Roadmap to the Plastics Industry for 110 Years

When something unprecedented happens, our perspective almost automatically widens. In this time of pandemic, “the biggest challenge since the second world war” has become a common yardstick. But, celebrating its 110th anniversary this year, the German Kunststoffe goes back much further than this.

In this edition, we will briefly be remembering the historic dimension of the industry as a whole. At the last K show, we were at last able to bolster the memory of Dr. Richard Escales, founder of our journal, by presenting the award bearing his name.

However, the 110th anniversary is also a welcome opportunity to cast an appreciative glance at his eldest son, whose efforts (with brief interruptions) have covered over half of the present lifespan of the current Kunststoffe journal. Erich, born in 1907, played a supporting role at first, when his father fell ill in 1923, and died a year later. After studying chemistry, he officially took on the position of editor in 1933. Following difficult years, Dr. Erich Escales was able to continue the Kunststoffe tradition again after the Second World War until his death in 1979, offering researchers a platform for publishing their practical findings, as well as helping the plastics processor to “impart optimum properties to his products.”

But apart from this brief recourse to history, this edition is looking to the future. For example, in the round-table discussion about the industry’s current predicament, and ways out of the twofold crisis (p. 10). Since, even in difficult economic times, it is still the aim of Kunststoffe and the English-language edition, Kunststoffe international, to give you a roadmap for plotting a course in which plastics can fulfill their destination as “irreplaceable materials for everyday articles,” as Erich Escales noted in July 1946 in his lead article on the journal’s relaunch in Carl Hanser Verlag.

Editorial Klotz

Klotz, Karlhorst, Dr.

Central Hub for Digitization  in Plastics Processing

The Plastics Innovation Center 4.0 Is under Construction at the Campus Melaten in Aachen, Germany

Because it has not yet been possible to exploit the full potential of digitization in plastics processing, the Institute for Plastics Processing at RWTH Aachen University is building a new application-oriented research infrastructure along the lines of a Smart Factory. Kunststoffe is accompanying the building of the Plastics Innovation Center 4.0 with a series of publications. Part 1 describes the concept and the initial demands on the physical infrastructure.

Digitization is now making inroads into industrial production worldwide in all sectors. Despite the many opportunities promised by the implementation of innovative Industry 4.0 technologies, the benefits for the plastics industry characterized by SMEs have been minimal. Recognizing the potential of Industry 4.0 and actually implementing it in a company will often require extensive investment as well as a relationship of trust and confidence in a system partner who is familiar with the production operation and able to extend it with useful system modules.

When implemented in industrial production, insular solutions frequently fall short due to a lack of scalability or user proximity. For this reason, holistic approaches are needed. Buzzwords such as Smart Factory, Smart Manufacturing or Smart Production are therefore increasingly becoming the subject of research projects. Whereas the number of publications in the Google Scholar search engine for these terms shows that research in the field of Smart Factory is generally developing into a focus topic, a clear reference to plastics is almost completely lacking (Fig. 1).

Holistic Approach of Consistent Digitization in the PIC 4.0

With its Plastics Innovation Center 4.0 (PIC 4.0), the Institute for Plastics Processing (IKV) at RWTH Aachen University aims to enable research in the field of digitized plastics processing by adopting a holistic approach. For this, existing research projects focused on digitization will be seamlessly integrated into the new research infrastructure, and new projects will be initiated in three topic areas:

<ul><li>Digital Engineering,</li><li>Value Chain, and</li><li>Global Connectivity.</li></ul>

In Digital Engineering, during the physical construction phase, it is a question of combining methods of part and process development with the real processes in the PIC 4.0 technology center. For this purpose, continuous simulation chains and virtual process models are needed that enable a transfer of simulation models between conventional systems of component and process design without any loss of information and in an easy-to-use procedure. In addition to this, a routine is being developed to autonomously compare the predicted part quality with the attained part quality, and thus draw conclusions about the simulation quality.

To be able to compare the simulation results with the subsequently documented component and process quality, it is important to link the processing processes closely with each other in the PIC 4.0 technology center. A heterogeneous machinery equipment, on the other hand, frequently makes it difficult to transfer the developed solutions into industrial practice. In addition to complex interactions along the value chain – from preparation of the material through the processing process right the way through to quality assurance – an analysis of the age and functional scope of heterogeneous machines in the Complex Value Chain is of particular interest. It involves not only matters of digital retrofitting but also of data collection/processing and the meaningful utilization of these data.

Finally, focusing on consistent data collection and the information infrastructure needed for this is performed in the area of Global Connectivity. This involves above all collecting the available data in a uniform manner, and specifically analyzing this data for the data-driven optimization of the processes and systems in which it was collected. For companies in plastics processing, the possibility should also be created to analyze not only their own processes but also to make their production data available without risk to an independent research partner to find out what benefits can be generated from this.

In addition to the three described topic areas, work will also be carried out on digital teaching and learning possibilities both in the skilled crafts and in university teaching in order to qualify the experts of tomorrow in matters of digitization.

The Physical Infrastructure  of the PIC 4.0

The gross total surface area of the infrastructure under construction is more than 4200 m² and includes, in addition to the nearly 1000 m² technology center, a workshop with an area of around 570 m² for maintenance and service and for building testing molds (Fig. 2). Mold-making is thus integrated directly into the information/value chain to achieve cross-domain collaboration without information loss.

In the technology center itself, space will be allocated to various testbeds, for example, “complex value chain”, “heterogeneous machinery equipment”, and “material processing”. Here, it is important at the planning and building phase to provide the necessary data connection, taking account of the expected network traffic and the bandwidth potentially needed in future applications – in addition to the usual infrastructure such as power lines, water pipelines and compressed air.

