The process chain of the direct coating process has now been optimized. Self-healing, fast-curing PU casting coatings and polycarbonate compounds are now available for this manufacturing process.

The DC process makes it easier and faster to produce sophisticated-looking components with integrated sensors and light elements

16:9

Direct Coating with Polyurethane Coatings Creates Opportunities in Design and Functionality

Automotive

Elektronik

Kunststoff Werkstoffe

Oberflächentechnik

Polyurethan

Kunststoff

Bauwesen

Baustoffe

Polycarbonat

Thermoplaste

Short Cycle Times and High Productivity for Smart Components

Selected Makrolon RE grades from Covestro are climate-neutral from cradle to gate, thanks to the usage of renewable electricity for Covestro production processes and the introduction of raw materials coming from mass-balanced bio-waste and residues.

For the production of its climate-neutral polycarbonates Covestro uses mass-balanced renewable feedstock and renewable energies.

Technische Kunststoffe

Erneuerbare Energie

Energieerzeugung

Kreislaufwirtschaft

Covestro Produces Climate-Neutral Polycarbonate

Electrical and electronics manufacturers want to reduce greenhouse gas emissions from their products and optimize waste management and recycling for them. This can be achieved, among other ways, by using more sustainable thermoplastics and quality-assured recyclates. A close cooperation between companies to establish material cycles and the recycling-friendly design of equipment are also important.

Driving Sustainability Trends in the Electrical and Electronics Industry with Polymers

Recycling

Umweltmanagement

Kunststoff-Recycling

Kunststoffverarbeitung: Verfahren

Kunststoff-Aufbereitung

Kunststoff-Rezyklat

Support for a Greener E&E World

Lightweight construction, functionality and design are characteristic of material development in all areas of application for PC compounds, composites and films. The range of materials has enormous opportunities when it comes to the mobility of the future, lightweight structural construction with continuous fiber-reinforced composites, 5G technology and medical technology.

In electric vehicles, the original function of the radiator grille, namely to supply air to the engine, is no longer needed. It can therefore be used entirely as a design element, for example by integrating luminous logos and fade-out effects

Polycarbonate (PC)

Medizintechnik

Medizinprodukte

Present in a Multitude of Trends

Harmoniously integrating displays into the lines of a vehicle cockpit has always been a real challenge. Continental now uses a combination of film insert molding, in-mold decoration and injection-compression molding to produce large, three-dimensionally formed plastic panels.

Two displays are seamlessly integrated into the continuously 3D-formed instrument panel

Large-Area Curved Plastic Panels with Integrated Displays

Spritzgießen

Kfz-Elektronik

Kunststoffe

Photonik

Optik

HMI, Bedienelemente, Displays

Display im Automobil

Thermoformanlagen

Kunststoffverarbeitung: Maschinen und Komponenten

Warmformen / Thermoformen

Automotive Display: A Matter of Form

Polymaker will offer the Polymaker PC-r 3D printing filament made from recycled polycarbonate (PC). The PC for the filaments comes from materials supplier Covestro and consists of a combination of recycled plastic waste and virgin material.

The combination of recyclates and virgin material reduces the carbon footprint of the polycarbonate and still allows it to be extruded into filaments

Filamente für additive Verfahren

Andere Werkstoffe

Werkstoffe für additive Verfahren

Additive Fertigung

Water Bottles Become Filaments

One year after its spin-off from Bayer, Covestro will showcase new developments, strategies, and projects. With the completion of the new industrial production plant for CO2-based polyurethane foam, an advanced and sustainable research project has been commercialized. The company plans to move further in this direction. At the K fair, it will present a new concept vehicle with wraparound polycarbonate glazing. 

Covestro Makes its Premiere and Commits itself to Sustainability 

Schaumstoffe und Vorprodukte

Verbände, Institutionen, Messen

Familiar Face with a New Look 

Covestro AG, Leverkusen, Germany, goes public with an additive-made demonstrator for a shock absorber. The special feature of this shock absorber, in addition to its high functionality, is the production of the individual parts from three different products and with the aid of three different manufacturing processes. The outer spring of the 40 x 7 cm part is made of powdered thermoplastic polyurethane (TPU). It was shaped layer by layer using selective laser sintering and is notable for its elasticity and high abrasion resistance. 

