It depends on yourself whether you want to use the new year as a brake or as a motor.

That is how Henry Ford is supposed to have put it. Here in the Kunststoffe editorial office, we clearly prefer motorization. After all, we are entering a K year – and K years have been a motivating force for the industry for decades. That is precisely why many large manufacturers plan their development cycles in a three-year rhythm. And with two very challenging years behind us, there are very high expectations for this fall’s trade show program. We have already blocked the first dates in our calendars. And we writers are already in the starting blocks to bring you reports on the most exciting trends and new developments.

One of the main topics of this year’s K show is the circular economy. We are dedicating a Special to this topic in this edition. An extra treat here is certainly our exclusive interviews with Tomra, dealing with the use of AI in sorting plastic packaging (from page 30) and with Ingemar Bühler, Managing Director of PlasticsEurope Deutschland, on chemical recycling (from page 16).

To mark the 2022 relaunch, we have modernized our magazine here and there. Let us know if there’s anything that strikes you as you browse through it. We welcome your feedback!

Susanne Schröder <a href="mailto:Susanne.Schroeder@hanser.de">Susanne.Schroeder@hanser.de</a>

Editorial Susanne

Schröder, Susanne

Part 7 of the Series: How the Digital Shadow Enlightens Real Processes in the PIC 4.0

The digital shadow is the core concept of the Cluster of Excellence “Internet of Production” at RWTH Aachen University. It represents the data trace of an asset to describe its real behavior. In the Plastics Innovation Center 4.0 (PIC 4.0), digital shadows, e.g. the data trace of a sensor, are used to optimize processes taking into account real behavior and to determine simulation quality.

Industry and science are constantly striving to fully capture and model production processes in order to manufacture high-quality products in the shortest possible time and with the least possible use of resources. The possibilities of predicting complex interactions between process settings and control variables and influencing product quality are increasing, although predictions are becoming more computationally intensive and automated matching with reality is still very cost-intensive or fails completely. The digital shadow, on the other hand, aims at capturing the real behavior of a process, for example, through the data trace of a sensor, and taking it into account in model calculations [1].

Testbeds Create Use-Case-Related Digital Shadows

The consistent interconnection of machines and peripherals within the PIC 4.0 makes it possible to capture a wide range of real process data. However, in order to integrate scientific methods and approaches seamless into real production environments, these different data traces must be processed and analyzed in a targeted manner. For this purpose, testbeds are set up in the PIC 4.0, which can be used to test the interaction of software services and real testbeds for a specific research question [2]. The initial testbeds focus, among other things, on the influence of the use of recycled material in injection molding production, including the associated material preparation, and, on the other hand, on the synchronization of quality-relevant data traces in order to improve data-driven quality controls and to determine the simulation quality with regard to the real process behavior.

A modular measuring cell is being integrated into an injection molding process for the focused examination of quality control issues. In addition to determining the weight of the molded part, the extent to which optical 3D measurement is currently being examined. This includes CAD output of the real part and measurement of the surface structure using e.g. white-light interferometry and laser scanning methods suitable for this purpose. The individual data traces of these measuring systems are to be supplemented by the data traces of the injection molding machine as well as a fully comprehensive recording and evaluation of cavity pressure and temperature signals. Finally, the nozzle of the injection molding machine is also to be equipped with sensors so that the processes in the screw antechamber can be taken into account for model optimization. The setup of the testbed allows to determine the full potential of the individual measuring systems in the production environment either individually or in combination.

On the software side, there are challenges in data handling as well as in the automated synchronization and assignment of data traces to a production order or even the individual product. On the other hand, new analysis services for the optimization of the process and the prediction models become possible through the interconnection. To this end, a system is being developed which assigns sensor signals directly to a simulated soft sensor in the filling simulation and calculates the real flow-front-velocity for comparison with the simulated ideal at the operator terminal. This will make it possible to implement further assistance systems, e.g. for optimizing the setting parameters to achieve a constant flow-front-velocity as a quality criterion.

Investigations into flow-front-velocity and geometry-dependent process-control are currently the subject of various research projects at the Institute for Plastics Processing (IKV), Aachen, Germany. The planned testbed as a real demonstrator will make the research results available for rapid technology-transfer to industrial applications.

Simulation, Machine and Mold Provide Different Digital Shadows

Particularly in the case of complex-shaped injection molded parts, flow-front-velocities that are too high or too low can occur due to changes in the flow cross-section [3–5]. One approach to prevent quality defects occurring as a result is to ensure a constant flow front velocity by smart adjustments of the injection speed [6–8]. However, it is hardly possible to track the flow-front-velocity even at constant injection speed or even to correlate it with an injection profile. A solution is offered by the filling-simulation, which, however, only corresponds to the real process to a limited extent.

For the implementation of the envisaged assistance system, it is assumed that the filling simulation maps the basic filling behavior and the flow path sufficiently accurate. The fine tuning of the simulated flow-front-velocity to the real process is achieved by correlating the data traces from the machine, sensors and simulation. An operator interface near the injection molding machine should make it possible to intuitively assign the simulated sensor positions to real sensor signals. In addition, the correlation between sensor signals and a defined filling level is ensured by this interconnection. The simulation software, the mold sensor system and also the injection molding machine itself provide data traces with different information content for this (Fig. 1).

The digital shadow of the machine provides insight into the real acceleration of the screw and the volume flow induced by it. This acceleration behavior and the non-ideal volume flow and pressure transfer from the plasticizing-unit are the main reasons for the deviations between simulation and reality. The closing behavior of the non-return valve and the volume-loss that flows back via the screw flights also play a significant role in the fact that, measured against the screw position, a deviating melt volume must be dosed and injected. Even with knowledge of a simulated filling process and the virtually optimized process point, it is difficult to determine the correct parameter setting on the injection molding machine.

