How long is a trend actually a trend? More specifically, can the circular economy still be called a trend? After all, the plastics industry has spent years making the circular economy an ongoing issue.

For us scribes on the sidelines, it is practically part of our everyday routine, given how much newsworthy information we receive about it. And functional closed-loop systems already exist, at least in some areas. A widely quoted example is PET bottles.

Nevertheless, the term trend still applies. After all, the existing closed-loop systems are still the exception and are only just now being set up for other plastics and products. They are not – yet – the norm. In addition, the circular economy is currently hugely influencing new developments and improvements in the industry. Plastics producers as well as machine manufacturers are working constantly on products and technologies for this. That applies independently of the manufacturing process – be it injection molding, extrusion, blow molding or additive manufacturing.

The circular economy is definitively no longer a new topic, but along with digitization, it is currently the most potent driver of innovation. And, after all, the characteristic of a trend is not that it is new, but that it drives change. In this regard, there is no avoiding the circular economy.

You can find insights into the most important and exciting innovations in the Special in this edition (from page 9). On its 40 pages, we present technology trends in plastics processing – going well beyond the circular economy.

Florian Streifinger [<a href="mailto:florian.streifinger@hanser.de">florian.streifinger@hanser.de</a>]

Editorial Streifinger

Streifinger, Florian

Measurable and Reproducible Processes in the Cleanroom

In order to certify its products for the required cleanroom class for food, pharmaceutical, and medical industries, the plastics processing company Pöppelmann relies on software by CAQ AG.

The food, pharmaceutical, and medical industries place the highest demands on product safety. Parts that Pöppelmann manufactures for this sector are injection molded or thermoformed under cleanroom conditions. In order to certify for the required cleanroom class, the plastics processing company relies on software by CAQ AG.

Pöppelmann GmbH & Co. KG has in the more than 70 years of its existence become one of the leading manufacturers in the plastics processing industry and the company’s product portfolio includes a total of four divisions (see Box p. 8).

The Famac division occupies a special position with regard to standard requirements and official regulations to be complied with. It is a manufacturer of components and packaging for the food, pharmaceutical, and medical products industries and is therefore subject to the highest requirements for product and user safety. Certified to DIN EN ISO 9001, ISO 13485, and BRC Packaging, among others, Pöppelmann’s Famac division manufactures parts using injection molding and thermoforming processes under cleanroom conditions in accordance with DIN EN ISO 14644–1 Class 7, GMP Class C.

Today, the Famac division is supported in terms of quality assurance by CAQ AG’s holistic CAQ.Net software solutions. One of the reasons for implementing CAQ.Net was that previously there was no dedicated software for QM processes. Procedural and work instructions were managed on paper, and training management was accomplished with a non-validatable Excel solution. In general, too many isolated applications were in use at Famac, which, in the absence of interfaces, led to redundant, incorrect data. Due to a lack of user rights structure and audit trail, the legacy system, which consisted in part of HTML programming on the intranet, was generally not validatable and prevented the fulfillment of standards and customer requirements with regard to the validation of computer-based processes and the guarantee of data security and data integrity.

The use of CAQ.Net software at Pöppelmann began in 2015 with the introduction of the modules for document management, process management, and training management in connection with the central quality control module. In 2018, the modules for incoming goods inspection, production inspection, complaint management, and gauge management were added, as well as audit management and supplier management in 2019. This was followed in 2020 and 2021 by the solutions for gauge capability testing, change control, initial sample inspection, and KPI visualization.

Step by Step Expansion of Quality Management Instruments

During the successive rollout of additional modules, the company was able to draw on the experience and concepts gathered during the initial implementation of CAQ.Net in 2015 as well as the expert know-how of those responsible for computer software validation (CSV) in accordance with ISO 13485 and GMP.

ISO 13485 and GMP? Successful Validation Requires the Correct Approach

When it comes to validation, you cannot just run off blindly – you have to know exactly where you want to go and have a clear approach. In terms of specifications, documented evidence, VMP, RA, plans or reports, Pöppelmann first had to define what the (GMP-) critical operations and processes were and how they would be tested and validated before going live. Instructions and tutorials had to be drafted describing workflows and system configurations and containing work instructions for all modules and workflows as well as technical reports on configurations (system settings, etc.). Since there was to be no user authorization without proof of training, clear qualification requirements were defined for user groups, which could conveniently be monitored directly with CAQ AG’s training and qualification management module. Finally, a decision had to be made regarding an update strategy. The company chose a frequency of one update per year, including regular update evaluations, risk analyses, and relevance assessments, as well as continuous re-qualification with new, comprehensive plans and tests. CAQ AG supports this strategy by regularly providing complete documentation of all changes and enhancements made to the software modules. In the context of validation, there was still the issue of the user rights concept. In the course of the validation, Pöppelmann had to develop a concept that regulated in detail who from the staff is allowed to do what, when and how in the software. The decision was made to divide the software into viewer, user, key user, and admin/subject admin.

