Another three years have gone by. K is not only the world’s leading trade fair for plastics and rubber, but also a good indicator of how fast time passes.

At the last event in 2019, I wandered as a newcomer in the Kunststoffe team through the exhibition halls in Düsseldorf, Germany. A fantastic initiation. It’s not often that you find so much concentrated plastics knowledge in one place. That is why I’m so pleased that it is kicking off again.

Circular economy, digitalization and climate protection top the agenda at this year’s show. So at first sight, it seems as though time has stood still since 2019. Even at that time, these themes were at the heart of K. But quite a lot has changed since the last show. The discussions about and implementations of the circular economy have become more concrete. Announcements and plans from those days can now be viewed as market-ready products and processes. And now the much-cited necessary cooperation between companies along the value chain is taking place more intensively. This is shown by successful projects between waste recyclers, plastics manufacturers, processors and OEMs. Chemical recycling has also made advances. Skepticism about the processes is decreasing, more plants are being built and many material manufacturers offer the relevant products, even if in small quantities so far. So time has by no means stood still since the last K.

This is particularly well demonstrated in our extensive “Plastics World Market” Special from page 12 in this edition. This gives an overview of the market situation and the most important trends in the individual plastics classes. And it shows that there has been a lot of progress with the circular economy for all polymers since 2019. I can therefore only recommend taking a closer look at it. What applies to K, also applies – in a more monothematic form, of course – to our “World Market”: it’s rare to find so much concentrated plastics knowledge in one place anywhere else.

Wishing you many new insights also in Düsseldorf!

16:9

Editorial Streifinger

Streifinger, Florian

When We Break through  Material Boundaries

The pathways to plastics can be many – even metalworking in the case of AIM3D. That is what first got this start-up up and running. Fast forward to now and the young Rostock company can cover both bases.

AIM3D is making material limits in additive manufacturing a thing of the past – in fact the Rostock start-up has now rolled out a metal- and plastic-compatible 3D printer. And the groundbreaking progress goes even beyond glass fiber-reinforcements. We got the inside view from founder and Chief Technology Officer (CTO) Clemens Lieberwirth about the company, its process and the current 3D printer challenges as part of our New Plastic Heroes series.

Kunststoffe: Could you give us a brief overview of the company?

Clemens Lieberwirth: AIM3D is a machine manufacturer, which develops and sells 3D printing equipment, develops material profiles and supports customers in application development.

Kunststoffe: What sets AIM3D systems apart from the competing systems?

Lieberwirth: First of all, our patented print head technology. This is how we process high-filled thermoplastics economically and efficiently, while also ensuring for visually appealing component qualities and high repeatability.

Lieberwirth: It was the private 3D printing component, which made up part of my master‘s thesis in 2014 at the University of Rostock. However, the inaugural topic for AIM3D was “3D printing with metal injection molding pellets“.

Kunststoffe: How did you ultimately start handling plastic?

Lieberwirth: Right from day one, we tailored our extruders to optimally handle this very demanding high-filled thermoplastic compound, which also put us on the radar of carmakers. Most of the interest here was focused on glass-fiber-filled polyamides with at least 40 % fiber filling. Things picked up speed and once Brose International decided to invest in us, our contacts in the plastics processing industry spiraled. Today, around two thirds of all our inquiries are about plastics and one third about metal.

Kunststoffe: What are the key challenges you face in 3D printing with glass fiber-reinforced polyamides and how can you leverage your technology to solve them?

Lieberwirth: Nothing is more challenging than extruding the material as gently yet reliably as possible. The glass fibers should remain as long as possible during extrusion and the material feed and melt zone must be designed such as to preclude any risk of the material clogging, degrading or becoming separated in the extruder. We solve these issues by minimizing the length/diameter ratio of the screw and the interplay between different actuators when feeding the material.

Kunststoffe: Regardless, where do you currently see the greatest need for development in the additive manufacturing industry?

Lieberwirth: The key issues in this context are technical suitability (strengths and material selection) and affordability (machine costs, material costs, post-processing costs and scrap). We can offer competitive advantages in many such areas by using series material, since strength and anisotropy in particular remain priorities for 3D-printed components. I can‘t reveal too much at this point – but anyone who visits us at Formnext this year will see that we are also approaching a major milestone achievement in the AM area too.

CTO Clemens Lieberwirth (pictured), who founded the company in 2017 together with Dr. Vincent Morrison.

Versatile: the 3D printer developed by this young company can process virtually all fusible materials.

Name - Hauptartikel

<ul><li>Name: AIM3D GmbH</li><li>Founded: 2017 in Rostock, Germany</li><li>Number of customers: around 50</li><li>Number of employees: 17</li><li>Homepage: <a href="https://www.aim3d.de/en/" target="_blank">www.aim3d.de</a></li><li>AIM3D at K 2022: hall 4, booth A08</li><li>AIM3D at Formnext 2022: hall 12.1, booth E81</li></ul>

Verfahren für die additive Fertigung

Anlagen Additive Fertigung / 3D-Druck, andere

Anlagen für die Additive Fertigung

Start up

Wirtschaft

Unternehmen und Unternehmer

3D-Drucker (für FDM, FFF, etc.)

Anlagen Additive Fertigung / 3D-Druck, Metall

Additive Fertigung

Polyethylene (PE): Shaping New Trends in Power Generation and Packaging

Consumption and manufacturing capacities are growing most in North America and China. In Europe, companies are working on specific paths.