In addition to the marked switchover point (Fig. 1 top left) at 1.368 s for volumetric filling of the product, four sensor positions are highlighted. Four piezoelectric combined temperature and pressure sensors are installed inside the cavity, providing insight into the real filling behavior of the product. Due to the different acquisition systems, e.g. directly via the injection molding machine or via a separate edge-device, the difficulty of how to synchronize the measurement records stands out. If the flow front reaches a sensor, this is very clearly recognizable by the temperature deflection, as is the abrupt drop in temperature at sensor signal 4 at the time of the switchover point (Fig. 1 bottom left). This also allows the other sensor signals to be clearly assigned, so that the relevant measuring time of the sensors in the digital shadow of the injection molding system can be directly correlated with the filling time.

The third figure (Fig. 1 right) shows a simulation of the filling process corresponding to the process point. The sensor positions can be positioned analogously to the real mold in order to match simulation and real process. Based on the results of the process simulation, the flow front can be traced and the average flow-front-velocity can be calculated for each filling level. For this purpose, the time of filling, filling level, pressure drop and melt velocity are simulated for each node of the simulation mesh. Due to the idealized system assumptions made when setting up the process simulation and neglecting the machine-related influences, the filling time as well as the times at which the nodes of the sensor positions are reached deviate from reality.

Finally, the correlation of the individual data traces makes it possible to match simulation and reality (Fig. 2). For this purpose, both the simulated flow-front-velocity is adjusted to the real filling and the time intervals between the respective simulated and realized sensor signals, at which the melt reaches the sensors.

The assistance system will enable the operator to fine-tune the injection profile directly at the machine, taking into account the product geometry. At the same time, the system will enable researchers within the PIC 4.0 to evaluate this and other optimization approaches for industrial application in a data-based manner by combining digital shadows, for example by adding data traces on the melt pressure in the screw antechamber or by taking into account the automated comparison between realized and simulated product quality through integrated 3D measurement of the product. This makes the PIC 4.0 a demonstration platform for innovative optimization services from research concept to industrial application.

[1] Becker, F.; Bibow, P.; Dalibor, M.; Gannouni, A.; Hahn, V.; Hopmann, C.; Jarke, M.; Koren, I.; Kröger, M.; Theissen-Lipp, J.; Maibaum, J.; Michael, J.; Rumpe, B.; Sapel, P.; Schäfer, N.; Schmitz, G.; Schuh, G.; Wortmann, A.: A Conceptual Model for Digital Shadows in Industry and its Application. Proceedings of 40th International Conference on Conceptual Modeling, 2021

[2] Hopmann, C.; Schmitz, M.; Bibow, P.: The PIC 4.0 as Part of the Internet of Production. Kunststoffe International (2021) 2, pp. 7–9

[3] Bichler, M.: Prozessgrößen beim Spritzgießen – Analyse und Optimierung. Beuth Verlag, Berlin, Vienna, Zurich 2012

[4] Chen, X.: A Study on Profile Setting of Injection Molding. Dissertation, Hongkong University of Science and Technology 2002

[5] Johannaber, F.; Menges, G.: Injection molding machines. A user’s guide. Hanser; Hanser Gardner, Munich, Cincinnati 2008 (ISBN: 978–3–446–45011–0)

[6] Gruber, J.-M.: Process control based in cavity pressure for the injection moulding process of thermoplastics. Dissertation, RWTH Aachen University, Aachen 2005 (ISBN: 3–86130–843–6)

[7] Michaeli, W.; Bourdon, K.; Haupt, M.; Hunold, D.; Robers, T. F.: Das Volumenstromübertragungsverhalten in der Einspritzphase. Plastverarbeiter 41 (1990) 9, pp. 186–195

[8] Yang, Y.; Chen, X.; Lu, N.; Gao, F.: Injection molding process control, monitoring, and optimization. Hanser Publications; Hanser Publishers, Cincinnati, Munich 2016 (ISBN: 1569905932)

The construction of the PIC 4.0 proceeds and throws its shadow on the Campus Melaten.

16:9

Fig. 1. Data traces of the injection molding machine about the screw acceleration, from simulation about the flow-front-velocity and from sensors about the real filling-behavior exemplary for a honeycomb-structured part.

Fig. 2. The interconnection of data traces from simulation and machine enables further extension of optimization strategies with respect to injection profiles at an injection molding machine. 

Name - Hauptartikel

The Cluster of Excellence Internet of Production (IoP) is an interdisciplinary research project funded by the German Research Foundation (DFG). More than 25 institutes and further institutions near the university cooperate in the first funding period (01/2019 – 12/2025) on topics of digitized production technology to enable sustainable competitiveness of the German industry. The future technologies of the IoP should result in real demonstrators inside the PIC 4.0.

Univ.-Prof. Dr.-Ing. Christian Hopmann has held the Chair of Plastics Processing as Head of the Institute for Plastics Processing (IVK) in Industry and Craft at RWTH Aachen University, Germany, since 2011.

Pascal Bibow, M.Sc. RWTH, has been working since September 2016 on intelligent production systems at IKV. Since January 2020, he has been Managing Director of the Plastics Innovation Center 4.0;

<a href="mailto:pascal.bibow@ikv.rwth-aachen.de">pascal.bibow@ikv.rwth-aachen.de</a>

The construction of the Plastics Innovation Center 4.0 is funded by the State of North Rhine-Westphalia and by the European Regional Development Fund (ERDF).

The following contribution describes how flexible structures enable a versatile research environment and thereby a continuous innovation management. It appears in one of the next issues.

Spritzgießen

Kunststoffverarbeitung: Verfahren

Sensorik für Kunststoff-Verarbeitungsmaschinen

Industrie 4.0

Industrie 4.0 für die Kunststoffverarbeitung

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Spritzgießsimulation

Software

Simulation

Digitaler Zwilling

Formnext 2021: Successful Relaunch as a Face-to-Face Show

Over the four trade-show days in November, Formnext 2021 transformed the metropolis of Frankfurt am Main, Germany, into an international innovation center of global additive manufacturing and modern industrial production. At the plastics side, some of the focuses were on the manufacture of voluminous parts, the use of injection molding pellets as a material basis, and the processing of high-performance plastics.

