The Austrian machine manufacturer presents the latest innovations for automotive industry. Digitization and circular economy are the other highlights at the K show
by Andrea Lori
E-mobility and autonomous driving are presenting new challenges in a vast number of different areas for car manufacturers. Lightweight multi-material composites will replace heavy structural metals, freeing up the weight needed to enable this coming electronic revolution. Interiors will change, needing to become more homelike with controls replaced by high-quality surfaces. This evolution requires new technologies and industrial processes. At K show, Engel (Hall 15, Booth C58) shows the latest innovation in this challenging field, including the large-series production of thermoplastic-based lightweight composites, functionalised surfaces, and lighting technology for the automotive industry.
Lightweight solution for the automotive industry
Thermoplastic composites are growing in importance when it comes to lightweighting in the automotive industry. There are two main reasons for this. Firstly, the consistent thermoplastic approach makes it possible to efficiently integrate the forming and functionalisation of fibre-reinforced prepregs, which reduces unit costs. Secondly, the use of exclusively thermoplastic polymers makes it easier to develop recycling strategies.
Engel’s answer to the need for sustainable transport is organomelt. In the organomelt process, fibre-reinforced prepregs with a thermoplastic matrix such as organic sheets and tapes are heated, inserted into the mould, formed there and directly overmoulded with thermoplastic. The well-developed process has already been used in high-volume manufacturing, with Engel organomelt used for fully automated production of items such as front end carriers. As this process undergoes further development, Engel is working together with its customers and partners on the production aspects of designing composite components with a targeted load distribution.
The moulding process to be exhibited at K was developed in partnership with automotive supplier Brose. Three differently shaped organic sheets between 0.6 mm and 2.5 mm in thickness are produced for the first time in a fully automated process involving integrated IR ovens. The different stresses on the individual component areas can be dealt with thanks to the targeted selection of organic sheets on the basis of load distribution – an outcome that Brose has helped to ensure through a variety of simulation processes. The demo part to be produced at the K show, for instance, is more rigid in its window frame area than on the inside of the door.
Compact IR oven integration
One of the challenges with processing organic sheets is the heating of the prepregs. The time they take to heat and cool depends on their thickness. Heating the material quickly without damaging it is important, as is a fast and straightforward transition to the mould for the heated prepreg. The organomelt production cell to be featured at K is based on a duo 3660/800 injection moulding machine and includes two integrated IR ovens for this reason. There is a vertical IR oven positioned directly above the clamping unit to heat up the organic sheet, which is only 0.6 mm thick. This way, the thin organic sheet reaches the mould in a very short time, ensuring that it has not yet cooled down and become impossible to form. A standard, horizontal IR oven on a pedestal above the moving platen is used for the two thicker organic sheets (1 mm and 2.5 mm). This arrangement shortens the distance between the oven and the mould, as well as saving space since the oven does not need separate floor space. Both of the IR ovens were developed and manufactured in-house by Engel. These and the three easix robots are fully integrated with the IMM’s CC300 control unit and can be centrally controlled via the machine’s display.
All three organic sheets are heated up at the same time. Two of the three easix robots are then available to handle the organic sheets. These are located next to one another above the clamping unit. While the first robot is responsible for handling the two thicker organic sheets, the second robot takes care of the thinnest sheet. During the entire heating process, it holds the organic sheet in front of the vertical radiation field so that it can be placed into the mould after the set heating-up period is over. The third robot is located next to the clamping unit. Its job is to remove the moulded part, while at the same time moving one of the three organic sheets into the mould for the injection moulding process.
The organic sheets, which were obtained from Chinese raw material producer Kingfa, are made of glass fibres and use polypropylene as their matrix material. When the mould – built by Georg Kaufmann Formenbau (Switzerland) – closes, the organic sheets are formed. Immediately afterwards, they are overmoulded with glass fibre-reinforced polypropylene within the same mould. Reinforcing ribs are shaped on the back of the component, while a leather-look grain is shaped on the visible side.
Combining new functionalities with design requirements
Autonomous driving opens the scenario to greater integration of intuitive controls in vehicle interiors, which blur the boundaries between the digital and analogic world. This new development concept allows data to be displayed on surfaces. Therefore, the functional and decorative surfaces of vehicle interiors will increasingly merge in the future. With the clearmelt and foilmelt, Engel has two extensively tried-and-tested technologies used for the processing of both functional and design foils. At K 2019 the Austrian company demonstrates the flexibility of this production-ready, roll-to-roll IMD injection moulding process by producing complex, three-dimensional sample parts with different decor on a victory 1060/300 injection moulding machine with an integrated viper 20 linear robot. The joint development with system partners (Leonhard Kurz, Schöfer and Iso-sport Verbundbauteile) makes it possible to thermoform, back inject and die-cut a limitless selection of surface systems from roll to roll in the mould in this one-step process.
The wide range of possible material combinations is remarkable. It is possible to process both multi-layer foil systems with paint film surfaces, as well as structured, backlightable and functionalised foils with capacitive electronics. To change the decor, the structure and the functionality, only the roll has to be changed, not the mould. In addition to typical materials such as ABS, PC and PC/ABS, it is also possible to use PP and recycled material for back injection. The application on display at the fair works with mixes recycled material in the form of plant scrap shredded together with the foil.
For K 2019, Engel has further increased the foilmelt technology’s degree of integration, with the contouring process taking place directly in-mould. As a result, an external laser station is no longer needed, cutting out an entire step of the process. Engel demonstrating a second IMD application (IMD PUR) at its partner Leonhard Kurz’s stand in (Hall 5, Booth A19), where sample parts based on front panels are produced via the clearmelt process on a duo 2460/900 injection moulding machine with an easix articulated robot. These parts meet the new requirements for sensors. The clearmelt process involves refining the surface using a polyurethane top coat, which is especially effective in exterior use due to its highly glossy and scratch-resistant properties. The thermoplastic and PUR processing can either be carried out in sequence or in parallel using a horizontal rotary table, depending on the number of parts and the conditions in the injection moulding shop. The other partner companies involved in this exhibit are Hennecke, Votteler, Sabic and Velodyne LiDar.
Lighting: the ultimate clean look for optical fibres
LEDs are becoming more and more versatile in their use in vehicles, increasingly being add- ed as distinctive design elements. The level of variation in their shape is growing accordingly, creating new challenges for optical fibre manufacturers. Engel has developed a new plasti- cising process specifically for PMMA processing to ensure high luminous efficiency, even in cases featuring complex shapes and long structures, such as outline lighting.
This increases the homogeneity and purity of the melt, making new options available to lighting designers. To highlight the great potential, an all-electric and tie-bar-less e-motion 310/120 TL injection moulding machine will be put through its paces at K fair. Engel has joined forces with its development partners INglass and HRSflow to test out a variety of injection systems with electrically operated needle valves, and will be exhibiting a solution that has been fine-tuned in every detail. The other partner companies that have been helping to make the exhibit possible are Volvo and Arkema.