Apart from that, provision will initially be made for traditional Ethernet connections, although the basis will also be laid for future integration and testing of 5G technologies. The adaptability of the Smart Factory which needs to be ensured for this will be required for the later, long-term research work, because test rigs and production cells must, depending on the focus of analysis, be set up and combined for the complex cross-process interactions.

Communication not only between Machines  and Equipment

All learning and working activities will be located in the building complex. The planned “open space offices” will not only enable communication between machines and equipment to be at the focus of the PIC 4.0, but will also facilitate open and flexible cooperation between scientific staff and students. Ideally, this exchange will create innovative research approaches.

To be able to carry out demanding tasks in digital engineering and in the data analysis of comprehensive real datasets from the ongoing processes, high-performance servers will be installed. The PIC 4.0 will thus offer, for all matters of digitized plastics processing, a contact point for partners from science and industry.

Fig. 2. Planned room allocation on the ground floor of the PIC 4.0

Visionary overall picture of the expanded IKV in future, supplemented by the Plastics Innovation Center 4.0

Fig. 1. Number of publications in the Google Scholar search engine (as at 2020–03–31) on various buzzwords, listed by year

Name - Hauptartikel

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

Pascal Bibow, M.Sc. RWTH, has been working since September 2016 on smart 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).

In the following article, the authors report on examples of real applications of digitization. The article will probably appear in Edition 9/2020.

The concept of the PIC 4.0 expressly pursues the aim of data-networking various production technologies along a complex value-added chain, and of optimizing them under application conditions. The focus here is above all on the necessary information architecture and technology transfer to industrial practice.

<a href="http://www.ikv-aachen.de/forschung/efre-pic-40/">www.ikv-aachen.de/forschung/efre-pic-40/</a>

Smart Factory

Energieeffizienz

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Kunststoffverarbeitung: Maschinen und Komponenten

Industrie 4.0 für die Kunststoffverarbeitung

Industrie 4.0

Current Challenges and Options for Action in the Plastics Industry

For almost two decades, an expert committee, meeting once a year, has supported Kunststoffe magazine in determining the state of play in the plastics industry and identifying current technical developments. This time, the traditional spring meeting gave it an opportunity to debate the consequences of the Corona virus.

There were a lot of things different at this 18th session of the Kunststoffe editorial advisory board. It is not only that Dr. Rüdiger Baunemann, who had supported us for a decade as advisor, was not able to take part any more (see Box p.12), but also that, in this time of Corona, the meeting had to be held by video conferencing for the first time (Title figure).

Kunststoffe: First the crisis in the automotive industry and the worsening image of plastics, now the Corona crisis as well. How is the plastics industry faring?

Michael Weigelt (TecPart): Suppliers to the automotive industry are in a very dire position, not least because automotive manufacturers have closed down their production without warning, and so far have not given any precise information about how things will continue. As a result, many processors no longer knew how they were supposed to plan and manufacture. The suppliers currently face huge difficulties in adapting their material planning to actual customer demand and their own manufacturing. It still remains unresolved whether the material supply will remain secure, or a situation like that ten years ago will arise, when the polyamide plants and crackers were shut down.

Dr. Guiscard Glück (BASF): The Lehmann crisis, which led to the collapse of entire supply chains, taught many companies a lesson. Suppliers who at that time couldn’t supply their customers when the conveyor belts started up again are now taking great care to be well prepared for any event. However, this sensitivity stands and falls with the extent of the crisis. If it lasts for several months, it could lead to the failure of particular stages in the supply chains and to domino effects, and ultimately to a scenario that we can hardly imagine at present.

Will the supply chains now become more regional as a reaction to global problems?

Dr. Glück: The supply chains were also in a critical state after Fukushima, and companies tried to develop alternatives. However, these considerations were pretty quickly dropped, since companies are always looking for the optimized process chain. Globalization has contributed so much to optimization that I would be very cautious in predicting whether the current crisis will lead to greater regionalization, since that could mean additional costs. The entire economic system will rather try to find a way back to the optimized globalized mode. There will certainly be attempts at regionalization, but since that comes at a price, I am skeptical whether it will be tenable in the long term.

Just a few minutes before the beginning of the meeting with our publisher advisory committee, on April 21, 2020, the news reached us of the unexpected death of Dr. Rüdiger Baunemann. He was Managing Director of the association of the plastics-producing industry from 2002 and, from 2011, General Director of PlasticsEurope Deutschland, as the association was renamed, and in this capacity, member of our publisher’s advisory committee. He was also a sought-after press spokesperson for the emerging issues of plastic waste and marine littering. He will also be remembered for his commitment to national and international standardization work: he was appointed Chairman of the sponsor group of the DIN standards committee plastics (FNK) in 1997 and, in 2003, Chairman of the FNK; in 2016 he received the DIN Ehrennadel (pin of honor).

After all, the automotive industry was already ailing before Corona, and was then hit again. Are there also winners in the plastics industry, such as the medtech sector?

Dr. Glück: I wouldn’t talk of winners. Even companies that are showing a strong peak in demand now and are expected to provide capacities are experiencing a difficult situation. And it can be expected that sooner or later they will have to deal with reduced demand. That is a very difficult balancing act – such demand peaks are certainly very welcome in the short term, but are difficult to manage and usually not sustainable.

Prof. Dr. Christian Hopmann (IKV): Even in the medical field, though some protective products, for example, are in very great demand, there is suddenly only very low demand for many other products, as the admission rate to hospitals has fallen drastically, since many less urgent operations have been postponed. So we can’t speak of a boom in medical technology in general.

