The Circular Economy is not only the theme topic at the K 2019. It is also the “green” thread running through the fair exhibit by Engel, the provider of injection molding machines and integrated system solutions. Industry 4.0 is turning out to be a driving force for recycling. This is a most timely insight, since the branch is in for several economically cool years.

Engel Supports Strong Involvement by the Plastics Industry in a Circular Economy

Spritzgießen

Kunststoffverarbeitung: Verfahren

Doriat, Clemens, Dr.

Künstliche Intelligenz für die Qualitätssicherung

Industrie 4.0

Industrie 4.0 für die Qualitätssicherung

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

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Verbundwerkstoffe / Werkstoffverbunde

Kunststoff Werkstoffe

Spritzgießmaschinen

Kunststoffverarbeitung: Maschinen und Komponenten

Co-Injektion (Barriere-/Sandwich-Spritzgießen)

Kunststoff-Recycling

Kunststoff-Aufbereitung

Organobleche (gewebeverstärkte Thermoplast-Halbzeuge)

Halbzeuge und Zwischenprodukte

Kunststoff-Halbzeuge

Ressourcenmanagement

Produktion

A Second Life for Plastics

Composite materials are often the key to lightweight design for many applications. However, these hybrid materials face a major challenge where recycling is concerned.

A Research Project Highlights the Recycling Potential of Lightweight Composites

Composite-Halbzeuge

Kohlenstofffasern / -matten

Verstärkungsstoffe

Anlagen zur Composite-Herstellung

Spritzprägen

Bruchmechanische Prüfung

Messtechnik

Werkstoffprüfung

Harzsysteme für Composite-Herstellung

UD-Tapes

Presswerkzeuge, Kunststoff

Werkzeuge für die Kunststoffverarbeitung

Pressen von Kunststoffen

Faserverbundwerkstoffe

Andere Werkstoffe

Qualitätssicherung Kunststoff

Qualitätssicherung

Zero-Waste Concept for Carbon SMC

Lightweight construction, functionality and design are characteristic of material development in all areas of application for PC compounds, composites and films. The range of materials has enormous opportunities when it comes to the mobility of the future, lightweight structural construction with continuous fiber-reinforced composites, 5G technology and medical technology.

Polycarbonate (PC)

Automotive

Elektronik

Recycling

Umweltmanagement

Technische Kunststoffe

Thermoplaste

Kunststoff

Bauwesen

Baustoffe

Medizintechnik

Polycarbonat

Medizinprodukte

Present in a Multitude of Trends

Plastics processors have a wide range of colors at their disposal to color their products. Choosing the right color can ultimately be the key to success. But colors are just as subject to trends as materials and designs. Kunststoffe asked manufacturers of pigments, masterbatches, and colorants which colors would be particularly popular in the coming year.

Trend Report on the Coloration of Plastics

Pigmente

Additive

Pigmente, bunt

Masterbatches

Farbstoffe und Pigmente

Kunststoffe

Photonik

Optik

Streifinger, Florian

Farbkonzentrate (Batches)

Farbstoffe

Effektpigmente

Farben, flüssig

What Will Be the Color of 2021?

Plastic waste in the sea has been shaping the negative image of the industry for several years. Various initiatives and mergers of companies have therefore launched projects to tackle this Ocean-bound Plastics (OBP). Components made of OBP could become a symbol for a sustainable use of plastics.

Flame Retardant for Compounds Based on Recycled Ocean-Bound Plastics

Polybutylenterephthalat

Polyethylenterephthalat

Flammschutzmittel

From the Sea to Electronics

Plastics are among the materials most widely used for food contact applications. While there is pressure to use recycled plastics in packaging in order to combat plastic waste, certain conditions must be met before food packaging can be considered safe.

Plastics Recycling for Direct Food Contact and Alternative Applications

Verpackungsmittel aus Kunststoffen

Kunststoffverarbeitung

Food Safe Post Consumer Recyclate

Today plastics recycling is usually only classified as being either mechanical or chemical. However, precise differentiation is crucial for any assessment of the possibilities and limitations of plastic recovery processes and whether materials are actually being recycled or merely their raw materials recovered.

