From the Sector

At this year's JEC World, STFI will be presenting highlights from carbon fibre recycling as well as a new approach to hemp-based bast fibres, which have promising properties as reinforcement in lightweight construction.

Green Snowboard
At JEC World in Paris from 5 to 7 March 2024, STFI will be showcasing a snowboard from silbaerg GmbH with a patented anisotropic coupling effect made from hemp and recycled carbon fibres with bio-based epoxy resin. In addition to silbaerg and STFI, the partners Circular Saxony - the innovation cluster for the circular economy, FUSE Composite and bto-epoxy GmbH were also involved in the development of the board. The green snowboard was honoured with the JEC Innovation Award 2024 in the “Sport, Leisure and Recreation” category.

VliesComp
The aim of the industrial partners Tenowo GmbH (Hof), Siemens AG (Erlangen), Invent GmbH (Braunschweig) and STFI united in the VliesComp project is to bring recycled materials back onto the market in various lightweight construction solutions. The application fields "Innovative e-machine concepts for the energy transition" and "Innovative e-machine concepts for e-mobility" were considered as examples. On display at JEC World in Paris will be a lightweight end shield for electric motors made from hybrid nonwovens - a mixture of thermoplastic fibre components and recycled reinforcing fibres - as well as nonwovens with 100% recycled reinforcing fibres. The end shield was ultimately manufactured with a 100% recycled fibre content. The tests showed that, compared to the variant made from primary carbon fibres using the RTM process, a 14% reduction in CO₂ equivalent is possible with the same performance. The calculation for the use of the prepreg process using a bio-resin system shows a potential for reducing the CO₂ equivalent by almost 70 %.

Bast fibre reinforcement
To increase stability in the plant stem, bast fibres form in the bark area, which support the stem but, in contrast to the rigid wood, are very flexible and allow slender, tall plants to move in the wind without breaking.A new process extracts the bast bark from hemp by peeling.The resulting characteristic values, such as tensile modulus of elasticity, breaking strength and elongation, are very promising in comparison with the continuous rovings made of flax available on the market.The material could be used as reinforcement in lightweight construction.At JEC World, STFI will be exhibiting reinforcing bars that have been processed into a knitted fabric using a pultrusion process based on bio-based reinforcing fibres made from hemp bast for mineral matrices.

From April 25^th to 27^th, 2023, the Institute of Textile Machinery and High Performance Material Technology (ITM) of TU Dresden will be exhibiting at the pavilion SAXONY! at JEC World 2023.

The ITM will provide a comprehensive overview of its current research in the field of machine and product development along the entire textile process chain.

The upcoming JEC 2023 exhibition will highlight innovative Customised Connective Cores (CCC), which are custom-made core-insert structures additively manufactured using cellular metal and a form-fit integrated insert. These CCCs can be seamless integrated either as patches or as full-surface core material into lightweight panels, offering significantly improved load-bearing behavior (especially 4 times the load-bearing capacity and fail-safe behavior) compared to existing technologies. This breakthrough opens up new possibilities for fastening lightweight panels.

Another highlight at the exhibition is the repair process for fibre-reinforced composites (FRP) developed at the ITM. Instead of mechanically grinding the damaged area, the matrix in the repair area is locally dissolved using a UV-rays-induced depolymerisation process. Damaged fibres can thus be replaced by a customized repair patch. Free yarn ends on the textile repair patches are spliced with the UV-exposed yarn ends in the repair area using an adapted splicing process. In this way, a very clean, simplified and mechanically improved repair area can be achieved compared to the state of the art.

The diverse possibilities offered by the structure and process simulation of textile high-performance materials and textile manufacturing processes will also be presented. By means of multi-scale modelling and simulation, a profound understanding of materials and processes is achieved at the ITM. Finite element models on the micro, meso and macro scale have been developed and validated for this purpose. Examples from current ITM research projects demonstrate the various possibilities and areas of application of modern simulation methods in the field of textile technology.

