Textination Newsline

Adhesives are almost always based on fossil raw materials such as petroleum. Researchers at Fraunhofer have recently developed a process that allows to utilize keratin for this purpose. This highly versatile protein compound can be found, for instance, in chicken feathers. Not only can it be used to manufacture a host of different adhesives for a variety of applications, but the processes and end products are also sustainable and follow the basic principles underlying a bioinspired circular economy. The project, developed together with Henkel AG & Co. KGaA, addresses a billion-dollar market.

Adhesives are found nearly everywhere: in sports shoes, smartphones, floor coverings, furniture, textiles or packaging. Even auto windshields are glued into place using adhesives. Experts recognize more than 1,000 different types of adhesives. These can bond almost every imaginable material to another. Adhesives weigh very little and so lend themselves to lightweight design. Surfaces bonded with adhesive do not warp because, unlike with screw fastenings, the load is distributed evenly. Adhesives do not rust, and seal out moisture. Surfaces bonded with adhesive are also less susceptible to vibration. Added to which, adhesives are inexpensive and relatively easy to work with.

Feathers from poultry meat production
Traditionally, adhesives have almost always been made from fossil raw materials such as petroleum. The Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB has recently adopted a different approach. Researchers there have been using feathers as a base material instead of petroleum. Feathers are a by-product of poultry meat production. They are destroyed or mixed into animal feed. But feathers are far too valuable to go to waste because they contain the structural protein keratin. This biopolymer is found in animals and makes up talons, claws, hooves or feathers. Its fibrous structure is extremely strong.

Why keratin is perfect for manufacturing adhesives
Keratin is a biodegradable and thus eco-friendly material whose structure has specific properties that make it particularly suitable for the manufacture of adhesives. Keratin's polymer structure, i.e., its very long-chain molecules, as well as its ability to undergo cross-linking reactions predestine it for the manufacture of various adhesives. “The properties required for adhesives are to some extent already inherent in the base material and only need to be unlocked, modified and activated,” explains project manager Dr. Michael Richter.

Platform chemical and specialty adhesives
Over the past three years, Fraunhofer IGB has been working with Henkel AG & Co. KGaA on the KERAbond project: “Specialty chemicals from customized functional keratin proteins” — Kera being short for keratin, combined with the English word bond. Henkel is a global market leader in the adhesives sector.

The partners in the project have recently developed and refined a new process. In the first stage, feathers received from the slaughterhouse are sterilized, washed and mechanically shredded. Next, an enzyme process splits the long-chain biopolymers or protein chains into short-chain polymers by means of hydrolysis.

The output product is a platform chemical that can serve as a base material for further development of specially formulated adhesives. “We use the process      and the platform chemical as a “toolbox” to integrate bio-enhanced properties into the end product,” says Richter. This means parameters can be specified for the target special adhesive such as curing time, elasticity, thermal properties or strength. Also, it’s not just adhesives that are easy to manufacture but also related substances such as hardeners, coatings or primers.

In the next stage, the Fraunhofer team set about converting the feathers on a large scale. Ramping up the process fell to the Fraunhofer Center for Chemical-Biotechnological Processes CBP in Leuna. The aim was to prove that the keratin-based platform chemicals can also be manufactured cost-efficiently on an industrial scale. This involved processing several kilograms of chicken feathers, with the material produced being used for promising initial material trials at Fraunhofer IGB and Henkel.

Foundations of a bioinspired economy
This bioinspired process is of particular significance for the Fraunhofer-Gesellschaft. Biotechnology is in fact one of the main fields of research for the Fraunhofer-Gesellschaft: “We draw our inspiration from functionality or properties that already exist in nature or in natural raw materials. And we attempt to translate these properties into products through innovative manufacturing methods. This generates a bioinspired cycle for valuable raw materials, Richter explains.

The project carries some economic weight. According to Statista, around one million tons of adhesives were manufactured in Germany alone in 2019. Total value is around 1.87 billion euros.

