Climate change and the transport revolution are demanding smart fiber-reinforced composite solutions. In sectors such as the marine industry, infrastructure, and rail vehicle construction, many different fire protection concepts are competing. The composites industry is paying increased attention to recycling.

The first natural fiber-reinforced satellite panel permits safe space exploration and completely burns up on re-entry into the earth’s atmosphere

16:9

20:7

Fiber-Reinforced Composites Drive Innovation in the Transport and Construction Sectors

Composite-Halbzeuge

Halbzeuge und Zwischenprodukte

Kunststoff-Halbzeuge

Glasfasern / -matten

Kunststoff Werkstoffe

Verstärkungsstoffe

Kohlenstofffasern / -matten

Sekundärfasern

Kunststoff-Rezyklat

Fasern

Faserverarbeitung

Kunststoffverarbeitung: Maschinen und Komponenten

Faserverbundwerkstoffe

Andere Werkstoffe

Composites Are Trendsetters in Lightweight Design

Optics play an increasingly important role in plastic components. Glossy and even surfaces are decisive for an attractive appearance. With glass fiber-reinforced polyamides (PA), these requirements can usually only be achieved with an additional coating. A PA specially developed for surface design offers an alternative approach.

For visible components, an even, glossy surface is often desired, which is often difficult to achieve with glass fiber-reinforced PA. PA Grivory G7V from EMS now solves this problem

Aliphatic High-Performance Polyamide for Plastic Surfaces

Spritzgießen

Kunststoffverarbeitung: Verfahren

Polyamide

Thermoplaste

Oberflächentechnik

Kunststoff

Bauwesen

Baustoffe

Kunststofffasern

Glossy Components without Painting

The traditional markets for glass fiber-reinforced thermoplastics remain stable. Thermoplastic composites are gaining fast with 3D-printing and hybrid processing techniques. The fiber composite industry is tackling the recycling issue with pragmatic ideas.

The Oechsler Drivematic drive actuator can be integrated into the 3D-printed CFRP monocoque frame of an Arevo „e-bike“

The Manifold New Collection of Reactive Systems and Thermoplastic Composites

Reaktionsharze

Duroplaste

Verbundwerkstoffe / Werkstoffverbunde

Aramidfasern

Harzsysteme für Composite-Herstellung

Phenolharze

Harzwerkstoffe

Werkstoffe für additive Verfahren

Harze, Epoxid

Duroplastische Werkstoffe

Hochleistungskunststoffe

Fiber-Reinforced 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.

The experimental components were manufactured in a fully automated SMC manufacturing cell, developed by Engel, with an Engel v-duo 700 machine and an easix KR35 articulated robot

A Research Project Highlights the Recycling Potential of Lightweight Composites

Anlagen zur Composite-Herstellung

Spritzprägen

Bruchmechanische Prüfung

Messtechnik

Werkstoffprüfung

UD-Tapes

Presswerkzeuge, Kunststoff

Werkzeuge für die Kunststoffverarbeitung

Pressen von Kunststoffen

Kunststoff-Recycling

Kunststoff-Aufbereitung

Qualitätssicherung Kunststoff

Qualitätssicherung

Zero-Waste Concept for Carbon SMC

CFRP components are often in continuous use under harsh environmental conditions, for example in aircraft and motor vehicles. If any damage occurs, the CFRP structures are simply replaced by new components in most cases. This is mainly due to the high cost of established repair methods. With a newly developed process, defective CFRP structures can now be repaired locally much more easily.

Fig. 1. Overview of the simulation-based repair method for CFRP components: the method enables targeted repair of the damaged area

Process for Repairing CFRP Components without Machining

Repairing instead of Replacing

Lightweight design with fiber-reinforced plastics saves energy resources in the use phase of automobiles and aircraft. However, the savings are often offset by higher consumption in production. Therefore, the focus is increasingly shifting to sustainability in manufacturing. The Research Institute Neue Materialien Bayreuth has conducted a corresponding sustainability analysis for the processing of thermoplastic UD tapes into functionally integrated components.