Since its invention, polyethylene (PE) has created new areas of application, replaced other materials in their traditional functions and continuously shifted its own limits of use. This has made PE the most widely used plastic in the world, with 115 million t consumed annually. Consumption and manufacturing capacities are growing most in North America and China. In Europe, companies are working on specific paths.

The average growth rate of PE over the last five years was 4.6 % per annum worldwide, leading to a consumption of 115 million t in 2021. This increase in consumption also remained unbroken in the pandemic years of 2020 and 2021. On the contrary, with 5.7 % and 5.2 % growth in 2020 and 2021, respectively, PE has increased disproportionately to its own growth average, but more importantly to the general global Gross Domestic Product (GDP). Worldwide, investments of about 10 so-called “world-scale” plants per year are needed to ensure that the supply and demand structure is not permanently impaired.

Of course, there are segment-specific differences in growth. At the same time, it is remarkable that, with a few exceptions, none of the ten application segments defined by the market research company Chemical Market Analytics have recorded negative growth over the same period (Fig. 1).

Market researchers assume that the usual growth rates of the recent past of 4 to 5 % on average will continue unchanged. There is a significant difference in the world regions though. While growth in mature markets is only moderate and flattening out, Northeast Asia and especially China are almost solely responsible for the overall global growth (Fig. 2).

If we look at the capacity expansions for the period from 2016 to 2022 and venture a capacity outlook up to 2031, we find something surprising (Fig. 3). Capacity growth is keeping pace with consumption growth, but utilization rates remain very high at 85 to 90 %. It is particularly striking that the traditional chemical location of Western Europe has not played a role in terms of capacity expansion in the last decade and this will remain the case for this decade. Also, Eastern Europe is hardly significant in the overall global capacity picture. The Middle East, which functioned as a capacity engine especially in the last decade, is weakening enormously. In contrast, the USA is sticking to its strategy of refining cheap shale gas and thus ethane into polyethylene, not only to cover its own needs but also to increasingly establish itself as a global export region for PE. If we take a closer look at the USA, it has added about 11 million t of PE capacity in the last five years and plans to add another 13 million t by 2026.

The situation in China is similarly impressive. It is expected that China will build up an additional 13 million t of PE capacity. The self-sufficiency rate, i.e. the ratio between Chinese production and Chinese demand, was 57 % in 2017. Therefore just under half of Chinese consumption had to be imported. One would think that with the massive capacity increase of 10 million t since 2017 and an additional 13 million t by 2026, China would make itself independent of imports; however, this is not the case. While the expected self-sufficiency rate will improve to up to 62 % in 2026, it still keeps the door open for imports of around 20 million t.

Neither a significant increase in demand nor capacity expansions in Europe, especially Western Europe, are foreseeable. This forecast refers to conventionally produced PE, i.e. PE from polymerization plants and based on fossil raw materials. Similar to the electricity discussion in Europe, the focus is not on growth but on sustainability. In other words, how to enjoy the undisputed usefulness of this material and at the same time avoid or at least reduce undesirable side effects, such as its CO2 footprint and especially its waste. The answers are either already commercially available or at an advanced stage of development.

Conventional high-density polyethylene (HDPE) of fossil origin has an average cradle-to-gate carbon footprint of 1.84 CO2 equivalent; i.e. the production of 1 t of HDPE causes the emission of 1.84 t of CO2, considering the entire value chain starting from crude oil (cradle) until the finished HDPE product leaves the respective industrial site (gate). If crude oil is replaced by plant-based waste or biomass, the CO2 footprint is reduced by 3.71 CO2-eq to a negative value of –1.87 CO2-eq. This means that the plant-based raw materials behind the biomass have absorbed more CO2 from the atmosphere during their current growth than the entire manufacturing process of PE releases again. Not many refineries are currently designed to convert vegetable waste and biomass into cracker-ready naphtha, but this journey has begun, nonetheless. Close cooperation between Finnish refiner Neste and polyethylene producer LyondellBasell is making it possible to produce PE based on renewable raw materials that match the quality of conventional PE.

In the case of plastic waste generated after its initial use, the aim is to offer an alternative to conventional disposal and preserve the value of plastic as a material, keeping it in circulation for as long as possible. The value creation chain is complex and not easy to organize. It starts with collecting the waste and not simply disposing of it. Once this has been done, the waste mixture must be separated largely according to type. The shredded, largely unmixed PE is then cleaned, melted down, extruded for granulation, and used again as re-granulate for consumer goods that are not subject to more stringent regulations, such as food approvals or medical applications.

There is a big interest in the valorization of single use plastics and packaging. The switch to such a circular value chain is expected to significantly reduce plastic packaging waste. A notable example of how this can be done is the cooperation between the waste management company Veolia  and the Polyolefin manufacturer LyondellBasell. Together, the two companies operate the joint venture QCP (Quality Circular Products), which involves the production interface between the collection and processing of plastic waste and the marketing and sale of this unconventional product category.

High Usage of Recyclates through Improved Sorting and Cleaning

The same strict specifications regarding product safety are applied to recyclates as to comparable virgin materials. This requires constantly improving sorting and cleaning processes, which will ensure that the addressable market for mechanical recyclates will increase significantly in the coming years. One example of this is the use of such materials in cosmetics packaging. Here, the industry consortium Cospatox, which brings together companies along this value chain, is working on the creation of scientifically sound criteria and processes that will allow the safe use of recyclates. Optimized sorting and cleaning processes also allow the use of raw material streams that would not be accessible to mechanical recycling with previous technologies. In addition, the industry is looking for solutions that simplify recycling. Examples include the replacement of composite films made from a range of plastics with mono-material solutions or a new generation of tube packaging in which the tube body, shoulder and cap are made from PE and can therefore be recycled without further separation.