The organizers counted over 600 exhibitors from 36 countries and almost 18,000 visitors, about half of them from abroad. You did not have to look far to become aware of what was probably the biggest product campaign among machine manufacturers. Peter Alderath, General Manager DACH at Stratasys, in a conversation with Kunststoffe, summarized the renewed portfolio as follows: “Since last year, we have supplemented our tried-and-tested PolyJet and FDM technologies with three more, which we lacked until now: stereolithography, DLP and SAF.”

In detail, since taking over the start-up Origin about a year ago, Stratasys has also had a foothold in the fast growing segment of mass production of parts with a photopolymer platform. Origin’s so-called P3 technology – it stands for “programmable photopolymerization” technology and is an evolution of digital light processing (DLP) – uses light to cure liquid photopolymers. With the 3D printer Origin One, according to Alderath, users can achieve the quality of injection molding and their surface finish with high accuracy and a large number of high-performance materials. Only a little later, Stratasys took over RP Support (RPS) of the UK in order to add the Neo system line to its portfolio, which comprises three models in two sizes.

In April 2021, Stratasys had already presented the H350 3D printer, the first system that works with selective absorption fusion (SAF) technology, a powder-bed fusion process developed by Xaar 3D. Here, the polymer powder particles are wetted with an infrared-sensitive fluid and then irradiated to fuse them together in discrete layers. The H350 even incorporates a dozen components that were 3D printed by the SAF process. Now, Stratasys has also taken over Xaar 3D.

But there are innovations in other areas, too: the F770 FDM printer is especially suitable for large components; according to the manufacturer it has the longest fully heated build chamber available on the market, and a generous build volume of almost 0.4 cubic meters. And with multimaterial 3D printers such as the J35 Pro and J55 Prime, product designers can manufacture ultrarealistic prototypes, for example of packaging, in a single printing operation using the PolyJet process (Fig. 1).

Expanded Material Spectrum:  PEEK for Medical Technology

Arburg is using PEEK (polyether ether ketone), which is particularly suitable for medical purposes, to further extend the applications scope of Arburg Plastic Freeforming (APF). At Formnext, a Freeformer 300–3X designed for high-temperature applications processed, for the first time, the plastics pellet stock “Vestakeep i2 G” from Evonik to produce skull-implants (Fig. 2). “The fact that it is a medically approved original plastic pellet material for permanently implantable medical products is exciting interest within the additive manufacturing sector. In addition, this material is also interesting for technical parts,” says Martin Neff, AKF department manager at Arburg.

The machine is specially equipped for processing high-temperature plastics: the build chamber can be heated to 200 °C, and optimized temperature management ensures the necessary cooling of the system, in particular the axis drives, which position the part carrier highly precisely with 0.022 mm accuracy in the x, y and z directions. The Freeformer is also predestined for practical use in medical technology, because “the process quality can be reliably documented and each component can be clearly tracked,” says Neff. With the “ProcessLog” app developed especially for the Freeformer, available via the customer portal “arburgX world,” various process and build job data can be clearly represented in graphical form for all parts. To demonstrate this at the trade show, each part received a label with QR code. The QR code can not only be used in the ProcessLog to inspect details of the machine, the materials to be used and job start and end, but also the recorded process data throughout the entire build time, with detailed information about melt pressure, screw position, drop frequency and volume output.

In this context, the “MachineCenter” app is also useful. It provides a clear overview of all the customer’s Freeformers. For each machine, documents can be called up, for example on material profiles, software packages, sample parts and materials data sheets. Operating and maintenance manuals, as well as installation plans are also stored here. To allow use of these functions – as well as of the newly available remote service, in which Arburg hotline support staff, by agreement with the customer, connect directly to the machine control system via a secure and encrypted data connection – all the new Freeformers are equipped with an IIoT gateway.

Another medtech application was demonstrated as part of a joint project with the University Clinic of Basel, Switzerland, using a Freeformer 200–3X. The set-up exhibited in Frankfurt manufactured resorbable implants from a composite of poly(L-lactide-co-D,L-lactide) and tricalcium phosphate (β-TCP). The material (type: Resomer LR 706, also from Evonik) contains 30 % ceramic additives – this makes the implant strong and also releases calcium to promote bone growth.

Even materials that have not been accessible by additive manufacturing before can be processed by the AKF process, as was demonstrated by Arburg with the example of a part of semicrystalline PBT. The material is flame retardant with a high dielectric strength and is suitable for electronics housings. In a joint process with Balluff and the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA), a Freeformer produced individualized sensors. A housing was additively manufactured from PBT and the process interrupted from time to time in order to manually insert the coil, circuit board and plug, and to create conductor paths.

As was demonstrated by tesa, plastic freeforming can also be applied to unusual materials. The brand-name manufacturer renowned for its self-adhesive system solutions developed its own adhesive granules for particularly sustainable solutions. Thus, smartphone components can be bonded with almost zero-waste by means of self-adhesive strips, just a few layers thick, applied in the Freeformer. This compares with traditional stamped adhesive materials, in which 90 % of the starting material must be disposed of as scrap.

A pioneer of liquid additive manufacturing (LAM), innovatiQ, recently became part of Arburg’s subsidiary Arburgadditive GmbH + Co KG. With the aid of this process, highly elastic components, such as gasket rings can be economically printed individually and in quantities as low as 1. In a live demonstration, the industrial printer LiQ 320 manufactured components such as hand protectors or shoe soles from liquid silicone rubber (LSR). With the newly designed LiQ 7, innovatiQ also unveiled a solution for the series production of colored LSR components. Color dosage can also be controlled in detail, and thereby a wide spectrum of colors achieved.

For first time in Europe, the US company Essentium presented its HSE 280i HT 3D printer, the first genuine independent dual extrusion system (Idex, Independent Dual Extruder), which was developed for the requirements in industrial production. Dr. Blake Teipel, CEO of Essentium, stated that “Whereas most Idex systems have print heads that are independent in the X-axis but connected to one another in the Y-axis, the Essentium HSE 280i HT is completely independent in both axes. Users can employ five print modes: single head mode, support mode, multi-process mode, copy mode and independent mode. “The build volume in multi-process mode is 595 x 495 x 600 mm; the throughput – HSE stands for high-speed extrusion – is up to 200 g/h. The machine is suitable for functional prototyping and series production with technical high-performance filaments.

