  Extrusion based 3D Printing (E3DP) is an Additive Manufacturing (AM)
technique that extrudes thermoplastic polymer in order to build up components
using a layerwise approach. Hereby, AM typically requires long production times
in comparison to mass production processes such as Injection Molding. Failures
during the AM process are often only noticed after build completion and
frequently lead to part rejection because of dimensional inaccuracy or lack of
mechanical performance, resulting in an important loss of time and material. A
solution to improve the accuracy and robustness of a manufacturing technology
is the integration of sensors to monitor and control process state-variables
online. In this way, errors can be rapidly detected and possibly compensated at
an early stage. To achieve this, we integrated a modular 2D laser triangulation
scanner into an E3DP machine and analyzed feedback signals. A 2D laser
triangulation scanner was selected here owing to the very compact size,
achievable accuracy and the possibility of capturing geometrical 3D data. Thus,
our implemented system is able to provide both quantitative and qualitative
information. Also, in this work, first steps towards the development of a
quality control loop for E3DP processes are presented and opportunities are
discussed.
