Description of transmitted energy during laser transmission welding of polymers

It is important to describe the laser energy distribution in polymers properly when modeling heat transfer during laser transmission welding of thermoplastics. This paper presents an analytical model that describes the energy transmission in laser transmission welding of light scattering polymers. The model considers that the transmitted laser beam in a scattering polymer can be represented by scattered and unscattered components. The distribution of the scattered energy from any point in the incident beam is Gaussian. The transmitted power from the discretized input beam is summed to create a normalized power flux distribution model. The model was validated using the measured laser energy distributions after transmission through parts made of polypropylene, as well as unreinforced and glass fiber reinforced polyamide 6.