A process for packaging a product arranged on a support comprising unrolling a film, moving the film to a packaging assembly defining at its inside a packaging chamber, progressively moving a number of supports inside the packaging chamber of the packaging assembly, closing the packaging chamber with the film sheets held above the respective support, optionally causing one or both of: a gas withdrawal from the hermetically closed packaging chamber and gas injection of a gas mixture of controlled composition, heat sealing the film to said support, wherein the heat sealing uses one or more heaters having heating surfaces which are heated for discrete and short time periods only. An apparatus for performing the above process is also disclosed.

A method for connecting a thermoplastic line element to a connecting element includes the steps of: providing the at least one thermoplastic line element; providing the connecting element having a thermoplastic body wherein a heating element is embedded in the body for generating heat in a welding region for welding the body to the at least one line element; joining the connecting element to the at least one thermoplastic line element; providing a welding device for welding the connecting element to the at least one thermoplastic line element; welding the connecting element to at least one thermoplastic line element by generating heat in the welding region using the welding device. The welding of the connecting element to the at least one thermoplastic line element is stopped by the welding device before the end of the planned welding duration if an error criterion is met.

The present invention relates to a method for connecting two joining elements, these elements being connected by means of a thermally activatable adhesive with a flat heating element arranged therein, by suitable heating of the adhesive. The invention also relates to an assembly produced in this way from two joining elements and to an arrangement designed for carrying out a corresponding method.

An exemplary air cushion inflation machine includes: a first terminal connected to a direct current input; a second terminal; a reference resistor powered by the direct current input; an op-amp; and a transistor. The first terminal of the op-amp is connected to a variable voltage source and the second terminal of the op-amp is connected to the reference resistor. The transistor has a base connected to an output of the op-amp, an emitter connected to the reference resistor, and a collector connected to a first terminal of a sealing band apparatus having first and second terminals. A meltable material placed between the first and second terminals is melted by resistance of current flowing between the first and second terminals. The variable voltage source changes voltage based on a voltage drop measured across the first and second terminals by a voltage measurement device and the constant current.

A device for welding electrofusion fittings, the device including a welding power supply with a communications interface, at least one connection cable connected to the welding power supply for connecting and heating a heating wire of an electrofusion fitting, and at least one removable extension cable is arranged on the at least one connection cable. The device is configured to provide a current or a voltage such that the current or the voltage is remains constant despite an increase in a resistance due to the connected extension cable.

Provided is an electric power control apparatus of an electrofusion coupling pipe using a conductive polymer composite as a heating element and a method of controlling electric power using the same. The electric power control apparatus supplies electric power to the electrofusion coupling pipe using a conductive polymer composite as a heating element to detect resistance variation of the conductive polymer composite and then controls electric power supplied to the synthetic resin pipe electrofusion coupling pipe on the basis of the detected resistance variation.

An array of resilient floor tiles is assembled into a continuous sheet after being laid down. An array of included, sacrificial resistive wires is buried along the edges of the tiles and is controllably heated in order to cause welding of the edges of tiles across the paths of the wires to neighboring tiles. Subsequently the wires may be used to give the array integral tensile strength. The welded array is provided with greater strength for resisting use, expansive and contractile forces caused by environmental heat and cold and also long-term tile contraction owing to loss of plasticizer as may be seen with PVC-based tiles.

A welding apparatus includes: a first heating stack, wherein a first heating layer is electrically connected to a first electronic control circuit and is located between a first cover layer and a first electric insulator which is mounted on a first ledge; a second heating stack, wherein a second heating layer is electrically connected to a second electronic control circuit and is located between a second cover layer and a second electric insulator which is mounted on a second ledge, wherein the first heating stack and the second heating stack are coupled to a drive to provide a linear relative movement between the first heating stack and the second heating stack, and wherein the first electronic control circuit is adapted to provide electric energy to the first heating layer and wherein the second electronic control circuit is adapted to detect an electric resistance and/or an electric impedance of the second heating layer.