Individualized and controlled laser beam pretreatment process for adhesive bonding of fiber-reinforced plastics—Part I: Optical detection of impurities on the component surface

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering, vol. 234, pp. 426–435

Abstract

This paper deals with the detection and localization of impurities such as release agent residues and fingerprints on fiber-reinforced plastic surfaces in an inline process step. This information can be used to carry out a locally individual and controlled surface pretreatment using laser radiation in order to improve the adhesion conditions. In this paper, surfaces from polyamide 6 reinforced with glass fiber are considered. To detect the impurities, inline images of the joining surfaces are taken using a laser line triangulation system. These image data are then examined with a specially developed algorithm of digital image processing. The real-time algorithm is based on the method of material-specific threshold values. In addition to real impurities, the algorithm was validated with artificial impurities. The central result of this work is the detection and local impurities of release agent residues and fingerprints down to a detail size of 0.3 mm.

Authors 7

1. Josef Weiland corresponding Aachen ISF – Welding and Joining Institute

   RWTH Aachen University

   Affiliation as printed

   ISF—Welding and Joining Institute, RWTH Aachen University, Pontstrasse, Aachen, Germany

2. Billy Kunze Aachen ISF – Welding and Joining Institute

   RWTH Aachen University

   Affiliation as printed

   ISF—Welding and Joining Institute, RWTH Aachen University, Pontstrasse, Aachen, Germany

3. Hagen Dittmar

   Laser Zentrum Hannover

   Affiliation as printed

   LZH—Laser Zentrum Hannover e.V., Hannover, Germany

4. Alexander Schiebahn Aachen ISF – Welding and Joining Institute

   RWTH Aachen University

   Affiliation as printed

   ISF—Welding and Joining Institute, RWTH Aachen University, Pontstrasse, Aachen, Germany

5. Peter Jäschke

   Laser Zentrum Hannover

   Affiliation as printed

   LZH—Laser Zentrum Hannover e.V., Hannover, Germany

6. Ludger Overmeyer

   Laser Zentrum Hannover

   Affiliation as printed

   LZH—Laser Zentrum Hannover e.V., Hannover, Germany

7. Uwe Reisgen Aachen ISF – Welding and Joining Institute

   RWTH Aachen University

   Affiliation as printed

   ISF—Welding and Joining Institute, RWTH Aachen University, Pontstrasse, Aachen, Germany