A Comparison of Physical and Chemical Plastics Recycling

Kreislaufwirtschaft

The Role of Chemistry in  Plastics Recycling

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.

On the Image of Plastics and their Responsible Use

Polymer Materials

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.

Current Challenges and Options for Action in the Plastics Industry

Wirtschaftspolitik in Deutschland

Verpackungsmaterial

Logistik

Klotz, Karlhorst, Dr.

Internationale Wirtschaft

Verpackungsanlagen

Coilhandling

Kunststoff-Verpackungsmaschine

Sondermaschinen

Starting up under the Shadow  of Corona

The increasing volume of plastic waste and the growing pollution of the oceans by such waste have brought the sustainable handling of plastic products into the focus of society and politics. Both recycling and bioplastics can be a part of a strategy for greater sustainability, but they are not free of side effects. In order to avoid irrational decisions, it is important to assess their effects comprehensively.

3D View of Sustainability

Flachfolienanlagen

Extrusionsanlagen

Blasfolienextrusion

Flachfolien- und Plattenextrusion

Extrusion

Nachhaltigkeit

Folien

Folienblasanlagen

Why Recycled Films Are Not Necessarily Sustainable

The beneficial processing and service properties of plastics are increasingly determining the ecological fate of the world. The plastics industry has now realized that it is not enough to put the blame on consumer behavior. As K 2019 showed, numerous initiatives and technical developments are paving the way for the urgently needed establishment of a circular economy.

A Stock-Take of K 2019: The Plastics Sector Has Owned up to Its Responsibility

Messe K-Kunststoffmesse

kunststoffe-international.com

Wiederaufbereitung

The Dawning of the Circular Economy

There is little doubt where we are heading: multilayer packaging will have to become easier to recycle – but what does that mean for the technology? And what solutions will the market need and accept? Manufacturers of branded goods are not the only ones who will have to rethink their specifications.

How Film Packaging Will Have to Develop

Europe Needs to Catch up

The announced motto for the fair was the “circular economy,” and the exhibitors are answering the call, as plastics’ tarnished image makes it imperative to scrutinize the recyclability of products. Nevertheless, the plastics trade show in Düsseldorf, Germany, has other exciting facets.

Kunststoffverarbeitung allgemein

Kunststoffe, synthetischer Kautschuk

Kunststoff-Erzeugung

Hilfs-und Zusatzstoffe für die Kunststoff-Industrie

Kunststoffverarbeitungsmaschinen

Industrie 4.0 für die Kunststoffverarbeitung

Fahrzeugbau

Herstellung von Gummi und Kunststoffwaren

What K 2019 Has to Offer in and around the Circular Economy

Smart assistance systems are paving the way for self-optimizing production. Automatic correction of quality-relevant parameters is already reality for individual phases of the injection molding process. At K 2019, Engel presented the iQ weight control with the example of a recyclate application for the first time.

The iQ weight control Assistance System Ensures Higher Process Stability

Werkzeuginnendrucksensoren

Sensoren / Messwertaufnehmer

Steuern, Regeln

Software

Messgeräte für Viskosität

Kunststoff-Rezyklat

Opening up a Broader Range of Applications for Recyclates

Currently, recyclates are in high demand, including the automotive industry. Previously, component suppliers had reservations about using recyclates in safety-related areas, because mechanical properties varied too widely. Now, materials producer JSP has developed an expanded polypropylene with 25 % recyclate content precisely for these application areas. But to ensure high quality, close cooperation with the recycling company is essential.

Circular Economy for Expanded Polypropylene (EPP)

Polypropylen

Automotive Components  Made of Packaging

New Compound Materials for Durable Technical Applications

In the research project “UPcyclePET”, and together with Easicomp GmbH, Fraunhofer LBF developed a new material that had to prove its qualities in practical tests.

In the research project “UPcyclePET”, and together with Easicomp GmbH, Fraunhofer LBF developed a new material that had to prove its qualities in practical tests. The resulting technical component was able to demonstrate the mechanical advantages of long glass fibers, combined with the benefits of PET such as low swellability and high dimensional stability.