With the HSE 240 HT Dual Extruder, Essentium has also designed a 3D print platform with dual extrusion print head for small and medium-sized production facilities and university laboratories (Fig. 3). It features three print modes (single head/support/multi-process), which allow parts to be produced from different materials in one print operation. With a build volume of 430 x 350 x 375 mm, 3D printers offer performance characteristic such as 3D high-speed printing, automatic spool switching for long print jobs and an internal camera for remote monitoring. In addition, it has a build chamber that can reach temperatures up to 185 °C and a heated nozzle that can reach up to 550 °C in order to ensure the mechanical strength of the production parts.

AIM3D GmbH is a startup founded in 2017 as a spin-off of the University of Rostock, Germany. The company manufactures industrial 3D printers working by the CEM (composite extrusion modeling) process. It allows the manufacture of parts from reinforced thermoplastics, metal and ceramics based on commercially available injection molding pellets without retrofitting work on a multimaterial 3D printing system. In the two last-mentioned cases, in the pellet stocks known from metal or ceramic injection molding (MIM/CIM), only the plastic component (binder) is melted to generate a green compact. As unique selling point, the 3D printers have a patented CEM extruder that can process almost any injection molding pellet stock up to a diameter of 3 mm (Fig. 4).

Now, with the ExAM 510, AIM3D has presented a 3D printer for larger build volumes, higher precision and build rates. The new multimaterial printer is an enhancement of the smaller ExAM 255 version, and can process up to three materials in parallel – two build materials and a support material. The significantly increased build rate is up to 250 cm³/h, depending on the material (if a 0.4 mm nozzle is used). According to Clemens Lieberwirth, CTO at AIM3D: “This extruder class allows an extrusion rate that is higher by a factor of up to 10 than a commercial filament extruder. Due to the use of linear motors and a stable mineral cast bed, it is possible to work with high precision even at high speeds, and thereby tap the potential of the technology.”

The enlarged build chamber of 510 x 510 x 400 mm can be temperature controlled up to 200 °C in order to reduce stresses in the part. The heated process chamber also allows high-performance plastics such as PEEK, PEI, PSU or PPS, with and without fiber reinforcement, to be processed as pellet. This means a huge cost advantage for raw materials. With the example of PEEK, the high economic efficiency can be seen most clearly: with a PEEK filament price of approx. EUR 700/kg on conventional AM systems, the ExAM 510 can use PEEK pellet, whose market price of about EUR 50 kg represents a costs factor of about 14.

The traditional fields of applications for these materials can be found in the automotive industry, medtech or aerospace, where AIM3D’s pilot customers are also based. After a beta phase with pilot processors, the ExAM 510 should be ready for series production by Formnext 2022, according to the manufacturer.

Connection between Incompatible Materials

Another tried-and-tested solution for the additive manufacturing of high-load-bearing large-volume parts is the SEAM process. “Screw extrusion additive manufacturing” is characterized first by the use of standard pellet and on the other hand by high throughputs of more than 5 kg/h. At Formnext, Yizumi again presented an application that – although of small dimensions – had already been shown at Fakuma: the processing of high-strength polyamide based on castor oil, which is reinforced with 40 % recycled carbon fibers (PIR), on a stainless steel sheet (Title figure). A firm bond between these normally incompatible materials is created by depositing a wafer-thin film of adhesion promoter on the sheet using plasma treatment before the start of the print job.

“The throughputs and material properties that can be achieved with the SEAM process, combined with a component-appropriate design, make it possible to achieve quantities of over 10,000 by additive manufacturing, and offer an alternative to injection molding,” explained Dr. Nicolai Lammert, head of the Additive Manufacturing business unit at Yizumi Deutschland. “Scaling via the number of systems or, within a manufacturing cell, via the number of extruders and dies multiplies the production rate at low investment costs.”

A genuine example of “large format additive manufacturing” (LFAM) was presented by the Italian manufacturer CMS (Costruzioni Macchine Speciali) with the manufacture of a part over one meter long. This, together with the hybrid manufacturing system Kreator, which was developed together with the Fraunhofer Institute and took up roughly the space of a garage at the tradeshow booth, combined a SEAM unit (up to 7 kg/h output) with a 5-axis milling machine for secondary finishing.

By the way, with Italy, a European partner country was presenting itself at Formnext for the first time. One of the many exhibitors from there, with a notable new development in its suitcase was Roboze. The company presented a machine, which is claimed to be the biggest one available, with a heated process chamber for additive processing of composite materials and high-performance plastics, such as PEEK. The new model Argo 1000 has a build chamber of one cubic meter (1000 x 1000 x 1000 mm) and a patented dryer integrated in the machine bed (Fig. 5). The high performance control system from B&R and the beltless technology, also patented, from Roboze increase the printing rate and effect six times higher repeatability than belt-driven printers. The printing technology is reminiscent of the kinematics of industrial machine tools.

The high mechanical properties and the dimensional tolerance of the manufactured parts are the result of precise temperature management during the entire process. The material is extruded at up to 450 °C, while a homogeneous temperature of 180 °C prevails in the entire process chamber. This is achieved by means of a constant heat flux, generated by a collector, which is mounted on the underside of the build structure, sucks in the introduced air and, after heating it, guides it back into the chamber through the holes in the side walls.

The fully networked machine based on the B&R control system (“Roboze Automate”), with its sensors and remote control and diagnosis functions, simplifies the entire workflow and the generation of reports from all phases of the printing process. The digitalization also permits predictive maintenance and constant automatic updating of new functions and software parameters. “The Argo 1000 will be a pioneer in metal-replacement applications in challenging industries, such as aerospace, as well as the mobility and energy sectors,” said Alessio Lorusso, founder and CEO of Roboze. Market launch is planned for the third quarter of 2022 – in time for the next Formnext. This year, the trade show takes place from November 15 to 18.

A high-strength carbon fiber-reinforced polyamide is printed on a plasma-treated stainless steel sheet.