Demonstrator Made of Three Materials by Three Processes 

3D-Printed Shock Absorber  

The colorful logo and the name Covestro are already well known. New to the team since summer is Dr. Markus Steilemann who heads the manufacturer of polycarbonates, polyurethanes and specialty chemicals. In our interview he talks about the transformation of the former Bayer division into an independent plastics producer, the pitfalls of large-scale chemistry and what sets him apart from his predecessor other than the consuption of Cola light and coffee. 

Covestro CEO Dr. Markus Steilemann Emancipates the Group, Makes it Digital and  Globally Agile 

Kunden-Lieferanten-Verhältnis

Unternehmenskultur

The Decathletes 

Leonhard Kurz’s “Iconic Space Grille”, does not only illustrates modern vehicle design but was also produced in a new production process.

The Iconic Space Grill can be adapted to the design of electric vehicles. With different lighting, it enables communication with other road users and an individual design according to the request of the user

Award-Winning Front Panel Combines Exciting Design with an Efficient  Manufacturing Process

An Eye-Catching Addition  to Electric Vehicles

Covestro is collaborating with Fairphone, a Dutch social enterprise building a market for ethical smartphones, on the use of circular material solutions for its smartphones.

With partially recycled polycarbonates and thermoplastic polyurethanes (TPUs), Covestro is helping smartphone manufacturer Fairphone achieve its sustainability goals.

Covestro Supports Circular Material Solutions for Smartphones

Electrical architecture in an E-car is significantly more challenging than for conventionally powered vehicles. Particularly for insulation of high-voltage (HV) components, the demands on the materials used are increasing. With specially-tailored materials for electric vehicles, challenges in automotive high-voltage technology can be overcome.

Insulation of high-voltage components in electric vehicles makes high demands on the materials used

Polyamide Specialties for Electromobility

Elektromobilität

Mobilität

Polyamide

High Voltage in Cars

Lehvoss will be coming to Fakuma with compounds for lightweight construction applications, including those intended to serve as metal substitutes.

Lehvoss will be coming to Fakuma with compounds for lightweight construction applications

Compound

Messe Fakuma

kunststoffe-international.com

Faserverbundwerkstoffe

Replacing Metals with PPA Compounds

The transition to electric cars is transforming automotive design. And so polymers producer Röhm has developed special polymethyl methacrylate (PMMA) molding compounds with this in mind. These are sold under the company’s well-known Plexiglas brand. At Fakuma, the company will be demonstrating how they can be used to combine design requirements and functional properties.

Plexiglas Resist AG 100 is used, for example, in Volkswagen’s ID.3 electric vehicle

Polymethylmethacrylat

Greater Design Freedom for Electric Cars

Premium-quality automotive interior surfaces are becoming increasingly important from the customer’s point of view. This insight prompted Asahi Kasei to develop its Leona SG series of semi-aromatic polyamides (PA), which the Japanese group will be presenting at this year’s trade show Fakuma.

Automotive interiors require materials with good mechanical properties that will also produce premium-quality surfaces

Superior Surface Quality in Automotive Interiors

Producing Large Exterior Parts with Integrated Functions and High-Quality Finishes

The combination of injection compression molding, direct coating and partial film insert molding enables a novel design for the front module of the BMW iX electric vehicle. Important in the development were extensive trials carried out by plastics manufacturer Covestro in its technical lab.

The combination of injection compression molding, direct coating and partial film insert molding enables a novel design for the front module of the BMW iX electric vehicle. Important in the development were extensive trials carried out by plastics manufacturer Covestro in its technical lab. On the material side, a base carrier made of polycarbonate flooded with polyurethane proved to be a successful combination.

The ShyTech design played a formative role in the development of the all-electric BMW iX. What this means is that functions such as the sensors for semi-autonomous driving should only be visible to the driver when he needs them. This requirement also had to be implemented in the development of the front module of the iX, called the kidney (Fig. 1). The electrical system also opened up additional freedom in the design of the vehicle front away from the classic radiator grille. The aim of the design was to develop an aesthetic front component with a three-dimensional depth effect that integrates certain driver assistance functions. At the same time, it was also to feature a multicolored Class A finish.

It also had to be ensured that the sensors function reliably under all operating conditions and that there is no icing of the outer skin above them, for example. In addition to the design goals, the high demands of the sensor technology also had to be met. For example, the radome had to be integrated seamlessly into the surface. All this required a finely tuned interplay between material, component and production development so it was only possible to realize this in close cooperation between the project partners.