A logical next step would be the use of PE post-consumer recyclate in food applications. However, it will be crucial for value chain collaboration to be in place to overcome the challenges inherent in using PCR materials in highly regulated applications.

Chemical Recycling – the Next Step towards  a Closed-Loop Economy

PE products produced by mechanical recycling have their limits, either because of their quality compared to conventional polyethylene, or because of regulations that do not allow the use of mechanically recycled products for certain applications. This is where chemical recycling comes into play. Chemical recycling is characterized by the fact that polymer chains are converted back into hydrocarbon molecules via a pyrolysis process and sometimes by using suitable catalysts, which in turn can be used in crackers as a naphtha substitute. This achieves many objectives simultaneously. The use of virgin crude oil is reduced and at the same time plastic waste is reduced without loss of the quality level and approval status of the polyethylene finished products produced. Drop-in products manufactured in this way can also be used for articles that have to meet very high hygiene requirements.

Europe has played and continues to play a pioneering role in the development of new process technologies for the production of PE. At the same time, Europe’s engineering spirit is going into application development with this raw material. It can be assumed that Europe will also remain true to its pioneering role in the field of sustainability and set new standards that are successfully met with the help of process technologies developed in Europe. Analogous to conventional PE polymerization processes, it can be assumed that European de-polymerization processes will not only make their necessary contribution to addressing the issue of plastic waste within Europe but could also be marketed or licensed outside Europe.

Europe sets quality standards in many application areas that are rapidly spreading internationally. At the same time, the European Union sets regulatory frameworks that lead the way and continually tests them. Environmental and chemical regulations are often the toughest in the world and are becoming increasingly more stringent. There are both risks and opportunities in this approach. Risks in that regulatory conditions make the development and marketing of products more difficult; opportunities in that new products and applications are created through development work, which can also open up new business areas. The following are examples of current significant developments that will have an impact on and change the PE business area from a regulatory perspective.

In the field of PE pipe systems, materials with particularly high stress crack resistance, the so-called PE 100 RC types, were included in the European standard for gas pipe materials for the first time; a corresponding extension of the standard for drinking water materials and a transfer to the ISO standards is expected soon. This confirms the trend towards more robust materials that are designed in particular for the requirements of unconventional installation (Fig. 4). These methods, for example trenchless pipe laying, are often superior to conventional methods when it comes to the energy and efforts invested in the laying of pipes, demonstrating a clear sustainability gain to which these innovative PE materials contribute.

Trenchless Laying for the Energy Turnaround

PE-based pipe systems also play an important role in the field of alternative energy supply. Within the framework of the energy transition, at least 80 % of electricity supply is to come from renewable energies by 2050. In order to ensure a stable and secure power supply in the future, the power grids must be adapted to meet the changed generation structure. Because of more decentralized power generation, underground high-voltage distribution networks are necessary. High-performance direct current lines (up to 525 kV), which are laid as underground cables, play a decisive role here. The high-voltage cables used place special demands on the insulation materials, and in addition to special compounds, synthetic materials based on cross-linked PE (XLPE) are getting established in this application.

The cables also require cable protection pipes that can withstand temperatures around 70 °C for a long service term. To facilitate the replacement, the underground cables are often laid with the help of cable protection pipes made of HDPE. The use of such pipes also allows the cables to be easily replaced at the end of their service life without having to carry out earthworks again.

Another high profile topic in connection with the energy transition is the use of hydrogen, both in industrial applications and as a possible substitute in household energy supply. Investigations into the use of PE pipes in hydrogen supply have shown that PE is chemically inert to hydrogen and is therefore in principle also suitable for hydrogen transport. Further studies on this topic are in progress, e.g. to evaluate the permeation properties of PE.

The electrification of the power train of automobiles will continue to progress, and hybrid-electric vehicles are also included in this terminology. It is generally assumed by industry experts that between 2030 and 2035, the share of electric vehicles will predominate the market. In the case of PE, the elimination of carbon containers is offset by the use of battery separator films. PE is therefore not going out of fashion in spite of different technologies and thus required life cycles in the automobile (Fig. 5).

Packaging – Tethered Caps and Mono-Materials

The Single-Use Plastics Regulation (EU) 2019/904 will require the tethering of movable components to the packaging base for a number of plastic articles beginning in 2024. This is valid, for example, for bottle caps, so called tethered caps (Fig. 6). The reduction of plastic waste envisaged thus requires optimized material distribution to maintain product properties without additional material consumption. LyondellBasell product portfolio provides robust materials for new cap designs. Through optimized strength and stiffness, a variety of “tether” geometries can be realized, which leave nothing to be desired in the area of conflict between design requirements, packaging integrity and user-friendliness.

Flexible multi-material packaging is currently widely used in the packaging industry. It is made of many different types of plastic, which makes recycling difficult. From the point of view of the intended circular economy, multi-material solutions must be replaced by mono-material structures. This change requires a redesign of the packaging. To improve recyclability, the laminated PET film in the outer layer is to be replaced by a stretched PE film. Accordingly, the bag will then also be recognized as PE during IR sorting. To achieve this, orientation of the PE film is necessary, which can be achieved by using a monoaxial or a biaxial orientation process. Both technologies produce PE film with excellent mechanical and optical properties, comparable to the properties of multi-material packaging.

Due to the trend towards mono-material packaging solutions, so-called aluminum barriers are being replaced by plastic laminate barriers. With special PE materials, the requirements for high strength and toughness can be balanced and the laminate can be reduced in its dimensions, so that the amount of plastic waste is reduced. These new barrier solutions can be used primarily in product applications such as cosmetics, body care, oral care or food packaging.