Fig. 1. PolyJet printing allows designers to create full-color packaging with integrated graphics and labels in one step.

Fig. 2. Skull implants of PEEK. The support structures behind it are so loosely designed, they can be mechanically detached. 

Fig. 3. The HSE 240 HT Dual Extruder is a 3D printing platform with dual extrusion die head. 

Fig. 4. The new CEM-E2 extruder is a multimaterial print head, which can print the materials metal, plastics and ceramic.

Fig. 5. The Argo 1000 is the biggest machine with a heated process chamber for additive processing of reinforced materials and high-performance plastics.

Doriat, Clemens, Dr.

Anlagen Additive Fertigung / 3D-Druck, Kunststoff

Anlagen für die Additive Fertigung

Anlagen für die Stereolithografie, Kunststoff

3D-Drucker (für FDM, FFF, etc.)

Anlagen Additive Fertigung / 3D-Druck, Metall

Additive Fertigung

Hochleistungskunststoffe

Kunststoff Werkstoffe

Thermoplaste

The Possibilities of  Cross-Company Digitalization

Way2K: Interview between VDMA and Markus Gschwandtner

In the lead-up to K 2022, the trade fair for the plastics and rubber industry in Düsseldorf, Germany, Markus Gschwandtner, CEO of Brückner Servtec GmbH, talks about the advantages of digitalization for predictive maintenance and for the circular economy.

Mr. Gschwandtner, your company has to ensure that Brückner film lines run trouble-free at customer sites. What role does digitalization play in this operation?

Digitalization is of crucial importance to us as the interface between Brückner and the customer, which is why we continuously drive forward integration and exchange of data and information. To this end, we have set up a digital service platform where the customer can access our services online. Let me give you an example: the delivery scope of a plant includes extensive documentation. Up until now, it has always consisted of many folders. If the customer wanted some information, it could take a while to find the relevant passages. On our service platform, this documentation is now available online at any time. The service technician standing in front of the machine then has easy and quick access to the necessary information via a tablet or smartphone.

Consequently, access to information is becoming easier. What other advantages are there?

The fundamental advantages are transparency and simplicity. Here is another example: we install about 30,000 parts in each machine. Many of these are labelled with a QR code, including parts from suppliers. It identifies each component from the beginning of its life with Brückner until it is used at the customer’s site. All customers need to do is scan the part they want to replace; both we and the customer then know exactly which part is concerned and when it will be available. This allows us to react much more quickly and, if necessary, to fix a problem much sooner.

Many companies hesitate when it comes to handing over data. How do you convince them?

We have to ensure that the data is truly secure. At our company, there are no leaks. We are TÜV-certified. But that assurance alone isn’t enough to convince a customer; the decisive factor is that we need to make sure the customer sees the enormous advantages. The benefits of data integration are the greatest where corporate boundaries are crossed. Over 70 percent of our customers are already on our digital platform. Basically, it’s the same principle as a smartphone: you see what’s possible with it, and soon after, you find you can’t do without it.

What is the next big digitalization topic?

The big digital project of the future is predictive maintenance. When one of our production lines comes to a standstill, the customer loses around 10,000 euros on average in revenue, and that figure is per hour. It is therefore important to keep these stoppages as brief as possible, but in any case, to be able to predict them. We are already well on the way to doing that, installing sensors, for instance, to assess the status of critical components. In the future, we will also use artificial intelligence to predict when a part might break or when maintenance should be carried out. The goal is to increase the ability to plan necessary maintenance work ahead, because that will save considerable costs and increase the production uptime.

Predictive maintenance helps make utilization of the production line and also all subsequent steps more sustainable. For example, if maintenance is carried out without it actually being necessary at the time, spare parts will also be replaced needlessly early. So, you will need a lot more material over the life cycle of a plant. But resources are also conserved if, for example, we install more energy-efficient motors during upgrades and modifications. The goal must be to use as few resources as possible, be it material, energy, or raw materials. Only through digitalization can we achieve the transparency necessary for this purpose.

How are digitalization and the circular economy interrelated?

Without digitalization, it would be very difficult to enable a circular economy. With it, however, we can for example label products during the production process. Then machines can recognize later in the waste collection cycle what the packaging film is actually made of. It is then possible to identify that a piece of packaging film is made of polyethylene and does not contain more than five percent different and foreign materials. This means it is fully recyclable. But the production lines have to be prepared. Such mono-material structures require numerous modifications to the plants. Only then can a high-quality plastic packaging film, which is ready for circular economy, be guaranteed.

What’s the next phase in the circular economy?

With regard to packaging films, circular economy can only work if we aim for mono-material structures. But it is also important to have a better collection system for plastics, comparable to that for bottles. It must be made as simple as possible for the consumer. Next, the plastic has to be separated so that you get single-source plastics. The next step is single-source recycling. But then there is the question of what to use the recyclate for. Turning a packaging film back into a packaging film remains a vision for the time being but turning recycled packaging film into good products that can be used in injection molding, for example, would make sense.

The technical challenges will be overcome. It will be more difficult to implement a viable collection system. And then it is important that the circular economy is established all over the world. A lot is collected in Germany or Austria, but not so much yet elsewhere in Europe and in many other parts of the world. The quantities are still too small for the circular economy to be economically viable. That has to change, too.

Markus Gschwandtner, CEO of Brückner Servtec GmbH.

On the digital service platform the documentation is available online at any time.

VDMA Industry Interview Brückner

“The Big Digital Project of the  Future Is Predictive Maintenance.”

Messe K-Kunststoffmesse

kunststoffe-international.com

Instandhaltung

Kunststoffverarbeitung: Maschinen und Komponenten

Vorbeugende Instandhaltung für die Qualitätssicherung

Industrie 4.0 für die Qualitätssicherung

Kreislaufwirtschaft

“There’s No Point in Arguing over Chemical versus Mechanical Recycling”

Interview with Ingemar Bühler from PlasticsEurope Deutschland

Over the last year, the German branch of the Association of Plastics Manufacturers, PlasticsEurope Deutschland, consistently advocated the technology of chemical recycling. Meanwhile, chemical recycling has not only been criticized by environmental organizations but also from parts of the industry. Kunststoffe interviewed Ingemar Bühler, CEO of the Association, about this criticism and the competition between mechanical and chemical recycling. In the interview, Bühler also addresses further requirements for a circular economy with plastics and explains why he considers a label for plastics products a sensible idea.