A patent application has been filed for the new process and an article published in a scientific journal. Two PhD students who have conducted extensive research on the project at Henkel and Fraunhofer are expected to complete their theses in the first quarter of 2024. This new keratin-based technology will allow a host of platform chemicals to be produced in a sustainable, bioinspired way.

The KERAbond project has been funded and supported over the past three years by Fachagentur Nachwachsende Rohstoffe (FNR) in Gülzow on behalf of the Federal Ministry of Food and Agriculture (BMEL) under the Renewable Resources Funding funding program (grant number 22014218).

When nanoplastics are not what they seem ... Textiles made of synthetic fibers release micro- and nanoplastics during washing. Empa researchers have now been able to show: Some of the supposed nanoplastics do not actually consist of plastic particles, but of water-insoluble oligomers. The effects they have on humans and the environment are not yet well-understood.

Plastic household items and clothing made of synthetic fibers release microplastics: particles less than five millimetres in size that can enter the environment unnoticed. A small proportion of these particles are so small that they are measured in nanometers. Such nanoplastics are the subject of intensive research, as nanoplastic particles can be absorbed into the human body due to their small size – but, as of today, little is known about their potential toxicity.

Empa researchers from Bernd Nowack's group in the Technology and Society laboratory have now joined forces with colleagues from China to take a closer look at nanoparticles released from textiles. Tong Yang, first author of the study, carried out the investigations during his doctorate at Empa. In earlier studies, Empa researchers were already able to demonstrate that both micro- and nanoplastics are released when polyester is washed. A detailed examination of the released nanoparticles released has now shown that not everything that appears to be nanoplastic at first glance actually is nanoplastic.

To a considerable extent, the released particles were in fact not nanoplastics, but clumps of so-called oligomers, i.e. small to medium-sized molecules that represent an intermediate stage between the long-chained polymers and their individual building blocks, the monomers. These molecules are even smaller than nanoplastic particles, and hardly anything is known about their toxicity either. The researchers published their findings in the journal Nature Water.

For the study, the researchers examined twelve different polyester fabrics, including microfiber, satin and jersey. The fabric samples were washed up to four times and the nanoparticles released in the process were analyzed and characterized. Not an easy task, says Bernd Nowack. "Plastic, especially nanoplastics, is everywhere, including on our devices and utensils," says the scientist. "When measuring nanoplastics, we have to take this 'background noise' into account."

Large proportion of soluble particles
The researchers used an ethanol bath to distinguish nanoplastics from clumps of oligomers. Plastic pieces, no matter how small, do not dissolve in ethanol, but aggregations of oligomers do. The result: Around a third to almost 90 percent of the nanoparticles released during washing could be dissolved in ethanol. "This allowed us to show that not everything that looks like nanoplastics at first glance is in fact nanoplastics," says Nowack.

It is not yet clear whether the release of so-called nanoparticulate oligomers during the washing of textiles has negative effects on humans and the environment. "With other plastics, studies have already shown that nanoparticulate oligomers are more toxic than nanoplastics," says Nowack. "This is an indication that this should be investigated more closely." However, the researchers were able to establish that the nature of the textile and the cutting method – scissors or laser – have no major influence on the quantity of particles released.

The mechanism of release has not been clarified yet either – neither for nanoplastics nor for the oligomer particles. The good news is that the amount of particles released decreases significantly with repeated washes. It is conceivable that the oligomer particles are created during the manufacturing of the textile or split off from the fibers through chemical processes during storage. Further studies are also required in this area.

Nowack and his team are focusing on larger particles for the time being: In their next project, they want to investigate which fibers are released during washing of textiles made from renewable raw materials and whether these could be harmful to the environment and health. "Semi-synthetic textiles such as viscose or lyocell are being touted as a replacement for polyester," says Nowack. "But we don't yet know whether they are really better when it comes to releasing fibers."

If you’ve ever gotten stitches or had surgery, you may have had a suture. They’re the threads used to close wounds or join tissues together for other purposes.

But did you know that there are different types of sutures which can have an effect on your experience at the doctor or surgeon’s office?

Barbed sutures, for example, can reduce the amount of time you spend on the operating table and lower the likelihood of surgical complications. That type of suture has its roots in the Triangle and is being advanced by students and faculty at the Wilson College of Textiles.

