Spectrum Transmission Measurement of a Fiber Laser Beam in Polymethyl Metacrylate for Laser Sintering Processing

A novel procedure is applied to evaluate the performance of Polymethyl Metacrylate (PMMA) plates as a pass through window for laser beam transmission, as a part of laser sintering machine construction. The method for laser beam spectrum transmission measurement consists basically in the exposure of a Kapton polyamide film, with the laser in a pulsed mode, in order to obtain variance diameter measurements. Measurements were analyzed in matched paired experiment levels in order to evaluate the effect of the laser beam transmission through the plates.A negligible effect of the presence of PMMA during the process was found. Selection of this polymer was then validated in performance, besides it owns transparency for purposes of process control and stable properties under harsh environmental conditions. Nevertheless, optical state of the material needs to be preserved in order to ensure consistent results in a long term.