Vibration welding orbital

There are many different, cost-effective welding methods suitable for industrial mass production of plastics engineering components including ultrasonic, laser, spin, hot plate, linear and orbital vibration welding. Here we will deal with inexpensive manual methods for low quantities which can be carried out in small workshops or on site. 

There are two types of vibration welding Unear and axial. Linear vibration welding is most commonly used. Friction is generated by a linear, back and forth motion. Axial or orbital vibration welding allows irregularly shaped plastic parts to be vibration welded. In axial welding one component is clamped to a stationary structure the other component is vibrated with orbital motion. 

Figure 26.30 In linear vibration welding (left) the top part moves back and forth in a line, while in orbital vibration welding (right) every point on the moving part forms a small orbit around a fixed point on the stationary part.

The process parameters affecting the strength of the resulting weld are the amphtude and frequency of motion, weld pressure, and weld time. There are two types of vibration welding linear, in which friction is generated by a linear motion of the parts, and orbital, in which one part is vibrated using circular motion in all directions. Examples of these processes are illustrated in Figure 7.26. 

Linear vibration and orbital welding are essentially the same technique with the obvious difference being that one oscillates back and forth in a linear motion and the other oscillates in an orbital path. These techniques are applicable to parts that are larger (200-1500 mm) than those handled by ultrasonic welding. Large automotive under the hood air boxes and manifolds are vibration welded from PA (nylon). Recently, high-temperatnre polyamide oil sumps have been welded with this technique. 

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