For over a decade, Centexbel, the Belgian research centre for textiles and plastics, is highly involved in the development and implementation of biopolymer fibres and textiles. Drop-in biopolymers such as Bio-PE or Bio-PET intrinsically have the same properties as their oil-based counterparts and can be implemented with limited technological developments.
Therefore, our focus lies on new biopolymer types since they offer a real challenge to develop appropriate processing conditions and additive selection and to maximise the specific properties offered by these new polymers such as PLA (PolyLacticAcid), PHA’s (PolyHydroxyAlkanoates), PHB (PolyHydroxyButerate), PBS (PolyButyleneSuccinate), TPS (ThermoPlastic Starches) or PEF (PolyEthyleneFuranoate). At present, PLA is the most economic biopolymer and available in the highest amounts. The majority of the research projects are directed to the use of this biopolymer in textile applications. This is illustrated by 3 European projects, representing our past and present research activities.
“BIOAGROTEX” was one of the first large-scale projects on biopolymers, coordinated by Centexbel. The project aimed at developing fully biobased agrotextiles, exploiting the specific properties of biopolymers such as PLA to be composted after its normal lifetime. To those agrotextiles requiring a guaranteed lifetime of several years, but preferentially have to be composted after reaching its end-of-life, this polymer can offer an attractive solution. In the project we succeeded in defining appropriate grades and processing conditions for production of fibres, monofilaments and tapes, which fulfilled the requirements of the specific applications.
Based on the positive results, several industrial partners launched specific new biobased Agrotextiles into the market; amongst others:
• DURACOVER® – Bonar Technical fabrics: Woven groundcovers from PLA tapes.
• HORTAFLEX® – DS Textiles: needlefelt groundcovers from PLA fibre
• FILBIO®PLA –Texinov: Knitted insect screens from PLA monofil
The products have been successfully implemented in the market and a market growth is expected in those countries where public procurement rules define the use of biodegradable or more ecologic, sustainable products, especially in the case of large public projects (railways, highways, public green space, … ).
Example: DURACOVER from Bonar Technical Fabrics from Bonar Technical Fabrics
Example: DURACOVERExample: HORTAFLEX® from DS Textiles
Example: FILBIO®PLA from Texinov
In a second more recent project, the development of biobased textile products is continued but instead of focussing on biodegradable properties, more durable applications are envisaged. The development looks into the possibilities of spinning yarns from PLA staple fibres, in combination with other natural fibres such as wool or cotton. The yarns will be further processed into fabrics for a variety of high-end clothing applications, including in casual menswear and ladieswear, protective clothing and workwear. Via this route 100% biobased articles will also be generated, avoiding the use of oil-based polyester fibres. It is obvious that in these applications durability and comfort aspects are of a much higher importance than biodegradability.
This H2020 “Fast-Track-To-Innovation” project, coordinated by Aimplas, joins the expertise of 3 industrial partners representing the different production steps: fibre extrusion, yarn spinning, weaving and confection and is supported by 2 research institutes. Centexbel supports the development of functionalised formulations and the fibre extrusion processes in close collaboration with DS Fibres who has also participated in the Bioagrotex project.
The project was started just recently. The first industrial products into the market are expected in 2019. Further information is provided by the project website: http://fibfab-project.eu
Spinning and weaving PLA/wool and PLA/Cotton yarns.
The objective of the third example of European projects, BIO4SELF, is to develop a further high-end and durable application of PLA materials. In this project, coordinated by Centexbel, a consortium of 16 research centres and industrial partners, representing the complete value chain, have set themselves the task to improve the PLA filament production to allow the production of novel fully biobased composites using the self-reinforcement technology.
To achieve this goal, high performance nanofibrillar PLA fibres will be developed, with a high tenacity and a higher melting temperature, that can act as reinforcement fibre in the composite. This reinforcement fibre itself is additionally reinforced with a bio-based thermotropic liquid crystalline polymer nanofibrils (bio-LCP) to reach the requested high mechanical properties.
For the matrix, lower melting PLA fibres will be developed and combined with the high melting reinforcement fibres to create hybrid yarns and preforms. These hybrid PLA preforms will be made with different fibre architectures, e.g. chips with short fibres in random orientations, and fabrics with long fibres in controlled orientations.
These intermediates will be further processed by injection moulding or compression moulding routes, to a range of high-level composite products.
Self-reinforced composite obtained by combining a low and high melting PLA grade.
A further goal is to develop self-functionalization of the composite materials, aiming to induce inherent self-cleaning (via photocatalytic fibres), self-healing (via tailored microcapsules) and self-sensing (via deformation detecting fibres) properties. Prototype parts for automotive and home appliances will be developed with the novel materials to demonstrate the broad application potential of the biobased self-reinforced materials.
BIO4SELF requires innovation all along the value chain.
This project example clearly shows that biopolymers are no longer solely used and developed for biodegradable and biobased purposes, but for the highest application levels and that they have the potential to outperform standard oil-based products in some applications.
For further information and updates on the BIO4SELF project, feel free to sign up for the project newsletter at the website: www.bio4self.eu.
The projects mentioned above, are only a few examples of the research projects performed at Centexbel in relation to the biobased economy. Other projects are dealing with alternative biopolymers such as TPS, PBS or PHA. Moreover, our projects not only address extrusion applications but are also evaluating alternative biobased formulations for coating and finishing processes.
Although the introduction of biobased polymers and chemicals in the textile industry is still taking place on a very small scale, we are convinced that this will gradually change in the near future. The ongoing research will surely result in new “eye-catcher” applications within a few years that will boost the implementation of biobased textiles and support the global change towards the biobased economy.
Luc Ruys, Centexbel, Technologypark 7, 9052 Gent, Belgium