Fig. 4. The demonstrator component “2D-MultiMat” was manufactured with laminates of woven fabric organosheets and UD tapes (CF or GF/CF hybrid) based on PP and injection-molded functional integration (PP-GF) with the FORCE process chain.

Evaluate the Environmental Impact of the Production of FRP Components

Nachhaltigkeit

Umweltmanagement

Organobleche (gewebeverstärkte Thermoplast-Halbzeuge)

Schnüre, Bänder, Tapes

How Sustainable Is  Lightweight Design Really?

Particularly two industries have shown considerable interest in FPP technology: aerospace industry in automating the lay-up processes of multi-material lightweight components with sandwich cores, as well as manufacturers of CFRP pressure vessels for hydrogen-powered vehicles (FCEVs), who can thus achieve savings in the double-digit percentage range. In both areas, FPP is the first technology to automate critical fiber lay-up processes in order to industrialize the production.

Laminate reinforcement of filament-wound pressure tanks. The shape of the patches and the gripper is adapted to the size and complexity  of the component.

New Applications for the Automated Production of Fiber Composite Components

Greifer

Automatisierungstechnik

Handling, Handhabungstechnik

Inspektionssysteme

Fertigungsautomation

Bildverarbeitung

Industrieroboter

Montagetechnik

Reinforcement on Approach

Continuous fibre-reinforced polymers (FRP), based on flat sheets, benefit from excellent weight-specific features. These include the possibility of load path optimised design and the option of functional integration. Consequently, FRP offer a high potential for lightweight design. Materials using thermoplastic-based polymers (so-called „organic-sheets“) allow fully automated and fast manufacturing based on their physical processing and are environmentally sustainable because of their recycling capability. Additionally, through improved optical and aesthetic characteristics, new applications can be developed for a mid to high scale production range.

Leichtbau

Surface optimisation of continuous fibre reinforced thermoplastics

Susanne Schröder will become editor-in-chief of the magazines Kunststoffe and Kunststoffe international on December 1, 2020. The current editor-in-chief Dr. Karlhorst Klotz will leave the company by mutual agreement.

Susanne Schröder will become editor-in-chief of the magazines Kunststoffe and Kunststoffe international on December 1, 2020. Until now she has been editor-in-chief of the trade journal FORM+Werkzeug

Werkzeuge für Leichtbauwerkstoffe

Präzisionswerkzeuge

Tiefziehwerkzeug

Dienstleistungen

Werkzeug-, Formen- und Modellbau

Werkzeugüberwachung

Toolmanagement

Werkzeugwechselsysteme, Spritzgieß

Spritzgießwerkzeuge

Werkzeug- und Formenbau

Modulare Werkzeugsysteme

Absaugungen für Werkzeugmaschinen

Betriebsausrüstung / Betriebsmittel

Absaugvorrichtungen

Fluorkunststoffe

Werkzeugverwaltungssoftware

Prüfen von Kunststoffen

Biokunststoffe

Werkzeugreinigung, Kunststoffe

Standardkunststoffe

Kunststoffverarbeitung

Lohnfertigung

Technische Kunststoffe

Füllstoffe für Kunststoffe

Kunststoffhandel

Handel

Betriebstechnik für Kunststoffverarbeitung (Peripherie)

Change in the Chief Editorial Office of Kunststoffe

The non fossil fuel-based portfolio offers same high quality and performance for applications in all industries.

The Bornewables portfolio is suitable for the production of the most demanding applications, including hygiene and food-contact

Gehäuse aus Kunststoff

Elektromechanik

Kühlkörper

Polyethylen

Polystyrol

Polypropylen

Kunststoff-Regenerate

Borealis Launches Portfolio of Circular Polyolefins

Bio-based plastics can lock away vast quantities of CO<sub>2</sub> in durable, recyclable applications and make a real contribution to climate protection. All that is needed for this is the right product design and a functioning circular economy. By focusing more on this approach, the plastics sector has the chance to evolve into a key industry of a green economy.

