bag is removable individually, comprising arranging the plastic films or plastic bags in a stack and bonding the plastic films or plastic bags together in an edge zone of the stack by means of ultrasonic welding;

• wherein the ultrasonic welding is carried out by a pen-shaped sonotrode which penetrates the plastic films or plastic bags that are to be welded and forms a welding ring while doing so;
• wherein the pen-shaped sonotrode has a projection with a larger diameter that, at the end of the welding operation, rests on the top plastic film or plastic bag of the stack;
• and
• wherein the projection has at least two points located opposite each other that are aimed at the stack in order to weld the top plastic films or plastic bags together.