Polyethylene – a Material for the Future

While the market in North America and China is driven by increasing demand and capacity expansion, alternative raw materials and regulations are opening up new areas of application in Europe. It remains exciting to see how the availability of renewable raw materials and recyclates, as well as the refinement of new production technologies, to make products easier to recycle and introduce back into the value chain, will continue in the coming decades. The pandemic years have shown that polyethylene is and will remain a crisis-proof material which is resilient in changing market conditions.

Fig. 3. PE capacities as well as demand will presumably grow uniformly. 

Source: Chemical Market Analytics by Opis, a Dow Jones company; graphic: © Hanser

Fig. 2. Worldwide PE demand according to regions: market growth in Asia is strong, and expected to increase even more by 2031. 

Fig. 4. Trenchless pipe laying is less energy and work intensive than conventional methods. It is also suitable for installing high-voltage power cables, e.g. during the change in energy distribution to decentralized supplies.

Fig. 5. Instead of fuel tanks, PE is used e.g. for parts of the batteries of electric vehicles.

Fig. 6. Sealing covers firmly attached to the product, so-called tethered caps, will be compulsory, e.g. for bottles, from 2024 onwards. This requires an adaptation of design and materials to prevent excessive waste of material.

PE films with monoaxial and biaxial orientation help to replace multi-material compounds for packaging.

Fig. 1. Development of worldwide growth of PE consumption in different processing and application areas: also in the crisis years 2019 and 2020, consumption increased in practically all areas. 

KUint8-22_LyondellBasell - Hauptartikel

 Dr.-Ing. Ugur Akgün is Head of Application Development & Technical Service, Polyethylene Europe, at LyondellBasell.

Michael Berger is Director PE Specialties, Polyethylene Europe, at LyondellBasell.

Dr. Patrik Schneider is Associate Director R&D, Polyethylene Product Development and Circular Design EU, LyondellBasell.

Messe K-Kunststoffmesse

kunststoffe-international.com

Verpackungsmaterial

Logistik

Polyethylen

Kunststoff Werkstoffe

Thermoplaste

Rohre, Profile

Metall Werkstoffe

Kunststoff-Rohre

Halbzeuge und Zwischenprodukte

Kunststoff-Halbzeuge

Kunststoff-Recycling

Kunststoffverarbeitung: Verfahren

Kunststoff-Aufbereitung

Rohre, allgemein

The Future of Polypropylene Lies  in the Circular Economy

Polypropylene (PP): Growth despite Crisis

PP is a material with good future perspectives. It is attractive as it combines several different properties. It is economical, covers a wide application area – and can be readily recycled.

PP is a material with good future perspectives. It is attractive as it combines several different properties. It is economical, covers a wide application area – and can be readily recycled. The big PP producers have already established their own product lines for recyclates. The quality of these recyclates has also improved in recent times: even the demands regarding appearance and emissions required for automotive interior uses can be fulfilled.

It is not every day, that someone produces a feature movie about a piece of furniture. However, the “Monobloc,” a chair that has been produced from polypropylene in pure or mineral-reinforced form since the mid-1960s, is something really special. As the German movie director Hauke Wendler found out in his research, the Italian company Proserpio alone has so far produced more than 250 million units of this chair. Worldwide, production is estimated at several billion units, making the “Monobloc” the most frequently sold item of furniture. For many people it is also the only affordable one (Title figure), and can even be recycled, as it consists of only one material type. Wendler‘s movie also shows the many possibilities of this chair, from repair with diverse materials to its adaptation as a wheelchair.

This movie is therefore a symbol for polypropylene (PP), covering four important aspects of this material:

<ul><li>PP is globally available in large quantities, with a production of about 75 million t in 2020 [1],</li><li>PP is an economical material,</li><li> with its copolymers and composites, it covers an extremely broad property range,</li><li>PP can be recycled in multiple ways.</li></ul>

Growth despite Crisis: Stronger Demand in Hygiene and Packaging

The production volume of PP has suffered hardly at all from the Covid-19 pandemic, as production declines in areas like the automotive sector were compensated for by stronger demand in hygiene and packaging. One could even say that one article produced from PP – the FFP2 respirator mask – has become a symbol of the pandemic.

It is consequently very important that innovations are also related to such mass-produced articles. The masks are produced from PP grades with a melt index (MFR) of more than 1000 g/10 min. via the meltblown process. These materials are available from several producers, such as Sabic and Borealis. These two companies also support recycling of the masks after use. Sabic, together with Procter&Gamble and Fraunhofer, has set up a pilot project for pyrolytic conversion of single-use masks, in which valuable petrochemical raw material is generated. In the collaboration between Borealis and Grabher, a fiber and mask producer, mechanical recycling is used (Fig. 1), in which, after sorting, washing, sterilizing and drying, the material is used as filling for pillows and oil absorption applications; a process for re-pelletization is under development.

Market development of PP is, however, distributed unevenly on a global scale. The stronger growth in Asia, and here especially in China, which has already been ongoing for some time, has resulted in a share of over 50 % of the global volume for this region (Fig. 2). This development is likely to continue, as the growth of 4 to 6 % per year forecast for the coming years will rather be exceeded by Asian countries [1]. This is explicable by the factors for market growth, such as dynamics in areas of hygiene, healthcare and packaging of convenience products, but also infrastructure and mobility.

