In the early 1960s, there were a limited number of techniques to join plastics components. The methods were fairly simple and basic: glues, screws, solvents, and hot-plate welding. That was until Branson Ultrasonics test engineer Bob Stevenson came up with his invention in a Danbury, Conn., laboratory in 1963.
Stevenson was testing an ultrasonic cell disrupter for a separate project when he mistakenly welded shut a polystyrene coin box. Company officials saw the potential for plastics and adapted a hand drill press for the earliest version of an ultrasonic welder for rigid plastics. The first Branson Series 100 welder was introduced in 1964. It included an ultrasonic stack (converter, booster, and horn) and a 200-watt power supply.
Ultrasonic welding took plastics assembly to a new level, helping to optimize design and productivity in a range of industries. The repeatability, quality, and speed of the process was like no other and it transformed plastics assembly into a more reliable and highly efficient operation while also opening up new market opportunities.
The first use of ultrasonic welding was in toys, pioneered by Mattel and Knickerbocker. At the end of the 1960s, automotive companies like General Motors’ Guide Lamp Div. (now Delphi) in Indiana used ultrasonic welding for taillamps and turn signals. In the early 1970s, the process had moved on to medical applications.
Today, ultrasonic welding is considered the leading assembly method for rigid thermoplastics. Other North American suppliers besides Branson include Herrmann Ultrasonics, Dukane Ultrasonics, and Sonics & Materials. The current global market for ultrasonic welding equipment is about $500 million.
Very few readers of this issue can remember, or even imagine, what it was like when an injection mol...