Ultrasonic welding is an industrial welding process that uses high-frequency ultrasonic acoustic vibrations which are locally applied to the pieces being joined. The pieces that are being welded together are typically held in place using pressure which creates a solid state weld. This welding technique is primarily used to join plastics and dissimilar materials. Ultrasonic welding does not require the use of any connective bolts, nails, soldering materials or adhesives to create the weld.
The process of using ultrasonic welding on thermoplastics causes the localized melting of the plastic due to the absorption of vibration energy. The vibrations are introduced along the joint that is to be welded. When using ultrasonic welding to join metals the process is completed by applying high amounts of pressure to disperse the surface oxides and local motion of the materials; during this process there is a small amount of heat used but not enough to melt the base metals being joined.
The practical applications for ultrasonic welding were first used to join hard plastics during the 1960’s. During this time the process could only be performed on hard plastics. In 1965, Robert Soloff and Seymour Linsley were awarded the patent for the process of ultrasonic welding. Soloff, made the discovery when he unknowingly moved the probe close to a plastic tape dispenser and the joint of the dispenser was welded together. It was then that he realized that the probe didn’t need to be moved around the pieces being welded but that the ultrasonic energy that was created was able to travel around and through hard plastics to create a welded joint. In 1969 the process of ultrasonic welding was used to create a car that was made entirely out of plastic; although the process of creating plastic cars did not catch on, car manufacturers recognized the benefits that ultrasonic welding offered.
After years of advancements, the process of ultrasonic welding can now be used to weld both hard and soft plastics and metals. As the process of ultrasonic welding continued to grow, its ability to join many different types of materials has caused it to become more widely accepted in the production of electronics. Ultrasonic welding is still growing as more uses and knowledge about the process are discovered. The process of ultrasonic welding offers many benefits including the ability to create welds faster than using an adhesive or solvent to join materials. The drying time is fast and the pieces that were joined do not need to be left in a jig for a long period of time. It is also becoming more popular in the manufacturing industries due to its ability to be easily automated, which allows for clean and precise welds to be performed.
The process of ultrasonic welding will continue to grow as its abilities to perform welds are being developed in the electronics, aerospace, automotive and medical industries. Ultrasonic welding allows for welds to be completed on large pieces as well as smaller ones that were normally hard to perform. The fact that ultrasonic welding also creates clean welds which require little cleanup work after is also an appealing aspect of this process. As more and more uses for ultrasonic welding are developed, the process will continue to see growth. Ultrasonic welding allows manufacturing companies the ability to perform high quality welds at a faster rate than any other method of joining materials. It is because of this, that ultrasonic welding will continue to grow for years to come.