EU Recycling Targets Are Becoming  a Challenge

However, this positive trend is countered by some factors ranging from a general skepticism about single-use plastic articles to legal requirements, as for example resulting from the EU strategy for plastics [2]. For PP this mostly means that the demand for recycled material will increase. This is presently at about 7 % of the overall market (higher in Europe, significantly lower in North America), but it should double in the foreseeable future. This development will also be required for meeting the recycling target of the EU of 65 % by 2030 (together with a landfilling rate of only 10 %) [3]. The trend towards recycling is presently also supported by the price development, with an increase of about 25 % from 2019 to 2021 [1].

Producers Starting Large Chemical Recycling Projects

The currently predominant mechanical recycling operations will therefore need to be supplemented with chemical processes, for which several important polymer producers have announced large projects [4]. It is important here that processes targeted at direct production of monomers or at least valuable intermediates for monomer production have especially high requirements for cleanliness and composition of the respective raw material [5]. Targeted collection and pre-sorting will therefore very likely remain a necessity, and the decision about the chosen recycling path should be based on objective criteria such as energy demand and emissions in the process. It is, however, clear that the decarbonization of the polymer industry necessary for protecting the climate requires a shift in the raw material base for monomer production from natural oil and gas (as well as coal, at least in China) towards plastic waste and renewable sources.

Regarding the latter, some of the major PP producers have already defined dedicated product lines – Borcycle (for recyclates) and Bornewables (for production from regenerative sources) at Borealis, Circulen at LyondellBasell, Trucircle at Sabic and Exxtend at ExxonMobil. The definitions are somewhat different, but both have the same two targets: international certification such as via ISCC, which verifies the material balance and raw materials source, and guarantees identical performance. The latter was proven several times in recent years, for example by Greiner Packaging. Here, Bornewables grades were processed in thin-wall injection molding with in-mold labeling for certification first (Fig. 3), and a joint project with Emmi for “Caffè Latte” cups has since been started on that basis, but also a Circulen grade has been successfully tested for coffee capsules.

The possibility of recycling should, however, already be considered when designing articles and assemblies based on PP [6]. A reduction of material diversity is required here, and there are some encouraging examples of this. The “Pure Line” films of the packaging producer Südpack received the German packaging award in the sustainability category. These are based on mono-materials and are consequently easy to recycle, but still show the typical packaging properties (such as barrier against oxygen and carbon dioxide). One step further was taken by Radici in designing single-use protective overalls: Radipeople Eco is the first fully recyclable protective gear from 100 % polypropylene, as the fabric, coating, zipper and even sewing thread are made from this single material (Fig. 4).

Why Price Development Does Not Affect Sales Volumes

In the period between December 2020 and May 2021 the price for standard PP in Western Europe increased by 80 to 100 % and is now in the range of 2 EUR/kg [1]. As the development has taken place in parallel for nearly all plastic types, this has neither retarded growth nor resulted in substitution. However, the already mentioned trend towards increased use of recyclates has clearly been supported, and the rising prices in this segment, too, are fueling the expansion of the production plant volumes. Here, too, cooperations are considered in many cases, frequently between polymer producers and disposal and sorting specialists. Examples are the acquisition of QCP by LyondellBasell and Suez, or the joint pilot plant of Borealis und Tomra established in Germany. A high degree of automation, such as sorting using infrared sensors, and the adaptation of grinding and purification to the base material allow the production of recyclates of much better quality than in earlier years.

Hardly Any Spectacular Innovations, as the Spectrum Is Already Broad

In the development of primary produced PP materials the number of spectacular innovations is limited for several reasons. First, a transition to catalysts systems without phthalates has become necessary in recent years, and, second, the available property spectrum is already very broad today. Figure 5 shows this for the mechanical performance of PP copolymers with ethylene. It should be considered here that the E-modulus range for PP homopolymers extends up to more than 2 GPa (2000 MPa), and for compounds and composites to more than 13 GPa.

For random copolymers, RACOs, there is a new review [7] which highlights the possibilities for varying these transparent materials by changes in the catalyst system and multimodal distribution of comonomer or molecular weight. A recent example of this is the bimodal BorPure RF777MO of Borealis for bottle closures with film hinges (MFR 13 g/10 min., Fig. 6), which excels through shorter cycle times and improved toughness. RACOs are also playing an important role in medical technology, such as Purell RP375R of LyondellBasell (MFR 25 g/10 min.) with its resistance against sterilization by γ- or electron irradiation.

For soft PP copolymers with RACO-matrix and C2C3-elastomer, RAHECOs and SoftPPs, quite different products can be found in the market today. Depending on modulus and transparency, these are used in the technical area of roofing membranes and thermoplastic cable insulation, but also for pharmaceutical packaging as films or blow-molded containers. There are hardly new developments right now, but the foreseeable need to replace plasticized PVC could generate new dynamics in this field.

Classical high-impact copolymers, HECOs and RTPOs, have an extremely wide application area, both as pure materials and in the formulation of compounds with reinforcements and fibers. The full design spectrum can only be realized with modern production plants consisting of two or more reactors, which can be controlled individually, and a catalyst with a long “lifespan”. “Post-phthalate”-types are equally well suited here, as can be seen from patents [8] and publications [9]. But also products based on renewable resources have been tested, such as BorECO BH381MO of Borealis (MFR 35 g/10 min.) or Flowpact FPC45 of Sabic (MFR 45 g/10 min.) – both well suited for thin-wall injection molding and food contact.