Martin Würtele (KraussMaffei): That is also the feedback we have received from our customers, such as in Switzerland in the area of high-speed injection-molding machines – basic instruments and disposable diagnostic articles, for example, are still selling well, but fewer medical articles are being consumed at present, since fewer people are going to their doctor or into hospital.

Dr. Achim P. Eggert (VDI): Hospital utilization is low throughout Germany, since beds are being reserved for Corona patients, and fewer operations are therefore being performed, so that many medical products are no longer in demand in the usual quantities.

What does the packaging sector look like? Can it profit from the fact that people are more conscious of hygiene, i. e. currently appreciate packaging more and the advantage of disposable products in medical applications is becoming clear?

Dr. Glück: What will be sustainable is the discussion we were having before about the circular economy. Here, we will continue to set standards in recycling and top quality recyclates with chemical recycling. The positive image of plastics in the context of protective clothing will not roll back the discussion about the carbon footprint, but I can imagine the two complementing one another.

Weigelt: Yes, we are now discussing in many areas how we can introduce more recyclates into the supply chain, which criteria could be used to standardize them, etc. The Corona crisis, by dominating the current news, could perhaps help us to continue this work in peace, so that we will be able to present advances when there is an interest in environmental issues again. But those who have argued against plastics in the past – not only NGOs, but also companies offering competing materials, which are under pressure from the success of plastics – will fuel the debate again even after Corona. It is now up to us to show in which direction the next steps must be taken.

Prof. Hopmann: Plastics recycling will remain a burning issue in the coming years. We are aware that, due to the Corona epidemic, plastics are in great demand, because consumers are increasingly welcoming disposable packaging, but I have not noticed from the public media that plastics are therefore presented more advantageously than just a few months ago. The somewhat more positive or less critical publications will very quickly fade away again. We will be left with the discussion about sustainability. Whether, and how, the appraisal will change here is closely linked with the question of whether and how the industry is capable of plausibly offering transparent and independently verifiable solutions. The Corona crisis can certainly give us a few months’ breathing space, but no more than that.

Weigelt: But what does “a few months” mean? Politicians are very cautious in withdrawing the restrictions – the question will be how long we can continue along this road. But as long as this issue is simmering, everyone will enthusiastically buy packaged foods and goods because they want to protect people. It will certainly push back the “withdrawal effect” of avoiding plastics.

Würtele: My hope is that the Corona crisis will make the differentiation more precise, and that plastics in general will not be demonized, but the insight will grow that plastics can be very useful. I already believe that the Corona crisis will contribute to people seeing plastics as valuable materials and a wider popular approval emerging. But that will not spare us the discussion about marine litter – and that is good, since it must remain an issue. The challenge of coming years and decades will thus be to establish these circular streams.

Eggert: The main problem we have with plastics wastes is a logistical one. There is a great need to catch up. In Germany, we have good collection systems in principle, but abroad, no one can trace the paths, and that is something we have to solve together with the politicians.

Weigelt: The crucial thing is how sustainably we dispose of plastics. Our problem is that plastic wastes are lightweight, float and that there are too many obscure issues in disposal. And that is used against us. I support a complete ban on plastics exports with exceptions for companies that dispose of the material in a certified way. However, within Germany, we are very well placed in plastics recycling. Unfortunately a backdoor was opened for waste management with the help of the German Federal Environment Ministry, since plastics wastes are counted as recycled if they are exported for recycling – no matter what actually happens to them. And the fact that most of them disappear in dubious ways in remote countries is less a failing of the plastics industry than, first and foremost, of those who are paid for this, namely the waste management sector. As an industry, we have to curb this and find a solution in our own country for about a million tons per year of often heavily contaminated plastics. We have to work to ensure that energy recycling is also possible even if it is often unjustifiably frowned upon, because in principle the material could be repelletized – even though that makes neither environmental nor economic sense with these waste categories.

To return to the Corona situation – what would you advise as companies?

Dr.-Ing. Erwin Bürkle (ThiM): The situation is very difficult regarding the procedures and financing, but we must make use of the breathing space for new developments, especially as regards digitalization. In recent years, we have strongly advanced productivity, but placed less value on innovation. Because of the growing competition from the USA and Asia, we have to develop products in this country that will still earn us revenue in the future.

Weigelt: To ramp up the economy, we will have more time available than we would like. It’s exacerbated by the fact that it will not be a V-shaped recovery as ten years ago, since not only one branch of industry is affected but the entire economy on a scale that hardly anyone has seen before. Many small companies in the hospitality sector or trade-show services will simply no longer exist anymore. Consequently there will be a shortage of money in the economy and also among consumers, which will mean a huge drop in purchasing power in this year and the next. As for catch-up effects in the field of consumer or investment goods, I don’t see any signs of that yet. Most companies therefore don’t have the money for innovations at present.

Prof. Hopmann: The dilemma is that you either have no time for innovations because business is going so well, or no money because business is not going well. We have to find a way out of this quandary. It goes without saying that the challenges companies face are huge, but nevertheless they not only have to focus on the ramp-up in the coming months but also prepare for the time after that. And I agree completely with Mr. Bürkle – the topic of innovation has fallen by the wayside in the recent, predominantly very very good years. If we lose even more time due to the crisis, there is a very high risk we will fall behind.

Dr. Bürkle: Paving the way for innovation will require a very delicate balancing act. But, here in Europe, we must concentrate on innovations. Since in the long term, that is our chance of survival.