Dr. Gregory Ruff, a nationally-renowned plastic surgeon, first invented the innovative closure in 1991, just down the road in Chapel Hill, North Carolina.

“I was thinking about the fact that we sew wounds together with a loop and a knot and if you tie it too tight, it can constrict the circulation and kill the tissue in that loop,” Dr. Ruff remembers.

“I was thinking about animals, and a porcupine’s quill came to mind. And the aha moment was, ‘What if we put a quill on one side of the wound and another one on the other side of the wound, so there’s no loop: the barbs go in but they don’t come out?’”

As the name suggests, barbed sutures have small projections shooting out of them that can latch onto tissues: think about barbed wire or a fishing hook. Those “quills,” or barbs, allow the suture to self-anchor. Since no knot is needed to secure the suture, the closure is faster, and the lack of knots and constricting loops promotes healing. This also allows surgeons to schedule more surgeries.

Soon after his aha moment, Dr. Ruff started his own company, Quill Medical, to fabricate these barbed sutures. While he had the medical expertise and a solid business partner, Dr. Ruff was looking for someone who could advise him in terms of the material makeup of the suture. The Wilson College’s Biomedical Textile Research Group, under the direction of Professor Martin King, quickly proved to be the perfect partner.

Using the Wilson College’s labs, King’s graduate students conducted a number of tests on Ruff’s sutures across different types of tissues (such as skin, muscle, etc.). One of those students, Nilesh Ingle, found that the barbed sutures worked best when the angles of the barbs were tailored specifically to the type of tissue being sutured.

Years later, one of King’s current graduate students is building on that research insight.
 
Understanding challenges and innovating solutions
Nearly three decades after the barbed suture’s invention, the majority of surgeons still use conventional sutures despite the advantages documented by researchers and surgeons. Why?

Karuna Nambi Gowri, a fiber and polymer science doctoral student in King’s research group, says it comes down to two reasons. The first of these is resistance to change. Most practicing surgeons learned how to use a suture before barbed sutures became more broadly available.

The second obstacle to the use of barbed sutures is procuring them. Barbed sutures tend to be both expensive and low in supply. That’s because the current process for making them (mechanical and blade-based) is inefficient in terms of both time and resources.

That’s where Nambi Gowri’s research with the Wilson College’s Biomedical Textiles Research Group comes in. She’s developing a faster and cheaper method for making the same quality of barbed suture.

“If I fabricate using a laser, the fabrication time is pretty short compared to a mechanical barbing technique,” Nambi Gowri says.

Moving from a mechanical method to a laser method has another advantage.

“The manipulation of the barbed suture itself is easier using a laser,” she says.

In other words, using the lasers will allow Nambi Gowri to apply the custom barb geometries, or angles, suggested by prior researchers on a commercial scale. These custom geometries will allow the barbed suture to be optimized for the type of tissue it will be connecting.

In addition to the new process, Nambi Gowri is also developing a new suture.

“I’m the first one to actually study Catgut barbed sutures,” she explains.

Catgut was actually one of the earliest materials used to make sutures. The filament is made from tissue taken from an animal’s stomach – especially cattle stomachs – hence the name. While the industry had moved away from this material in favor of synthetic polymers, Nambi Gowri sees the potential for Catgut in barbed sutures because of their quick degradation rate.

“These are useful external wound closures,” she says. “Because our body contains so much collagen and Catgut is made up of 90% collagen, it’s a more suitable polymer that can be used in human tissue.”

Hands-on experience informs research
In the meantime, Nambi Gowri has gained hands-on experience to inform her research by fabricating all of the barbed sutures used in Dr. Ruff’s micro facelift surgeries.

The surgery itself is made possible because of the shape and the material composition of the sutures: poly 4-hydroxybutyrate (P4HB). This polymer is already present naturally within our bodies, so sutures made from P4HB are naturally and safely absorbed by the body over time. That means patients don’t have to schedule an appointment after surgery for the sutures to be removed.
 