E-Mobility Pushes Compounds  and Composites

Especially the automotive sector has proven a source of constant inspiration for innovation in recent years, and the trend towards electromobility has further heightened the requirements regarding weight reduction [10]. In terms of mechanical strength, the focus is clearly on long glass fiber composites (PP-LGF), which require special processing technique but yield the highest elastic modulus. For extreme requirements these can be combined with unidirectional glass-fiber tapes, as demonstrated by Sabic with Stamax for the toolboxes of trucks, for example.

But even without further reinforcement, Fibremod GB416LF of Borealis with 40 % glass fibers, for example, achieves a tensile modulus of more than 10 GPa, allowing novel designs: in the new Volkswagen Multivan T7 this enables the largest so far realized tailgate structure from PP-LGF alone, contributing significantly to design freedom and weight reduction. A key advantage is the good surface quality, eliminating the need for post-treatment or painting. This combination is clearly trending, as also shown by the use of Celstran LFT of Celanese in the VW ID.3 [11].

But this is just one of many positive contributions, which PP can deliver for E-mobility. At Ansmann AG, for example, the second generation of the GreenPack rechargable battery system is presently being developed (Fig. 7), for which Borealis has designed a halogen-free flame-retardant compound with glass fibers. The combination of electrical insulation and fire resistance with high mechanical strength and warpage-free processing is achieved here with a special polymer base and 20 to 30 % of glass fibers. For these exchangeable battery backs, dimensional stability even at elevated temperatures and drop resistance are decisive. Compared to polyamide or polycarbonate/ABS blends, the production carbon footprint is also reduced massively.

Recyclates Also Used in  Automotive Applications

Compounds are also playing an important role for mechanical recycling, where requirements are becoming more diverse and complex. Borealis Brazil has recently presented Borcycle ME1490SYB, a compound with 47 % recyclate and 10 % talc for automotive applications. The grade has been approved by Stellantis and is used in the new Fiat Strada, a bestseller in the small pickup category in the South American market (Fig. 8).

So far, the use of recyclate in cars has been mostly limited to exterior applications, as the demands on appearance and emissions for interior use hardly seemed accessible. Better sorting and cleaning in combination with targeted post-treatment allows innovations also here, as in the case of Borcycle EE1300SY, which offers bright colors, high toughness and scratch resistance at a content of 30 % recycled polymer – and even fulfills low emission and odor levels. With this, the pathway towards “renewable plastics in the car” seems already very realistic.

[1] Statista Online Daten, sämtlich unter <a href="http://www.statista.com" target="_blank">www.statista.com</a>

[2] European Commission, A European Strategy for Plastics in a Circular Economy, Brussels 2018, available online at <a href="https://ec.europa.eu/environment/pdf/circular-economy/plastics-strategy-annex.pdf" target="_blank">https://ec.europa.eu/environment/pdf/circular-economy/plastics-strategy-annex.pdf</a>

[3] Plastics Europe, Plastics – the Facts 2021, available online at <a href="https://plasticseurope.org/knowledge-hub/plastics-the-facts-2021/" target="_blank">https://plasticseurope.org/knowledge-hub/plastics-the-facts-2021/</a>

[4] Gahleitner M., Chemical Recycling: The silver bullet for plastic waste?, Express Polymer Letters 16 (2022) 557. <a href="https://doi.org/10.3144/expresspolymlett.2022.41" target="_blank">https://doi.org/10.3144/expresspolymlett.2022.41</a>

[5] Vollmer I., Jenks M.J.F., Roelands M.C.P., White R.J., van Harmelen T., de Wild P., van der Laan G.P., Meirer F., Keurentjes J.T.F., Weckhuysen B.M., Beyond Mechanical Recycling: Giving New Life to Plastic Waste, Angewandte Chemie International Edition, 59 (2020) 15402–15423. <a href="https://doi.org/10.1002/anie.201915651" target="_blank">https://doi.org/10.1002/anie.201915651</a>

[6] Knebel A., Beim Design schon ans Recycling denken, Kunststoffe 01/2021, p. 22–24.

[7] Paulik C., Tranninger C., Wang J., Shutov P., Mileva D., Gahleitner M., Catalyst Type Effects on Structure/Property Relations of Polypropylene Random Copolymers, Macromolecular Chemistry and Physics 222 (2021) 2100302. <a href="https://doi.org/10.1002/macp.202100302" target="_blank">https://doi.org/10.1002/macp.202100302</a>

[8] EP 3 443 035 B1, Polypropylene Compositions, Basell Poliolefine SrI, 2016

[9] Pellecchia R., Shutov P., Wang J., Gahleitner M., Copolymer Structure and Performance Consequences of High-Impact Ethylene–Propylene Copolymers Based on a Ziegler–Natta Catalyst with Novel Internal Donor, Macromolecular Reaction Engineering 14 (2020) 2000022. <a href="https://doi.org/10.1002/mren.202000022" target="_blank">https://doi.org/10.1002/mren.202000022</a>

[10] Grestenberger G., Kralicek M., Leichter ans Ziel – PP-Compounds für den Automobilleichtbau, Kunststoffe 03/2020, p. 56–59.

[11] Pfeiffer B., Long Fibers, Smart Look, Kunststoffe international 04/2022, p. 42–45.

The “Monobloc” from PP, here in a green version, is one of the most affordable and versatile seating furnitures worldwide (photo from the movie “Monobloc” by Edition Salzgeber).

Fig. 1. The FFP2 mask by Vprotect, a 100 % daughter company of Grabher Group, mainly consists of meltblown PP by Borealis and can be recycled mechanically.

Fig. 2. Distribution of PP production by global regions. 