Moreover, an innovative process for the integral manufacturing of 3D rib-stiffened preforms with complexly arranged stiffeners in 0°, 90° and ± 45° orientation was developed and successfully implemented at the ITM. Due to the process-integrated structure fixation and the continuous fibre reinforcement between shell and rib structure, the 3D preforms are perfectly suited for the production of highly load-bearing FRP components with increased bending stiffness, which will be exhibited at JEC. Hence, the lightweight construction potential of high-performance fibres can be fully exploited.

A successfully established development are partially flowable 2D textile reinforcement fabrics that are continuously manufactured in one single process step. For this purpose, the entire process chain was developed at the ITM, which allows a cost-effective and high-volume production of load-bearing thermoplastic 3D FRP components with continuous fibre reinforcement between shell and stiffeners.

At JEC 2023, the ITM will also present a partially embedded textile latice girder as reinforcement for carbon concrete applications, which was produced by means of an innovative textile manufacturing process based on the multiaxial warp knitting technology. Through the development of a customized warp insertion, manipulation and take-off system as well as appropriate shaping methods, it is now possible to produce tailored textile semi-finished products, e.g. for use in wall and ceiling panels. These textile latice girders represent a resource-saving alternative to conventional steel girders due to the reduced among of concrete required and the additional cavity for media and cable guidance.

The integration of textile actuators and sensors in FRP provides structures with additional functionalities. The research and application of such interactive FRP with different matrix materials (e.g. with thermoset, elastomer or concrete matrix systems) for structural health monitoring or adaptive systems is one of the key research areas of the ITM.

Moreover, the development and implementation of innovative yarn constructions based on recycled high-performance fibres (e.g. rCF, rGF, rAR) for sustainable FRPs is successfully promoted at ITM. By use of a special carding machine, recycled fibres are opened up, separated and joined to form a wide, uniform ribbon. Subsequently, innovative hybrid yarn constructions made of evenly mixed recycled high-performance and thermoplastic fibres with variable fibre volume fractions can be manufactured by means of various spinning technologies. Selected yarn constructions and components will be showcased at JEC.

Monforts will highlight its technologies for special technical textile applications at this year’s ITMA ASIA + CITME which takes place at the National Exhibition and Convention Center in Shanghai, China, from November 20-24.

One of Monforts' developments is the Montex 8500 XXL stenter system for the production of technical fabrics in widths of up to 6.8 metres. Among the products made on this system are treated nonwovens for the geotextiles and filter media markets, tarpaulins, advertising banners, black-out curtains, membranes and many more.

On Montex©Coat coating lines, meanwhile, the possibilities range from the single-sided application of finishing agents for outdoor clothing and adding functionality to home textiles, to the creation of materials for sophisticated lightweight construction and automotive and aerospace components.

“Many more applications are possible, such as the overdyeing of denim, the creation of double-face coated materials, fabrics awnings, tents and medical drapes and the pre-treatment of substrates for digital printing”, explains Gunnar Meyer, Monforts area sales manager for China. “A range of different doctor blades and their combinations can be supplied to meet individual requirements, including air knife, roller knife, foam, screen and magnetic roller coating. The latter option is recommended for lines with working widths of over 2.4 metres.”

In addition, Monforts can provide the necessary explosion-proof ranges for solvent-based coatings and high temperature processes up to 320°C, such as the PTFE coating of nonwoven filter material. These lines are equipped with special burners, stenter chains, and insulation.

The annual highlight of the industry is the International Conference on Cellulose Fibres in Cologne, where the latest innovations were showcased: new cellulose fibre technologies for various feedstocks and a wide range of hygiene and textile products as well as alternatives to plastics and carbon fibre for lightweight constructions.

This year, for the first time, there were 230 participants from 27 countries. About 60 were able to attend on site – with strict Corona safety measures – while the others were able to attend online and participate in questions and discussions.

The conference gave deep insights into the promising future of cellulose fibres, which fit perfectly into the current trends of circular economy, recycling and sustainable carbon cycles.

An important focus at the conference was alternative sources of cellulose. The increasing demand for cellulose fibres cannot be met in the long run with wood and used textiles alone. At the conference, a variety of agricultural by-products and biogenic waste were presented in presentations and panel discussions, such as orange and banana peels, grain and hemp straw. Much of this is high-volume and has not been put to high-value use so far. Exciting opportunities for the future cellulose fibre industry.