Würtele: However, in some companies it will be increasingly difficult to implement innovations, since companies have to keep hold of their money. That is quite clearly a question of priorities. If we are arguing that innovations are important in the long term, half a year is neither here nor there at the moment.

Weigelt: Where would the fields of innovation lie? The typically German navel-gazing often reaches the conclusion that we are not really very good. At present, for example, we have 4800 effective patents on autonomous driving, 2000 of them, i. e. almost half, come from German companies. It’s undeniable that it would sometimes be desirable to be faster in addressing this or that issue. But here, too, there is global competition, which allows innovative companies to achieve higher margins, though they are permanently on trial, and by far no longer in such a comfortable position as they used to be. The big sellers today are digital products, which our industry doesn’t manufacture.

Prof. Hopmann: Autonomous driving is a good example, since there are many patents about this in Germany, though these are not innovations yet, but inventions at best. Innovation means building them into a business – and often that does not take place in Germany. We have very good ideas and develop them, but are often too slow to realize them on the market. The issue of digitalization illustrates this perfectly. There is a lot that can be digitalized, the potential is there for the asking.

The Kunststoffe advisory committee member Dr. Marco Wacker is responsible for the field of head protection at uvex Arbeitsschutz GmbH, Fürth, Germany, and was not able to take part in the round table discussions. We therefore spoke to him on the phone afterwards.

Kunststoffe: Mr. Wacker, you are going through turbulent times at present. How long has this been the case?

It started in December with the bushfires in Australia, which had impacted the distribution of respirators for firefighting. After that, the crisis started. We had already been aware of it in January as we have our own factory in China for sales of safety products in the Chinese market, and quickly realized what was happening. Demand has now been picking up in Europe, too. Although we predominantly supply industrial customers, we have suddenly experienced a huge demand from the public sector, hospitals and other medical institutions, which we weren’t prepared for.

How do you respond to sudden surges in demand?

We manufacture the goggles here in Fürth, and had to increase the capacity by working overtime, including on Sundays, and even that isn’t enough at the moment. That is to say, we are restructuring the work yet again after a few weeks. Shortly we will have significantly increased our capacity again within about four months. The expansion itself would be OK, but we have to manage it all under difficult circumstances – some employees are working from their home office, and shouldn’t meet in person if possible, etc. It is thus not only a question of expanding capacities, but at the same time protecting against viral infection, and keeping operational.

How quickly can you obtain additional tools or production lines?

In this respect, the automotive crisis is playing into our hands. Tool and plant manufacturers currently have free capacities. Injection-molding machines can be delivered almost immediately. It is more difficult to free up space in our buildings, and to adapt our own infrastructure. We therefore have many external companies on the company grounds. Nevertheless, we have to ensure that the virus is not introduced, since it would be fatal if we had to completely shut down a shift.

At first, we distributed simple injection molding orders to affiliated companies and outsourced orders to our factory in China. But now we also work with 7 x 3 shifts per week in Fürth, so Sundays as well, and that is not possible without temporary staff, and we are also looking for cooperations. Under these stressful circumstances, I’m trying to motivate people by telling them that in other companies, people are worried about their jobs, but despite that, with such a heavy workload, even working on holidays, the employees sooner or later become burnt out.

Indeed, many companies have free capacity, while your company is inundated with demand.

We have to make a distinction. Uvex is mainly known in the sports sector, which has not only suffered from the extremely mild winter, but of course from the faltering demand due to the Corona restrictions. There is short-time working here in the non-operational area and, even in our industrial safety area, demand is much lower, e. g., for protective clothing and shoes, which we supply to the automotive industry – where there is also short-time working. But everything worn on the head – respirators, visors and goggles – as well as disposable suits and disposable gloves – is in huge demand.

Do you see yourselves as winners in the crisis?

I would say it is ambivalent, we will have to see the figures at the end of the business year. If we have a global recession, then, despite appearing positive at first, it will not have turned out to have been a sustainable development. The crisis is threatening, for example, many processors and mold manufacturers, and that would be bad for the entire industry if companies go under. We are left with the challenge of securing the production capacities that are now planned in the medium and long term.

Taking new paths: during the Corona crisis, certain technical obstacles were also overcome by the Kunststoffe publisher advisory committee, who held a round table discussion by video conference for the first time. Present by video link were, among others, (top, from left) Dr. Guiscard Glück, Prof. Christian Hopmann (bottom, from left) Martin Würtele and Dr. Achim Eggert

16:9

Dr.-Ing. Erwin Bürkle, Technology Platform Hybrid Innovative Material Foam Systems ThiM, Berlin, Germany

Dr. Achim P. Eggert, VDI Department of Plastics Technology, Düsseldorf, Germany

Dr. Guiscard Glück, Product Development Performance Materials Europe, BASF SE, Ludwigshafen, Germany

Prof. Dr. Christian Hopmann, Institute of Plastics Processing (IKV) at RWTH Aachen, Germany

Michael Weigelt, General Manager GKV/TecPart Verband Technische Kunststoff-Produkte e. V., Frankfurt/Main, Germany

Martin Würtele, Head of Technology Development, KraussMaffei Technologies GmbH, Munich, Germany.

Wirtschaftspolitik in Deutschland

Verpackungsmaterial

Logistik

Internationale Wirtschaft

Verpackungsanlagen

Coilhandling

Recycling

Umweltmanagement

Kunststoff-Verpackungsmaschine

Sondermaschinen

Kunststoff-Recycling

Kunststoffverarbeitung: Verfahren

Kunststoff-Aufbereitung

Medizintechnik

On the Image of Plastics and their Responsible Use

Polymer materials, including synthetic polymers, have a bad reputation. These image problems do not just arise from the current environmental debate but also have earlier origins. In the past, too, polymer materials were subject to unjustified criticism. This often stemmed from non-scientists and frequently betrayed a lack of scientific knowledge.

