Dr.-Ing. Oliver Schnerr is head of sales, Integrated Solutions Automation Solutions / Vision Systems / Fastening Technology at Kistler.

Kurz and Engel have sought further support for this ambitious project. In addition to tool maker Schöfer, structure expert Reichle as well as materials suppliers Sabic and Röhm are involved. Burg Design, also a Kurz subsidiary, rounds out the team of partners.

Dual-component injection molding with in-mold decoration produces stunning effects from a single-step production process.

The objective is to achieve consistently smooth and efficient part handling throughout the entire test process. Integrated safety concepts monitor the systematic progression of the individual steps in the process — as well as the “handshakes” — to guarantee process reliability while preventing data loss. The automatic system then sends the collected data via an OPC UA interface to the operator's higher-level quality assurance system and to relevant databases for analysis.

The term 2K signifies “dual-component injection molding with in-mold decoration (IMD) technology." Two different plastics are used — acrylonitrile butadiene styrene/polycarbonate (ABS/PC) and transparent thermoplastic polymethyl methacrylate (PMMA). “This special blend of materials allows us, for example, to provide backlighting with targeted light separation, without any undesirable light diffusion. This is the series-ready answer to market requirements in terms of multi-component technology,” explains Martin Hahn, Head of Application, Technology, & Innovation at Leonhard Kurz’s Plastic Decoration business. “And best of all, thanks to our careful choice of materials, the components can later be mechanically recycled together. This means that they can be reused as a post-industrial recyclate.”

When starting to design an inspection concept of this sort, the focus initially is on the requirements for the part being tested. The project team collaborates with manufacturers to develop the required quality-relevant test parameters, mostly related to surface defects and dimensional accuracy. They also identity the appropriate test methods. Kistler-developed sensors make it possible to integrate mechanical pressure and force and torque tests. Experts from the company’s competence center then design the test cell accordingly. In addition to determining the number and positioning of camera stations with lighting elements, the key factor at this stage is outlining the inspection path for the part.

The research project with the IWK Institute for Materials Technology and Plastics Processing is focused on injection molding of a medical part. The objective is to develop a system that provides medtech manufacturers with comprehensive automated random sample inspection, generating accurate AI-based quality predictions while injection molding is still in progress.

Following inspection, the autonomous vehicle transports the tested parts to the warehouse and the test cell sends the analyzed data to higher-level QA or MES systems. Experts can then compare the quality data with the quality forecasts previously generated by ComoNeo PREDICT. If variances occur, the AI models are retrained using new test data.

A research project is exploring new avenues for AI-assisted automated optical quality assurance during the injection molding process.

The molded parts are serialized using individual QR codes and sorted onto trays. While production is still in progress, Kistler’s ComoNeo system monitors cavity pressures via pressure sensors. With support from appropriately trained AI, ComoNeoPREDICT software generates quality predictions for the individual parts. Driverless transport vehicles convey parts selected for spot checks to the optical test cell. This is the first time autonomous transportation has been used in this context. The parts then pass through the predefined inspection program and are checked for dimensional stability and surface defects as well as injection molding anomalies, such as black specks or moisture splay. Issues specific to plastics processing such as shrinkage due to cooling and crystallization are also taken into account.

A new machine and process technology that enables the use of a 2K material mix was developed in tandem with Kurz subsidiary Schöfer.

When one considers the vehicle of tomorrow, we imagine futuristic exterior brand design, 3D lighting effects, and intelligent functions, even on the exterior. All of this is already possible today, as thin-film specialist Leonhard Kurz will soon demonstrate in cooperation with injection molding machine builder Engel. They have pooled their expertise and will present a future-proof design concept for vehicle rear areas at K 2022 in Düsseldorf, Germany, from Oct. 19 to 26.

Manufacturers typically rely on statistical process control (SPC) to verify quality. The frequency and scope of sample testing is defined, enabling users to monitor the production process according to predefined quality parameters.

