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.

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 single sealing zone, and a weakening zone disposed within the single sealing zone. The single sealing zone may be a heated perforator, includes 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.

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 at an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop. The heating wire may 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 may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.

A method for forming a structural member and a structural member produced thereby includes positioning a first composite section and a second composite section within a tool. The tool has an inner surface and a wall intersection and is supported by a tool platform. The tool platform and a pressure platform are relatively movable between an open position and a closed position. The tool has a non-planar outer surface against which the member may be pressed. A composite splice member is positioned at least partially overlapping both the first composite section and the second composite section to form a joint in the composite structural member. The composite structural member is pressed against the non-planar outer surface of the tool by applying pressure to the joint from a pressure bladder. Heat is applied to the composite structural member at the joint to cure the composite splice member to the first composite section and the second composite section.

A method and apparatus to mitigate the severity of the bond-line read-out defect, and more specifically microwave heating to locally cure adhesive bond-line in a single or two stage process comprising heating thermoset adhesive with microwave radiation until the adhesive is fully cured or partially cured. If the adhesive is partially cured, it can be fully cured by being subjected to an additional thermal cycle.