The designed user rights concept – including single sign-on (LDAP) – was transferred to all individual CAQ.Net software modules in the company using the cross-modular System.Net system settings control module:

<ul><li>The Viewer is a guest user of a module. He can start the module and view contents but has no editing rights.</li><li>The User is a user of a module who requires specific training/qualification. He may access an application but has no configuration rights.</li><li>The Key User is a specially trained user with additional user rights. He can e. g. edit module-specific libraries.</li><li>The Admin/Subject Admin is an employee with administration rights. In total there are two system admins and one subject admin per module.</li></ul>

The need for a well-thought-out user rights concept becomes clearly evident in the case of inspection planning, inspection data acquisition, and SPC at Pöppelmann. While only three trained inspection planners create and monitor the approx. 1850 active articles as well as article variants and family inspection plans in inspection planning, the subsequent inspection data acquisition is of a much different order of magnitude. Around 150 trained employees and inspection data recorders gather inspection data at 20 measuring stations on the production shop floor itself and at dedicated quality assurance/quality control (QA/QC) sites.

For this purpose, six measuring machines, three tension-pressure machines and various hand-held measuring devices are used. The order control for the inspection data acquisition is carried out by means of an interface to the ERP and PDA system and regulates both the fully automatic registration and updating of the inspection orders as well as the assignment to the individual measuring stations at production and QA/QC levels. The distribution of user rights distinguishes here, for example, in manual inspection data acquisition between the “IDA” user group in production, which only has rights for data acquisition, and the “IOP” user group in QA and QC, which has more extensive rights for order logoff and inspection order processing.

Intelligent Software Facilitates Standards-Compliant Processes

Today, Pöppelmann has a holistic, validated software solution at its disposal, which is characterized not least by an intelligent user rights concept, a uniform system interface, and a high degree of networking and integration into the existing system landscape. Through secure and valid workflows and processes, as well as the avoidance of redundant data, the CAQ solution creates the highest levels of data security and accompanying trust in production-wide processes and quality management. The detailed validation process thus created intelligently implemented software that consistently enables standards-compliant work in accordance with ISO 13485 and GMP. In addition to consistent audit security, this also leads to increased product quality and associated customer satisfaction.

The product portfolio of Pöppelmann includes laboratory supplies that meet highest quality requirements

16:9

Cleanroom conditions according to DIN EN ISO 14644–1 Class 7, GMP Class C apply in production

CAQ - Hauptartikel

Martin Hammoor is Head of Quality Systems at Pöppelmann GmbH & Co. KG.

Since 1949, the company Pöppelmann GmbH & Co. KG, with 2500 employees at five production sites in three countries and 700 injection molding machines, thermoforming lines and extruders, has become one of the leading manufacturers in the plastics processing industry. Pöppelmann’s solution portfolio is divided into four divisions that operate principally on an industry-specific basis:

<ul><li>The Kapsto division is one of the world’s leading manufacturer of caps and plug, according to company statements</li><li>K-Tech is a supplier primarily to the automotive industry</li><li>Teku provides plant pots, trays, and individual solutions for commercial horticulture</li><li>Famac is a manufacturer of components and packaging for the food, pharmaceutical, and medical device industries</li></ul>

Software Qualitätsmanagement

Software

Qualitätsmanagement

Innovative Injection Molding in Times of Pandemic

Over past months, many in-house workflows and development processes have slowed down and also changed. Nevertheless, time has not stood still, also not in injection molding technology. The debate and development have been shaped by two themes: digitalization and the circular economy. Below are some examples of developments and projects that underpin this trend.

Anyone trying to report on developments and innovations in times of the corona pandemic feels as though they are commenting on a soccer game that is not taking place. Trade shows, congresses, customer events and visits were being canceled for a long time or took place online, if at all. The following overview – written on a home computer, in order to illustrate some of the trends in injection molding – can therefore only be selective.

3D-Formed Plastic Panels with Integrated Displays

Continental uses a combination of film insert molding (FIM), in-mold decoration (IMD) and injection-compression molding to produce large, three-dimensionally formed instrument panels with integrated displays (Title figure). The challenge here is to synchronize the technical properties of displays arranged side by side regarding white point, color temperature, color coordinates and black homogeneity, and to harmoniously integrate the display surfaces into the lines of a cockpit [1].

To implement the project, Continental has combined several special injection molding processes. A two-dimensional printed film is first formed in the HPF (high pressure forming) process to the three-dimensional contour of the final part. This preform is subsequently inserted into a mold and back-molded by the FIM method. In the IMD process, the hard coating is finally applied to the part in a roll-to-roll process, which, in combination with injection-compression molding, ensures a very low stress distribution in the part. With the combination of all steps, according to Continental, this was a new process at the time of commissioning, in which the machines used are unique in the world.

The injection mold, into which the printed 3D film is inserted before back-molding, weighs a total of 16 t. Because of its complexity, it has a certain intelligence in the form of a programmable logic controller (PLC), which supports, e. g., operation by smartphone and WLAN. The PLC is responsible for monitoring and coordinating the over 60 actuators and sensors that are located in the mold, and independently handles the interplay between the injection molding machine and two further secondary ancillary units. Continental’s project is thus a flagship for innovation – strictly speaking the implementation of an idea as new products, services or processes – and for the interplay of technology and digitalization in injection molding.

New Approaches to Thermoplastic Foam Injection Molding

Foamed parts have a three-layer structure, in which a porous core is surrounded by two non-foamed cover layers. Classical density reductions in the TFIM (thermoplastic foam injection molding) process are around 10  %, as new developments in the tool and process technology permit (local) density reductions of up to 50  % – which greatly reduces the lightweight construction potential of this technology. Another advantage is the recyclability, since the sandwich structure consists of a single material.

