A resistance welding apparatus can employ a modular power supply system with multiple power supply modules and leads for electrically connecting the modular power supply system to a welding resistor. The resistance welding apparatus is selectively configurable in at least three of (i) a first configuration in which the leads connect the first power supply module to the resistor and the second power supply module is disconnected from the resistor; (ii) a second configuration in which the leads connect the second power supply module to the resistor and the first power supply module is disconnected from the resistor; (iii) a third configuration in which the leads connect the first and second power supply modules to the resistor in series; and (iv) a fourth configuration in which the leads connect the first and second power supply modules to the resistor in parallel.

A welding device includes a pair of pressure rollers for pressurizing a web and a strip member, a feed device configured to intermittently or continuously feed the web and the strip member through the pair of pressure rollers, and the laser device configured to irradiate the web or the strip member with a laser beam at a position upstream of the pair of pressure rollers. The welding device may include a movement device configured to move the pair of pressure rollers upstream with respect to the web and the strip member during pause or stop of feed. Alternatively, the feed device may pause or stop the web and the strip member after retracting the web and the strip member by a certain length.

A machine converts a web of preformed pouches, which are defined by transverse seals extending from a remote edge, into inflated dunnage units. A sealing arrangement is positioned to provide a longitudinal seal intersecting the transverse seals to close the preformed pouches and form a dunnage unit. The sealing arrangement has at least two sealing belts. Each belt is positioned so that respective first sides engage a surface of the web and pull the web through sealing elements positioned on either side of the web. A heating element is on a second side of the first belt not engaging the web. A compliant material is on a second side of the second belt not engaging the web. As the web passes between the heating element and compliant material, imperfections in the web are smoothed by the compliant material and the layers of the web are sealed by the heating element.

Applied power as a function of time is ramped up at the onset of an RF welding process in a manner that is predetermined to match source and load impedance as reflected by maximized forward power during at least the majority of the welding process. The ramp-up portion takes the form of a non-linear curve, such as an S-shaped curve, as opposed to one or more discrete steps. The applied power may then be maintained at or near that maximum required value at least a majority of the remainder of the heating portion of the welding process. The shape of the non-linear ramp-up portion of the applied power curve may be predetermined using, for example, virtual motor control using applied power as a virtual axis.

A welding device includes a pair of pressure rollers for pressurizing a web and a strip member, a feed device configured to intermittently or continuously feed the web and the strip member through the pair of pressure rollers, and the laser device configured to irradiate the web or the strip member with a laser beam at a position upstream of the pair of pressure rollers. The welding device may include a movement device configured to move the pair of pressure rollers upstream with respect to the web and the strip member during pause or stop of feed. Alternatively, the feed device may pause or stop the web and the strip member after retracting the web and the strip member by a certain length.

Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding of a composite part. The method includes locating a linear fiber optic sensor along a composite part comprising a matrix of thermoplastic reinforced by fibers, measuring temperatures along the weld line via the linear fiber optic sensor, performing induction welding at the composite part along the weld line, determining a continuum of weld temperatures along the weld line, and controlling the induction welding based on the continuum of weld temperatures.

A machine for converting two different types of webs of inflatable material to two different types of inflated cushioning material includes an inflation arrangement, a sealing arrangement, and a tensioning device. The inflation arrangement is configured to provide air at a lower pressure to a first web of a first type of inflatable material to inflate the first type of inflatable material, and to provide air at a higher pressure to a second type of inflatable material to inflate the second type of inflatable material. The inflation arrangement includes a guide pin configured to the first and second webs and align the first and second webs on the machine. The sealing arrangement is configured to seal the first type of inflatable material and the second type of inflatable material to create the two different types of inflated cushioning material. The tensioning device is configured to provide a lower tensioning force to the first web as the first web moves between the inflation arrangement and the sealing arrangement, and to provide a higher tensioning force to the second web as the second web moves between the inflation arrangement and the sealing arrangement.

A machine includes an inflation arrangement, a sealing arrangement, and a tensioning device. The inflation arrangement provides air at a first pressure to inflate a first web of a first type of inflatable material, provides air at a second pressure to inflate a second web of a second type of inflatable material, receives the first and second webs, and aligns the first and second webs on the machine. The first pressure is different from the second pressure. The sealing arrangement seals the first and second types of inflatable material. The tensioning device provides a first tensioning force to the first web as the first web moves between the inflation and sealing arrangements and provides a second tensioning force to the second web as the second web moves between the inflation and sealing arrangements. The first tensioning force is different from the second tensioning force.

A device and a method for applying cover sheets to cross-bottoms of tubular sections made of a plastic material. The device includes conveyor devices for transporting the tubular sections and for depositing the cover sheets on the cross-bottoms in a deposit area. The device includes a hot gas device with a gas heater and a nozzle connected to the gas heater and oriented toward the deposit area for the cover sheets so when gas is supplied to the gas heater, the gas flows along a flow path from the gas supply through the gas heater and the nozzle into the deposit area. The hot gas device has a hot gas reservoir with an internal volume for the temporary storage of hot gas, the flow path running through the hot gas reservoir. A gas mass flow ({dot over (m)}1, {dot over (m)}2, {dot over (m)}ges) of gas supplied to the gas heater is adjustable by a control.

A device and a method for applying cover sheets to cross-bottoms of tubular sections made of a plastic material. The device includes conveyor devices for transporting the tubular sections and for depositing the cover sheets on the cross-bottoms in a deposit area. The device includes a hot gas device with a gas heater and a nozzle connected to the gas heater and oriented toward the deposit area for the cover sheets so when gas is supplied to the gas heater, the gas flows along a flow path from the gas supply through the gas heater and the nozzle into the deposit area. The hot gas device has a hot gas reservoir with an internal volume for the temporary storage of hot gas, the flow path running through the hot gas reservoir. A gas mass flow ({dot over (m)}1, {dot over (m)}2, {dot over (m)}ges) of gas supplied to the gas heater is adjustable by a control.