Low Power Laser Transmission Welding (LTW) of Clear-to-Clear Acrylic Transparent Polymers
D. Kumar, A.S. Kuar and N. Maity
Owing to the growing applications in medical equipment, the marine sector and automotive industries, laser transmission welding (LTW) is gaining increasing importance. LTW of two transparent acrylic thermoplastic materials, each of 4 mm thickness, was demonstrated using a diode laser-pumped solid-state Nd:YVO4 pulsed laser. The effect of process parameters such as laser power, pulse frequency and scanning speed have been investigated and a multi-objective optimization based on desirability function technique was used for the betterment of the results. A validation test has been performed which shows that the predicted results are compatible with actual value. Scanning speed was found to be the process parameter that mostly affects the weld strength. A scanning electron microscope (SEM) was used to study the morphology of the weld zone. It was observed from SEM micrographs that the heating zone in the weld area often generates bubbles and ablation which enhance the joining strength.
Keywords: Nd: YVO4 laser, acrylic, transparent polymer, laser transmission welding (LTW), low power, morphology, multi-objective optimization, response surface methodology (RSM)