Furniture and furnishings with a long service life are the ideal applications for bioplastics

How Bio-Based Polymers Can Help Sequester CO<sub>2</sub> for the Long Term

Kunststoffe, biobasiert

Recycling

Kunststoffe, bioabbaubar

Into the Future with Biopolymers

Fiber composite parts and fiber-reinforced molds have been traditionally manufactured by cutting them from wide semi-finished material. Due to part geometry, large amounts of waste cut are often the result. Such waste necessitates high costs for handling and excessive expense for materials. 

Reinforcement Fabrics: Semi-Finished Fabrics to Order 

Aside from high part costs, investment and development costs often constitute an additional obstacle to the implementation of lightweight solutions in fiber-reinforced plastic composites. In particular, parts that are produced by reactive processing require an integrated approach to product and process development. Systematic process simulation affords a way of considerably boosting efficiency during development. 

FRP Lightweight Engineering Based on Thermoset Matrix Systems Benefits from Integrated Process Development 

Spritzgießsimulation

Resin Transfer Molding

Faster to Series Production Through Simulation 

Non-woven fabrics of carbon fibers include a large potential for lightweight construction at the price of challenging impregnation properties. To reduce cycle times when producing components of carbon fiber-reinforced plastics (CFRP), processors can benefit from the high permeability of glass fiber mats. 

Glass Mats Improve the Impregnation Properties in CRP Processing  

Lower Pressure in the RTM-Process 

In the manufacturing of RTM structural components, semi-finished textiles can be locally reinforced at different angles using a special weaving procedure. This allows the mechanical properties to be improved in highly stressed areas. 

ORW Technology Enables Multi-Axial Local Reinforcement for RTM Structural Components 

Gewebe, technisch

From a Different Angle 

Composites Reduce Weight and Simplify Production of Electronics Housings

Continuous fiber-reinforced thermoplastic composites have also become established with thin-walled housings for consumer electronics and information technology. Not only do they offer high stiffness and help to reduce weight, but also enable the integration of classy appearance and functions. What is more, if the housings are produced using the hybrid molding process, costs, processing steps, and cycle times can be reduced.

Hardly any other sector exhibits such high global growth rates as the consumer electronics and IT business, with smartphones, laptops, and tablets as their main application areas. According to investigations by the Indian market research and consulting company Mordor Intelligence, the global market for smartphones alone had a volume of almost USD 715 billion in 2020. With annual growth rates of about 11.2  %, it is expected to increase to more than USD 1.3 trillion by 2026. For these fields, plastics producer Lanxess has developed continuous-fiber reinforced thermoplastic compound materials.

Named Tepex, the composites are plate-shaped semi-finished products (organosheets) and are also used for lightweight structural components in the automotive industry. Their matrix consists of polyamide 6 (PA6), polypropylene (PP), polycarbonate (PC), thermoplastic polyurethane (TPU) or other thermoplastics, and is usually reinforced with continuous fiber fabrics of high-strength glass or carbon fibers, or with long-fiber mats or fleeces. The fibers are fully impregnated with the matrix plastic and contain practically no air bubbles (fully consolidated). Consequently, all the load forces are transferred from one filament to the next via the matrix. Usually, the fabric fibers are arranged at right angles to each other and are evenly distributed in both directions (balanced). Frequently, warp-strong fabrics are also used, in which most of the fibers are oriented unidirectionally. Therefore, the properties of the corresponding semi-finished products – such as stiffness, strength, and thermal expansion – are direction-dependent.

Meanwhile, hybrid molding is the preferred method for processing the semi-finished items. The procedure starts with a semi-finished pre-cut item, which gives an indication of the component’s final shape. After heating above the matrix melt temperature, the item is positioned between the open halves of the injection mold. The mold closes and forms the pre-cut. Simultaneously, it is backmolded or overmolded with a short fiber-reinforced version of the matrix plastic (Fig. 1). As opposed to insert molding, thermoforming and injection molding are not separate stages, but occur in a single processing step. A separate forming tool is not necessary. The process is highly efficient, because the number of processing steps, the investment costs, and the cycle times are reduced. Another advantage of the semi-finished Tepex items is that they come fully consolidated. Therefore, consolidation in the mold is not needed – something that is not economically feasible with thermoplastics.