Plastic scrap and its improper handling result in global environmental problems. Particularly problematic hereby are packaging plastics that must be disposed of or find their way into the environment after a relatively short life cycle. One solution for this is to convert short-lived plastic scrap into high-grade materials that find new use in durable technical applications.

In the UPcyclePET research project, and together with Easicomp GmbH – experts for long glass fibers thermoplastics – Fraunhofer LBF developed a novel and low-cost material based on used beverage bottles made of polyethylene terephthalate (PET). Potential applications for the new material are found in lightweight automotive components such as engine supports or cross members.

Sustainable Materials from  Used Beverage Bottles

The main feature of this approach is that PET flakes from used beverage bottles (called rPET in the following) are processed directly in a highly integrated manufacturing process that involves compounding and pultrusion. Hereby, the mechanical benefits of the particularly long glass fibers are combined with the advantageous properties of PET, such as low swellability and high dimensional stability.

By means of tailored plastic additivation, together with an optimized process design for compounding and pultrusion, the properties of the melt and compound were adapted according to the requirements of the target applications. Hereby, the main focus was on the mechanical properties. For the long glass fiber-reinforced PET made of bottle flakes, the aim of the project partners was to obtain similar mechanical properties as exhibited by short glass fiber-reinforced plastics based on virgin material, e. g. those of polyesters or polyamides (PA-SGF, PET-SGF). On the contrary to clearly defined virgin materials, recyclates place special requirements – in terms of quality – on processing and the formulation to be developed. Numerous properties of PET – e. g. moisture sensitivity, degradation behavior during processing or slow crystallization – represent special challenges for material development and process design. In addition, the specific requirements of the pultrusion process and the glass fiber compound (e. g. regarding viscosity limits and wettability of the glass filaments) must be taken into account. This interaction, plus targeted optimization, requires deep understanding and experience of formulation and process design for the composite materials. Therefore, selected formulations with different methods were investigated systematically in the UPcyclePET project. As an example, this procedure will be described on the basis of two formulations with a 50 % content of long glass fibers (rPET-LGF50) in terms of the fiber/matrix adhesion. The behavior of these compounds were compared by scanning electron microscopy after a cold fracture (Fig. 1). By means of a coupling agent and a modified processing, it was possible to reduce the fiber pull-out; the latter is typically observed when poor interactions between fiber and polymer matrix exist. Reduction of fiber pull-out improves the mechanical properties of the composite considerably.

Furthermore, the analysis of crystallization behavior and morphology, provided a comprehensive understanding of the structure/property relationships for the upcycling of such recyclates. Subsequently, the final recipe of the new long glass fiber-reinforced rPET (called UPcyclePET in the following) was compiled. It has a 25  % glass fiber content and is named as rPET-LGF25 in the following.

CO2 Footprint of rPET and PA66

Figure 2 shows the stress-strain properties (dry as molded) of rPET-LGF25 based on PET recyclate as compared to that of PA66-SGF made of virgin material. The material properties of PA66-SGF25 and rPET-LGF25 exhibit a comparable tensile modulus, but differ slightly in tensile strength and elongation at break. Regarding CO2 footprint, the new material rPET-LGF25 based on recyclate has a decisive advantage over PA66-SGF25 based on virgin material polyamides. An indicative life cycle assessment, conducted by the project partner Öko-Institut, on material production revealed that the material UPcyclePET has a CO2 footprint of 5.1 kg CO2 equivalents/kg, whilst the material based on PA66-SGF25 has about twice as high with 11.0 kg CO2 equivalents/kg.

Based on the newly developed formulation, a component was selected which is currently being produced with short glass fiber-reinforced polyamide, and used in automotive construction. In order to evaluate the limit case (long versus short glass fiber-reinforced thermoplastics, produced in the existing mold which is designed and optimized for short glass fiber-reinforced polyamide 66), a relatively small component was chosen intentionally.