Technically, the homogeneous gas pressure minimizes the warpage and improves the fidelity of reproduction, with the gases acting as “plasticizers” during processing: depending on the gas and concentration, the viscosity is reduced by up to 50 %, which under certain circumstances permits smaller machines to be used. The Institute of Polymer Injection Molding and Process Automation (IPIM) at Johannes Kepler University in Linz, Austria, together with the Competence Center Chase and Engel, is developing a new process technology which uses optimized plasticizing screws (Fig. 1), as well as new methods for inline determination of the gas solubility under dynamic conditions [2].

The key factor here is the compression modulus of the mixture, which characterizes the volume changes as a result of the pressure rise. Based on these methods, process optimizations are also possible, such as the automatic reduction of the back pressure to the technically necessary minimum in order to reduce wear and energy consumption and improve the conveying behavior.

Even greater potential for optimizing foam processes is offered by artificial intelligence (AI); specifically the use of convolutional neural network (CNN) developed and trained at IPIM for optimizing the part surfaces by the TFIM process. The goal is to find suitable process settings for unknown processes without having to perform complicated tests. In future, the system should be capable of automatically counteracting deviations from the set process in correlation with the setting parameters.

Mold-Integrated Assistance System for Process Control in Injection Molding

Based on algorithms from machine learning, the project partners Schneider Form GmbH and the University of Schmalkalden, Germany, are developing a “mold-integrated assistance system for production control in the injection molding of highly complex and challenging part specifications,” abbreviated to Wasabi [3]. The digital assistant conducts an indirect permanent quality control during a production cycle, taking into account the mold breathing that occurs in every injection molding process.

The output of the system is intended to ensure an understandably prepared assessment of the current process cycle, with which even inexperienced personnel can assess the process stability and part quality. The system shortens the start-up procedure for re-setting up molds, ensures permanent monitoring in the cycle, registers unnecessary mechanical stresses and support the setter and QM employee. According to the project partners, knowledge about the process should stay permanently where it is required, namely on the mold.

For development of the system, a car bumper was chosen as research object because of its complex and challenging part specifications. To determine the measurement data, a total of 26 sensors (cavity pressure, melt front, mold temperature, displacement measurement and mold breathing) were distributed through the two mold halves (Fig.  2). Over several series of tests, the database for the design of experiments (DoE) was created in order to determine the relevant influencing parameters for the quality of the target criteria. Local deformations of the mold could be demonstrated, which have a negative effect on the part quality (flash) and the mold lifetime. For the linear relationships between parameters and quality criteria, as well as interactions between the parameters, feature combinations for a targeted approach to machine learning were worked out with the aid of specially modified programs. A suitable machine learning method is support vector regression (SVR) from the family of Support Vector Machines.

Injection-Compression Molding in Utmost Perfection

The injection-compression process itself is not a world innovation. In combination with smart applications, such as backlit panels for automotive sports seats it is at least a challenge. The lighting technology specialist Lumitec, together with Arburg, has optimized the injection-compression molding of electroluminescent films. This multilayer film less than 1 mm thick is characterized in that it emits light when an electrical field is applied. Between two electrodes, there is the so-called dielectric; one electrode usually consists of a light-permeable plastic film printed with indium-tin oxide structures and the other reflects the light [4]. They are installed in the backrests of the seats for example as identification carriers and “welcome indicator” with colored backlighting as soon as the vehicles are opened (Fig. 3).

In the process, the film is thermally preformed in the mold, so that the end forming is only achieved with the injection-compression process. Injection-compression is a low-pressure process in which the holding pressure phase is replaced by the compression process, so that, for example, inserts such as films or decorative layers are preserved.

Assistance Systems of the  Machine Manufacturer

The large injection-molding machine manufacturers, with products such as iQ weight control (Engel), aXw Control PressurePilot (Arburg), APC plus (KraussMaffei) or HiQ Flow (Wittmann Battenfeld), now offer adaptive process controllers in order to counter process fluctuations in a targeted way. Here, the setpoint profiles are adjusted during the injection phase (and partially during the holding pressure phase) so as to achieve a constant viscosity of the melt within the machine. The basis for this is formed, for example, by the control of injection work, holding pressure profile or dynamic adjustment of the changeover point from the injection to holding pressure phase.

The HiQ Flow assistance system from Wittmann-Battenfeld, for example, performs monitoring, documentation and control of viscosity deviations during the injection and holding pressure process in order to obtain a uniformly high part quality independently of the material viscosity [5]. Viscosity changes detected during the injection phase are actively corrected in the same shot (Fig. 4), in that the integral of the injection pressure, the cylinder surface area and the position of the injection piston is determined. Based on a reference shot, the changeover point and holding pressure level are determined in dependence on the injection work of the current shot.

Some of these functions are not new in principle, but were already registered for a patent in the 1980s [6]. The implementation alone took some years. In view of the growing processing of bioplastics and recycled materials, which is inevitably associated with relatively large process fluctuations, the principle of adaptive process control is certainly a step in the right direction. For the sake of completeness, it is also worth mentioning here that, for the melt, there is also a “life after the machine,” namely in the hot runner and in the cavities. To what extent these purely machine-based solutions are delimited for example in multi-cavity and family molds remains to be seen.