The inserts are heated in a separate oven and transferred to the open injection mold in the plastified state. In this step semi-finished items with a unidirectional orientation of the continuous fibers without transverse reinforcement are at a disadvantage, because they flow apart when the mold closes, whereby the fibers can be sheared off more easily (so-called mold slip). For semi-finished items with fabric reinforcement, the intermeshed warp and weft threads provide transverse reinforcement, which greatly simplifies the handling of inserts in the plastified state.

Housing parts for consumer electronics and IT in particular must exhibit smooth and usually glossy surfaces. Semi-finished composites fulfil these requirements, provided that they are produced in a hybrid molding tool with a controlled rapid heating/cooling system. This results in off-tool surfaces that hardly need any post-processing for subsequent painting steps. In contrast, die-casting metals, which are also used to produce e. g. tablet housings, mostly require smoothing with fillers, grinding, and polishing before being painted. Apart from the time and effort involved, this also produces more scrap. Hybrid molding with Tepex is considerably less energy intensive and has a lower CO2 footprint than metal die-casting.

Another substantial reason for the high suitability of Tepex for the production of housings for consumer electronics and IT is its high distortion resistance and stiffness with low material wall thickness. Both are significantly higher than for injection-molded thermoplastics, with which composites must compete mainly for small appliance housings. The specific bending stiffness when reinforced with carbon fibers is comparable with that of die-cast aluminum and magnesium, and the specific bending strength is significantly higher (Fig. 2). These properties are substantial contributions that enable housing parts, e. g. for smartphones, to be designed very thin and light, but also very stiff, thereby exhibiting a high resistance to deformation. This ensures good protection for the components of electronic equipment such as displays, circuit boards, and rechargeable batteries. For the manufacturers of such equipment stiffness is an important criterion and is verified by them in comprehensive system tests and/or force deformation tests of the finished component.

If the housing part is hybrid molded, reinforcing ribs are very easy to injection mold. Because the composite matrix and injection material are the same a very strong molecular bond between ribs and housing shell is achieved. In addition to the composite material’s specific stiffness this results in even higher stiffness which can be increased further by means of geometric elements such as e. g. beads or edges.

Among the first applications of Tepex in consumer electronics and IT were covers for smartphones from Research in Motion (RIM, still under the Blackberry brand name at that time). It was possible to design the covers stiffer and slimmer than conventional injection molded covers. The new covers were produced from a TPU-based semi-finished composite using the insert molding process. A visually very appealing element was the colored design that originated from regularly arranged colored glass fiber fabric in the compound material and was highlighted with a transparent lacquer coating.

A series application for Tepex is the A-cover for Dell business notebooks as substitute for die-cast magnesium components. Here semi-finished composites with PC matrix and reinforced with carbon and glass fiber fabrics are used. Apart from high stiffness and lower weight, further points favoring the use of composites instead of magnesium are better energy efficiency and safer processing and the very high off-tool surface quality of the components.

Particularly demanding are flame-retardant requirements: due to the high energy density in the processors, with corresponding heat generation, the semi-finished composites used must pass the UL 94 V0 flame-retardant test. For this, a halogen-free flame retardant concept was developed which does not influence fiber wetting and adhesion and therefore does not impair the composite’s mechanical properties. An attractive appearance is created by the visible plain-weave carbon fabric.

The notebook covers are one of the first series applications of the hybrid molding process with rapid heating/cooling temperature control system. The applications already exhibit a wide range of injection-molded integrated functions such as reinforcing ribs, fixing elements, and guides. Carbon-free antenna windows, which ensure good signal transmission, are integrated by injection molding.