Fig. 3. Prototype cup for yogurt packaging with in-mold labeling, produced from bio-circular PP Copolymer Bornewables by Borealis. 

Fig. 4. The single-use protective overall Radipeople Eco from 100 % polypropylene.

Fig. 5. Mechanical profile of different classes of ethylene-propylene copolymers (HECOs – heterophasic copolymers, RTPOs – reactor-based thermoplastic PO-elastomers, RACOs – random copolymers, RAHECOs – random-heterophasic copolymers, softPPs – special copolymers like Adflex or Borsoft).

Fig. 6. Cosmetics closure  with film hinge from BorPure RF777MO.

Fig. 7. The new GreenPack 2.0, 2nd generation battery-pack system by Ansmann in a casing from flame retardant PP composites by Borealis.

Fig. 8. Fiat Strada, a pickup with components from Borcycle ME1490SYB.

Borealis - Hauptartikel

Wachstum trotz Krise: Wieso Polypropylen (PP) ein Werkstoff mit guten Zukunftsperspektiven ist.

Trendbericht 2022 | Die Zukunft von Propylen (PP)

Klaus Bernreitner is Senior Project Manager in the research department,

Markus Gahleitner is Senior Group Expert PP in the research department,

Georg Grestenberger is Application Marketing Manager for Automotive Interior applications,

Susanne Kahlen is Application Marketing Manager for Circular Economy Solutions,

Peter Niedersüss is Application Marketing Manager for Flexible Packaging Systems,

Cornelia Tranninger is group leader for Polyolefin Design,

Technische Kunststoffe

Polypropylen

Kennzahlen

Qualitätsmanagement

Polycarbonate (PC): Functional Integration and New Specialties

A large proportion of the world’s polycarbonate is processed in Asia, especially in China. This is why capacity expansions are mainly taking place there.

A large proportion of the world’s polycarbonate is processed in Asia, especially in China. This is why capacity expansions are mainly taking place there. Outside Asia, manufacturers are increasingly focusing on specialties and products for new production technologies, such as functional integration in components. In the coming years, sustainability will also be the defining issue for all manufacturers.

Polycarbonate (PC) is marketed in the form of granules and granule compounds as well as film, sheet and composite semi-finished products. As a result of the coronavirus pandemic, the global PC market slumped slightly in 2020. However, it recovered to the 2019 level as early as 2021. According to Covestro estimates, global demand for the thermoplastic, including the PC content for blends, was over 4.5 million t in 2021. In the medium term, it is expected to grow by around 4 % per year. It is impossible, however, to reliably forecast how sales will develop in the near future on account of the war in Ukraine and the current disruption of supply chains worldwide due to occurrences such as the coronavirus pandemic.

The largest consumers of the polymer in 2021 were the electrical and electronics industry and household appliance manufacturers, accounting for around 35 %. Automotive producers accounted for about 20 % of sales, followed by the construction and consumer goods industries with about 15 % and nearly 10 %, respectively.

As in the previous years, China consumed the largest share of PCs in the world. The Middle Kingdom accounted for over 40 % of global sales in 2021. The entire Asia-Pacific region (APAC), including China, accounted for over 60 %. The Europe, Middle East and Africa (EMEA) region and the NAFTA region (USA, Canada and Mexico) followed at a considerable distance, with shares of almost 25 % and 15 % respectively.

The largest PC manufacturers are Covestro and Saudi Basic Industries Corporation (Sabic). Together, the two companies have about half of the world’s capacity. Other major players are Mitsubishi, Lotte Chemical and Teijin. The ranking behind the two leading PC manufacturers will, however, change in the medium term due to new Chinese producers.

At a predicted 5 to 6 %, PC sales in China will grow much faster in the next few years than in other regions of the world. Consequently, almost all investment in new capacity is concentrated in the country. Ten years ago, only four PC manufacturers were active in China. By the beginning of 2022, the number had grown to a total of 16. Covestro expects around 50 % of global PC capacity to be located in China by 2025/2026. The country is now able to meet almost all of its demands itself, as plants with a total nominal capacity of more than 2 million t have been built in recent years. In the next five years, China is expected to add another 2 million t of PC capacities. As a result, among other things, global PC capacities are expected to rise from 6.5 million t in 2021 to over 9 million t in 2025/2026.

Capacity Expansion in China Continues Undiminished

In China, capacity is being expanded by globally active producers, but also increasingly by local producers, some of whom are new to the market. These investments are mostly in the expansion of existing plants. For example, PC manufacturers Luxi Chemical and Wanhua Chemicals, which have been active in China for some time, are planning to successively expand their plants in Liaocheng and Yantai, respectively, in Shandong Province. In the mid-term, Cangzhou Dahua also aims to double the capacity of its plant in Cangzhou, Hebei province, which was opened at the end of 2020, to 200,000 t/a. Zhejiang Petroleum & Chemical plans to add a stage of equal capacity to its 260,000 t/a producing plant that came on stream in 2021 at Zhoushan in Zhejiang province by 2023/2024. Pingmei Shenma Group also intends to significantly expand its newly built capacity of currently 100,000 t/a at Pingdingshan in Henan province in several stages over the coming years. Likewise, the capacity of the Hainan Huasheng plant in Dongfang in Hainan Province, which only went into operation at the beginning of 2022, is to be doubled to 520,000 t/a by 2024/2025.