Autonomous vehicles transport parts to the test cell and storage area. Image courtesy of OST – Ostschweizer Fachhochschule.

The process can be burdensome, as the samples are removed, transported, and tested manually, tying up resources. Moreover, the quality of the data depends on the skills and expertise of the personnel performing the inspections. Critical parts may have narrower tolerances and require more frequent spot checks, increasing the potential for human error. Automated, reproducible random sample testing can optimize the process.

The duo 1300 Combi M machine from Engel is matched to the application at hand. “To enable the use of multi-edge cutter technology, the duo 1300 Combi M has a second moving injection unit on the movable clamping plate. The center mold halves are rotated using a horizontal turn table with a vertical adapter plate,” explains Michael Fischer, Head of Business Development Technologies at Engel. “The articulated robot of the Engel easix KR120 series takes care of the demolding and supports the decoration step beforehand with the additionally installed heating mirror. We have ideally coordinated all components, including the integration of Engel temperature control technology, to make production as efficient as possible.”

Additional injection molding machines producing different parts can be integrated into this setup and incorporated into the material flow with the use of autonomous vehicles. In other words, the concept allows for automation of quality control in complex production environments as long as the test cell is equipped with the appropriate inspection programs: The inspection system recognizes the different parts and triggers the relevant test program.

The complex technical application is based on Schöfer’s high-end “spin stack mold” technology, which is suited for the production of ready-to-install components in large dimensions. It enables the use of IMD technology in combination with the 2K material mix, allowing for the implementation of three-dimensional component geometries and structures for 3D light effects and light barriers in a single step. Manufacturers benefit from reduced production complexity that eliminates the need for deep drawing, punching, or stacking.

Thanks to advanced one-shot production, all processes can be implemented in a single work step. “This is made possible by the combination of injection molding, IMD, and high-end insert technology from Schöfer. For manufacturers, this means time- and cost-efficient production while simultaneously reducing CO2 emissions,” explains Hahn.

Quality control is an essential aspect of the production process, especially when it involves parts used in automotive and medical technology applications. The entire quality control process must be designed to ensure maximum precision and reproducibility, and typically requires reams of documentation. All of this is labor-intensive and time-consuming, and is reliant on expert personnel. Automation coupled with artificial intelligence (AI) may offer an alternative.

Switzerland-based Kistler, a developer of measurement systems and sensors, is collaborating with the Eastern Switzerland University of Applied Sciences (OST) in researching advanced quality-control technologies. In particular, Kistler is involved in a project with the university’s IWK Institute for Materials Technology and Plastics that fully automates the inspection of injection molded parts while harnessing the power of AI to hone quality predictions while injection molding.

Kurz and Engel will demonstrate this process at K 2022 at the Kurz booth (A19 in hall 5), where an Engel machine will mold rear-end covers. This component harmoniously combines design and functionality, says Kurz. The connected surface impresses with its seamless decoration, backlighting, and 3D lighting effects. “This means that the rear-end cover also facilitates communication with other road users,” explains Hahn. “Further highlights are only revealed at a second glance. The possible integration of touch operation offers, for example, activation of a Shy Tech charge level indicator for e-cars. The component is also permeable to radar waves and supports the latest driver assistance systems, right through to autonomous driving.”

The research project is also investigating possible ways to automate data matching and the adaptation of neural networks. Manufacturers not only gain the benefit of improved data quality from optical inspections, they can also design their entire process to be as rigorous and error-free as possible, even in complex production environments where a variety of different parts need to be tested.

He continues: “Our goal for the future is to develop a production platform for our customers that can be individually tailored to different project requirements. This year, we are demonstrating the further development of our IMD Decopur technology, which Kurz introduced back in 2019. This platform enables us to combine 2K thermoplastic technology with Decopur. This not only opens up different combination possibilities, but also offers smart manufacturing efficiency with low energy consumption.”