P4HB also provides the perfect combination of strength and elasticity to hold up the facial tissue until the wound has healed. The barbs, on the other hand, allow for the suture to be placed and stay secure within the skin without the need for large incisions.

“That skin tightens up right away,” Dr. Ruff says of the procedure, which draws patients from across the country. “So I don’t have to remove hair, and I don’t have to put a scar at the hairline.”

“These sutures are not available commercially anywhere in the world. So, to be able to mechanically barb different size sutures in a reliable and consistent manner for use in clinical practice, requires skill, experience and knowledge of quality control,” Professor King says of Nambi Gowri’s work.

This has given Karuna a hands-on understanding of the sutures she’s hoping to improve upon.

She says her fiber and polymer science knowledge has played a key role in helping her approach all sides of her research.

“All the analytical characterization techniques that are used for characterization of sutures – like identifying mechanical properties and measuring tensile strength – is actually from my knowledge of textiles,” she says. “I’m applying my polymer chemistry knowledge  to make sure that the laser doesn’t cause the sutures to degrade, melt or experience thermal damage.”

What’s next?
As she works to patent her designs, Nambi Gowri feels confident that her dissertation will set her up for success in the research and development (R&D) field after graduation.

In the meantime, she’s already finding out about the ways her research can have a broader impact.

“Dr. Dan Duffy, DVM, a surgeon at the NC State College of Veterinary Medicine is also interested in using barbed sutures to repair torn and failed tendons on his animals, but he finds the cost of buying commercial barbed sutures prohibitively expensive. So we need to collaborate,” King says. “Karuna to the rescue!”

Challa Kumar has developed methods to create novel plastic-like materials using proteins and fabric.

Every year, 400 million tons of plastic waste are generated worldwide. Between 19 and 23 million tons of that plastic waste makes its way into aquatic ecosystems, and the remaining goes into the ground. An additional 92 million tons of cloth waste is generated annually.

Challa Kumar, professor emeritus of chemistry, “fed up” with the tremendous amount of toxic waste people continually pump into the environment, felt compelled to do something. As a chemist, doing something meant using his expertise to develop new, sustainable materials.

“Everyone should think about replacing fossil fuel-based materials with natural materials anywhere they can to help our civilization to survive,” Kumar says. “The house is on fire, we can’t wait. If the house is on fire and you start digging a well – that is not going to work. It’s time to start pouring water on the house.”

Kumar has developed two technologies that use proteins and cloth, respectively, to create new materials. UConn’s Technology Commercialization Services (TCS) has filed provisional patents for both technologies.

Inspired by nature’s ability to construct a diverse array of functional materials, Kumar and his team developed a method to produce continuously tunable non-toxic materials.

“Chemistry is the only thing standing in our way,” Kumar says. “If we understand protein chemistry, we can make protein materials as strong as a diamond or as soft as a feather.”

The first innovation is a process to transform naturally occurring proteins into plastic-like materials. Kumar’s student, Ankarao Kalluri ’23 Ph.D., worked on this project.

Proteins have “reactor groups” on their surfaces which can react with substances with which they come into contact. Using his knowledge of how these groups work, Kumar and his team used a chemical link to bind protein molecules together.

This process creates a dimer – a molecule composed to two proteins. From there, the dimer is joined with another dimer to create tetramer, and so on until it becomes a large 3D molecule. This 3D aspect of the technology is unique, since most synthetic polymers are linear chains.

This novel 3D structure allows the new polymer to behave like a plastic. Just like the proteins of which it is made, the material can stretch, change shape, and fold. Thus, the material can be tailored via chemistry for a variety of specific applications.

Unlike synthetic polymers, because Kumar’s material is made of proteins and a bio-linking chemical, it can biodegrade, just like plant and animal proteins do naturally.

“Nature degrades proteins by ripping apart the amide bonds that are in them,” Kumar says. “It has enzymes to handle that sort of chemistry. We have the same amide linkages in our materials. So, the same enzymes that work in biology should also work on this material and biodegrade it naturally.”

In the lab, the team found that the material degrades within a few days in acidic solution. Now, they are investigating what happens if they bury this material in the ground, which is the fate of many post-consumer plastics.

