From vehicle interiors to the smartphones we hold in our hands every day, and even washing machine control panels: As consumers, we place high demands on the technology that surrounds us.
Manufacturers therefore face the particular challenge of combining smart features with excellent design - while at the same time keeping production cost-effective and sustainable. What sounds challenging can be made reality with the help of an innovative process devised by LEONHARD KURZ. The thin film expert is working with the KURZ subsidiary PolyIC and its partners Wittmann Battenfeld and Georg Kaufmann Formenbau in the implementation of the groundbreaking decoration technology IMD VARIOFORM® with In-Mold Labeling (IML). As a result, customers benefit from bundled expertise.
Design freedom and cost efficiency thanks to a single processing phase
IMD VARIOFORM® in combination with In-Mold Labeling (IML) makes it possible for the first time to integrate 3D-deformed touch sensors into plastic components and to perform the four process steps - decoration, thermoforming, injection molding, and punching - in one single processing phase. “Compared to conventional processes, this saves manufacturers a great deal of cost while at the same time offering a high degree of freedom in terms of design and the materials selected,” stresses Martin Hahn, Head of Application, Technology & Innovation for KURZ’s Plastic Decoration Business Area. Both continuous designs and single-image designs can be implemented. This technology also enables the use of recycled plastic materials.
The process was conceived as a further development of KURZ’s proven In-Mold Decoration technology (IMD) in order to realize the production of plastic components with sophisticated 3D geometry. For demonstration purposes, KURZ has had a concept component produced in an efficient production procedure with just one processing phase, that has already been demonstrated at various industry events. The groundbreaking technology was awarded the Bavarian Innovation Prize in 2020.
In the IMD VARIOFORM® process, a laminate film is transported via the specially developed foil feed device and heated via an infrared beam before it is drawn into the cavity of the tool through the vacuum system. A 3D-deformed sensor is placed on the opposite side, and a thermoplastic plastic melt is injected after closing the tool. The result is a plastic component with complete single-image decoration on the front and a capacitive touch sensor on the back.
Innovative sensors from PolyIC for functional integration and more design freedom
Ultra-thin, malleable sensors are essential for the desired freedom when it comes to design creativity. Here, KURZ relies on the know-how of its subsidiary PolyIC, a specialist in the custom production of metal-mesh touch sensors. The company relies on extra-thin sensor films, which can also be used in 3D components with curved surfaces, due to their particular flexibility and robustness. As a carrier, PolyIC uses a transparent plastic substrate (PET) on which high-resolution silver-based metal structures (metal mesh) with a thickness of less than 100 nm and a line width in the low micrometer range are applied in the rolling process. The sensors can later be easily crushed and recycled with the entire component or added back to the injection molding process as scrap during production.
Everything from a single source - Automation by Wittmann Battenfeld
Bundling the four process steps of decoration, thermoforming, injection molding, and punching requires a versatile system. KURZ relies on the expertise of the leading supplier of injection molding technology, Wittmann Battenfeld, who has developed an all-in-one concept. The machine manufacturer not only supplies the injection molding machine but also all peripheral components, such as the parts conveyor system, the tool tempering devices, and the clean room housing. This ensures that all devices are optimally coordinated with each other.
Innovative injection molding tools from Georg Kaufmann Formenbau AG
KURZ also relies on an established manufacturer for the injection molding tool used: The Swiss company Georg Kaufmann Formenbau AG (GKTool), which has been exclusively a supplier to the automotive industry for almost 50 years, has applied its innovative In-Mold Wrapping (IMW) bending and trimming system, and protected it with a patent. Thanks to the integrated tool technologies, the components are already finalized during the injection molding process. IMW technology also enables tool-integrated decoration of the front edge of the component, which does away with the need for subsequent work steps. The unique all-in-one tool technology from GKTool thus enables a drastic shortening of the process chain and reduces production and logistics costs long term.
Wide range of applications, a high level of sustainability
With IMD VARIOFORM®, KURZ has developed a series-ready process that can be used in various industries, e.g., in the automotive industry, in household appliance manufacturing, or in the consumer electronics segment. “We are pleased that we were able to implement this ambitious project in cooperation with experienced partners, who are as passionate about innovation and sustainability as we are,” emphasizes Martin Hahn, and adds: “With this technology, we combine different process steps into one, to enable the straightforward use of plastic recyclables and, at the end of the product life cycle, enable optimum recyclability of the components produced in this way.”