A method of closing a packaging tray comprises arranging a packaging tray between a lower tool and an upper tool of a sealing station, positioning a cover film above the packaging tray between the lower tool and the upper tool, and pressing together the cover film and the packaging tray by a lower sealing surface of the lower tool and an upper sealing surface of the upper tool cooperating with the lower sealing surface. During the pressing together, a connection is established between the cover film and the packaging tray along a sealing seam. While the cover film and the packaging tray are being pressed together, an overpressure is locally generated by supplying pressurized gas from a pressurized-gas source, the overpressure cooperating as a counterpressure with the lower sealing surface or with the upper sealing surface so as to press the cover film and the packaging tray together.

A method of closing a packaging tray comprises arranging a packaging tray between a lower tool and an upper tool of a sealing station, positioning a cover film above the packaging tray between the lower tool and the upper tool, and pressing together the cover film and the packaging tray by a lower sealing surface of the lower tool and an upper sealing surface of the upper tool cooperating with the lower sealing surface. During the pressing together, a connection is established between the cover film and the packaging tray along a sealing seam. While the cover film and the packaging tray are being pressed together, an overpressure is locally generated by supplying pressurized gas from a pressurized-gas source, the overpressure cooperating as a counterpressure with the lower sealing surface or with the upper sealing surface so as to press the cover film and the packaging tray together.

A method and apparatus for sealing a bag made of a polymeric material by applying heat activated layers on different portions of the bag, wherein the first adhesive layer and the second adhesive layer have respective heat activation temperatures below the softening point temperature of the polymeric material; after creasing the bag along a fold line, applying heat at a temperature below the softening point temperature of the polymeric material to activate the first adhesive layer and the second adhesive layer to adhesive states after the bag has been filled with contents; and folding the bag to form an adhesive-to adhesive seal by contact between the heat activated first adhesive layer and the heat activated second adhesive layer.

A method and apparatus for sealing a bag made of a polymeric material by applying heat activated layers on different portions of the bag, wherein the first adhesive layer and the second adhesive layer have respective heat activation temperatures below the softening point temperature of the polymeric material; after creasing the bag along a fold line, applying heat at a temperature below the softening point temperature of the polymeric material to activate the first adhesive layer and the second adhesive layer to adhesive states after the bag has been filled with contents; and folding the bag to form an adhesive-to adhesive seal by contact between the heat activated first adhesive layer and the heat activated second adhesive layer.

A heating unit is described and illustrated including at least two heating devices for at least partially heating with hot air end areas of package sleeves to be sealed, wherein the heating unit has an air supply device for supplying air to be heated to the heating devices, wherein the heating devices each have a heating element for producing hot air and a nozzle unit for blowing hot air produced in the heating device against the end area of the package sleeve. In order to be able to increase the leak tightness of the sealed end areas of the package sleeves without having to accept an excessive outlay and effort in terms of the equipment and/or in terms of the method for this, it has been proposed that the heating devices are each separately connected to the air supply device by means of at least one holder and are each separately held on the air supply device by means of the at least one holder.

A heating unit is described and illustrated including at least two heating devices for at least partially heating with hot air end areas of package sleeves to be sealed, wherein the heating unit has an air supply device for supplying air to be heated to the heating devices, wherein the heating devices each have a heating element for producing hot air and a nozzle unit for blowing hot air produced in the heating device against the end area of the package sleeve. In order to be able to increase the leak tightness of the sealed end areas of the package sleeves without having to accept an excessive outlay and effort in terms of the equipment and/or in terms of the method for this, it has been proposed that the heating devices are each separately connected to the air supply device by means of at least one holder and are each separately held on the air supply device by means of the at least one holder.

A method of closing a packaging tray comprises arranging a packaging tray between a lower tool and an upper tool of a sealing station, positioning a cover film above the packaging tray between the lower tool and the upper tool, and pressing together the cover film and the packaging tray by a lower sealing surface of the lower tool and an upper sealing surface of the upper tool cooperating with the lower sealing surface. During the pressing together, a connection is established between the cover film and the packaging tray along a sealing seam. While the cover film and the packaging tray are being pressed together, an overpressure is locally generated by supplying pressurized gas from a pressurized-gas source, the overpressure cooperating as a counterpressure with the lower sealing surface or with the upper sealing surface so as to press the cover film and the packaging tray together.

A method of closing a packaging tray comprises arranging a packaging tray between a lower tool and an upper tool of a sealing station, positioning a cover film above the packaging tray between the lower tool and the upper tool, and pressing together the cover film and the packaging tray by a lower sealing surface of the lower tool and an upper sealing surface of the upper tool cooperating with the lower sealing surface. During the pressing together, a connection is established between the cover film and the packaging tray along a sealing seam. While the cover film and the packaging tray are being pressed together, an overpressure is locally generated by supplying pressurized gas from a pressurized-gas source, the overpressure cooperating as a counterpressure with the lower sealing surface or with the upper sealing surface so as to press the cover film and the packaging tray together.

The seal plate assembly of this invention includes a base plate, an insulator pad positioned on the base plate, an electric heater pad positioned on the insulator pad and a pair of seal plates positioned on the electric heater pad, all of which have registering vacuum openings formed therein. The base plate, insulator pad, heater pad and seal plates are bolted together. The seal plates have spaced-apart cavities formed therein. A support plate is positioned in each of the cavities with each of the support plates having a length and width which is less than the length and width of the respective cavity to create a vacuum space at the perimeter of the support plates. The support plates are spaced above the bottom of the cavities.

The present invention relates to a method for bundle-packaging batches of products, wherein products are moved in a longitudinal running direction, grouped into batches and wrapped with a film of heat-shrinkable film. Each wrapped batch is heated to form a contraction of each sheet around said batch. Heating of a batch is performed by the circulation of at least one heated air stream and by the expulsion of said stream toward the interior of the enclosure of an oven provided, successively, with first and second sections; the sheet is cooled; during heating, along at least a part of the first section, a first air stream is shaped discontinuously and expelled toward the interior of said enclosure. The method consists, during heating, along said second section, in shaping a second stream as an air knife and expelling said air knife toward said sheet to be smoothed.