Yet completely new plants have also been and are still being constructed in China. Sinopec Sabic Tianjin Petrochemical (SSTPC), a joint venture between Sinopec and Sabic, for example, completed a new plant with a capacity of 260,000 t/a in Dagang in Tianjin Province towards the end of 2021. Chimei of Taiwan is planning to commission a first plant in China in 2025 at Zhangzhou in Fujian province with 180,000 t/a capacity. A joint venture involving Sabic and Fujian Petrochemical is also expected to start up a 290,000 t/a capacity plant in Gulei, also in Fujian province, in the same year.

A number of major PC manufacturers are also strategically focusing their activities more closely on the requirements of the market. One of the goals here is to benefit disproportionately from business with higher-value and faster-growing applications. Covestro has established two new segments for this purpose: “Performance Materials” bundles, among other things, the business with standard materials such as PC for water bottles, for which reliable supply at competitive market prices is particularly important. “Solutions and Specialties” places the focus on complex plastics production with high innovation speed, coupled with application technology services for the customer. For instance, this includes the business with PC compounds, for example for electromobility and medical technology, or with PC composites for lightweight construction. According to Covestro’s estimates, sales of these materials will grow by 7 % annually in the mid-term, and thus at significantly higher rates than standard PC. The company therefore plans to expand its compounding capacities by 230,000 t/a in the next few years. The two further compounding lines that recently went into operation at the Greater Nodia plant near New Delhi in India are already making a first contribution to this.

Trinseo has also split its “Performance Plastics” segment. In addition to the “Base Plastics” segment, the “Engineered Materials” segment has been established. It combines the business with compounds and blends for demanding applications, for example in consumer electronics. Sabic plans to stock-list its Specialty Chemicals business, which includes PC-based copolymers and compounds. The aim is to restructure this business in order to better exploit the growth potential of the materials.

Currently, some Japanese PC manufacturers are also reorganizing. Mitsubishi Chemical, for example, pulled out of its joint venture with Sinopec, based in Yanshan in Beijing province, at the end of October 2021 as part of a portfolio reorganization. Mitsubishi Chemical plans to transfer half of its share in the 50:50 joint venture Mitsubishi Engineering Plastics to its partner Mitsubishi Gas Chemical in April 2023 as part of a restructuring of its plastics activities.

There is an increasing trend towards backward integration, especially among Asian producers, in some cases as far as phenol and acetone. Apart from the limited availability of raw materials, the underlying reason for this was probably the fact that the prices for bisphenol A in particular, one of the main raw materials for PC, have been very volatile in the last two years and have reached levels not seen for a long time. As a result, some Asian manufacturers who were not backward integrated had to reduce capacities or temporarily shut down plants.

In addition to PC base resin, capacities for films, sheets and composites are also being expanded worldwide. For example, Covestro commissioned additional production lines for high-quality specialty films at its Dormagen site in 2021 (Fig. 1). The focus is on multi-layer flat films, which are used for example in medical technology, the electrical industry, in automotive interiors and exteriors or for security features in identity documents. This project is part of a global initiative to expand the company’s film capacities.

Climate change, resource scarcity and the global waste problem with plastics have led virtually all PC manufacturers to adopt circular products and consider entry into the circular economy as the key to climate neutrality, resource conservation and environmental protection. Covestro, for example, is fully aligning its corporate vision towards a circular economy and aims to become climate-neutral by 2035. To achieve this, greenhouse gas emissions from its own production, external energy sources and upstream and downstream processes in the value chain (scopes 1, 2 and 3) are to be reduced.

The alignment of material cycles leads PC manufacturers to switch their production of compounds, films, sheets and composites to alternative raw material sources such as recyclates and bio-based materials. Production sites and products are being certified in order to demonstrate the sustainability of these raw materials to customers. So far, the ISCC-Plus standard (International Sustainablility and Carbon Certification), an international system for the sustainability certification of biomass and bioenergy, among other things, has been particularly successful. Trinseo, Sabic, Lotte Chemical and LG Chem have announced they have received ISCC certifications. Covestro has had production at its Shanghai (China), Map Ta Phut (Thailand), Antwerp (Belgium), Krefeld-Uerdingen (Germany), Leverkusen (Germany) and Dormagen (Germany) sites certified to the standard.

More and More Materials Comply with the ISCC-Plus Standard

The ISCC-Plus standard is associated with mass balancing during production. This chain-of-custody method allows fossil and alternative raw materials to be mixed in production but separated in accounting. As a result, materials can be tracked through value chains and raw materials can be allocated to selected end products. The mass-balanced raw materials are identical to their fossil counterparts and as such can be integrated into existing production processes as a drop-in solution.

One example of a switch to alternative raw materials in PC production is an agreement entered into by Covestro and Mitsui Chemicals. The Japanese chemical company will supply Covestro with the PC raw materials acetone and phenol from ISCC Plus-certified mass-balanced sources at its sites in Shanghai and Map Ta Phut, Thailand.

Virtually all major manufacturers of PC now offer products certified to the standard as part of their product range. For instance, Sabic launched renewable-based PC compounds in 2019 as part of its Trucircle initiative, and more recently film and sheet products (product name: Lexan). Covestro has recently unveiled the world’s first carbon-neutral PC compounds under the name Makrolon RE. They are derived from biowaste and residual materials and are produced in part using renewable electricity. The designation “climate neutral” is the result of an assessment of a section of the entire product life cycle. The section from resource extraction (cradle) to Covestro’s factory gate was considered. The assessment is based on ISO standard 14040 and was checked for plausibility by TÜV Rheinland. The assessment takes into account biogenic carbon sequestration based on preliminary data from the supply chain and the use of renewable electricity in the production process. Electricity was apportioned on the basis of so-called “Guarantee of Origin” certificates. Compensation certificates were not applied.