Plastic parts are welded in a laser welding system. An infrared laser source in a laser chamber is controlled by a controller using closed-loop feedback control with a corrected feedback signal that is compensated for background infrared radiation in the laser chamber. Prior to the infrared laser source being turned on, the controller senses with the optical sensor an intensity of background infrared radiation in the laser chamber. Once the laser is on, the controller senses with the optical sensor an intensity of infrared laser radiation in the laser chamber. The controller calculates the corrected feedback signal by subtracting the intensity of the background infrared radiation sensed when the infrared laser source was off from the intensity of the infrared laser radiation sensed when the infrared laser source is on.

An ultrasonic welder includes dynamic adjustment of a weld parameter used to control welds of weld cycles during serial operation of the ultrasonic welder. The ultrasonic welder includes a power supply controlled by a controller and the controller sets a value of the weld parameter for a next weld cycle based on a value of a stack heat energy parameter indicative of heat energy in the ultrasonic stack prior to beginning the next weld cycle. The controller controls the power supply based on the value set for the weld parameter to control a weld in the next weld cycle.

Various device embodiments perform a sealing operation on a moving web, and comprise, among other things a plate assembly with an air cylinder assembly. The air cylinder assembly comprises a mount, a back plate, at least one air cylinder positioned between the mount and the back plate. The first plate assembly further includes a linear servo motor for linearly moving the air cylinder assembly with respect to the first base, and a first tooling plate with a sealing surface area. The first tooling plate coupled to the back plate.

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 method attaches a liquid-repellent filter to an air vent of a resin molded article accommodating a component/electronic part. A thermal processing tip and a thermally welding tip and a molded article are provided. The thermal processing tip (22) forms a filter attachment surface (14) at the inlet or outlet of an air vent (16) in a thermoplastic resin molded article (13). A filter fixing rib (15) is formed around the attachment surface. The porous filter (18) is dropped onto the filter attachment surface, and a thermal welding tip (2) is used to melt the filter fixing rib such that the melted resin flows onto and covers a circumferential edge portion of the filter, penetrating the body of the filter. The melted resin penetrating the filter 18 and covering the circumferential edge portion of the filter are cooled to solid, whereby the filter is fixed to the filter attachment surface.

A system and method for welding thermoplastic components by positioning and moving a heated plate between the components to melt their respective faying surfaces, and as the plate moves, pressing the components together so that the melted faying surfaces bond together as they cool and re-solidify, thereby creating a composite structure. The plate has a heated portion which is positioned between and heated to melt a portion of the first and second faying surfaces. A manipulator mechanism moves the plate along an interface from between the portion to between a series of subsequent portions of the first and second faying surfaces, thereby welding the thermoplastic components along the entire interface to create the composite structure. The heated portion may contact the faying surfaces and melt them through conduction, or may be suspended between them and melt them through radiation and convection.

Sensors incorporated within a waveguide detect a laser light output from at least a laser delivery optical fiber to provide in situ feedback of the laser light intensity detected by the sensor. The sensors may detect laser light directly from the laser delivery optical fiber or as reflected back from a plurality of work pieces during a weld cycle. In various aspects, the feedback provided from the sensors is used to control the laser light intensity or to alert an operator that the laser light intensity is below a predetermined parameter.

A portable conveyor belt splicing apparatus is provided that includes an upper press assembly and a lower press assembly which include, respectively, upper and lower platen assemblies. The upper and lower press assemblies may each include a forced air cooling system for rapidly cooling platens of the platen assemblies. The upper and lower press assemblies may include insulating assemblies with resilient members that support the upper and lower press assemblies. The resilient members provide structural support and insulate the platens from the frame which reduces the power required to heat the platens. In one form, the apparatus includes a power supply circuit that can alternate between providing power to upper and lower heaters in response to the apparatus being connected to different types of standard power supplies. Further, the power supply circuit permits the use of a single recipe for a particular belt irrespective of the type of power supply.

A film fin sealing device is disclosed herein which may have a groove defining a base. The base of the groove of the fin sealing device may be oriented at a skewed angle with respect to a longitudinal direction of the conveyor of a heat sealing machine. Edges of a thermoplastic sheet or two stacked layers of thermoplastic sheets are introduced into the groove of the film fin sealing device and placed in contact therewith to both heat and fuse the distal edge portions of the thermoplastic sheet(s) to join the edge portions thereof to form a fin seal.

Various device embodiments perform a sealing operation on a moving web, and comprise, among other things a plate assembly with an air cylinder assembly. The air cylinder assembly comprises a mount, a back plate, at least one air cylinder positioned between the mount and the back plate. The first plate assembly further includes a linear servo motor for linearly moving the air cylinder assembly with respect to the first base, and a first tooling plate with a sealing surface area. The first tooling plate coupled to the back plate.