They have demonstrated that the protein-based material can form a variety of plastic-like products, including coffee cup lids and thin transparent films. It could also be used to make fire-resistant roof tiles, or higher-end materials like, car doors, rocket cone tips, or heart valves.

The next steps for this technology are to continue testing their mechanical properties, like strength or flexibility, as well as toxicity.

“I think we need to have social consciousness that we cannot put out materials into the environment that are toxic,” Kumar says. “We just cannot. We have to stop doing that. And we cannot use materials derived from fossil fuels either.”

Kumar’s second technology uses a similar principle, but instead of just proteins, uses proteins reinforced with natural fibers, specifically cotton.

“We are creating a lot of textile waste each year due to the fast-changing fashion industry” Kumar says. “So why not use that waste to create useful materials – convert waste to wealth.”

Just like the plastic-like protein materials (called “Proteios,” derived from original Greek words), Kumar expects composite materials made from proteins and natural fibers will biodegrade without producing toxic waste.

In the lab, Kumar’s former student, doctoral candidate Adekeye Damilola, created many objects with protein-fabric composites, which include small shoes, desks, flowers, and chairs. This material contains textile fibers which serve as the linking agent with the proteins, rather than the cross-linking chemical Kumar uses for the protein-based plastics.

The crosslinking provides the novel material with the strength to withstand the weight that would be put on something like a chair or a table. The natural affinity between fibers and proteins is why it’s so hard to get food stains out of clothing. This same attraction makes strong protein-fabric materials.

While Kumar’s team has only worked with cotton so far, they expect other fiber materials, like hemp fibers or jute, would behave similarly due to their inherent but common chemical properties with cotton.

“The protein naturally adheres to the surface of the protein,” Kumar says. “We used that understanding to say ‘Hey, if it binds so tightly to cotton, why don’t we make a material out of it.’ And it works, it works amazingly.”

With the support of TCS, Professor Kumar is currently seeking industry partners to bring these technologies to market. For more information contact Michael Invernale at michael.invernale@uconn.edu.

Electronically conductive fibres are already in use in smart textiles, but in a recently published research article, ionically conductive fibres have proven to be of increasing interest. The so-called ionofibres achieve higher flexibility and durability and match the type of conduction our body uses. In the future, they may be used for such items as textile batteries, textile displays, and textile muscles.

The research project is being carried out by doctoral student Claude Huniade at the University of Borås and is a track within a larger project, Weafing, the goal of which is to develop novel, unprecedented garments for haptic stimulation comprising flexible and wearable textile actuators and sensors, including control electronics, as a new type of textile-based large area electronics.

WEAFING stands for Wearable Electroactive Fabrics Integrated in Garments. It started 1 January 2019 and ended 30 June 2023.

These wearables are based on a new kind of textile muscles which yarns are coated with electromechanically active polymers and contract when a low voltage is applied. Textile muscles offer a completely novel and very different quality of haptic sensation, accessing also receptors of our tactile sensory system that do not react on vibration, but on soft pressure or stroke.

Furthermore, being textile materials, they offer a new way of designing and fabricating wearable haptics and can be seamlessly integrated into fabrics and garments. For these novel form of textile muscles, a huge range of possible applications in haptics is foreseen: for ergonomics, movement coaching in sports, or wellness, for enhancement of virtual or augmented reality applications in gaming or for training purposes, for inclusion of visually handicapped people by providing them information about their environment, for stress reduction or social communication, adaptive furniture, automotive industry and many more.

In Claude Huniade’s project, the goal is to produce conductive yarns without conductive metals.

"My research is about producing electrically conductive textile fibres, and ultimately yarns, by coating non-metals sustainably on commercial yarns. The biggest challenge is in the balance between keeping the textile properties and adding the conductive feature," said Claude Huniade.

Currenty, the uniqueness of his research leans towards the strategies employed when coating. These strategies expand to the processes and the materials used.

Uses ionic liquid
One of the tracks he investigates is about a new kind of material as textile coating, ionic liquids in combination with commercial textile fibres. Just like salt water, they conduct electricity but without water. Ionic liquid is a more stable electrolyte than salt water as nothing evaporates.

