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 plastic tube sealing device includes a clamp which has a pair of jaws that can move relative to each other for inserting and crimping a plastic tube, the jaws containing high-frequency (HF) jaw electrodes, and includes an electrical HF power supply circuit including an HF generator and the HF jaw electrodes. The plastic tube sealing device further includes an impedance control device (9) for acting towards maintaining an impedance of the HF power supply circuit constant during a respective welding operation by correspondingly controlling the variable impedance HF resonant circuit. For this purpose, the HF generator includes a variable impedance HF resonant circuit with a capacitor unit and a coil unit, and includes the jaw electrodes, wherein the inductance of the coil unit and/or the ohmic resistance of the HF resonant circuit is/are variably adjustable and/or wherein the capacitance of the capacitor unit is variably adjustable and the capacitor unit has an electrically controllable capacitance diode or at least one movable capacitance-altering capacitor electrode arranged in the clamp.

A method keeps a voltage or a current constant during a welding process of an electrofusion fitting. The method includes: connecting an extension cable between a connection cable of a welding power supply and the electrofusion fitting to be welded; detecting the extension cable by the welding power supply; detecting and recording the electrofusion fitting to be welded and its data by the welding power supply; autonomously supplying the current or the voltage with the welding power supply; and autonomously regulating the current or the voltage based upon the detection of the connected extension cable and a resulting resistance due to the connected extension cable. The current or the voltage is adjusted such that the current or the voltage remains constant during the welding of the electrofusion fitting.

A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar, having a first sealing zone, and an adjacent weakening zone. The weakening zone may be a heated perforator, includes a heating wire, or be disposed to create an auxiliary sealed area. The heating wire can have connected thereto, a source of power that is an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop. The heating wire ay be an NiCr wire and make intermittent contact with the web and be disposed in an insert. The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone, or includes a heat film, a toothed blade, a row of pins, a source of air, or a source of vacuum. The sealing zones ma include temperature zones, cartridge heaters, cooling air, or hated air, or a source of ultrasonic, microwave or radiative energy.

A method for sensing intensity of laser light in a simultaneous laser welding system includes placing a smart part in a weld area. The smart part includes at least a laser light intensity sensor for sensing laser light directed at it. Laser light intensity is sensed by the laser light intensity sensor of the smart part which provides an output signal indicative thereof to a controller.

A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar, having a first sealing zone, and an adjacent weakening zone. The weakening zone may be a heated perforator, includes a heating wire, or be disposed to create an auxiliary sealed area. The heating wire can have connected thereto, a source of power that is an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop. The heating wire ay be an NiCr wire and make intermittent contact with the web and be disposed in an insert. The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone, or includes a heat film, a toothed blade, a row of pins, a source of air, or a source of vacuum. The sealing zones ma include temperature zones, cartridge heaters, cooling air, or hated air, or a source of ultrasonic, microwave or radiative energy.

An installation for welding a stack of parts made of thermoplastic composite materials (20) in a local welding plane (P), this installation including an electromagnetic induction head (8), pairs of elements for guiding and pressing the workpiece stack (20) in this local plane (P), and, on each side of the induction head (8), at least one pair of guide elements, each pair of guide elements having a lower guide element (14) and an upper guide element (10) that are superposed, receiving between one another the stack of parts (20) by guiding it in the direction perpendicular to the local welding plane (P).

A method for sensing intensity of laser light in a simultaneous laser welding system includes placing a smart part in a weld area. The smart part includes at least a laser light intensity sensor for sensing laser light directed at it. Laser light intensity is sensed by the laser light intensity sensor of the smart part which provides an output signal indicative thereof to a controller.

The present invention provides a device which can uniformize heat distribution by using an existing heater mat for repairing or joining members. A heat dispersion device includes a bag with a fluid sealed inside, and is disposed on a second surface of a heater mat which has a first surface to be directed toward an object to be heated and the second surface opposite to the first surface. The fluid inside the bag is preferably heated with a heat source.

A machine and method for converting film into bags or other articles includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar with a sealing zone and a weakening zone, or it can include or at least one sealing die that extends in the machine direction. The single sealing zone or sealing die may be a heated perforator, and may include a heating wire. The heating wire may be an NiCr wire stitched into the heater, and be disposed on a cap or on the seal bar. The weakening zone may create a line of weakness that is uniform or varies in intensity. The sealing zone may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.