Plastics have a massive image problem. They are often seen as a symbol of environmental pollution. In addition, they are still considered by many consumers to be an inferior, cheap material used as a substitute for supposedly higher-quality materials. These currently widespread views are no new phenomenon but have long been associated with these materials and to some extent have historical origins. There are also some difficulties in defining the term plastics. That is why it is better to refer to this material group as “polymer materials” (poms).

Polymer materials is the generic term for:

<ul><li>biogenic polymers (natural polymers) such as cellulose, starch, proteins, natural resins, natural rubber,</li><li>modified biogenic polymers (semi-synthetic plastics, chemically modified natural polymers), for example vulcanized natural rubber, cellulose nitrate, cellulose acetate, casein formaldehyde,</li><li>synthetic polymers (synthetic plastics) such as thermosets, thermoplastics, elastomers, and thermoplastic elastomers (TPE),</li><li>biopolymers such as biotechnological polymers (enzymatically produced or genetically engineered, e. g. polyhydroxybutyrate and proteins similar to spider silk) and bio-based polymers, in which the starting materials or monomers are biogenetically or biotechnically accessed and then synthetically polymerized, such as bio-based polyethylene (PE).</li></ul>

There are some difficulties in defining the term plastics. On the one hand, the term also covers resins (natural and synthetic) and even polymer emulsions and dispersions (International Organization for Standardization ISPO 468/3-Part 3, Terminology of Resins, 1999) [1], on the other, rubbers are not included. The term plastics has acquired a negative connotation in the constant debate about “plastics waste”, the “plastics dilemma”, and the “plastics catastrophe”.

There has often been controversy over plastics in the past – it is nothing new. Topics that have triggered concern include plasticizers, colorants, and other constituents, when toxic. At present, debate centers mainly around the global spread of macro- and microplastics. This has given rise to a massive image problem and hostility to the material, frequently referred to as “plastics bashing”. This is now having an impact on the use of plastics and composite materials indispensable to our lives in the technical, medical, and sports sectors.

However, this image problem can also be traced back in large part to historical origins. Since the first production of semi-synthetic plastics such as cellulose nitrate (Celluloid, John W. Hyatt, 1868/70), they were used, among other purposes, to imitate and substitute for ivory, horn, tortoiseshell, coral, and mother-of-pearl. But, of course, not just for that, since from very early on unique patterns and colors were achieved with Celluloid that had no models in nature. Nevertheless, students of art history are still taught that the early plastics just fulfilled a substitute role and carried the taint of being artificial, inferior, cheap, and mass-produced. In Germany, this image was propagated in particular by members of the Deutscher Werkbund, in English German Association of Craftsmen (artists, designers, architects and industrialist).

One of the protagonists of the Werkbund, the art historian Gustav E. Pazaurek [2], created a “classification system for esthetic aberrations” and fought for the dissemination of good taste in arts and crafts, since imitations were anathema to him. Through this, he had a lasting influence on the attitude of the Werkbund. As far as the new plastics were concerned, the members of the Werkbund neglected to see the new coloration and patterning opportunities they offered, of which there were enough examples. Neither were they able to grasp the potential technical uses of the new materials because of their fixation on art and crafts. They failed to recognize the possibilities of, for example, vulcanized rubber for raincoats (Charles Macintosh), electrical insulation, bicycle or car tires, and as a hard rubber for the electrical industry, telephone receivers, hammers, clarinet mouthpieces, and fountain pens; cellulose nitrate (Celluloid) and cellulose acetate (Cellon) for paints and films; and casein formaldehyde (Galalith) as a low-frequency insulator. The entire subsequent development of the electrical industry was only made possible by phenolic resins (Bakelite), which served as an insulating and construction material.

The actual use of plastics as substitutes during the raw material blockade in The First World War dealt another blow to their image, especially in Germany. Inferior-quality viscose staple fibers were not particularly popular. The first synthetic methyl rubber was laborious to produce, had low productivity, and its soft rubber properties were neither very reproducible nor comparable with those of natural rubber. It only found adequate use as a hard rubber. In this time of emergency, materials such as “artificial fiber” and ”artificial silk” – just like “artificial honey”, “artificial pepper” and “artificial cinnamon” – were branded in the collective memory as cheap surrogates. Outside professional circles, they could never fully shed the image of inferior quality.

Equally influential and detrimental to the image of plastics among art critics and art historians was an essay on “Plastic” by the French philosopher Roland Barthes in 1957 [3]. Among other things, he writes that: “Despite having names of Greek shepherds (polystyrene, phenoplastic, polyvinyl, polyethylene), plastic, the products of which have just been gathered in an exhibition, is in essence the stuff of alchemy. […] So, more than a substance, plastic is the very idea of its infinite transformation. […] whatever its final state [...] the mind does not cease from considering the original matter as an enigma.”

In his words, Barthes clearly shows his ignorance of natural sciences and chemistry. This is betrayed by his “naïve” surprise. He is obviously not aware, either, that his description of the material also applies exactly to the age-old cultural material glass. To this day, Barthes is readily and extensively quoted in liberal arts circles, particularly among art historians.

