Abstract: A system for providing power to more than one ultrasonic welding probe from M power supplies includes N multipoint units and a base. Each of the N multipoint units includes: a housing, a plurality of analog or digital inputs configured to carry distance information regarding probe distance of a plurality of ultrasonic welding probes, a dedicated high voltage input connector connectable via a high voltage cable to a dedicated high voltage output connector of one of the M power supplies, and a microcontroller. The microcontroller is configured to: direct power from the dedicated high voltage input connector to a corresponding one of the plurality of ultrasonic welding probes, and sample the distance information of the plurality of ultrasonic welding probes at a rate of at least once per millisecond. The base houses the M power supplies, wherein M and N are both integers greater than or equal to 1.

Abstract: The present disclosure can provide for an ultrasonic welding method for a pair of workpieces. The method can include first pressing an ultrasonic welding stack against a first workpiece in the pair so that the first workpiece comes into contact with a second workpiece in the pair. The method can then provide for initiating a weld phase by outputting energy from the ultrasonic welding stack to the first workpiece. The method can provide for monitoring, with at least one sensor, a sensed parameter. The sensed parameter can be, for example, weld force and/or weld force rate of change. The method can provide for determining whether the sensed parameter has reached a predetermined level. Based on determining that the sensed parameter has reached the predetermined level, the method can provide for ending the weld phase.

Abstract: A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

Abstract: An improved ultrasonic system and method. The ultrasonic stack is moved at a low, constant (or slowly varying) speed at the initiation of the welding operation, with this speed being maintained until the predetermined condition is satisfied. In some applications, this produces a higher quality weld, such as in applications involving plastic material that softens very quickly once ultrasonic energy is imparted to the workpieces being welded, which causes the force between the workpieces to decrease rapidly. Advancing the ultrasonic stack at a low speed or slow acceleration can avoid scuffing or marking of the surface of the workpiece in contact with the ultrasonic horn, decrease audible noise produced during the welding process, and improve the consistency of weld quality in such applications compared to conventional techniques.

Abstract: A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

Abstract: A method for optimizing a welding process to produce a weld joint having a predetermined strength includes measuring a plurality of melt layer thicknesses of weld joints for a plurality of sample assemblies formed by the welding process, measuring a plurality failure loads of weld joints for the plurality of sample assemblies, each of the measured plurality of failures loads being associated with one of the measured plurality of melt layer thicknesses, selecting a first failure load from the plurality of measured failure loads responsive to determining that the first failure load corresponds to a predetermined weld strength, and selecting a first melt layer thickness from the plurality of measured melt layer thicknesses that is associated with the selected first measured failure load.

Abstract: A laser welding method and system join portions of two workpieces of thermoplastic material by clamping together the portions of the workpieces to be joined, against a baseplate engraved or etched to form an image to be replicated in the joined portions of the workpieces, and applying laser radiation to the portions of the clamped workpieces to be joined, to melt those portions of the clamped workpieces to be joined and to replicate the image in the joined portions of the clamped workpieces when the material solidifies. The thermoplastic material of the workpieces can be optically transparent but absorbs a portion of the laser radiation, so that both workpieces are heated and melted by the laser radiation. A portion of the melted workpiece material flows into the engraved or etched portions of the baseplate, forming an embossed surface on the lower surface of the area where the workpieces are joined.

Abstract: A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

Abstract: An ultrasonic welding system includes a movable ultrasonic welding stack for applying vibrational energy to a workpiece. A motion control system controls the motion of the ultrasonic welding stack and one or more sensors sense a control variable and output a corresponding control signal. A controller provides control inputs, based on the control signal, to the motion control system and causes, following initiation of a welding operation, an automatic change of speed of motion of the ultrasonic welding stack. The automatic change of the speed is a function of at least one control variable until the control variable reaches a predetermined value.

Abstract: An ultrasonic welding system and method for joining first and second thermoplastic parts includes least one energy director formed on at least one surface of the first thermoplastic part, with the energy director projecting from the surface of the first thermoplastic part toward an opposed surface of the second thermoplastic part. The distal end portion of the energy director has a curved or flat surface that initially engages the opposed surface of the second thermoplastic part when the first and second parts are brought into engagement with each other. The first and second thermoplastic parts are ultrasonically welded by pressing the parts together while vibrating at least the first part in a direction parallel to the direction of projection of the energy director. The energy director may include a pair of substantially flat side walls joined to opposite ends of the curved or flat end surface.

Abstract: An ultrasonic welding system includes an ultrasonic welding stack that is movable to initiated a welding operation. A plurality of sensors measure respective control variables and output control signals corresponding, respectively, to the control variables. A motion control system is coupled to and causes controlled movement of the welding stack, including initiating the welding operation. The motion control system determines, based on the control signals, control inputs such that any motion of the welding stack, subsequent to the initiating, is initially delayed until the control signals satisfy a predetermined condition. In response to the predetermined condition being satisfied, the motion control system causes the welding stack to move in accordance with a weld profile.

Abstract: An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

Abstract: A vibration welding system and method having an operating vibration frequency of 260 Hz or higher. A pressing action between two workpieces is effected by directly controlling, with a control system and a sensor, the relative positions of the workpieces during some or all of the weld cycle, or by controlling the speed between the workpieces during some phase of the weld cycle and controlling the force between the workpieces during other phases. An external control device can be coupled to a control system, to produce an input signal to adjust the speed of relative motion between the workpieces, the force therebetween, or both speed and force based on the input signal.

Abstract: An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

Abstract: An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

Abstract: An ultrasonic welding system includes a movable ultrasonic welding stack, an electrically powered linear actuator with a servo motor and a movable element, a controller, and at least two sensors. The controller causes the ultrasonic welding stack to apply a predetermined positive initial force to at least one workpiece prior to initiation of welding. The controller further causes the ultrasonic welding stack to initiate subsequent movement of the ultrasonic welding stack, following initiation of welding, only after the signal outputs from the at least two sensors indicate that a combination of control variables satisfies a predetermined condition.

Abstract: An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

Abstract: An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

Abstract: An ultrasonic welding system and method for joining first and second thermoplastic parts includes least one energy director formed on at least one surface of the first thermoplastic part, with the energy director projecting from the surface of the first thermoplastic part toward an opposed surface of the second thermoplastic part. The distal end portion of the energy director has a curved or flat surface that initially engages the opposed surface of the second thermoplastic part when the first and second parts are brought into engagement with each other. The first and second thermoplastic parts are ultrasonically welded by pressing the parts together while vibrating at least the first part in a direction parallel to the direction of projection of the energy director. The energy director may include a pair of substantially flat side walls joined to opposite ends of the curved or flat end surface.

Abstract: An ultrasonic welding system includes a movable ultrasonic welding stack, an electrically powered linear actuator with a servo motor and a movable element, a controller, and at least two sensors. The controller causes the ultrasonic welding stack to apply a predetermined positive initial force to at least one workpiece prior to initiation of welding. The controller further causes the ultrasonic welding stack to initiate subsequent movement of the ultrasonic welding stack, following initiation of welding, only after the signal outputs from the at least two sensors indicate that a combination of control variables satisfies a predetermined condition.