The invention relates to a process for the production of at least two-layer thermoplastic sheets via thermal welding of at least one thinner thermoplastic sheet with density (D1) and of at least one second thinner thermoplastic sheet with density (D2), where the density (D1) of the first thinner thermoplastic sheet is smaller than the density (D2) of the second thinner thermoplastic sheet. The process introduces at least one first heating element and at least one second heating element along mutually offset planes between the two thinner thermoplastic sheets, where the surfaces of the thinner thermoplastic sheets do not touch the surfaces of the heating elements. The first heating element transfers a quantity of energy (E1) to the surface of the first thinner thermoplastic sheet, and the second heating element transfers a quantity of energy (E2) to the surface of the second thinner thermoplastic sheet, where the quantity of energy (E1) is smaller than the quantity of energy (E2).

A device, a method and a movable welding apparatus for thermal joining of respective two material sheets over a connecting piece arranged areally on a bottom side, wherein the material sheets are arranged with a respective side surface facing one another abutting against each other at least partially with a respective bottom side lying areally on a top side of the connecting piece are provided. In particular, the two material sheets and the connecting piece can be joined together in one pass.

An automatic welding machine for thermally joining sheets of material, in particular for edge side joining of an overlapping upper material sheet to a lower of material sheet, to be connected to one another in a materially bonded manner under the application of heat and subsequent application of pressure, is provided comprising: a heating device for at least partially heating the material sheets to be joined in a connection region; a support frame with a housing; a pressure roller; at least two traveling rollers; wherein the pressure roller and the traveling rollers are arranged on the support frame and together with the support frame form a chassis, wherein the chassis comprises a longitudinal axis and a transverse axis perpendicular thereto, which span a chassis plane; wherein at least a first travelling roller of the two travelling rollers and/or the heating device is arranged to be movable by a telescopic pull-out relative to the support frame in directions parallel to the transverse axis; wherein the first travelling roller and the heating device are with respect to a longitudinal center of the chassis arranged on opposite sides of the chassis. Further a corresponding method is provided.

A machine for welding an overlapped region of two adjacent strips of material and a method of using the same. The machine includes a housing with front and rear ends, a wheel train engaged with the housing for moving the housing across the material; a nozzle on the housing having a welding head at a free end; the nozzle being positionable at least partially beneath the housing's bottom wall for welding the overlapped region; front and rear pressure rollers engaged with the housing, where the front roller is positioned forwardly of the welding head and the rear roller is positioned rearwardly of the welding head; wherein the rear pressure roller applies pressure to the overlapped region when the wheel train moves the housing in a forward direction; and the front pressure roller applies pressure to the overlapped region when the wheel train moves the housing in a reverse direction.

Apparatus and methods for impinging a heated fluid onto the surface of a substrate and then locally removing the impinged fluid. The apparatus and methods may be used to heat a surface of a substrate e.g. so that the substrate can be melt-bonded to another substrate.

Herein are disclosed apparatus and methods for impinging fluids, e.g. heated fluids, onto the surface of substrates and then locally removing the impinged fluid. The apparatus may comprise at least first and second fluid delivery outlets that are in diverging relation to each other. The apparatus may comprise at least first and second fluid capture inlets that are locally positioned relative to the first and second fluid delivery outlets, respectively. The apparatus and method may be used e.g. to impinge fluids onto two converging substrates and may be used to heat the surfaces of the substrates so as to facilitate melt-bonding the substrates to each other.

The invention discloses an apparatus for aligning and supporting a first and a second length of thermoplastic tubing, preparatory to and during cutting and welding of said lengths of tubing, that includes a first holder arranged to accommodate portions of the first and second lengths of tubing in a first and a second elongated holding space respectively, a second holder arranged to accommodate portions of the first and second lengths of tubing in a third and a fourth elongated holding space respectively, and movable in a direction essentially perpendicular to the holding spaces of the first and second holders from a cutting position, a cutting means arranged between said first and second holders for cutting said lengths of tubing when the second holder is in the cutting position and an aligning means to align these lengths of tubing with each other.

A method for manufacturing an acoustic panel by welding of at least two acoustic components made of thermoplastic material, a thermal gradient being applied on the acoustic components during the welding operation so as to apply a temperature higher than the glass transition or melting temperature of the material on the area to be welded and so as to apply a temperature lower than or equal to the geometric stabilization temperature of the material on the parts furthest from the area to be welded.

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.

Herein are disclosed apparatus and methods for impinging fluids, e.g. heated fluids, onto the surface of substrates and then locally removing the impinged fluid. The apparatus may comprise at least first and second fluid delivery outlets that are in diverging relation to each other. The apparatus may comprise at least first and second fluid capture inlets that are locally positioned relative to the first and second fluid delivery outlets, respectively. The apparatus and method may be used e.g. to impinge fluids onto two converging substrates and may be used to heat the surfaces of the substrates so as to facilitate melt-bonding the substrates to each other.