Most industry representatives agree that the circular economy is a key future issue for the plastics industry. But when it comes to the specifics of its implementation, there are differing opinions, such as on the method of chemical recycling. Lately, the German branch of the Association of Plastics Manufacturers, PlasticsEurope Deutschland, has strongly advocated for the chemical recycling of plastics waste. In our interview with Ingemar Bühler, the Managing Director of the association, we dived a bit deeper in order to understand the rational for this advocacy. Furthermore, Mr. Bühler gave us a brief progress report on his first year at the helm.

Kunststoffe: Mr. Bühler, you have now been in office for a year. Can you give us a progress report on your first twelve months?

Ingemar Bühler: There are two things in particular of which I am proud: despite the difficult pandemic situation, I was able to get to know many people from the industry, sometimes in person, both plastics manufacturers as well as plastics processors and packaging and machinery manufacturers. I am delighted I was allowed to learn about many different perspectives and having personal conversations while making sure every meeting was held in a responsible manner. In addition, we as an association have succeeded by significantly expanding our communications activities. We have further developed our presence in trade publications and yet had to build new relations with leading dailies and online media. Gladly, we have been able to reach significantly more people and opinion leaders than in the past.

Kunststoffe: In recent months, it has seemed like the plastics trade associations have been cooperating more closely together. Was that prompted by a concern of yours or was it mainly a response to the tarnished reputation of the industry?

Bühler: Indeed we are working more closely together. And we are in constant touch with each other. This was not always the case. To me, however, it is absolutely crucial for our industry. The strong criticism experienced by the plastics industry has also played a role in this. Cooperation between the trade associations is very important because the industry itself is very much fragmented in organizations that operate in different areas across the value chain. However, our common goal – which is to create a circular economy and enable a climate neutral way of doing business – can only be reached if our industry’s main actors work closely together. And the current transformation is changing this for the better. Companies that have traditionally been far apart from each other in the value chain now have to act as partners in a circular and deeply connected, intertwined economy.

Kunststoffe: The trade associations often represent different interests. This surely makes cooperation difficult.

Bühler: Absolutely. Yet, I was surprised to learn that these differences were frequently argued out vehemently and loudly in the past while the companies we represent are actually customers of each other who are interested in a close, long-term relationship.

Kunststoffe: In October last year you published a joint position paper on the circular economy with the recycling associations BDE (Federation of the German Waste, Water, and Raw Materials Management Industry) and bvse (German Federal Association for Secondary Raw Materials and Waste Management). In the past, PlasticsEurope Deutschland and these two associations have taken very different positions in relation to chemical recycling. Has that changed?

Bühler: We continue to take different positions on chemical recycling. In my opinion, what has changed is an understanding of each other’s viewpoint. From the recyclers‘ perspective, these processes are not considered recycling as such but rather as chemical recovery. This viewpoint is legitimate and we don’t want to get hung up on that. The crucial thing for us is to achieve the highest possible recovery rate for plastics waste. To get there, we must use every technology proven to be safe and effective. What is more difficult, on the other hand, is a second point. Through chemical recycling, plastics manufacturers are going to become recyclers for the first time. Many companies feel threatened by this. However, this point also works the other way. Through mechanical recycling, some recyclers become plastics manufacturers or at least very close partners of the manufacturers.

Kunststoffe: So are mechanical and chemical recycling in competition then? In the past, Plastics Europe Deutschland has always spoken of the two as complementary processes.

Bühler: There is a competitive aspect for sure. Yet, in my opinion, the fear of some companies to no longer receive sufficient plastics waste to process in the long run, has no basis. This fear is a result of missing the crucial point. The plastics industry has the task of achieving CO2-neutral production. At the same time, we are sitting on a global pile of waste that contains a very large quantity of plastic. Arguing over chemical and mechanical recycling will not take us any further forward on either of these issues. We must keep our eyes on the big picture. To achieve a successful circular economy, it is not necessary to make a definitive choice between chemical and mechanical recycling. In fact, I believe that four technologies are key to get to a climate neutral plastics industry.

Bühler: The technologies required are mechanical and chemical recycling, carbon capture utilization and biomass utilization. These four are necessary to make the plastics industry climate-neutral and create a circular economy for plastics. For this transformation, a large amount of energy is required. The industry can only achieve CO2-neutral production if all plants are converted to electrical operation and the power for them comes from regenerative sources. This is, by the way, the only point at which thermal recycling will possibly have a place in the future – to supply the recycling processes with energy. I see the upcoming K trade fair for plastics and rubber as a very important milestone for this transformation. At the last K in 2019, there was already a great deal of talk about the circular economy. Now we must make it happen. The transformation must be completed in the next 25 years. If we do not succeed in this, that would be a disastrous failure.

Kunststoffe: So far, efforts to create a circular economy have been very piecemeal. Where should the comprehensive view come from?

Bühler: Green energy, recycling technologies, biomass and CO2 utilization – all huge topics in themselves already. We therefore require a national or European strategy to encompass them. For this, we need a coming together of bright minds from all sectors, who can drive the transformation forward together. The buck-passing between politicians, business and society that we have seen so far will not take us any further forward. All participants must look beyond their own horizon. The plastics industry has learnt this from painful experience with marine littering. It is not a fair position to argue that our industry only manufactures the products and is not involved in their disposal, particularly when it comes to unsealed landfill. For me, this is no argument. A global industry with innovation and market leaders carries immense communicative and political weight as well as a certain degree of shared responsibility for their products. If we have solutions available beyond our own market radius, then we must offer them. Unfortunately, our industry has often lacked this mindset in recent decades.

Kunststoffe: Besides the position paper with the BDE and bvse, you have also published a recommendation paper with the German Chemical Industry Association (VCI) and the Expert Network for Chemical Engineering and Biotechnology in Germany (Dechema) especially on chemical recycling. Do you see a particular need for action there?