However, assistance systems are not only limited to adaptive process control; their application spectrum is continually being extended with many areas – process optimization, production, predictive maintenance and service, to name but a few. In conversation with Johannes Kilian, Head of the department of process technologies at Engel, is becomes clear where the journey is headed: it is a matter of optimally adjusting the process so as to make as few errors as possible and largely simplify the route there. As an example, he quotes the iQ process observer, which has been in use with selected customers since May 2021. The system, which is not a process controller, checks, based on statistical indicators and other stochastic methods, where the process is heading and calculates proposals for changes. The system, which is also planned as a web application, should also make the process more transparent, and thereby simplify the application as much as possible.

The Machine Knows the Part – Machine-Integrated Simulation

The Engel approach to using simulation data tends in the same direction. Sim link is an intelligent interface to Autodesk Moldflow, which transforms the dataset from the injection molding simulation and checks its accuracy. In principle, this product is regarded as an 80 % solution, and thus as a support for the user. Finally, the customer must optimize his process, which then should be kept constant with intelligent assistance systems such as iQ weight control. In general, Johannes Kilian confirms that the iQ products at Engel have grown rapidly and were not developed as an end in themselves but also have to pay off economically.

At Arburg, too, the link between simulation and machine control is already reality, with the machine manufacturer here working with the software supplier Simcon. In an interview, Eberhard Duffner (Arburg) and Paul F. Filz (Simcon) have explained the concept [7], which is to be realized in two stages. In the first step, a filling assistant is implemented from the simulation, which visualizes the filling process in 3D (Fig. 5). Here, too, the aim is make the work easier for the setter so that he no longer has to interpret complex diagrams, such as the screw motion or the pressure profile over time.

In a second step, it is a matter of eliminating quality problems and illustrating process fluctuations in an easily understandable presentation. The limits for this approach currently lie both in the application and at the material side. Molds with a lot of cavities and high hot-runner volumes are currently excluded because of the compressibility and the fact that the hot runner has a control-life of its own, which cannot be considered at all in the simulation.

The term “digitalization” is used in a very generalized way where data of any kind have to be communicated. For some SMEs, this already begins with the use of project management tools, such as Microsoft Teams. For other companies, the term is a synonym for interfaces and protocols of measurement data and other digital information, while premium class users understand it to mean completely networked MES systems for production planning, and the like (Fig. 6).

Digitalization solutions are for the large part already available at all stages – either machine-integrated or from external suppliers, as shown by the product and trade names Arburg host computer system ALS, KraussMaffei Plastics 4.0, Engel inject 4.0, Wittmann 4.0, Sumitomo (SHI) Demag myConnect and KePlast EasyNet (an extract from the Keba Smart Factory portfolio; Fig. 7). They form the basis for future developments, for example for increasing production efficiency or simplifying the process and making it more transparent.

To remain competitive in the long term, Vorwerk, together with the Institute of Product Engineering (IPE) of the University of Duisburg-Essen, Germany, decided to examine the added value of 100 %-inline quality-related data recording, as well as direct prediction of part quality based on the process data [8]. With a filter cover for a vacuum cleaner (Fig. 8), the complete forming of the sealing lip of TPE and the correct, surrounding position of the TPE contour were examined in more detail. To record the variation of the width dimension, a camera system with black-white sensor and a resolution of 21 megapixels was used, with which the parts are scanned immediately after removal.

The molding dimensions were first defined, then automatically recorded and provided with a time stamp. For this reason, the times of the injection-molding machine and camera system must be synchronized via a time server of the company network. In addition to optical inline quality-related recording, it was investigated whether the quality characteristics considered can also be indirectly predicted, with modeling playing a key role. Seven state-of-the-art learning processes (including neural networks, support vector methods, Gaussian process regression) are trained in parallel and compete against one another, so that in the end only the model with the best validation data is used for the prediction (Fig. 8).

Here, too, this is a very interesting approach, but, as so often, has to struggle for universal application. For example, it must be considered that the shrinkage of the parts is not yet complete at the point of recording with the camera system. Vorwerk also points out that a prediction is only possible if a high standard of the quality data used in the learning phase can be presupposed.

A good example from the field of digital transformation is a new product marking system from matriq for injection molded, blow molded and thermoformed plastic articles (Fig. 9). Herein, the individual products are individually provided with an inseparable product marking by “branding” each part manufactured with a unique code. Each code is cyclically generated each time, so that the parts themselves are clearly traceable. In contrast to downstream systems, such as laser, printing or bonded marks, this is performed directly during manufacture of the parts. The benefit of a complex and expensive network solution is thereby significantly increased.

Sustainability is the great theme of our age and will probably also determine the coming trade shows. It is not yet decided where the focuses will lie. Certainly, recycling will play a major role, as KraussMaffei has already enriched the topic of the circular economy with an example of upcycling. Here, injection-molded buckets are externally shredded and fed back into the material loop as regrind.

With the aid of a twin-screw extruder, the secondary raw material is turned into a new upcycled pellet stock with the addition of a pigment and 20 % talc. From this “postindustrial material,” the covering of an A-pillar with textile surface – a high-tech part from the automotive industry – is ultimately manufactured by injection molding (Fig. 10). KraussMaffei sees itself as the only manufacturer on the market offering the turnkey systems necessary for this cycle from a single supplier, and thereby as a solution supplier for the circular economy [10].