A 3D structure with prisms of varying depths was specified for the front component, which is incorporated in a transparent polycarbonate (PC) base substrate. Further finishing steps on the back of the component ensure a two-tone design. Together with the structure of the blank, they create the desired optical 3D depth effect. This approach results in wall thickness variations of up to 100 % on the back of the injection-molded PC base substrate. The volumetric shrinkage of the thermoplast also leads to some waviness in the surface of the component front. Consequently, it would not have been possible to achieve a Class A finish with conventional hardcoating processes. To solve this problem, integration of the direct coating (DC) process into the overall process was the obvious solution. In this process, the coating is applied with increased layer thickness in a closed injection mold.

This is where plastics manufacturer Covestro came into the picture. As one of the technological pioneers in automotive glazing from PC, DC for coating plastic parts and Film Insert Molding (FIM) for producing printed, functionalized and back-injected 3D film decorative components, the company has extensive experience in the relevant technologies. Over and above that, as one of the most important manufacturers of PC and polyurethane (PUR), the company was able to contribute its materials technology and application-specific expertise in these material families. This combined expertise played a major role in Covestro becoming a project partner for the front kidney of the BMW iX.

Successful Combination of FIM, DC and Injection Compression Molding

Together with BMW and other partners, a manufacturing concept was developed for the kidney that combines injection compression molding and FIM with DC. In this process, a 3D film insert is placed in an injection mold and backmolded with the transparent PC Makrolon AG (Automotive Glass-like) from Covestro. This produces a thermoplastic part with a partial film area, which is then coated with a transparent PUR coating system in the same mold using a RIM (reaction injection molding) mixing head (Fig. 2).

The coating layer is based on the materials Desmodur and Desmophen from Covestro. It imparts high scratch resistance to the component finish and is self-healing. Minor scratches simply disappear on their own after a short time. One benefit of the PUR reaction system is that it has little effect on the very good mechanical properties of the PC substrate. The PUR coating for the front panel meets all BMW’s requirements for exterior components in terms of adhesion to the thermoplastic substrate, abrasion resistance, color stability and weather resistance, among other things.

Integrated Heating Function Ensures Ice-Free Sensors

The partial 3D foil insert is placed in front of the radar sensor and fitted with heating wires and a plug connection on the back. The purpose of the heating function is to keep the radar sensor free of snow and ice in cold conditions. The insert consists of Makrofol UV244, a PC film from Covestro that is provided with UV protection. This ensures that the film does not yellow in the long term in the event of damage to the scratch-protection layer.

As previously mentioned, the back-molded material is made of Makrolon AG. This PC, which was specially developed for glass-like finishes in automotive exteriors, has been in mass production use in various components for many years. It boasts crystal-clear transparency. The material can be used to manufacture components with very good surface finish quality, which are characterized by high impact strength even at low temperatures. Its very high product quality and purity are based on the raw materials utilized and a dedicated production process that includes a filtration step for the melt. In addition, it contains only weathering-stable colorants to prevent fading of the component over the vehicle’s service life.

Covestro provided detailed support to BMW in the development of the front panel throughout the entire project phase. For example, various development molds were trialed at Covestro’s technical lab in Leverkusen, Germany. In the first step, a plate mold was provided with the design structure of the front panel in order to find the optimal wall thickness differences for the injection compression molding step. Important process-determining parameters were worked out and subsequently incorporated into the final component design. For example, it was possible to avoid air streaks resulting from the design structure. It was also important to determine the optimum distance between the foil preform and the gate and to check how process parameters affect the subsequent function of the heating foil.

Experience from the Technical Lab Makes It Easier to Set up Mass Production

In the next step, all these findings were incorporated into the construction of a mold that was already designed for the FIM and DC processes. The first coated components with integrated film were produced on an injection molding machine with a sliding table. With these it was possible to reproducibly evaluate the quality of the finish and the visibility of the transition between the film and the PC substrate. Processing parameters could be optimized and important conclusions drawn about the correct positioning and fixing of the film in the mold. For the first time, it was also possible to assess how efficient the entire manufacturing process is. Important functions such as the behavior of the component under environmental conditions or the reliability of the radar function could be demonstrated realistically and the corresponding results validated by BMW’s technical departments. Based on the experience gained, the company built a near-series prototype tool in original geometry. It was also tested in its entirety in the Covestro technical lab under near-production conditions. The experience accumulated in the various construction stages was a great help in smoothly setting up mass production at BMW in Landshut, Germany.

