TY - JOUR

T1 - Improvement of the adhesive bonding properties of an polyamide 6 injection molded fiber reinforced plastic component by laser beam pre-treatment

AU - Weiland, Josef

AU - Dittmar, Hagen

AU - Beier, Christoph J.A.

AU - Ramesh, Chiranth

AU - Marx, Bernd

AU - Schiebahn, Alexander

AU - Jaeschke, Peter

AU - Overmeyer, Ludger

AU - Reisgen, Uwe

N1 - Funding Information: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The IGF-project 19727, “ProKleb – Prozessbeobachtung und -regelung der Klebvorbereitung PUR – und thermoplastbasierter, faserverstärkter Kunststoffe mittels Laser” of the research association “DVS German Welding Society” is funded within the framework of the industrial collective research program (IGF) by the Federal Ministry for Economic Affairs and Energy on the basis of a decision by the German Bundestag.

PY - 2021/11

Y1 - 2021/11

N2 - Fiber-reinforced plastics (FRP) are widely used in the automotive industry due to their lightweight construction potential. Especially, injection-molded components are very popular because of their short cycle times. Unfortunately, this manufacturing process results in some disadvantages for delayed adhesive bonding. On the one hand, such thermoplastics have a very low surface energy (Polyamide 6 (PA6) 36 mJ/m), on the other hand residues of release agents on the surface hinder adhesion between product and adhesive. These disadvantages have to be overcome by the right surface pre-treatment process. Currently, a solvent-containing process is usually used for this purpose. If necessary, the use of primer is common. In the presented paper, the pre-treatment process of an injection-molded component made of polyamide 6 reinforced with glass short-fibers is presented. First, material-specific properties are measured. The influence of laser pre-treatment at 355 nm and 1064 nm wavelength is investigated. Measurements of surface free energy and surface roughness are conducted. The bonding strength is validated by peel test and tensile shear tests. The shear strength was doubled by laser pre-treatment at a medium energy level, partially cohesive failure of the adhesive was achieved. Both investigated wavelengths led to a great improvement of bonding strength at suitable parameters.

AB - Fiber-reinforced plastics (FRP) are widely used in the automotive industry due to their lightweight construction potential. Especially, injection-molded components are very popular because of their short cycle times. Unfortunately, this manufacturing process results in some disadvantages for delayed adhesive bonding. On the one hand, such thermoplastics have a very low surface energy (Polyamide 6 (PA6) 36 mJ/m), on the other hand residues of release agents on the surface hinder adhesion between product and adhesive. These disadvantages have to be overcome by the right surface pre-treatment process. Currently, a solvent-containing process is usually used for this purpose. If necessary, the use of primer is common. In the presented paper, the pre-treatment process of an injection-molded component made of polyamide 6 reinforced with glass short-fibers is presented. First, material-specific properties are measured. The influence of laser pre-treatment at 355 nm and 1064 nm wavelength is investigated. Measurements of surface free energy and surface roughness are conducted. The bonding strength is validated by peel test and tensile shear tests. The shear strength was doubled by laser pre-treatment at a medium energy level, partially cohesive failure of the adhesive was achieved. Both investigated wavelengths led to a great improvement of bonding strength at suitable parameters.

KW - Adhesive bonding

KW - laser beam

KW - polyamide 6

KW - surface pre-treatment

UR - http://www.scopus.com/inward/record.url?scp=85097318541&partnerID=8YFLogxK

U2 - 10.1177/0954407020976195

DO - 10.1177/0954407020976195

M3 - Article

AN - SCOPUS:85097318541

VL - 235

SP - 3243

EP - 3255

JO - Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

JF - Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

SN - 0954-4070

IS - 13

ER -