Clear-on-clear plastic welds made possible through the STTlr process. [Image courtesy of Emerson]
The welds, according to the company, are the latest advance in its patented Simultaneous Through-Transmission Infrared Laser Welding (STTlr) process.
Medical device manufacturers are widely using the Branson STTlr laser technology because it delivers precise, particle-free welds that combine hermetic sealing with superior aesthetic quality, Emerson said.
Until recently, STTlr welds required an upper part that was transmissive or “clear” and a lower part that was absorptive or “black.” Laser energy transmitted through the transmissive part accumulates in the weld zone of the absorptive part, creating a melt area which, when the assembly is held under pressure, compresses to form a clean, particle-free weld.
Said Emerson: “Only recently was clear-on-clear part welding made possible when Emerson and Sono-Tek teamed up to create a technique by which Sono-Tek’s ultrasonic fine-line coating system applies a thin band of laser absorber to the weld area of a clear part prior to STTlr welding. The laser absorber enables the weld zone of the clear part to absorb energy and melt, making the weld possible.”
The STTlr technology is able to meet highly specialized manufacturing demands of small geometrically complex devices and does not use vibration force, making it ideal to accommodate delicate parts or those embedded with electronics.
