From automotive through aviation to urban mobility, industry experts and visionaries discussed challenges and trends, new market opportunities and technological possibilities at the ENGEL Mobility Days 2023, supported by KTM Technologies, in Austria in mid-June. The two-day event with top ranking keynote speakers and future-orientated machine exhibits combined and expanded the previous ENGEL conferences trend.scaut and Lightweight Future Day to create a new networking event.
Mobility is becoming increasingly diverse, reflected not only in the list of participants but also in the conference programme. The keynotes covered individual transport by car, (motor)bike or e-scooter, and public transport by bus, train, people mover or air cab, as well as aerospace and logistics mobility solutions from the classic truck to drones. There is one thing which unites all sectors of mobility, and that is making mobility more sustainable.
Whether new drivetrain solutions or autonomous driving, these trends are fundamentally changing the demands on mobility, requiring completely novel material and manufacturing solutions in some cases. This gives rise to huge opportunities for the injection moulding industry.
“Plastics will play an even more significant role in future mobility than they do today,” as Franz Füreder, Business Unit Vice President Automotive & Mobility at ENGEL, was quick to point out. “Polymer materials are lightweight materials in themselves, and they allow for conservative use of energy and raw materials. They can be processed in a very efficient way in injection moulding, and this makes innovative technologies accessible to the mass market.” The ENGEL Mobility Days 2023 showcased numerous examples of this.
Autonomous driving promotes the use of plastics
Michael Fischer, Head of Business Development Technology at ENGEL, highlighted another advantage of the material group: “Plastics are permeable to sound waves and electromagnetic radiation, and this makes them indispensable for autonomous driving.”
Autonomous driving is all about connectivity, communication between the vehicles themselves, and with other public and private transport users and the environment. The sensors used for this purpose rely on electromagnetic and acoustic approaches. Distance sensors, for example, work with ultrasound, while adaptive cruise control works with radar, and night vision assistance systems with infrared.
“Plastics let all of these waves through, which is why they have already replaced aluminium and steel in automotive front and rear ends,” said Fischer. “Autonomous driving is a massive opportunity for plastic injection moulding. More efficient than any other method of plastics processing, injection moulding helps to combine sensor systems and electronic features with a visually appealing design.”
Among other processes, ENGEL developed its clearmelt technology for this purpose, a two-component process that combines in-mould decoration (IMD) with polyurethane flood-coating. “Flood-coating with polyurethane in the mould allows for a perfectly repeatable, smooth surface with a uniform wall thickness,” said Fischer. “This predestines the technology for integrating optical sensors.”
BMW in Landshut uses this technological basis to produce the ‘kidney’ panels for the BMW iX electric vehicle in a cleanroom setup. Once the radiator grille, this characteristic design feature of all BMW models has taken on a new role following electrification of the drivetrains. The kidney-shaped panels protect a series of sensors for assisted and, in the future, autonomous driving.
To make sure that the sensors also work reliably in the winter, BMW back-injects a heatable functional film with polycarbonate, which is then flood-coated with polyurethane. Following several applications for the vehicle interior, this is the first time that BMW is using a combination of film back-injection and flood-coating in the series production of functional parts on the exterior, where they are exposed to particularly high stress.
The sensitive electronics are well protected under the scratch-resistant polyurethane surface. The high gloss level and depth effect, which even a thin coating of polyurethane achieves, convey a very elegant impression. ENGEL is the system supplier for this demanding project. The production cell integrates an ENGEL duo combi M injection moulding machine with a horizontal rotary table, two large articulated robots for handling the films and moulded parts, a film cleaning system, an inline quality-control station and peripheral units, including the polyurethane feed.
ENGEL is collaborating with development partners in the field of combined back-injection and PUR flood-coating, including Leonhard Kurz Stiftung, Schöfer and Votteler Lackfabrik. In the scope of a project study, the partner companies were able to demonstrate that flood-coating with polyurethane, which is equivalent to in-mould painting in terms of the process, accounts for only 20% of the total energy consumed in the production process. This means that the integrated process offers significantly improved energy-efficiency compared with painting the parts outside of the injection moulding process.
Efficient lightweight composites with thermoplastics
Lightweight plays a central role in achieving climate protection targets. At its own interdisciplinary technology centre for lightweight composites at the St. Valentin production plant in Austria, ENGEL has been developing innovative composite solutions in cooperation with partner companies for more than ten years. The primary development goal is integrated and automated processes for cost-efficient high-volume production.
One focus of the development work is on the use of thermoplastic fibre composite materials. “The reasons for this are the highly efficient processes for processing thermoplastics on the one hand, and greater sustainability on the other,” said Füreder. An approach which consistently relies on thermoplastic material paves the way for recycling the parts later on.
In the ENGEL organomelt process, thermoplastic fibre composite prepregs – for example, thermoplastic sheets and UD-Tapes – are shaped and functionalised in a single integrated step. To achieve this functionalisation, reinforcing ribs or assembly elements are moulded immediately in the same mould after thermoforming using a thermoplastic from the same matrix material group as the thermoplastic sheet.