The trend for functional integration in the consumer electronics and IT field continues. One outstanding example of this is the recently introduced world’s first carbon smartphone: the Carbon 1 Mark II from the Carbon Mobile start-up in Berlin, Germany (Title figure). Previously, networked devices with carbon fiber housings were assumed to be impossible, due to the electromagnetic shielding of the fibers and the resulting blocking of radio signals. However, with Carbon Mobile’s HyRECM (hybrid radio enabled composite material) technology, carbon fibers and an associated composite material are combined in such a way that the resulting compound allows radio signals to pass. Also integrated in the carbon fiber housing is a conducting 3D printing that assists the antenna function.

The housing is based on a semi-finished composite with TPU matrix. It is built as a single shell like the load-supporting chassis of Formula 1 racing cars. This monocoque design makes very good use of the carbon composite material’s stiffness. Weighing just 125 g, the smartphone is about one third lighter than conventional mobile phones and with a height of only 6.3 mm it is 25 % thinner.

The demand for sustainable materials is also increasing for consumer electronics and IT. The aim is to reduce scrap and to recycle the resources from end-of-life components. As purely thermoplastic systems, Tepex organic sheets are easily recycled in the sense of closed-loop material cycles (Fig. 3). Tests conducted by Lanxess showed that under the right conditions, shredded scrap – singular or mixed with unreinforced or short fiber-reinforced virgin compound material – can be injection molded and extruded on standard machines without problems. The recyclate’s mechanical properties – e. g. strength, stiffness, and toughness – are on the level of conventional short fiber-reinforced plastics with corresponding fiber contents.

Recently, Tepex semi-finished composites were introduced of which half the matrix is PC recyclate from the reclamation of returnable water bottles. The composites are aimed at applications such as laptop covers or housings for smartphones, tablets, e-book readers or mobile phones. For example, a halogen-free flameproof material with a chopped strand core of recycled carbon fibers is almost ready for series use in laptop covers.

Fully Bio: Semi-Finished Biopolymer Items with Bio-Based Reinforcement

Also ready for series production are semi-finished composites with polylactic acid (PLA) or PA11 as bio-based matrix, which are reinforced with continuous glass or carbon fibers. Their mechanical properties such as bending stiffness and e-modulus are comparable with those of similar PA6 and TPU grades.

Currently, Lanxess is also working on the use of bio-based reinforcing fibers in Tepex (Fig.  4). Special focus lies on flax fibers which are being discussed as a natural alternative for carbon fibers. Suitable semi-finished items with PP-matrix were investigated. Although their mechanical properties are significantly lower than those of their counterparts (reinforced with continuous carbon fiber or continuous glass fiber), they are still higher than those of injection molding materials reinforced with short carbon or glass fibers. Particularly sustainable is the combination of flax fiber fabrics with biomatrices. Entirely based on renewable materials, these semi-finished items produce surfaces with an appealing biocarbon look and feel.

LANXESS Deutschland GmbH  

Ausgabenartikel

The Carbon 1 Mark II smartphone from Carbon Mobile was developed in Germany. The matt-black carbon fibers lend the smartphone a classy high-tech look

Fig. 1. Schematic of hybrid molding sequence with rapid heating/cooling temperature control: thanks to fast heating and cooling of the mold, the resulting component surfaces can be painted directly

Fig. 2. Comparison of bending properties of standard materials for consumer electronics and IT equipment housings: Tepex dynalite semi-finished items with a halogen-free flame-retardant PC matrix are superior to die-cast metals, particularly in the system deformation test

Fig. 3. Tepex organosheets are easily recycled and subsequently reused for technical components. Strength, stiffness, and toughness of the recyclate correspond to those of short fiber-reinforced plastics with the same fiber contents

Fig. 4. Reusable water bottles are made of high-purity transparent PC, which is approved for foodstuffs contact. Tepex recyclates, which are used e. g. for laptop housings, benefit from these properties

KU 8-21_Lanxess - Hauptartikel

 Dr. Dirk Bonefeld is head of Marketing and Sales for Tepex in the “Consumer Electronics and Sport” sectors at Lanxess.