If you consider the last K show in Düsseldorf, Germany, there are two themes that stick in your mind: digitalization with Industry 4.0 and the circular economy. While the first hype was at its peak, the second was just at the beginning of an incredible development. The aids to digitalization in the form of hardware and software platforms, interfaces and ancillaries are now extremely widely and universally present. The homework has been done, but often, unfortunately, not standardized and rarely compatible. Now comes the more interesting and considerably more innovative part in terms of simplification and process automation. This requires ideas, algorithms as well as a portion of artificial intelligence. The field of process control will separate the wheat from the chaff. As regards sustainability, on the other hand, the zenith has by no means been reached. We can wait eagerly to see how the industry gets to grips technically and commercially with the political requirements of a green deal.

1 Lenz, M.; Hohmann, K.: Automotive Display: A Matter of Form. Kunststoffe international 110 (2020) 3, pp. 20–23

2 Kastner, C.; Kienzl, W.; Kobler, E.; Steinbichler, G.: A Special Process that Is Becoming a Sustainable Normal Case. Kunststoffe international 111 (2021) 2, pp. 34–37

3 Werner, M.; Seul, T.; Wenzel, A.; Greifzu, N.; Lehr, M.: Scharfe Prozessdigitalisierung. Kunststoffe 111 (2021) 4, pp. 36–40

4 Müller, R.-U.: A Luminous Greeting. Kunststoffe international 111 (2021) 2, pp. 26–27

5 Pearson, B.; Pazour, P.: No More Weight Problems. Kunststoffe international 110 (2020) 7, pp. 25–27

6 Lampl, A., Patentschrift AT 381 670, Verfahren zur Kontrolle des Formfüllvorganges einer Kunststoff-Spritzgiesseinrichtung, 1986

7 Doriat, C.: “You Can See What Is Happening in the Mold” – Interview with Eberhard Duffner and Paul E. Filz. Kunststoffe international 109 (2020) 6, pp. 21–24

8 Schulze Struchtrup, A.; Mahl, A.; Kvaktun, D.; Thalemann, M.; Schiffers, R.: Inline Quality Monitoring and Data-Based Quality Prediction. Kunststoffe interntional 110 (2020) 6, pp. 17–20

9 Mitzler, J.; Pöpel, C.-P.; Kruppa, S:: Today Packaging, Tomorrow Raw Material. Kunststoffe international 109 (2019) 8, pp. 97–100

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

Fig. 1. The geometry of the specially developed PFS plasticizing screw (physical foaming screw) improves the homogeneity of the gas-containing melt

Fig. 2. Wasabi system concept: 16 sensors are installed on the moving mold half, and ten on the fixed side

Source: Schneider Form; graphic © Hanser

Fig. 3. The panels are installed in automotive sports seats and light up as a welcome

Fig. 4. The HiQ Flow assistance system corrects viscosity deviations during the injection and holding pressure phases in the same shot

Source: Wittmann Battenfeld; graphic © Hanser

Fig. 5. The “aXw Control FillAssist“ shows the operator what is currently taking place in the mold

Fig. 6. The ALS host computer system ensures end-to-end IT networking

Fig. 7. KePlast EasyNet MES is a user-friendly program for the inexpensive networking and monitoring of injection-molding machines, which is ideal for centralized data acquisition and backup on stationary and mobile devices. The new production management feature allows deep vertical integration of production orders from the ERP system directly to the machine operator – these orders are dispatched to the HMI in real time and all collected data are returned again to the production status

Fig. 8. Concept for modeling for quality prediction. The studies for introducing Industry 4.0 measures centered around complete molding of the vacuum-cleaner cover and the correct, surrounding position of the TPE contour

Photo: © Vorwerk; graphic: source IPE, © Hanser

Fig. 9. The new product marking system Dynamic Mold generates a cyclical code for clear traceability of the plastic parts

Fig. 10. A-pillars from buckets: KraussMaffei shows a closed material and manufacturing loop from extrusion and injection molding technology in combination with digital solutions

Name - Hauptartikel

Dipl.-Ing. (FH) Christopherus Bader was CEO of Priamus System Technologies AG, Schaffhausen, Switzerland, until 2015, and until 2021 managing director of the Priamus System Technologies, branch of Barnes Group Suisse Industries LLC at the same site. He currently holds a consulting position in the injection molding industry.

Spritzgießen

Kunststoffverarbeitung: Verfahren

Schaumspritzgießen

Künstliche Intelligenz für die Qualitätssicherung

Industrie 4.0

Industrie 4.0 für die Qualitätssicherung

Steuern, Regeln

Mehrkomponenten-Spritzgießen

Folientechnik (IMD, IML, FIM, u.a.)