The PA66 component has a size of about 57 mm x 48 mm x 23 mm (length x width x height, see Figure 3) and consists of PA66-SGF25. The component was produced by K. S. Kunststoff-Innovation GmbH, who is a specialist for high-quality technical injection molded parts.

It was shown that injection molding of long glass fiber-reinforced rPET-LGF25 (length of LGF granulates: 11 mm) was possible with the same mold, normally used for processing the short glass fiber-reinforced PA66-SGF25, just by varying the injection molding parameters. As expected, the filling process was sub-optimal due to the longer glass fibers compared to the much shorter glass fibers of PA66-SGF25. As a result the component homogeneity and thus the quality of the component were affected.  This indicates clearly through the typical sink mark near the sprue (Fig. 4). The reason for this is that due to its long fibers, rPET-LGF25 melt cannot flow unhindered through the narrow channels in the mold within the needed short time. The result is “freezing” in the sprue region. Accordingly, the dwell pressure cannot be maintained, which leads to the sink marks. Identification of suitable components (e. g. larger, less complex components) plus optimization of fiber and granulate length of rPET-LGF25 represent the next qualification steps for the new material.

By comparison, the component made of PET-LGF25 exhibited far less shrinkage and higher dimensional accuracy than that of PA66-SGF25. A non-contact photo-optical measurement of the PET-LGF25 component showed that local shrinkage was far less than that of PA66-SGF25 component (Fig. 5). This is due to the inherent properties of PET.

In summary, the project UPcyclePET supported by the Federal Ministry of Education and Research (BMBF) successfully developed a new long glass fiber-reinforced material based on a secondary PET. It exhibits mechanical properties that are comparable to those of virgin plastics reinforced with short glass fibers (PET SGF and PA66-SGF). The material rPET-LGF25 exhibits a significantly lower CO2 footprint as compared to PA66-SGF25.

Moreover, the BMBF UPcyclePET project also showed that it is possible to use rPET-LGF25 to produce a small component with complex geometry (previously made of PA66-SGF25) in the same mold as the established product.

The demonstrator component of rPET-LGF25 features low shrinkage and particularly high dimensional accuracy.

Within the scope of the subsequent project UPcyclePETPlus, material flows other than used PET bottle flakes will be investigated. Also larger demonstrator components will be aimed for, which can be produced in molds with wider channels and sprues.

Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Bereich Kunststoffe

https://www.lbf.fraunhofer.de

Easicomp GmbH  

https://www.easicomp.de

Ausgabenartikel

Upcycling of used PET beverage bottles into long fiber-reinforced thermoplastics

16:9

Fig. 1. Comparative REM images after cold fractures in correlation to achieved mechanical characteristics of different rPET-LGF50. These rPET-LGF50 differ in composition and processing and are compared with PET-SGF45 

Fig. 2. Mechanical characteristics of rPET-LGF25 compared with those of PA66-SGF25 

Fig. 3. The selected component made of rPET-LGF25 is a technical part in a window roller blind system that places high demands on geometrical accuracy and mechanical properties

Fig. 4. Challenges: the left photo shows an encircled sink mark, whilst the long fibers at the sprue end are visible in the photo at right

Fig. 5. Non-contact photo-optical measurement of components. At left, the original component made of PA66 – at right, the demonstration component made of UPcyclePET

Name - Fraunhofer

Dr. Frank Schönberger is department head of Polymer Synthesis in the plastics division of Fraunhofer LBF in Darmstadt, Germany; <a href="mailto:frank.schoenberger@lbf.fraunhofer.de">frank.schoenberger@lbf.fraunhofer.de</a>

Shilpa Khare is head of the Technical Center in the plastics division of Fraunhofer LBF in Darmstadt; <a href="mailto:shilpa.khare@lbf.fraunhofer.de">shilpa.khare@lbf.fraunhofer.de</a>

Dr. Tapio Harmia is CEO of Easicomp GmbH; <a href="mailto:tapio.harmia@easicomp.de">tapio.harmia@easicomp.de</a>

Under the grant number 033RK052, this project was supported by the Federal Ministry of Education and Research (BMBF) within the scope of its “KMU-innovativ” program.