Individualized and controlled laser beam pretreatment process for adhesive bonding of fiber-reinforced plastics. II. Automatic laser process control by spectrometry

2021 ◽  
Vol 33 (1) ◽  
pp. 012004
Author(s):  
Hagen Dittmar ◽  
Josef Weiland ◽  
Verena Wippo ◽  
Alexander Schiebahn ◽  
Peter Jaeschke ◽  
...  
Keyword(s):  
Process Control ◽  
Laser Beam ◽  
Adhesive Bonding ◽  
Fiber Reinforced ◽  
Laser Process ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Individualized and controlled laser beam pre-treatment process for adhesive bonding of fiber-reinforced plastics. III. Effects of contaminants

2021 ◽  
Vol 33 (4) ◽  
pp. 042051
Author(s):  
Hagen Dittmar ◽  
Christoph J. A. Beier ◽  
Josef Weiland ◽  
Alexander Schiebahn ◽  
Peter Jaeschke ◽  
...  
Keyword(s):  
Laser Beam ◽  
Adhesive Bonding ◽  
Treatment Process ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Pre Treatment

Surface Pretreatment of Fiber-Reinforced Plastics via VUV Radiation

2017 ◽  
Vol 742 ◽  
pp. 70-73
Author(s):  
Christoph Schmüser ◽  
Kira Rosanova ◽  
Christopher Dölle
Keyword(s):  
Surface Energy ◽  
Power Plants ◽  
Adhesive Bonding ◽  
Surface Preparation ◽  
Transport Sector ◽  
Contact Method ◽  
Fiber Reinforced ◽  
Release Agent ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Fiber-reinforced plastics (FRP) are of great importance for the transport sector, the aerospace industry, for wind power plants, in the building sector and in the field of sports and leisure applications. Optimization of the adhesive bonding process for FRP structures, especially the surface preparation prior to bonding, will be of a central importance in forthcoming expansion of FRP use. In this connection the key problem depends on the FRP polymer matrix. In the case of duroplastic matrix the main problem is the presence of release agent on the surface of joining components. For the thermoplastic matrix such as polypropylene (PP), the main problems are the low surface energy and the inertness of its surface. Conventional pretreatment methods, such as manual grinding, shall be replaced by energetic radiation technics like VUV lamps (vacuum ultraviolet spectral range: 100 – 200 nm). This approach is a non-contact method, characterized by high treatment homogeneity and material-saving properties, combined with no further fibers to be released. The surface of the thermoplastics is activated by the incorporation of oxygen, release agent contamination on the thermoset is cleaned or modified [1 - 8]. The results of the VUV surface activation of PP and CFRP with regard to the incorporation of functional groups, increase of surface energy, matrix degradation and the adhesion increase of adhesive bonds are presented. In addition, studies on the release agent coating and the release agent modification by VUV radiation are presented. The work is completed by considerations concerning possibilities to accelerate the process (in particular, wavelength dependence, influence of an inert gas or the moisture content). Finally, an evaluation of the VUV pretreatment is carried out on the basis of two specific applications.

scholarly journals Cold surface treatments on fiber-reinforced plastics by pulsed laser

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Jana Gebauer ◽  
Gerd Paczkowski ◽  
Jodok Weixler ◽  
Udo Klotzbach
Keyword(s):  
Adhesive Bonding ◽  
New Technologies ◽  
Thermal Spraying ◽  
Fiber Reinforced ◽  
Cold Surface ◽  
Promising Alternative ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Matrix Removal ◽  
Fiber Reinforced Plastics

When producing fiber-reinforced plastic (FRP) suitable for mass production, new technologies have to be developed to overcome existing challenges such as increased efficiency in resource consumption or higher process flexibility. In the past, laser processing has been shown to yield important advantages such as non-contact processing, no tool wear and high design flexibility.Pulsed laser ablation of FRP offers a promising alternative to state of the art mechanical blasting. The selective matrix removal enables a high potential to improve adhesive bonding, molding processes and coating deposition of lightweight materials, especially FRP-metal or FRP-ceramic hybrids. The resulting increase in surface area exhibits forms lock characteristics and simultaneously provides an expanded interface area. As a result, 40 % higher tensile strength can be reached in pull-off tests compared to a mechanically blasted organic sheet surface, joined by thermal spraying of aluminum on carbon fiber-reinforced epoxy (CFRP).

Numerical simulation of water jet–guided laser cutting of carbon fiber–reinforced plastics

2018 ◽  
Vol 233 (10) ◽  
pp. 2023-2032 ◽  
Author(s):  
Dong Sun ◽  
Fuzhu Han ◽  
Weisheng Ying
Keyword(s):  
Carbon Fiber ◽  
Laser Beam ◽  
Element Model ◽  
Water Jet ◽  
Fiber Reinforced ◽  
Laser Beam Machining ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced

Carbon fiber–reinforced plastics are now widely used in various industries because of its excellent properties. Although milling and drilling are the dominating processing methods for carbon fiber–reinforced plastics at present, laser beam machining, as a wear-free, contactless and flexible process, is considered a promising alternative method. However, the thermal damage is one of the most important issues for laser beam machining of carbon fiber–reinforced plastics because of the significant difference in thermal properties of carbon fiber and matrix. Water jet–guided laser technique has been proved an effective technique to reduce heat damage. Nevertheless, there are few studies about carbon fiber–reinforced plastics processing with water jet–guided laser to date. It is important to understand the mechanism of interaction between water jet–guided laser and carbon fiber–reinforced plastics. Hence, a three-dimensional finite element model was developed to investigate the transient thermal process. The influence of scanning speed on the surface appearance, heat-affected zone and shape of the cross section was illustrated. Experiments with same process parameters were conducted to validate the model. Based on the finite element model and experiments, the mechanism of material removal was explained. The epoxy is considered to be removed once it reaches the melting point and the carbon fiber is removed at the sublimation temperature. Because of the strong cooling effect of water jet, there is nearly no heat accumulation between pulses, leading to the constant heat-affected zone width at different scanning speed. The kerf sidewall is relatively vertical due to the homogeneous power distribution in water jet. The results demonstrate that water jet–guided laser cutting of carbon fiber–reinforced plastics has some advantages than traditional laser beam machining and is a potential processing method for carbon fiber–reinforced plastics.

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