To these virulent, historical taints that still plague the image of plastics, new ones have also continued to be added more recently. Around 2000, the biologist Eugene Stoermer and the meteorologist and Nobel prizewinner Paul Crutzen proposed that the latest period of the Holocene epoch should be named the Anthropocene, i. e. the Age of Man (Title figure). The basis for this was the geological deposits from the first atomic bomb tests [4 – 6]. Now, the remains of plastics waste are also often regarded as an identifier for the Anthropocene. Microplastics are verifiable globally according to geological standards. However, it appears this is not unspecific plastic waste but, measured by weight, is mostly the remains of packaging (films, bottles and containers).

At the present time, some 370 million t of plastics are produced annually worldwide. The increase is exponential (Fig. 1). Packaging accounts for more than one-third of all plastics production. Of the approximately 8300 million t of plastics produced globally between 1950 and 2015, about 6 % has been recycled, 8 % incinerated, and 55 % sent for waste disposal. Around one-third is still in use. In 2017, some 2 % of the 350 million t or so of plastic produced, i. e. about 7 million t, ended up in the sea.

Approximately 99 % of this waste is initially invisible, since it is degraded by slow weathering and fragmentation processes into plastic particles less than 5 mm in diameter – so-called secondary microplastics. The proportion not absorbed by marine organisms sinks to the bottom of the oceans, is deposited there, becomes embedded in the sediments, and gradually forms a new geological layer, the “plastics horizon”. As previously mentioned, this is seen as a further sign of the Anthropocene.

Of these secondary microplastics, a distinction is made between “primary microplastics” type A and type B. Type A includes deliberately manufactured small plastics particles for specific products such as cosmetics, polymer abrasives, laser sintering powder for 3D printing and semi-finished product powder. Type B microplastics originate through usage or abrasion processes, e. g. abrasion of rubber tires (highest share of 81 %), textile fiber fragments released during laundering of textiles, weathering of colorants and paints and agricultural plastics such as films. Deposition and layering of these microplastics also takes place on land – via global air pollution – in remote regions such as the High Alps, the Tibetan Highlands, and on Greenland ice.

Biogenic polymer materials (poms) such as amber, natural rubber, Asian lacquer, Chinese silk, paper and paper pulp, composite materials such as leather, horn and tortoiseshell, but also gelatine glue, casein- and egg white-treated painting grounds, shellac, linoleum, and the chemically modified biogenic polymer materials have an age-old history. They have all contributed significantly to the cultural development of mankind. Kunststoffe (the Journal for Plastics Technology), the world’s first trade magazine for the plastics industry, also included such polymer materials as part of its field of publication in the first edition of 1911 (Fig. 2).

The countless synthetic plastics show a potential for exploitation of their tailored properties that is far from being exhausted. They and modern biopolymers represent only a small proportion of all polymer materials; they form part of a very long line of polymers that have played an important role in the history of materials, technology and culture in terms of their properties, behavior, processing and use. Polymer materials (poms) are at any one time not just “substitute materials”, “cheap plastics”, “toxic”, and “ocean-polluting” but also a gateway to technical innovations and artistic possibilities – which is no different from ceramics, glass, and metals. For all these materials, the same thing applies: their advantages and disadvantages must always be carefully weighed up by producers, trade and consumers to achieve an optimum environment-friendly, sustainable use.

1 Günter Lattermann, Was sind eigentlich Harze? e-plastory (2013), Nr. 2

2 Gustav E. Pazaurek, Guter und schlechter Geschmack im Kunstgewerbe, Salzwasserverlag GmbH, Paderborn 1912, pp. 17–18.

3 Roland Barthes, Mythologies, Edition Sueil, Paris 1957; Perspecta (1988) 24, p. 92–93; URL: https://www.jstor.org/stable/1567125

4 Paul J. Crutzen, Eugene F. Stoermer, The Anthropocene, Global Change Newsletter (2002), 41, pp. 17–18.

5 Paul J. Crutzen, Geology of Mankind, Nature (2002), 415, p. 23.

6 Paul J. Crutzen, Geology of Mankind, in Paul Crutzen, H. Brauch (Hrsg.), “Paul Crutzen: A Pioneer on Atmospheric Chemistry and Climate Change in the Anthropocene”, Springer Briefs on Pioneers in Science and Practice, Band. 50, Springer, Cham 2016, pp. 211–215

Many changes to this earth are now man-made. The present epoch is therefore sometimes already being called the Anthropocene 

Fig. 1. Global plastics production (million t per year) is increasing exponentially since 1950 

Fig. 2. The first edition of Kunststoffe magazine in 1911 “with special focus” on biogenic and modified biogenic polymer materials 

Lattermann - Hauptartikel

Prof. Günter Lattermann lectures at the HTW Berlin University of Applied Sciences. He is President of the Deutsche Gesellschaft für Kunststoffgeschichte e. V. (dgkg; German Society for Plastics History) and the Plastics History European Association (PHEA).

Kunststoffe

Photonik

Optik

The Potential of Redesign and  Part Consolidation

Additive Manufacturing and Hybrid Molds in Combination with Conventional Machining

Hybrid production chains have been increasingly in the spotlight in recent years. This also applies to the combination of conventional manufacturing and additive processes in tool construction. With the example of an injection molding tool, it is shown how mold inserts produced by additive manufacturing can greatly shorten cycle times, and thereby significantly reduce unit costs. The important thing is to find a suitable combination of processes from the variety available.

Over recent years, additive manufacturing processes have greatly improved in terms of their performance, reliability and the range of materials available. There are many industrial applications now available and new ones are emerging all the time – as is shown by the examples during the Corona crisis.