Bühler: Yes, we do. Chemical recycling has so far been neglected at the national and European level. This is partly due to the fact that it has considerably higher energy and chemical consumption than mechanical recycling. Many have failed to understand that, despite its high energy demand, chemical recycling can be self-sustaining. There are also great reservations towards the chemical industry in general – both in the political sphere and in wider society.

Kunststoffe: There are also reservations towards the mass balance method normally used for quoting the content of chemically recycled plastics waste. Do you see possibilities for creating more confidence here?

Bühler: If the exact recyclates content in a product is not stated, this is difficult for consumers. But for the industry, the mass balance method is very important. Hence, to make it clear for consumers, we must radically simplify these highly technical and scientific topics. Simple labels are necessary that enable customers to make informed decisions. One possibility might be three-tier traffic light systems. This applies not just to recyclate content but also to the CO2 footprint of products. On this point, we are also in agreement with many other plastics trade associations.

Kunststoffe: The criticism of “greenwashing” is often leveled against labels issued by trade associations and companies. Are state-approved labels necessary to increase consumer trust?

Bühler: In Germany, consumer trust in public authorities and government institutions is a bit better than trust in industry. Consequently, state-approved labels are the way forward. By the way: many of the existing labels were originally initiated by industry. To strengthen trust in such labels, it is also important to include environmental and consumer protection organizations.

KUint 1-22_Intw.PED - Hauptartikel

For a year now, Ingemar Bühler has been steering the destiny of PlasticsEurope Deutschland as Managing Director. Before being in charge for the German branch of the Association of Plastics Manufacturers on January 1st 2021, the 40-year-old worked for the Bayer Group for twelve years. At the Leverkusen/Germany-based company, he held various positions in public relations and policy communication, ending up in the agricultural division of the company as Head of Public Affairs & Sustainability. Bühler studied Political Science and International Affairs at Friedrich-Alexander University Erlangen-Nuremberg, Germany, and Economics at Oxford University, United Kingdom.

“Transformation to a circular economy must be completed in the next 25 years. Otherwise that would be a disastrous failure.”

“Simple labels about the recyclates content of products are necessary to enable customers to make an informed purchasing decision.”

Streifinger, Florian

Verbände, Institutionen, Messen

Dienstleistungen

Recycling

Umweltmanagement

Kunststoff-Recycling

Kunststoff-Aufbereitung

How Chemical and Mechanical Recycling Complement Each Other

In addition to mechanical recycling, chemical recycling is increasingly coming into focus for more challenging plastic streams. This article provides an overview of different recycling processes – and the challenges that arise, particularly in the area of food packaging as a result of regulations or the cost-effectiveness of the process.

How can we manage to recycle significantly more waste packaging materials, and how can we successfully drive an ecological and cost-effective circular economy for plastics? Paper, glass and even aluminum have strong reputations as recyclable materials. As far as plastic is concerned, we are still a few steps behind, because for decades, since the development of this uniquely diverse material, the focus has been on where it can be used beneficially. Designing products so that they can be recycled, or thinking about what happens when a plastic product has served its purpose and becomes waste, hardly played a role. It is only in recent years that the drive for a circular economy has gained momentum. It will only be possible to take full advantage of all the positive characteristics of plastic once the circular economy has been implemented. Because the advantages are not only limited to the variety of possible applications or the price/performance ratio.

In the meantime, the entire industry is aware of this and is bringing together its know-how and commitment to find an answer to the question at the beginning of this article. It involves the conservation of natural resources, the reduction of waste, which in many places pollutes land and water, and it is also one of the keys to the reduction of greenhouse gas emissions and, as a result, a key to fighting against climate change. Many reports from the plastics industry relate to promising pilot projects based on improved sorting and recycling processes, new products made of recycled or organic-based plastics or recyclable packaging solutions.

Chemical Recycling as a Potential Solution for Difficult Cases?

More and more attention has recently been paid to chemical recycling as a potential solution for many particularly challenging plastic streams, especially for food packaging. In the case of PET, mechanical recycling has been very successful for many years, thanks also to Erema’s Vacurema technology. PET bottles and trays made from up to 100 % rPET meet the highest quality standards and are now increasingly the rule rather than the exception. The situation is different, however, for mechanically recycled non-PET materials. Their use in food packaging is severely restricted by the current EFSA (European Food Safety Authority) evaluation criteria. PCR plastics (except PET), produced from food packaging waste, can therefore only be returned to food packaging in a few cases in Europe, even if they have been processed completely separately. Mechanical recycling solutions with FDA (Food and Drug Administration) approval for defined input streams are available – including solutions provided by Erema – for HDPE beverage containers and for HDPE closures for HDPE, PP and PET bottles. The recyclate produced from these processes can be used in proportions of up to 100 % for food packaging.

In the EU, however, where the bar is set particularly high in terms of recycling targets, a final EFSA assessment for the recycling of HDPE food contact materials is still pending. This is one of the reasons why chemical recycling is gaining in interest. And indeed, consumers who are interested in recycling are increasingly noticing packaging with labels such as “made from xy percent certified circular polymer from post-consumer plastic” or “uses recycled plastic” on supermarket shelves. This does not mean, however, that the product the consumer is holding in their hands when they read these words actually contains recycled plastic. How can that be?

Chemical Recycling also Requires a Pre-Treated Input Stream

Mechanical recycling processes require separate treatment of the respective type of plastic if the recycled pellets are to be reused in materials with direct food contact. PET bottles, HDPE films, HDPE and PP hollow bodies, for example, are collected separately or sorted out and processed to form recycled pellets, which in turn are used to produce bottles, films or hollow bodies with a recycled content of up to 100 %. In the case of PET bottles, this cycle is traceable and transparent. The labelling on the bottle provides information about the actual proportion of recycled plastic it contains.

