Optical modelling of VCSEL-assisted thermoplastic tape placement

Due to high intensities and low response time, laser-assisted tape placement offers high processing speeds and precise temperature control. Therefore, the process and its systems gain more and more interest in several industries, which want to utilize continuously-reinforced thermoplastics. Especially high-volume production of structural and semi-structural components, like pressure vessels, pipes or automobile parts, is of interest. Further combinatorial potentials, like the combination with injection molding promise complex, yet cost-effective, product designs. Current laser-based tape placement systems are able to control the laser intensity distribution between tape and substrate by electro-mechanically tilting the laser optics or the whole laser beam source [1], [2]. The use of novel Vertical-Cavity Surface-Emitting Lasers (VCSEL) offers new possibilities to control the laser intensity distribution by use of discrete electrically-controllable emitter lines [3]. Tap e and substrate can be heated independently with adjustable intensity profiles in the width or in feed direction. The basis for a purposeful laser intensity distribution is knowledge of the intrinsic process intensity distributions in the process zone, which depends on the process geometry, the VCSEL angular intensity distribution and the effect of laser reflection. This paper proposes a method to calculate the process intensity distribution for VCSEL-assisted tape placement.