Process Monitoring of Extrusion Based 3D Printing via Laser Scanning

TL;DR

This paper presents a laser scanning-based monitoring system for extrusion 3D printing that detects errors early, aiming to improve accuracy and enable quality control during the manufacturing process.

Contribution

It introduces a modular 2D laser triangulation scanner integrated into an E3DP machine for real-time process monitoring and initial steps towards a quality control loop.

Findings

The system provides quantitative and qualitative geometrical data.

Early error detection potential demonstrated.

Discussion on developing a feedback control loop.

Abstract

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.