Innovation Award
Live at the conference, host nova-Institute and award sponsor GIG Karasek GmbH granted the “Cellulose Fibre Innovation of the Year” award to one of six highly interesting products.

• First Winner: Carbon Fibres from Wood – German Institutes of Textile and Fiber Research Denkendorf (Germany)
• Second Winner: Fibers365, Truly Carbon-Negative Virgin Fibres from Straw - Fibers365 (Germany)
• Third Winner: Sustainable Menstruation Panties: Application-driven Fibre Functionalisation – Kelheim Fibres (Germany)

At the joint stand of the Aachen Centre for Integrative Lightweight Construction (AZL) in Hall 5A, booth D17, the Institut für Textiltechnik of RWTH Aachen University (ITA) will demonstrate its expertise in the field of glass fibres, preforms and textile concrete 12-14 March 2019 in Paris.
The exhibits come from various fields of application and address the automotive, aerospace and mechanical engineering sectors.

1. Innovative glass fibre research at ITA
   The newly constructed induction heated glass fibre production line enables increased flexibility in research. For the first time, glass fibres will be produced live at the ITA booth at JEC World. One of the innovations of the system is the inductively heated bushing. It features a flexible design and consists of a platinum/rhodium alloy (Pt/Rh20) for use in high-temperature glasses.
   The glass fibre production line was designed in such a way that new concepts and ideas can be tested quickly. The modular design allows a high flexibility, the induction system a significantly faster operability.
   Research and development projects can therefore be carried out faster and more cost-effectively.
    
2. DrapeCube - Forming of textile semi-finished products
   The DrapeCube offers a cost-effective design for the production of fibre preforms from textile semi-finished products. It is used in the production of preforms for prototypes and in small series and is suit-able for companies active in the production of fibre-reinforced plas-tics (FRP).
   In the production of FRP components, the preforming process de-fines a large part of the subsequent component costs. In small- and medium-sized enterprises, this process step is often still carried out manually. This results in high quality fluctuations and component prices. Especially in the case of highly stressed structural components, the fluctuation in quality leads to oversizing of the components.
   Thus, the lightweight construction potential of fiber-reinforced plastics is underused. One solution is offered by the stamp forming process adapted from the sheet metal forming industry for shaping rein-forcing textiles. The textile is inserted between two mould halves (male and female) and automatically formed. Due to high plant and tooling costs, this process is used almost exclusively in large-scale production.
   The ITA has developed the DrapeCube forming station which offers a cost-effective alternative and is able to completely reproduce the current state of the art for forming textile half branches. The process steps will be demonstrated in a video at the booth.
    
3. Carbon fibre reinforced plastic (CFRP) preform
   The CFRP preform consists of carbon multiaxial fabrics formed by expanded polystyrene (EPS) to optimise draping quality. Preforms of increased quality can be produced by gentle, textile-compatible forming with foam expansion. For the first time, foam expansion was used to form preforms in such a way that the draping quality is improved compared to classic stamp forming.
   The advantages of the CFRP preform lie in the savings in plant costs, as the investment is much lower. In addition, the proportion of waste is reduced because near-net-shape production is possible. In addition, rejects are reduced, as fewer faults occur in the textile.
    
4. Embroidered preform with integrated metal insert
   The 12k carbon fibre rovings are shaped into a preform using Tai-lored Fibre Placement (TFP) which is a technical embroidery pro-cess. For the further layer build-up, a fastener is not only integrated under the roving layers but also fixed by additional loops. The highly integrative preforming approach offers the possibility of reducing weight and process steps as well as increasing mechanical perfor-mance.
   Until now, inserts were glued or holes had to be drilled in the com-ponent. Bonded fasteners are limited by the adhesive surface. The bonding of fasteners into drilled holes results in high drill abrasion and thus high tool wear.
   The advantages of the embroidered preform with integrated metal fasteners are the reduction of scrap due to TFP preforming and the increase in the specific pull-out force. In addition, it is possible to automatize the production of integrative preforms. This makes the preform with integrated metal fasteners interesting for the automotive and aerospace industries.