Chemical recycling technologies such as pyrolytic processes are capable to a certain extent, of separating mixed plastic waste materials – especially polyolefins (PO) – into their chemical components (hydrocarbons) by introducing thermal energy and, if necessary, catalysts. That is how pyrolysis oil is obtained, which can be considered like a synthetic crude oil and is composed of various fractions (including naphtha). Following appropriate pre-treatment in the refinery, plastics – mostly polyolefins – can be produced again as a result of steam cracking and polymerization, among other things. Depending on the composition and chain length, the remaining components can be used as chemicals for new products or as fuels. The quality of circular naphtha and the extent to which it can be recovered from the respective plastic waste stream for plastics production also depends on its purity and the treatment process used. The decisive factor in these processes is that foreign components such as PVC, PET and PA are not present in the PO input stream, or only in small proportions.

Establishing separate processes for the chemical recycling of plastic to plastic by keeping each material flow separate, would require investments that are unlikely to be justified either economically or ecologically in the future. That is why chemically recycled materials are processed together with crude oil-based feedstock using existing petrochemical infrastructure (refinery, steam cracker, polymerization plants). Following this process, it is no longer possible to distinguish between original fossil chemicals and recycled materials. What is needed, is a method to determine the proportion of recycled materials obtained from chemical recycling that can be used in products such as new food packaging that can be marketed as recycled goods. To do this, the mass balance approach is used, as it is in a similar way for trading in green electricity. Figuratively speaking, just as green electricity and electricity from coal-fired or nuclear power plants flow at different rates along the same power line to arrive at the consumer’s wall socket, original fossil molecules and recycled molecules are processed in the same plants, although the products are marketed separately based on the mass balance approach. Here, too, the distribution rates can vary greatly. It would be possible, for example, for the consumer to hold in their hand packaging that actually contains 0 % recycled plastic, despite labelling to the contrary – ISCC Plus certification of the entire process chain has now become established as a reference for this. While this may sound strange at first, it does add up. Existing infrastructures can be used in a resource-saving way to further develop chemical recycling, which is still at the beginning of being industrialized.

How Material Preparation Supports the Recycling Process Chain

Erema has been behind the development of mechanical recycling over the past decades, and the company’s innovations have driven development forwards. Technological progress in chemical recycling is also supported using the experience of the Erema Group subsidiary Keycycle, both on the integration of recycling solutions into existing plants and on material preparation upstream of extrusion. Often, mechanical processes are at the beginning of the process chain for chemical recycling, in order to process post-consumer input streams and to ensure a reliable, continuous and energy-efficient material feed into the chemical recycling process, which contributes to maintaining output quality. Erema single-screw melting systems with preconditioning units (PCU) adapted to the respective requirements are already being used for this purpose at existing plants worldwide, because their technological advantages have also been proven for this application (see Info box).

By joining the Chemical Recycling Europe association, Erema wants to enhance its understanding of the needs of plant operators and promote cooperation and innovation. In order to achieve the transformation to a circular economy for plastics mentioned earlier, the technical capabilities of mechanical recycling need to be exploited to the full by expanding collection, sorting and recycling infrastructure and by further developing the technologies and end applications to be designed for recycling. For material flows where this recycling route is approaching its limits, it is important to regulate and apply additional processes. As an additional level in the recycling pyramid between mechanical material recycling and incineration with energy recovery, chemical raw material recycling is an addition that makes sense in the long term to keep a maximum of raw materials within the circular economy.

In addition to the technological development of chemical recycling and the implementation of the first industrial-scale plants, it is essential for the plastics industry as a whole to gain and strengthen consumer confidence. Plastic is not only the most versatile material, but also the most environmentally friendly in many areas of application when the entire life cycle is considered objectively. Transparent communication about the recycling process end-to-end, as well as certification and product labeling, are essential to close the loop and ensure that the potential of plastics as part of the solution for environmental and climate protection is appreciated by consumers and can be utilized to the full.

Chemical recyclers and raw material producers rely heavily on processes that are covered by the collective term thermal conversion, which includes pyrolysis.

Fig. 1. Physical (mechanical and solvent-based) and chemical recycling processes in the extended waste hierarchy.

Klaus Lederer, Technology Research Manager – Chemical Recycling: “In addition to the technological development of chemical recycling, it is essential for the plastics industry to gain and strengthen consumer confidence.”

Erema - Hauptartikel

Klaus Lederer works as the Technology Research Manager – Chemical Recycling at Erema Group GmbH.

The Chemical Feedstock Recycling Core Process (Pyrolysis) with Erema Melt Feed: Depending on the technology and the requirements for the intermediate product pyrolysis oil, post-consumer plastic waste is sorted and in some cases also washed, processed and melted in the single-screw melting system with preconditioning unit (PCU) and the melt is then fed into the main process. The input material is a key challenge for this process, especially in the case of increasingly lighter and thinner packaging films with very low bulk density. This is where Erema’s patented PCU comes into a class of its own, because it handles all the necessary processing steps – i.e. cutting, homogenizing, heating, drying, compacting, buffering and dosing – in one efficient process step. The patented Counter Current technology in the PCU provides a process window that is three times wider than conventional systems, which in turn allows the input variability that is needed due to the fluctuations in humidity and composition of the input stream material. Depending on the requirements, this system can be equipped with additional features such as online monitoring of the material composition and application of additives. The energy input is primarily generated from mechanical friction and shearing. This one-stop-shop solution also guarantees the highest possible energy efficiency, because the material can be fed directly into the chemical recycling process without having to be cooled down and reheated, so that all the energy already input is still available for the actual pyrolysis process.

Glycolic Depolymerization versus Mechanical Bottle-to-Bottle Recycling

Conventional PET recycling lines are based on single-screw extruders with maximum output rates of two and a half tons per hour. Since 2004, KraussMaffei has been researching a process to significantly increase these quantities with the help of glycol and the use of a twin-screw extruder. Given the current high demand for rPET materials, this technology is becoming increasingly important.

The recycling and new production of PET bottles is probably the best-known process in the field of plastics recycling. This process, in which sorted PET plastic bottles are washed, melted, filtered and pelletized before they are used as base material for new PET bottles, has for many years been one of the very few established recycling technologies. In general, a PET reuse rate of over 30 % is currently achieved worldwide.