Browsing by Author "Vieten, Tobias"

Now showing 1 - 4 of 4

Open Access
Feasibility study of soft tooling inserts for injection molding with integrated automated slides
(2021) Vieten, Tobias; Stahl, Dennis; Schilling, Peter; Civelek, Faruk; Zimmermann, André
The production of injection-molding prototypes, e.g., molded interconnect devices (MID) prototypes, can be costly and time-consuming due to the process-specific inability to replace durable steel tooling with quicker fabricated aluminum tooling. Instead, additively manufactured soft tooling is a solution for the production of small quantities and prototypes, but producing complex parts with, e.g., undercuts, is avoided due to the necessity of additional soft tooling components. The integration of automated soft slides into soft tooling has not yet been investigated and poses a challenge for the design and endurance of the tooling. The presented study covers the design and injection-molding trial of soft tooling with integrated automated slides for the production of a complex MID prototype. The design further addresses issues like the alignment of the mold components and the sealing of the complex parting plane. The soft tooling was additively manufactured via digital light processing from a silica-filled photopolymer, and 10 proper parts were injection-molded from a laser-direct structurable glass fiber-filled PET+PBT material before the first damage on the tooling occurred. Although improvements are suggested to enhance the soft tooling durability, the designed features worked as intended and are generally transferable to other part geometries.
Open Access
Integration of mechatronic functions on additively manufactured components via laser‐assisted selective metal deposition
(2024) Vieten, Tobias; Weser, Sascha; Schilling, Alexander; Gläser, Kerstin; Zimmermann, André
The current industrial revolution derives much of its momentum from value creation based on interconnected products and related data based services. Such products must fulfill both mechanical and electrical requirements, making them mechatronic systems. The production of such systems via additive manufacturing (AM) processes offers advantages in achievable complexity, reduction of the amount of individual components, and cost‐effective as well as sustaina ble production of small quantities. In this work, a process chain is presented that allows for refining additively manufactured 3D structures made from industry‐standard materials into mechatronic components by creating electrically conductive structures directly on their surfaces. The process chain is based on masking the component's surface and selectively removing the masking according to the circuit geometry using laser radiation. In a wet-chemical bath process, the surface is then exposed to palladium nuclei, the masking is fully removed and metal layers (copper/nickel/gold) are deposited by electroless plating. The procedure is developed using stereolithography as a model process for AM and transferred to four additional AM methods. In all cases, despite markedly different surface properties, good selectivity of metal deposition is observed as well as adhesion strength and conductivity comparable to industrially common injection‐molded laser direct structured mechatronic interconnect devices.
Open Access
Mechatronische Funktionsintegration auf additiv gefertigten Bauteilen aus Standardkunststoffen mittels laserbasierter Oberflächenbearbeitung und selektiver Metallabscheidung über nasschemische Prozesse
(2024) Vieten, Tobias; Zimmermann, André (Prof. Dr.-Ing.)
In der vorliegenden Arbeit wird eine Prozesskette vorgestellt, die es ermöglicht, additiv gefertigte 3D-Körper zu einem mechatronischen Bauteil zu veredeln, indem unmittelbar auf der Oberfläche elektrisch leitfähige Strukturen erzeugt werden. Die Prozesskette basiert auf der Maskierung der Bauteiloberfläche und dem selektiven Abtrag der Maskierung entsprechend der Schaltungsgeometrie mittels Laserstrahlung, bei dem auch die Bauteiloberfläche bearbeitet wird. In einem nasschemischen Badprozess werden dann nacheinander die Oberfläche mit Palladiumkeimen beaufschlagt, die Maskierung final entfernt und Metallschichten (Cu/Ni/Au) außenstromlos abgeschieden. Der Prozess ist somit nicht auf Spezialwerkstoffe angewiesen, sondern ermöglicht den Einsatz branchenbekannter Materialien aus dem Bereich der additiven Fertigung, sofern diese nicht elektrisch leitfähig sind. Als Maskierungsmaterial wurden eine anorganische Schicht in Form eines Natriumsilikatglases und eine organische Schicht in Form eines photostrukturierbaren Negativlacks untersucht. Das anorganische Maskierungsmaterial musste aufgrund starker Rissbildung auf 3D-Bauteilen jedoch zunächst verworfen werden. Das Verfahren wurde unter Verwendung des Digital Light Processing als Modellprozess der additiven Fertigung erarbeitet und die erzeugten Metallschichten hinsichtlich Haftfestigkeit (Hot-Bump-Pull-Tests), Leitfähigkeit (Vierleitermessung) und Oberflächenrauheit (Weißlichtinterferometrie) charakterisiert. Dabei konnten Haftfestigkeiten und Leitfähigkeiten der Metallschicht vergleichbar mit industriell gängigen, spritzgegossenen laser direktstrukturierten Mechatronic Interconnect Devices aufgezeigt werden. Zum Nachweis der Transferierbarkeit des Verfahrens auf andere additive Fertigungsverfahren wurden Bauteile mit vier weiteren Verfahren, Stereolithographie, PolyJet, selektives Lasersintern und HP Multi Jet Fusion, prozessiert und die Metallstrukturen charakterisiert. In allen Fällen konnte, trotz der stark unterschiedlichen Oberflächeneigenschaften, eine gute Selektivität der Metallabscheidung gezeigt werden. Abschließend wurden Designregeln für das Verfahren aufgestellt.
Open Access
Soft tooling-friendly inductive mold heating - a novel concept
(2021) Vieten, Tobias; Zanin, Davide; Knöller, Andrea; Litwin, Thomas; Eberhardt, Wolfgang; Zimmermann, André
In order to economize injection molded prototypes, additive manufacturing of, e.g., curable plastics based tools, can be employed, which is known as soft tooling. However, one disadvantage of such tools is that the variothermal process, which is needed to produce polymeric parts with small features, can lead to a shorter lifespan of the tooling due to its thermally impaired material properties. Here, a novel concept is proposed, which allows to locally heat the mold cavity via induction to circumvent the thermal impairment of the tooling material. The developed fabrication process consists of additive manufacturing of the tooling, PVD coating the mold cavity with an adhesion promoting layer and a seed layer, electroplating of a ferromagnetic metal layer, and finally patterning the metal layer via laser ablation to enhance the quality and efficiency of the energy transfer as well as the longevity by geometric measures. This process chain is investigated on 2D test specimens to find suitable fabrication parameters, backed by adhesion tests as well as environmental and induction tests. The results of these investigations serve as proof of concept and form the base for the investigation of such induction layers in actual soft tooling cavities.