The first high-volume production application of this technology went live in 2018 at Valeo Front End Modules in Smyrna, Tennessee, USA. Starting with thermoplastic sheets, Valeo Front End Modules manufactures front-end carriers with integrated air ducts for a German brand name OEM at its plant.
The systems solution supplied by ENGEL for automated high-volume production consists of an ENGEL duo 1700 injection moulding machine, three ENGEL easix articulated robots for preparing large quantities of metal inserts and for handling the thermoplastic sheet, an ENGEL viper 90 linear robot and an ENGEL IR oven.
The double-shell structure made it possible to integrate the air ducts directly into the carrier structure. The two half-shells are produced in a one-shot process. To do this, the two thermoplastic sheets are simultaneously heated in the IR oven, and then inserted into the mould, where they are formed and functionalised.
Innovative recycling for fibre composite parts
Recycling fibre-reinforced composite parts is another development focus at the ENGEL Technology Centre for Lightweight Composites. “In the future, we expect automotive recycling to play a role in returning many fibre-reinforced parts made of polyamide and polypropylene to the material cycles in a single grade process.
However, the glass fibres are shortened when the parts are shredded. To again produce high-quality fibre composite parts from the returned materials, new fibre material does need to be admixed during processing of the recycled materials,” explained Fischer. “We are working on a solution here that lets us tune the material properties in a very efficient way.”
The basis is the new two-stage process which ENGEL presented at the K show 2022. To be able to integrate a melt filter and a degassing unit, the production cell breaks down plasticising and injection into two independent, but mutually attuned, process steps. Thanks to this strategy, plastic waste can be processed as flakes in injection moulding directly after grinding to achieve excellent quality.
Since a complete processing step, repelletising, is eliminated, the two-stage process saves a huge amount of energy and work compared to legacy recycling. In order to be able to reprocess shredded fibre-reinforced plastic composite parts to create vehicle parts capable of withstanding high mechanical loads, ENGEL is now integrating a glass fibre feed into the production cell solution in addition to the melt filter. The fresh long glass fibres are admixed before injecting the melt. “We are in the trial phase here,” said Fischer. “Initial trials are very promising.”
Fuel cells drive innovation
Alternative drive technologies are also opening up new potential for the injection moulding industry. “Hydrogen technology is currently being promoted particularly strongly in Europe, especially in the truck sector,” reported Fischer. “The Cellcentric joint venture sees Daimler Truck and the Volvo Group bundle their experience in the development and production of fuel cell systems, and they have chosen ENGEL as one of their technology suppliers.”
In particular, the expertise which ENGEL has in processing elastomers and liquid silicone rubber (LSR) is crucial here. Fuel cells require many seals, some of which are moulded directly onto metal or plastic components. On top of this, there are cable lead-throughs made from LSR.
The bipolar plates, of which several hundred are needed for each fuel cell, are made from metal, but Fischer is convinced that this could change in the long term. “We are already developing injection moulding solutions for thermoplastic-based bipolar plates. The challenge is the sheet thickness of only a few tenths of a millimetre; we are combining thin-wall technologies with injection compression moulding for this.”
Thermoplastics are also increasingly replacing steel and aluminium sheet for battery housings and trays in electric, hybrid and fuel cell vehicles. For example, Envalior – which emerged from DSM Engineering Materials and the High-Performance Materials business unit of Lanxess – is developing an innovative battery tray made of polyamide with a high glass fibre content. The wall thickness is less than 7 mm with a single shot weight of 60 kg.
“The challenge is for the plastic design to be able to reliably absorb the high loads,” explained Fischer. “On top of this, the large-volume part and the very high shot weight require a particularly large injection moulding machine. We are planning on an ENGEL duo machine with a clamping force of 8000 tonnes.”
Injection moulding machines of 10 000 tonnes and more
While ENGEL duo injection moulding machines have been available with clamping forces of up to 5 500 tonnes as standard machines for a long time, ENGEL has now extended the series upwards for new applications in the mobility sector and other industries. Besides parts with a particularly large surface area and volume, these new mega machines with their extremely large mould mounting spaces enable even more extensive process integration – for example, in the glazing sector.
“Clamping forces of more than 10 000 tonnes and shot weights of several hundred kilograms are already technically feasible today,” said Stefan Engleder, providing an outlook and underlining the commitment which ENGEL has to building a new dimension of large machines. “We have created assembly capacity for this at both the large machine plant in St. Valentin, Austria, and in Shanghai, China. Around the world, we are helping our customers to solve the new mobility challenges,” concluded Engleder.
GreenTech Plastics Machinery distributes ENGEL in South Africa, with its main market being the automotive industry. ENGEL is a single-source provider of turnkey injection moulding solutions, with a machine for every requirement and preference. With more than 75 years’ expertise and experience, ENGEL has designed machines from 280 kN to 55 000 kN clamping force in hydraulic, fully electric, horizontal and vertical solutions.
For more articles on ENGEL Mobility Days 2023, visit the below links:
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