Thermal modeling and analysis of laser transmission welding of polypropylene: process mechanics and parameters

Abstract Laser transmission welding efficiently welds polymers by precisely applying concentrated heat with a laser beam, making it a widely used, non-contact, contamination-free, automated, and fast polymer joining method in automotive, medical, and electrical industries. This study presents a three-dimensional finite element model simulating the laser transmission welding of polypropylene, a widely utilized engineering thermoplastic with superior mechanical properties and exceptional chemical resistance. The primary objectives are to analyze thermal phenomena, predict parameters such as weld temperature and weld pool size, and conduct a thorough parametric analysis. The finite element model incorporates a volumetric heat source within COMSOL ® Multiphysics, incorporating a radiative beam in an absorbing media interface, while considering key thermal factors such as conduction, convection, and radiation. Experimental tests are conducted to validate the developed thermal model. The paper deepens comprehension of the mechanics behind laser transmission welding of polypropylene, providing insights into the impact of process parameters on the thermal field and weld pool size.