Simulations Reveal the Optimum Filling Pressure

As part of the project, Covestro carried out extensive simulations on the rheological behavior of both the injection compression molding material and the PUR reaction system during mold filling. This made it possible to minimize stresses in the injection-molded substrate, relocate weld lines to non-visible areas, avoid air traps and predict component quality in the back-molded film area (Fig. 3).

For the PUR filling, simulations enabled the optimum filling pressure for the selected wall thicknesses to be determined and the vents for the PUR cavity to be positioned with millimeter precision (Fig. 4). In addition, Covestro has developed simulation methods to precisely predict shrinkage and warpage of the components flooded with PUR and the occurrence of air bubbles in the cavity during filling.

Multi-Part Production Line with Advanced Processes

In component production at the BMW plant in Landshut, a completely new production line was set up for the kidney of the BMW iX, incorporating a range of advanced technologies. The production layout was designed with particular attention to technical cleanliness. The focus was not only on the individual production steps, but also on the transportation and storage of all intermediate states of the component. To ensure optimum design of the value stream, all steps take place within the same production building. This prevents additional dirt and moisture from entering the process.

After the production of the blank described above on an injection molding machine with indexable inserts and integrated PUR unit, further production steps follow (Fig. 5): the blank is first painted black on the back and then laser-abladed in both the 2D and 3D areas. An annealing step follows to reduce local stresses. The second color is then applied by means of a PVD (physical vapor deposition) process. The process ensures a metallic appearance without impairing the radar function of the integrated sensors.

A topcoat is then applied to protect the PVD layer from environmental influences and provide the final coloration. In the end-of-line area, the component edges are sealed by a robot to protect the PC from environmental influences. Finally, all components are subjected to radar and heating checks to ensure that they function properly. A new production monitoring system records all relevant parameters, thus guaranteeing their traceability to the components and even to each individual production step.

K 2022: New Front Panel Concept Integrates Additional Functions

Covestro has been developing its own concepts for novel automotive front panels made of PC since 2014. The latest culmination of this work will be on display at the K 2022 Plastics Fair in Düsseldorf, Germany: the concept of an injection-molded panel with additional design and functional features. These include FIM on both sides, elements for communicating with pedestrians and integrated functions such as edge-lit and hidden-until-lit functions that are only activated and backlit when operated.

Covestro AG  

https://www.covestro.com

Ausgabenartikel

Fig. 3. Simulation of mold filling in the injection-compression molding process: the analyses helped to optimize the design of the geometry and wall thicknesses of the rear 3D design structure.

Fig. 4. Simulation of the time sequence of PUR filling using the series geometry of the kidney as an example: the investigations helped to determine both the optimum process parameters and the mold geometry.

Fig. 5. The production process of the front module comprises several steps and procedures. 

Various production processes are combined to manufacture the front module of the BMW iX, known as the kidney.

Fig. 1. The striking front panel of the BMW iX is made of the PC Makrolon AG from Covestro. Camera technology, radar functions and other sensors for the driver assistance system are all integrated into the large-scale component.

Fig. 2. A transparent and back-molded 3D film insert made of Makrofol UV244 with a heating function is integrated into the base substrate of the panel to keep the radar sensor ice-free. The entire part is coated with deep gloss PUR.

KUint5--22_Covestro - Hauptartikel

Jochen Holzleitner is Production Manager in injection molding and pre-assembly for plastic exterior parts at BMW.

Stefan Wulfers heads development for front flaps, tailgates and the front side panel at BMW.

Joachim Wehner is Global Key Account Manager for BMW at Covestro Germany.

Benjamin Herzberg works in application development in the Engineering Plastics segment of Covestro Germany with painting and decorating technologies.

Hans-Jörg Dahmen is a Project Manager for complex exterior car body applications in the Engineering Plastics segment at Covestro Germany.

Christoph Klinkenberg is responsible for automotive exterior applications in global technical marketing in the Engineering Plastics segment of Covestro Germany.

Further information on direct coating and the rheological simulation of the process can be found in Kunststoffe international 7/21 from page 50 and at:

<a href="https://en.kunststoffe.de/a/specialistarticle/short-cycle-times-and-high-productivity--346596" target="_blank">https://en.kunststoffe.de/a/article-346596</a>

Read the German version of the article in our magazine Kunststoffe or at <a href="https://www.kunststoffe.de/a/fachartikel/facelifting-fuer-elektrofahrzeuge-2743628">www.kunststoffe.de</a>