Product Code: ICAL06_601

Through-Transmission Welding of Polymers: Effects of Particles on Laser Beam Scattering
Authors:
A Nichici, University of Timisoara; Romania
JC Kneip, LTm Laboratory; CHALON SUR SAONE France
M Ilie, LTm - IUT Le Creusot; Le Creusot France
Simone Mattei, LTm - IUT Le Creusot; Le Creusot France
Presented at ICALEO 2006

Among all the assembling processes of thermoplastic materials, through-transmission laser welding is becoming more and more frequently used for industrial applications. In this process, laser beam energy may be deposited directly into the structure, at the interface between a semi-transparent and an opaque slabs. Induced heating at the interface may be directly linked to the power density of the laser beam. Thereby the polymer compositions (presence of additives, pigments, reinforcements, ) may have a great influence on its shape, and then, on the energy deposition. The aim of our study is to evaluate the influence of particles in semi-transparent polymers on scattering phenomena. Firstly, the scattering of a laser beam into a polymer is explained as well as the mathematical modelings currently used. Next, a numerical study of the scattering is realized and compared with some experimental results obtained on PMMA polymers. We show here that, if the characteristics of the particles are known, it is possible to simulate the shape and the power distribution of the laser beam, and thereby, using a finite element program, the heating induced at the interface of the slab. We show here the interest of a good understanding of the scattering phenomena and the possibilities to simulate it for through-transmission laser welding process.