Vibration welding techniques

Vibration welding techniques have found several applications in the automobile industry including emission control canisters, fuel pumps and tanks, head and tail light assemblies, heater valves, air intake filters, water pump housings, and bumper assemblies. They have also been used for joining pressure vessels and for batteries, motor housings, and butane gas lighter tanks. 

ADVANCES IN VIBRATION WELDING TECHNIQUES ALLOW WELDING MULTIPIECE CONSOLE ASSEMBLY... 

With respect to the problems mentioned above, this is resolved using advanced vibration welding techniques. The vibration welding technique has demonstrated that it can produce parts of higher quality and better structure than other means presently available. 

However, the same mechanical techniques at the interface of two solid wood surfaces in the absence of any thermoplastic material, or any other binder, yields joints of considerable strength. " The equipment used for the mechanical vibration welding of wood in the absence of an adhesive is the same type of equipment as used for frictional welding of metals. Figure 1 shows the characteristic linear vibrational movement of the type of industrial metal welding machine used, as well as the frictional shift and force applied to the two pieces of wood during welding. 

Wood bonding by vibration welding A PIZZI Innovative technique for wood... 

Joining of plastic pipes is shown to be done more effectively, economically and in a much shorter time on-site by linear vibration welding , rather than the conventional hot plate welding or electrofusion welding techniques. 

Spin welding is just a special form of vibration welding. Because it is such a popular technique, it is considered a special assembly method. 

Welding Suitable welding techniques are fnction, vibration, hot gas and hot plate welding. Ultrasonic welding difficult while radio fiiequency welding not possible. 

Table 8.1 shows that PE is difficult to bond, paint, and plate high-density PE (HOPE) is easy to machine while low-density PE (LDPE) is not. Suitable welding techniques for both types of PE are friction, vibration, hot gas, and hot plate welding. Ultrasonic welding is difficult, especially for LDPE, while radio frequency welding is impossible for both types. 

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. 

Similar to vibration welding, induction welding allows the bonding of larger parts (on the size scale of a meter) than most of the fusion bonding techniques. The size scale means that both liquid tanks and pressurized gas reservoirs are welded with this process. This welding technique also accommodates polymer materials that contain fillers. 

Compared to Vibration welding the heating cycle is 2 to 4 times longer. Mnch depends on the match-up of the absorbency character of the materials to the spectra or power of the emitter. Despite this drawback, in comparison with the advantages (economics, size, design flexibility, etc.) iirfrared is a very viable technique. This is doubly so for large parts or parts with throughput needs of less that 900 units per shift. 

Ultrasonic head forming and welding is a fast assembly technique. It is a very rapid operation of about 2 seconds or less and lends itself to full automation. In this process high-frequency vibrations and pressure are applied to the products to be joined, heat is generated at the plastic causing it to flow, and, when the vibrations cease, the melt solidifies. The heart of the ultrasonic system is the horn, which is made of a metal that can be carefully tuned to the frequency of the system. The manufacture of the horn and its shape is normally developed by the manufacturer of the equipment. The results from this operation are not only economical, but also most satisfactory from a quality control standpoint. 

Welding ultrasound, friction, vibration and induction techniques give good results. Hot plate welding is not recommended. 

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