"The processable aspect is an important requirement since textile manufacturing can be harsh on textile fibres, especially when upscaling their use. The fibres can also be manufactured into woven or knitted without damaging them mechanically while retaining their conductivity. Surprisingly, they were even smoother to process into fabrics than the commercial yarns they are made from," explained Claude Huniade.

Ionofibres could be used as sensors since ionic liquids are sensitive to their environment. For example, humidity change can be sensed by the ionofibers, but also any stretch or pressure they are subjected to.

"Ionofibres could truly shine when they are combined with other materials or devices that require electrolytes. Ionofibres enable certain phenomena currently limited to happen in liquids to be feasible in air in a lightweight fashion. The applications are multiple and unique, for example for textile batteries, textile displays or textile muscles," said Claude Huniade.

Needs further research
Yet more research is needed to combine the ionofibres with other functional fibres and to produce the unique textile devices.

How do they stand out compared to common electronically conductive fibres?

"In comparison to electronically conductive fibres, ionofibers are different in how they conduct electricity. They are less conductive, but they bring other properties that electronically conductive fibers often lack. Ionofibres achieve higher flexibility and durability and match the type of conduction that our body uses. They actually match better than electronically conductive fibres with how electricity is present in nature," he concluded.

3D printing has been in use in architecture for a while, and now it is to become ecologically sustainable as well: Together with partners, the LZH is researching how to produce individual building elements from natural fibers using additive manufacturing.

In the project 3DNaturDruck, architectural components such as facade elements shall be created from natural fiber-reinforced biopolymers in 3D printing. To this end, the scientists will develop the corresponding composite materials from biopolymers with both natural short fibers and natural continuous fibers and optimize them for processing with the additive manufacturing process FDM (Fused Deposition Modeling). The project partners' goal is to enable smart and innovative designs that are both ecological and sustainable.
 
The goal: highly developed components made from sustainable materials
Within the project, different natural fiber-reinforced biopolymer composites will be investigated. The partners are researching both processing methods with very short natural fibers, such as from wood and straw, and a method for printing continuous fibers from hemp and flax in combination with biopolymers. The LZH then develops processes for these new materials and adapts the tools and nozzle geometries of the FDM printer. A pavilion with the 3D-printed facade elements is planned as a demonstrator on the campus of the University of Stuttgart.
 
The project partners want to explore how additive manufacturing can be used to simplify manufacturing processes for architectural components. Natural fiber-reinforced biopolymers are particularly suitable for producing components with complex geometries in just a few steps and with low material and cost requirements. With their research, the partners are also working on completely new starting conditions for the fabrication of newly developed architectural components: For example, the topology optimization of components according to their structural stress can be easily implemented with additive manufacturing.

Enabling the natural fiber trend in architecture also using additive manufacturing
There is great interest in the use of natural fibers in structural components in architecture and construction because natural fibers have several advantages. They have good mechanical properties combined with low weight and are widely available. As a renewable resource with in some cases very short renewal cycles, they are also clearly a better ecological alternative than synthetic fibers.

In additive manufacturing, large-format elements for the architectural sector have so far mostly been manufactured with polymers based on fossil raw materials. Research in the project 3DNaturDruck should now make the use of natural fibers in architecture possible for additive manufacturing as well.

About 3DNaturDruck
The project 3DNaturDruck is about the design and fabrication of 3D-printed components made of biocomposites using filaments with continuous and short natural fibers.

The project is coordinated by the Department of Biobased Materials and Materials Cycles in Architecture (BioMat) at the Institute of Building Structures and Structural Design (ITKE) at the University of Stuttgart. In addition to the LZH, project partners include the Fraunhofer Institute for Wood Research Wilhelm-Klauditz-Institut (WKI) and the industrial companies Rapid Prototyping Technologie GmbH (Gifhorn), ETS Extrusionstechnik (Mücheln), 3dk.berlin (Berlin) and ATMAT Sp. Z o.o. (Krakow, Poland).