However, it is also becoming clear that approval or certification is a stumbling block for rapid implementation in industrial series production. Especially where series production is concerned, not all processes are completely certified, or not all materials are available. This is because of the principle of layer build-up.

If 3D printing and conventional machining processes are combined with tool and mold making – the prerequisite is always adequate equipment and the corresponding expertise – then the disadvantages of part production in a hybrid production chain can be transformed into advantages by means of tool making.

Tools for injection molding elastomers, thermoplastics and thermosets have always been manufactured by the familiar material removal processes, such as lathe turning, milling and electrical discharge machining. Molds and mold inserts – which are for the most part subsequently hardened – have high surface quality, hardness and fatigue limit. The success here depends on many years of experience in the use of the tools. For example, with a long tool life, parts and components can be produced in uniformly high quality.

The Process Chain is Becoming  More Challenging

For many years, a switch toward smaller batch sizes and shorter availabilities has been apparent – with a uniformly high quality always being required. This results in a dilemma for mold makers, since tools manufactured faster (e. g. from materials that are easier to machine) offer a shorter lifetime. To compensate for this, new solutions, often more technically complex, are required. It is also necessary to call on new processes to find solutions that meet these challenging conditions.

Additive manufacturing (AM) – in particular metal layering processes – if correctly applied, offer many advantages for manufacturing tools, and allow unique features and functions to be realized, which were not conceivable until now (using conventional methods). However, these processes also have disadvantages in surface quality and in speed of manufacturing. Additive manufacturing proves to be a promising addition to conventional methods, particularly if it is combined with conventional methods such as HSC (high speed cutting), which, as is known, is suitable for rapid machining of surfaces. With this procedure, it is important to realize that, due to the combination of processes, the process chain is extended with an additional factor, but also becomes more challenging.

It is already becoming clear that there is no moldmaking process for rapid manufacturing of injection molds that could really satisfy all the demands. The conditions applying to machining only allow high-speed operation to a limited extent. 3D printing, by contrast, offers advantages that can be exploited if the correct process parameters and chains are chosen and can significantly improve the efficiency, despite process-dependent disadvantages in the surface structure and fatigue limit.

Given the aforementioned problems, Eisenhuth GmbH & Co. KG, Osterode, Germany, as part of the “KitkAdd” project, publicly sponsored by the BMBF (German Federal Ministry of Education and Research), after a great deal of creativity and empirical work, succeeded in developing the combination of mechanical tool manufacture and metal 3D printing into so-called “hybrid molding.” This approach essentially makes use of additively manufactured mold inserts, steel inserts manufactured by HSC, milled graphite electrodes and moldmaking standards, such as master molds, guide pillars and bushes (Fig. 1).

Each of these elements has positive material and manufacturing properties as a result of the process, which not only determine the injection mold but also its design [1] and construction. It is thus essential to combine the corresponding properties of the individual components and processes with one another. Combining the advantages of all manufacturing processes results in very efficient tools with their own unique features [2].

First the particular application must be described accurately. Based on their advantages and disadvantages, a strategy for utilizing the processes is created well before the design work is performed. The designer decides which parts are manufactured using which process, and which processes can be used. After the single part design has been completed, ready for manufacturing, the individual manufacturing steps are started simultaneously, even combining the individual manufacturing and secondary finishing processes. It is necessary to exercise especial care when planning and implementing this process. At the end, the parts are combined with one another and are available for production in a mold insert [3].

For all manufacturing technologies, the production parameters must be observed. For example, with HSC, the absolute material removal rates are relatively low, but very high strength materials can be machined. 3D printing offers advantages for complex structures and great geometrical freedom and flexibility, though, here too, the pitfalls lie in the details. Low build-up rates, and therefore a high price per built-up volume require the design to be adapted to AM in the early stages for the least possible material consumption.

Not all structures can be manufactured additively, so that, for example, small bridges, deep grooves or delicate structures can present difficulties. Since this is still dependent on the orientation of the part in the build chamber of the AM machine, the designer faces a particular challenge to produce designs suitable for manufacturing.

The advantage of the generative build-up of the metal tool components, namely the possibility of manufacturing extremely complex shapes, can also be utilized for combined application in electrical discharge machining. Thus, additively manufactured copper electrodes open up new machining possibilities here, and can supplement the graphite electrodes manufactured by HSC in the case of particularly difficult geometries.

In previous years, Eisenhuth gained a lot of experience in various industries with customer parts. The example of an injection mold for a simple part (Title figure) is used here to illustrate a suitable combination of processes from conventional and additive manufacturing. The part that is manufactured here is a spacer (Fig. 2) of a high temperature resistant, glass fiber-reinforced “triple-six polyamide” (PA6T/66, type: Grivory HT2V-3H, manufacturer: Ems-Chemie AG, Domat/Ems, Switzerland).

The aim of the project performed with this material is to examine what advantages can be achieved with AM parts, and how much influence additive manufacturing has on the cycle time, and therefore on the costs of the injection-molded part. And also to show that hybrid manufacturing is suitable and provides added value, even with comparatively simple parts [4].

The original approach was only to optimize the costs for the final serial part. However, since the spacer had already been optimized for series production (i. e. finalized) and could not be manufactured from the specified series material with the required strength, the workaround was chosen to optimize the tool in favor of shorter injection molding cycles. This was achieved using a temperature-control system with conformal cooling. It was also possible to reduce material consumption and therefore the costs for tool manufacture by means of a so-called “bionic design” [5].

The design of the mold insert is initially based on the target geometry, i. e. the original data set [5]. Implementation in 3D printing required one thing in particular: observation of the AM-specific design rules [1]. The ultimate design satisfied the loading, manufacturing and secondary finishing requirements for a mold insert that was produced by selective laser melting.