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Spritzgießwerkzeuge

Kunststoffverarbeitung: Maschinen und Komponenten

Werkzeuge für die Kunststoffverarbeitung

Biokunststoffe

Kunststoff Werkstoffe

Spritzgieß-Sonderverfahren

Nachhaltigkeit

Umweltmanagement

Spritzgießsimulation

Simulation

Schnecken und Plastifiziersysteme

Spritzgießmaschinen

Industrie 4.0 für die Kunststoffverarbeitung

Machine Learning / Künstliche Intelligenz für die spanende Fertigung

Industrie 4.0 für die spanende Fertigung

Kunststoff-Recycling

Kunststoff-Aufbereitung

Lasermarkieren

Oberflächentechnik

Laserbearbeitungen

Inline- / Online-Messsysteme

Qualitätssicherung

Qualitätssicherung Kunststoff

Kreislaufwirtschaft

Between New Material Mix and  Energy Efficiency

Impressions of the Current Status of Pipe and Profile Extrusion

Kunststoffe international asked manufacturers in the field of pipe and profile extrusion what developments are influencing their product portfolios – and what trends are determining their future. Due to the many different types of application – ranging from microcatheter tubes to gas pipes – these companies are faced with very different challenges. Even so, they have much in common where extrusion, the use of recyclates, or digitization  are involved.

Kunststoffe international asked manufacturers in the field of pipe and profile extrusion what developments are influencing their product portfolios – and what trends are determining their future. Due to the many different types of application – ranging from microcatheter tubes to gas pipes – these companies are faced with very different challenges. Even so, they have much in common where extrusion, the use of recyclates, or digitization are involved.

Rarely has planning or prognosis been as difficult as in the last two years. In the meantime, many machine manufacturers in the plastics industry are smiling again over well filled order books. Based on interviews with manufacturers, Kunststoffe international presents their impressions of the mood vis-à-vis the status quo in the field of pipe and profile extrusion.

The manufacturers are in a consistently positive mood. Following the challenges presented by last year’s pandemic, many have been reporting very positive developments in incoming orders in the previous year. “The increase in orders is largely due to growing demand for compounding extruders in the fields of food and medicinal packaging, emphasizes Clemente Bausano, Vice President of Bausano & Figli.

Mood and Economic Situation: Consistently Positive

Christoph Scabell, Managing Director at Extrudex Kunststoffmaschinen describes the situation thus: “In the wake of a very difficult two-year period, postponed investments are being caught up with. We expect a very satisfying annual statement for 2021 with further recovery in 2022.”

Dr. Friedrich Kastner, CEO and Managing Partner at Collin Lab & Pilot Solutions recently made this statement: “The year 2020 was challenging. Of course, we reckoned with setbacks that in fact took place. However, we used free capacities to proceed with our program of improvements and development even more intensively and continued to realize the resulting new opportunities in the very important medicinal/pharmaceutical area.” Collin also reckons with a positive annual financial statement for 2021.

What Trends Are Influencing Technology and Product Portfolios?

In recent years, various tendencies have shown up in product portfolios or in developments in system technology that differ from one application and/or segment to another. Clemente Bausano: “The developments in recent years have mainly affected applications of plastic pipe. From water and gas distribution networks to rainwater drainage and the transport of various fluids all the way to energy supply systems and sprinkler systems, worldwide demand has grown exponentially and will continue to strengthen. For this reason, Bausano has completely revamped its product portfolio for the extrusion of PVC, PP, and PE pipes in order to keep up with increasing demands from manufacturers for melt homogeneity, process flexibility, maximized throughput, and reduced energy consumption. After all, demand is growing for profiles made from materials that can be manufactured from recovered polymers and up to 80 % natural fibers: products that have proven to be better than wood in terms of reliability, performance, and production costs.”

KraussMaffei also offers a wide range of products in the field of pipe extrusion. Among other items they include systems for drinking and heating water, or gas pipes. Coextruded pipe can be produced from various combinations of materials in as many as seven layers. Some examples are PVC foam core pipes, PU foamed pipes, or a material mix of PP-R, glass fibers, adhesion promoters, and an EVOH oxygen barrier. “The classic product program for building construction is stable and has been expanded to include multilayer technologies. We are pleased that we will be able to introduce fair visitors personally to these multilayer technologies in particular at the Fakuma,” says Dr. Volker Nilles, Executive Vice President New Machines at KraussMaffei.

ETA Kunststofftechnologie is active in the field of (co)extrusion dies and manufactures mainly spiral distributor dies for the production of round products such as pipes, hoses, hollow body blow molded products, or blown films. With these dies, products can be manufactured with low single-layer thickness and tight wall thickness tolerances by mono and coextrusion in up to nine layers. The sizes of them range from dies for medicinal technology in weights ranging from a few kilos up to large pipe or hose heads weighing up to several tons. In the area of automation and digitization, ETA has developed the electromagnetic centering of extrusion dies in recent years. “This enables extrusion dies to be “set at the push of a button” in such a way that products can be extruded with uniform wall thickness. Defined setpoints are entered on a touch panel. We are planning to couple this system to existing wall thickness measurement systems with feedback and optimization of the real measured values next year,” explains Dr. Patrick Weiss, Managing Director of Development and Design at ETA. The thermal separation of individual plastics layers in coextrusion dies represents a further development. With it, high-quality coextruded products consisting of different plastics can be manufactured despite considerable differences in the melting temperatures. It will enable the manufacture of new types of functionalized composite products.

