Ultrasonic staking

Ultrasonic staking (Fig. 5.49) i. e. the enclosure of another material in plastic, takes place by inducing and ultrasonic stress in the plastic causing the stud to yield and eventually conform to the shape of the horn. The advantages of the technique are that ... 

With molded products, the stakes are usually molded into the part and then formed either by a hot tool or by ultrasonic staking with equipment similar to that used in ultrasonic welding. Often the tool has a specially shaped head that distributes the molten plastic in a uniform circle. 

Ultrasonic staking for light assembly work in plastics. 

Use of the ultrasonic machine for staking, in which the top of a plastic peg is melted to form a retaining head, in a similar manner to riveting. 

Responds well to joining technologies, such as chemical bonding, ultrasonic welding, vibration welding, and heat staking... 

Ultrasonic equipment can also be used for mechanical fastening operations. Ultrasonic energy can be used to apply threaded inserts to molded plastic parts and to heat stake plastic studs. 

Suggested adhesives include contact, pressure sensitive, urethane and epoxide. Some grades may contain microcrystalline wax which must be removed before joining is possible wash with isopropyl or methyl alcohol if necessary. If welded, or hot stamped, there is no need for this treatment. BDS components may be welded together using the ultrasonic, fiictional or hot staking techniques. 

Staking n. A term sometimes used for the process of forming a head on a protruding portion of a plastic article for the purpose of holding a surrounding part in place. Ultrasonic heating of the protrusion facilitates the staking operation. 

Besides spot welding, ultrasonics can be used to insert metals into plastic, stake materials to plastics, scan weld flat parts, and degate runner assemblies. 

In addition, experimental tests are recommended with materials to be welded or staked, etc., to determine the suitability of ultrasonic assembly, especially where dissimilar plastic resin systems are being joined. 

Figure 8.11 Ultrasonic joining operating, (a) Swaging the plastic ridge is melted and reshaped (left) by ultrasonic vibrations to lock another part into place, (b) Staking ultrasonic vibrations melt and reform a plastic stud (left) to lock a dissimilar component into place (right), (c) Insertion a metal insert (left) is embedded in a preformed hole in a plastic part by ultrasonic vibration (right), (d) Spot welding two plastic components (left) are joined at localized points (right).

Ultrasonic welding T ubular rivet Staking Nailing Solid rivet Cyanoacrylate Epoxy resin Solvent-borne rubber Toughened adhesives... 

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