Abstract: An apparatus is used for coating a web of material or a sheet of material with a hot-melt adhesive (14). In order to simplify the application of hot-melt adhesive to webs of material or sheets of material, it is provided that the apparatus (10; 110) has a heated surface (25; 124) and a supply roller (16) with hot-melt adhesive (14) movable perpendicular to its axis of rotation, the web of material or the sheet of material being movable relative to the supply roller (16) while in contact with the heated surface, a pressure apparatus, which presses the supply roller (16) against the heated surface (25: 124), and a drive apparatus being provided, which drive apparatus causes the supply roller (16) to roll on the web of material or the sheet of material.

Abstract: An impulse welding bar (10) for welding plastics films is provided with a detachable non-stick coating (20) which is held on lateral flanks (24) of the impulse welding bar (10). In order to facilitate the replacement of a worn non-stick coating (20), retaining elements (22) are provided which are made of two or more parts and which act in a form-fitting manner in order to detachably fasten the non-stick coating (20) to both flanks (24) of the impulse welding bar (10), wherein first parts (26) of the retaining elements (22) are arranged on the flanks (24) of the impulse welding bar (10) and second parts (36) of the retaining elements (22) are arranged on the non-stick coating (20).

Abstract: An impulse welding bar (10) for welding plastics films is provided with a detachable non-stick coating (20) which is held on lateral flanks (24) of the impulse welding bar (10). In order to facilitate the replacement of a worn non-stick coating (20), retaining elements (22) are provided which are made of two or more parts and which act in a form-fitting manner in order to detachably fasten the non-stick coating (20) to both flanks (24) of the impulse welding bar (10), wherein first parts (26) of the retaining elements (22) are arranged on the flanks (24) of the impulse welding bar (10) and second parts (36) of the retaining elements (22) are arranged on the non-stick coating (20).

Abstract: The invention relates to a device for the preferably continuous welding of plastic films by means of hot gas with at least one tubular body through which an electric current flows for the heating of the hot gas, wherein the device comprises at least one gas inlet opening (6, 106) and a plurality of gas outlet openings (12, 112) arranged next to each other, from which hot gas is blown onto the plastic film. It is provided that the at least one gas inlet opening (6, 106) is provided on a main tubular body (4, 104), which stands in gas communication with a plurality of branch tubular bodies (8, 108) at branching points (10, 110), wherein the branch tubular bodies (8, 108) each have at least one gas outlet opening (12, 112) and all the branch tubular bodies (8, 108) have electric current flowing through them.

Abstract: The invention relates to a device for the preferably continuous welding of plastic films by means of hot gas with at least one tubular body through which an electric current flows for the heating of the hot gas, wherein the device comprises at least one gas inlet opening (6, 106) and a plurality of gas outlet openings (12, 112) arranged next to each other, from which hot gas is blown onto the plastic film. It is provided that the at least one gas inlet opening (6, 106) is provided on a main tubular body (4, 104), which stands in gas communication with a plurality of branch tubular bodies (8, 108) at branching points (10, 110), wherein the branch tubular bodies (8, 108) each have at least one gas outlet opening (12, 112) and all the branch tubular bodies (8, 108) have electric current flowing through them.

Abstract: A device for welding plastic sheets using of hot gas heated in a tubular conduit through which an electric current flows. The device has at least one gas inlet and several gas outlet openings the electrical resistance of which changes depending on the temperature. At least one metal strip is electrically connected to the tubular conduit in the segment of the tubular conduit which is provided with the gas outlet openings in order to influence the temperature differences of the hot gas flows exiting the individual gas outlet openings. The segment of the tubular conduit provided with the gas outlet openings is located between two gas inlet openings which are arranged at an axial distance. At least one metal strip is attached in the central area of this segment of the tubular conduit.

Abstract: A device for welding plastic sheets using of hot gas heated in a tubular conduit through which an electric current flows. The device has at least one gas inlet and several gas outlet openings the electrical resistance of which changes depending on the temperature. At least one metal strip is electrically connected to the tubular conduit in the segment of the tubular conduit which is provided with the gas outlet openings in order to influence the temperature differences of the hot gas flows exiting the individual gas outlet openings. The segment of the tubular conduit provided with the gas outlet openings is located between two gas inlet openings which are arranged at an axial distance. At least one metal strip is attached in the central area of this segment of the tubular conduit.

Abstract: A process and device are used to weld plastic sheets with hot gas. Conventionally for welding with hot gas, the gas was conveyed over an electrically heated body. However, temperature fluctuations occurred that were difficult to correct and the result was a relatively high power consumption. In order to make a precise temperature guidance with a favorable efficiency possible, the gas is blown through a tubular heat conductor (10) with outlet openings (16) in its circumference wall and against a plastic sheet, and the tube body (10) is heated by an electrical current that is controlled by at least one temperature sensor exposed to the temperature of the tube body and/or the hot gas. Preferably, the tube body (10) itself is used as a temperature sensor, while its resistance, which changes with the temperature, is used to control the current intensity.