Extrudex’s product portfolio includes systems for media-carrying lines in the fields of medicine, vehicles, sanitary pipes, and lines for cable sheathing, as well as for the production of microfilaments. The manufacturer sees a trend toward energy optimized extruders and systems. For this area, the company has developed their patented Helibar line of single-screw extruders, touting its energy efficiency as a unique selling point. The Helibar principle is suitable for many different types of applications such as blow molding and films, as well as for processing PE, PC, PP, PMMA, PET and many other thermoplastics. With Helibar, a special application was developed to produce 3D filaments from PC in which up to four monofilaments can be produced simultaneously on one system. With only minimal retooling, the system can alternate between water and air cooling and thus be used for a wide range of materials.

Collin supplies systems for manufacturing pipes and hoses. They range from microcatheter tube with less than 0.5 mm overall diameter – even by multilayer coextrusion – to multilayer pipe systems in diameter up to approx. 60 mm. Their own modular die concept permits a number of materials combinations or even from one to several strips in various layers. Collin sees a strong demand for high-speed lines for various markets. Medicinal applications and 3D printing are pushing demand; the material mix is becoming more and more varied and presents new challenges. In the Collin Medical Line of products – these include hoses and strand systems – the requirements for precision are ever stiffer. That means ever tighter tolerances together with increased throughput. Among pharmaceutical strand systems the number of layers is increasing, all of which are laden with several different active ingredients. Here, too: more throughput and tighter tolerances.

Volker Nilles brings the role played by recyclates at KraussMaffei down to the point: “The recycling issue is playing an increasing role, of course. In the field of pipes and profiles, many solutions have been in place for years. KraussMaffei provides solutions for the production of multilayer pipes with recycled layers. Of course, where composite pipes are involved, recyclability is difficult to impossible – that has to be taken into consideration.”

“The use of recycled material is playing a main role in our sector,” says Clemente Bausano. “For instance, the recycling of post-industrial PVC residues by granulation offers a double benefit: environmental protection, since energy consumption by the production of the equivalent amount of new PVC is reduced, as is the emission of hot-house gasses from it. Moreover, company costs for the disposal of PVC wastes are minimized, creating a closed cycle that turns the administrative effort into an advantage. A closed cycle represents a real alternative, especially in times like this that are characterized by difficulties in the disposal of new raw materials. One of the greatest challenges in PVC recycling, however, is the transformation of regenerated materials into a high-quality product. To this end, machine manufacturers will be concentrating increasingly on researching and developing high-performance systems that can process such wastes.”

At ETA, as well, the recyclate issue is gaining in importance: “Among our customers, we have been observing the development toward a constantly increasing use of recyclates for a long time. The homogeneity of recyclate melts has a high priority here. To achieve it, ETA manufactures special mixing screws as well as plasticizing units,” says Patrick Weiss. At Collin, too, more and more recyclates are being used, whereby the processibility of shredded material is a major issue.

… Prof. Daniel Schwendemann, since 2010 Head of the Department of Materials Development, Compounding, and Extrusion at the Institute of Materials Engineering and Plastics Processing (IWK) at the Ostschweizer Fachhochschule (OST) in Rapperswil-Jona, Switzerland.

Many manufacturers see a trend toward multilayer composite products. Doesn’t that stand in the way of the greater goal of recyclability?

The path will be narrow between maximally feasible technology, on the one hand, and recyclability on the other. The decision to use a multilayer composite design or a monomaterial construction has to be made specifically for each component. My personal opinion is that the use of multilayer composites is justified by the properties gained. In the packaging field, however, the trend will be toward monopackaging. Pipes are very durable products whose service life is longer than 20 years in many infrastructure areas. Ultimately, the question will be to what extent are the polymers damaged, and whether materials recycling is still possible.

What trends do you see in the field of pipe and profile extrusion?

As is the case for injection molding, extrusion will be increasingly simulated. “Digital twins” will be created to enable faster and better targeted developments. This is failing now for two reasons: the lack of materials data and simulation tools, for example, for cooling, crystallizing, and calibrating extrusion profiles. Aside from that, the digitization of entire processes and the use of new production technologies such as additive manufacturing will find their way.

What role will the energy efficiency of systems play?

Everyone is talking about sustainability, and the CO2 footprint of products is playing an important role. In addition to the energy expense of plastics production, processing is an essential factor. The manufacturers of extrusion lines have already done a lot to optimize their extruders, but peripheral systems and devices have not been sufficiently included in the overall assessment.

Where do the challenges lie? Which “nut still has to be cracked?”

Pipe and profile extrusion is divided up into several different areas, and complete systems are made up of modules from various components. For digitization, there exist no or insufficient exchange protocols. The linkage is thus system specific and not fed with enough data from the periphery. Energy consideration and digitization must join hands here. At the moment, many processers do not know how much energy is being consumed by which parts of the system. In the future, processers will be faced with the challenge of having to supply such data to their customers. Solutions must be provided to do this.

Digitization is playing a main role in all fields. Collin is betting on an SPS platform capable of connecting all different types of bus systems. Components can be connected via ethernet-based field bus systems, such as EtherCAT, ProfiNEt, Ethernet/IP, or classically via CANopen, Profibus, or Modbus. Unless proprietary protocols are used, OPC UA is used as an interface.

Bausano recently introduced its Orquestra software that uses modern 4.0 technologies to control all components of an extrusion line. These include, among other items, intelligent diagnosis and predictive maintenance. The central control system is also suitable for revamping and ensures continuous monitoring of the entire line in real time. Moreover, it enables immediate reporting with intuitive graphs of performance indicators including machine status, waste production, and man hours. The analysis of the raw data collected and made available by Orquestra makes it possible for the end user to independently optimize the entire extrusion process, refine the final product, and avoid damage to the line.

