An Experimental Investigation on Laser Beam Welding of Acrylics

Laser beam welding (LBW) is nowadays increasingly used in the fabrication industry due to some of its distinct advantages. LBW offers high energy density around its focus thereby making it well suited for welding of certain category of materials that are considered difficult-to-weld. Since the laser follows the principles of optics, it is easy to regulate the laser beam by selecting appropriate lenses. In the present work, laser beam welding (LBW) is carried out to make lap joint of two acrylic flats- one opaque and the other transparent. Laser beam passes through the transparent piece of plastic flat and is focused on to the opaque flat around the interface region. Laser beam gets absorbed in the opaque flat in the interface region and generates heat energy causing local melting, and subsequent welding of both the flats. Clamping pressure is varied four times, and two levels of current flow and scanning speeds are set to find out a condition corresponding to sound, strong weld joint within the experimental domain. Good quality joint between transparent and opaque acrylic components with high weld strength of 8.33 MPa is obtained under 280 mm/min scanning speed and 2 MPa clamping pressure with 34 A weld current set, and hence, this condition may be recommended to apply to obtain enough weld strength.