Continuous ultrasonic welding

ISONIC - Complete Ultrasonic Weld Inspection Documentation by Continuous Recording of Manual Probe Manipulations, Acoustic Coupling and Echoes. 

Ultrasonic welding the two basic techniques are plunge welding and continuous welding. In plunge welding, the parts are placed under a tool or horn the horn descends to the part under moderate pressure and the weld cycle is initiated. In the continuous welding process, the horn may scan the part or the material is passed over or under the horn on a continual basis. 

Ultrasonic welding is clean and fast (20-30 parts per minute) and usually results in a joint that is as strong as the parent material. The method can provide hermetically sealed components if the entire joint can be welded at one time. Large parts generally are too massive to be joined with one continuous bond so that spot welding is necessary. It is difficult to obtain a completely sealed joint with spot welding. Materials-handling equipment can be easily interfaced with the ultrasonic system to further improve rapid assembly. 

Several companies produce automated ultrasonic-welding equipment for the garment industry. For example, Swiss manufacturer Schips (www.schips.com) has introduced several ultrasonic machines for hemming, continuous assembly of two fabrics with bonding tape, and welding of folded elastic to garment fabric. PFAFF (www. pfaff.com) has developed ultrasonic cut and seam equipment. 

This header has undergone repair after through-thickness cracking of an assembly weld after 108.000 hours of service, it is presently in operation and periodically submitted to ultrasonic inspection during planned maintenance shutdown. Continuous on-line AE monitoring of the integrity of critical welds is expected to contribute supporting continued and safe operation of the header until its replacement, platmed to take place in 1999. 

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