With smartAssist, KraussMaffei allows, at the touch of a button, worldwide service contact via professional and secure audio/video communication, e. g. between technicians at the machine and experts wherever they may be. Virtual texts and symbols can be superimposed on actual objects via augmented reality, increasing the quality and speed, e. g. for troubleshooting.

In the year of pandemic, system monitoring gained ever greater significance. “Remote maintenance has become a must, as all have established during the time of Corona,” emphasizes Volker Nilles. “With its multiple interfaces, KraussMaffei’s C6 control is well equipped for the data world of tomorrow. In addition to proven, conventional paths (USB, PDF Export), various network-based data interfaces (e. g., OPC UA, Euromag 84) are available to access to machine and operational data. Internal and external data recorders support the analysis and optimization of processes. The availability of remote diagnosis via internet and secure access to machine operation through contactless identification by RFID reader round off our digital portfolio.”

At Bausano, as well, remote maintenance is meanwhile standard: “Thanks to Orquestra software, we can remotely access operational machine data if our customer has granted us permission to transfer data to the cloud and report possible anomalies in advance,” says the company chief. “This simplifies the remote assistance performed via our Acty augmented reality app, which happens to be an interactive app. Our technicians have the option to make contact through 3D glasses in order to provide customers with qualified assistance and undertake remote start-up of the complex system.

At Collin, the option used most last year was remote machine observation. With it, their own Scada system can control machines remotely. Via remote access, the system can be monitored in home office. In addition to remote maintenance, the user has the opportunity to monitor production or laboratory procedures in home office.

What issues will be important for the field of pipe and profile extrusion in the future? Volker Nilles of KraussMaffei sums them up: “Energy savings, materials savings, digitization and recyclability”.

ETA is focusing on coextrusion and throughput maximization: “In pipe extrusion, besides ever higher system speeds, we are mainly observing further developments with new coextruded composite products to fulfill all sorts of requirements with a functionalization of single or multiple layers. In addition, a rising level of automation will become more and more important for extrusion processes in order to produce as efficiently as possible and prevent quality variations,” Patrick Weiss reports. In addition to introducing their product for electromechanical centering for extrusion dies and the further development of technology for thermal separation of individual plastics layers in coextrusion dies, ETA is working at the moment on the configuration of new melt distributor concepts to obtain additional process and production technical advantages.

“Environmental sustainability and recycling are the two most important topics that will influence the future of pipe and profile extrusion. We at Bausano are of the opinion that our current understanding of the production and consumption of plastics has to undergo a paradigmatic shift, so that the entire life cycle is truly sustainable and repeatable over the course of time. The real challenge consists in developing technologies that improve the environmental footprint of materials such as PVC in order to accelerate the transition to a circular economy and contribute to mitigating the climate change,“ according to Clement Bausano.

Christoph Scabell of Extrudex thinks that energy savings, good service lives, and low maintenance requirements together with high production quality will be decisive in the future. He spots a trend toward turnkey systems and away from individual components. Innovations at Extrudex include variable die heads with exchangeable sheets for various pipe superstructures, as well as energy optimized extruders with special insulating heat bands. Since the pandemic the company is also feeling increased use of the remote maintenance modules offered for several years.

Collin sees the future challenges mainly in high speed and smaller space requirements. Beyond that, the company perceives increased demand in the area of 3D printing. “A nut that still has to be cracked is the automated start-up,” Kastner adds.

To summarize the opinions of the manufacturers we interviewed, a difficult task is growing for the developers of extrusion systems. On one hand is the call for maximizing throughput and multi-material composites. On the other, energy and materials savings, as well as recyclability are being demanded. Kunststoffe international will continue to serve you with reports of the latest developments.

Dr. Patrick Weiss, Managing Director of Development and Design at ETA: “We are observing constant further developments in coextruded composite products with the functionalization of single or multiple layers.“

KraussMaffei supplies systems for up to 7-laser pipes; here we see a modular designed multilayer pipe head

Prof. Daniel Schwendemann: “The energy of the entire system can be optimized only with the aid of digitization.“

Clemente Bausano, Vice President of Bausano & Figli: “Environmental sustainability and recycling will be the two most important issues influencing pipe and profile extrusion in the future. Production hast to undergo a paradigm shift.“

Dr. Friedrich Kastner, CEO and Managing Partner at Collin Lab & Pilot Solutions: “We are seeing stronger demand for high-speed lines and 3D printing. A nut that still has to be cracked is the automated start-up.“

Dr. Volker Nilles, Executive Vice President for New Machines at KraussMaffei: “We are also offering solutions for multilayer pipes with recyclate layers. However, we must keep in mind that composite pipes are difficult to impossible to recycle.”

In Collin’s pharmaceutical strand systems the number of layers is increasing, all of which are laden with several different active ingredients. The challenges: more throughput and tight tolerances

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This article was written with the assistance of Prof. Daniel Schwendemann, since 2010 Head of the Department of Materials Development, Compounding, and Extrusion at the Institute of Materials Engineering and Plastics Processing (IWK) at the Ostschweizer Fachhochschule (OST) in Rapperswil-Jona, Switzerland.