Kunststoffmetallisierung mittels laserinduzierter Aktivierung und computergestützter Prozessmodellierung – KAP
The young interdisciplinary “KAP” research group of University Mittweida aims to develop a clean technology route for the pretreatment of plastics for the metallization of plastics. The English translation of KAP is “Plastic Metallization using Laser-induced Activation and Computer-aided Process Modelling”. With the combination of expertise from laser technology, electroplating technology, material characterization and computer simulation to develop a new procedure, in which the toxic hexavalent chromium in the current pre-treatment could be substituted and thus making the new procedure more environmentally friendly.
Projektbeschreibung
for the English version see below
In vielen Produkten des täglichen Gebrauchs wie Elektronik, Medizintechnik, Automobilindustrie und im Haushaltsbereich werden metallisierte Kunststoffbauteile (überwiegend ABS: Acryl Nitril Butadien und PA: Polyamid) verbaut. Aktuell ist für die Metallisierung von Kunststoffen ein rohstoffintensiver (Palladium- und Nickelverbindungen) und ein aufwendiger Vorbehandlungsablauf erforderlich. So werden beispielweise große Mengen an Wasser und Energie sowie toxische Chrom-VI-Säure benötigt. Das Vorhaben der Nachwuchsforschergruppe zielt darauf ab, den kostenintensiven und umweltbelastenden Vorbehandlungsprozess für die Kunststoffmetallisierung durch einen nachhaltigen Prozess mittels Laseraktivierung (LIG: laser induced graphene und PLD: pulsed laser deposition) der Kunststoffoberfläche und einem anschließenden Galvanisierungsprozess zu substituieren. Weiterhin sollen die Prozesse der Laseraktivierung und Galvanisierung in Form von Modellen visualisiert und simuliert werden. Mit diesem alternativen Vorbehandlungsablauf wird ein wesentlicher Beitrag hinsichtlich der Nachhaltigkeit geleistet, da keine Nasschemie und energieintensiven Vorbehandlungsprozesse benötigt werden sowie weniger schadstoffbelasteten Abwässer und nicht-recyclebarer Schlämme anfallen. Darüber hinaus wird eine erhebliche Zeit- und Ressourcenersparnis durch die computergestützten Prozessmodelle möglich. Mit der Bearbeitung des Vorhabens soll das Bewusstsein der Nachwuchsforschenden auf ein nachhaltiges Wirtschaften geschärft werden. Darüber hinaus werden die Nachwuchskräfte für den beruflichen Praxisalltag entsprechend weiterqualifiziert.
Our Teams
Team 1 | Coordination and Electrodeposition
The electrodeposition of various metal layers on laser-activated plastics for different applications is the main objective of Team 1 with Prof. Frank Köster and Scott Dombrowe. Before the laser-activated substrate can be coated, contamination on the surface must be removed to ensure good adhesion. Various environmentally friendly processes, such as atmospheric plasma, will be used for pre-treatment. Subsequently, various single layer coatings such as copper, nickel, gold and tin as well as multilayer coatings such as copper-nickel, copper-nickel-gold will be deposited using commercial electrolytes under constant current, pulsed current and electroless conditions on plastics for decorative and technical applications. The deposition parameters such as current density, convection and process time will be evaluated and optimized. In addition to performing the experiments, the project manager is also responsible for the general organization of the project. This includes writing reports, planning and conducting meetings, and internal data management.
Team 2 | Laser Activation
The main goal of team 2 with Prof. Weißmantel and Laura Dienelt is the activation of plastics by laser induced graphene (LIG) and coating by pulsed laser deposition (PLD). The plastic surface is functionalized by both processes, since an electrically conductive layer is created by the LIG and PLD processes. This layer should allow direct galvanic metal deposition. This means that the currently used wet chemical substrate pretreatment for plastic metallization can be omitted, and the entire portfolio of plastics can be used. The quality of the graphene formation is optimized by adjusting laser parameters such as wavelength, laser pulse fluence and scanning speed. PLD is also used to coat plastics with metals, depositing thin, homogeneous layers. The process conditions are analysed and optimized to ensure high conductivity and adhesion of the layers for subsequent process steps. The structures produced will be characterized by team 3 and compared with simulations from team 4 to further improve the processes.
Team 3 | Material Characterization
Team 3 with Prof. Frank Hahn and Nurul Amanina Binti Omar characterize the physical and chemical aspects of the graphene layer from the pulsed laser deposition and the metal coatings deposited on graphene by Team 2. We use RAMAN spectroscopy to identify the presence of graphene on the surface of the polymer as well as to measure its thickness and reflection high-energy electron diffraction (RHEED) to acquire structural information of the graphene nanolayer. The deposited metal coatings are characterized with the help of among others SEM for surface morphology, EDX for chemical content, four-terminal sensing for electrical conductivity measurements, colorimeter to determine the CIELAB color space, glossmeter for reflection gloss measurements of the metal surface, kaloMAXX for the tribological properties and coating adhesion test to determine their adhesive tensile strength. The experimental results will be compared to the simulated ones from Team 4 to validate the models used.
Team 4 | Simulation and Modeling of Fabrication Processes
The focus of Team 4, with Prof. Klaus Dohmen and Niyati Ajay Dave, is to simulate and model how materials are made in order to improve and optimize the process. We use advanced computational methods and Python-based tools, leveraging libraries such as NumPy, Matplotlib, and SciPy to develop efficient workflows and ensure reliable results. One of our key activities is the simulation of the Pulsed Laser Deposition (PLD) process to model thin film layers. By adjusting settings such as laser power, pulse frequency, and substrate motion, we ensure that the simulations are realistic and match real-world conditions. We also create visualizations of the electrical potential in graphene to understand its electronic properties. We also visualize the electric potential in graphene to gain deeper insight into its electronic properties. For the electroplating process, we developed a simulation to analyze critical parameters such as resistance, electrical conductivity, current density, electric field, and potential distribution. Using numerical methods to solve the Laplace equation, we modeled the steady-state potential distribution, which plays a crucial role in the controlled deposition of conductive layers on graphene.
English version
Many products of our daily lives, such as automotive and electronic components, medical and public devices are built with metallized plastics. The Plating on Plastic (PoP) process is complex and needs substantial raw materials, like water and electrical energy. In addition, only few types of plastics such as Acrylonitrile Butadiene Styrene (ABS), Polyamide (PA) are suitable for this process due to their good adhesion between the plastic and metal. Furthermore, hexavalent chromium, which is toxic and harmful to the environment, is used for the pretreatment of plastics. According to REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) chemicals regulation, chromium-VI compounds are banned in Europe and may only be used with a special authorization. The aim of this project is to substitute the carcinogenic conventional wet-chemical pretreatment process for the metallization of plastics with a novel and sustainable process. In the first step, the plastic surface is activated with a laser induced graphene (LIG) or pulsed laser deposition (PLD) process to produce an electrically conductive layer. Due to this conductive layer, it is possible to electrodeposit single or multilayer metal layers for functional or decorative purposes. Another goal in this project is to simulate both the laser and electrodeposition processes as a model. With computer-aided process modeling, predictions can be also made about the layer properties depending on process parameters. Overall, the innovative laser-activated and computer-simulated pretreatment of plastics is a clean technology, as no toxic chemicals are required, and no wastewater is produced. In addition to the technical objectives of the project, the project personnel are also to be qualified further in the areas of teaching, social, environmental and management skills.