Due to the layer-by-layer manufacturing process, the design could be optimized during CAD, such that the mold inserts could be produced with approximately 35  % lower material consumption. As a result, the process time in the AM machine – generally the cost driver [6] – was also reduced, so that the manufacturing of the inserts was accomplished in less than two thirds of the time [5]. In addition, the hybrid-molding design was chose so as to keep the effort for secondary finishing as low as possible.

All these measures – especially the conformal cooling – increase the part complexity significantly. This highlights the big advantage of additive methods since, unlike conventional machining, the complexity here has only a very small influence on the costs (“complexity for free”) [4].

Comparison of Process Chains: Complexity Has no Extra Costs

Within the publicly sponsored “KitkAdd” project [7], Eisenhuth, together with one of the project partners, the Institute of Production Technology at the Karlsruhe Institute of Technology (KIT), developed a calculation tool for determining the manufacturing costs and times in production. The starting data can now be changed at any time, and since it can be almost precisely predicted how the changes each influence the result, the effectiveness of a measure can be derived.

The calculation tool is based on a detailed analysis of the different process chains (Fig. 3). This can be used to determine all the data and parameters that influence the mold and injection molded part costs, as well as the production times. From the result, the three possible variants – conventional, hybrid and additive process chains – can now be compared.

In this context, hybrid means a combination of a conventional tool with additively manufactured mold inserts. In the scope of the project tool, the project partner KIT also determined what costs are generated by a purely additive tool. Here it was found that there is no break-even, i. e. the 100  % additively manufactured tool is more economical than a conventional tool.

In a detailed analysis of the process chains, the tool costs for the two variants, the one- and two-cavity tool, are considered and this information is also incorporated into the calculation tool. As a result, it is found that the hybrid tools are about 35 % more expensive than the tools manufactured conventionally. This is primarily because of the increased manufacturing and secondary finishing costs of the additively manufactured inserts.

However the crucial factor is that the pure consideration of tool costs only covers part of the process chain, since with the use of hybrid tools, the production costs of the final parts are reduced. Consequently, after the tool costs, it is also necessary to determine the part costs for the two tool variants. The developed cost model not only supplies the pure costs for the basic tool and mold inserts, all the cost factors, such as the cycle time, are also considered.

This is also found in practice: In the case of additively manufactured mold inserts, the cycle time is shortened significantly (25 s instead of 38 s) due to the conformal cooling in contrast to mold inserts manufactured conventionally. This leads to a significantly higher utilization of the machines and increases the capacities: thus, e. g., for 100,000 parts, the break-even is reached even earlier (Fig. 4). Consequently, the part costs of the hybrid AM production chain for this two-cavity tool are reduced by about 2.5  % compared to a tool manufactured conventionally.

The example shows that despite the higher tool costs and the necessary secondary finishing work, the productivity for using hybrid tools is increased significantly while the part costs are simultaneously reduced. The prerequisites for this, however, are, first, a greater design effort and the necessity for comprehensive process knowledge of the – very different – methods used. In summary, it can be stated that the additive manufacturing of tools and tool inserts leads to significant technical and economic advantages for producers who are open to new ways of thinking and are not afraid of the effort.

1 Adam, G. A. O.: Systematische Erarbeitung von Konstruktionsregeln für die additiven Fertigungsverfahren Lasersintern, Laserschmelzen und Fused Deposition Modeling. Forschungsberichte des Direct Manufacturing Research Centers; Dissertation Universität Paderborn 2015

2 VDI-Richtlinie 3405 & VDI-Statusreport: Realität in der industriellen Fertigung. Beuth-Verlag, Berlin 2019

3 Gebhardt, R.: Detaillierte Roadmaps weisen Additive Manufacturing den Weg in die Smart Factory. VDMA, https://am.vdma.org/viewer/-/v2article/render/27025768

4 Klemp, E.: Prozessketten der Additiven Fertigung – Möglichkeiten und Chancen. Präsentation an der HS Lippe/Lemgo, 8. November 2019

5 Hickmann, T.; Wiedenegger, A.: Das Potential von Redesign & Bauteilkonsolidierung. Präsentation auf dem 4. AM-Forum Berlin,12. März 2020

6: Langefeld, B.: Advancements in metal 3D printing – Additive manufacturing on the brink of industrialization. In: Studie Roland Berger, Oktober 2018

7 Kombination und Integration etablierter Technologien mit additiven Fertigungsverfahren in einer Prozesskette. Projekt KitkAdd (www.kitkadd.de), gefördert durch das Bundesministerium für Bildung und Forschung, ISBN 978–3–00–065337–7

Tool insert for a spacer of a glass fiber-reinforced PA66. The example shows that hybrid manufacturing is suitable and provides added value, even with comparatively simple parts

Fig. 1. Apart from conventional tool building, hybrid molding also includes additively manufactured mold inserts and HSC milling 

Fig. 2. The part is used during painting to  keep the engine hood at a defined distance 

Fig. 3. Graphic of the conventional, hybrid and additive process chains: the mold inserts for the tool for injection molding the spacer were manufactured by selective laser melting

Fig. 4. Production costs for 100,000 plastic parts in each case with a one- and two-cavity tool.  The hybrid process chain has the advantage

Thorsten Hickmann is Managing Director of Eisenhuth GmbH & Co. KG, Osterode am Harz, Germany.

Eric Klemp is an independent consultant; <a href="mailto:eric@klemp-online.de">eric@klemp-online.de</a>