ENERGY DIRECTOR JOINT DESIGN FOR ULTRASONIC WELDING OF THERMOPLASTICS

摘要

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.