The project is funded by the German Federal Ministry of Food and Agriculture through the Fachagentur Nachwachsende Rohstoffe e.V. under the funding code 2220NR295C.

Water-repellent and more: coating textiles sustainably with chitosan

Textiles can be coated with the biopolymer chitosan and thus made water-repellent by binding hydrophobic molecules. The good thing is that this can also replace toxic and petroleum-based substances that are currently used for textile finishing. In the last few years Fraunhofer IGB and partners in the HydroFichi project have researched how this can be done: A technology has been developed to provide fibers with the desired properties using biotechnological processes and chitosan.

The manufacture of textiles is, even nowadays, still largely characterized by the use of chemicals: biotechnological processes, enzymes and renewable raw materials have so far played a subordinate role. For example, at present chiefly perfluorinated chemicals are used when finishing textiles to obtain water- and oil-repellent properties. These are harmful to health and also only degradable to a small degree, which is why they remain in the environment for so long.

The Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB has been researching sustainable biobased alternatives for some time. In the HydroFichi project – short for Hydrophobic Finishing with Chitosan – which was completed at the end of January 2021, researchers at the institute developed a way of producing chitosan from waste streams and using the biopolymer not only as a sizing agent in the processing of yarns, but also for the functionalization of textiles in the finishing process.

Chitosan from waste for environmental protection, medical purposes or textiles
Chitosan is a renewable raw material that is derived from chitin; after cellulose, it is the second most common naturally occurring biopolymer. Sources of the nitrogen-containing polysaccharide can be crab shells from fishing waste, insect skins and shells that result from the production of animal feed, or – as a vegan variant – the cell walls of mushrooms. The structure of the two molecules is very similar; the only difference is an acetyl group, which is removed when it is converted to chitosan. Chitin is insoluble in water and most organic solvents. Chitosan is also not readily soluble; however, the addition of mild acids makes the biopolymer water-soluble and it can therefore be used as a textile auxiliary.

In order to isolate chitosan from a particular waste stream, chitin must first be obtained from the starting materials by means of demineralization and deproteinization and then its derivative chitosan. The properties of chitosan can be individually adapted by choosing the appropriate conditions. The biomolecule produced in this way can be used directly in a wide variety of practical applications – for example as a flocculant in wastewater treatment or as a drug carrier in medicines.

There are also numerous conceivable uses for chitosan in the textile industry. In sizing, for example, the efficiency of the natural substance has proved convincing in pilot scale tests carried out by the German Institutes of Textile and Fiber Research Denkendorf. Here, the effectiveness was shown in the significantly lower roughness of the yarns after weaving textile fabrics. The values achieved with chitosan from insects were comparable to those from commercial crab shells. In the future, this fact will enable completely new possibilities of extraction in line with the bioeconomy.

As a renewable raw material, chitosan replaces fossil chemicals
“Our aim in the HydroFichi project was to provide the textile industry with a raw material for a wide variety of applications that can be obtained from renewable educts, at the same time avoiding chemicals that damage the environment and health,” explains project manager Dr. Achim Weber, deputy head of the innovation field Functional Surfaces and Materials at Fraunhofer IGB. “In addition to simple coating with chitosan, which protects the fibers, we were also able to use the substance as an anchor molecule to create cross-linking points for a wide variety of functional groups and thus to provide textiles with specific properties such as making them water-repellent. Chitosan can therefore function as a matrix material or template at the same time, and this can be done with a wide variety of fiber materials.”

The finishes were evaluated using standardized tests, but also with specially designed test stands and methods. For example, measurements on treated textiles showed contact angles of over 140°. This means that the fabrics are very water-repellent and confirms that the processing of the textiles has been successful. In a next step, the technology developed at the IGB is to be transferred from the laboratory scale to the much larger pilot scale in order to make the sustainable biomolecule ready for market use as quickly as possible, for example in the sports and outdoor sector.

For the first time biotechnological processes in textile finishing
In the project, the IGB scientists and four partners from the textile industry – the German Institutes of Textile and Fiber Research Denkendorf (DITF), J.G. Knopf's Sohn GmbH, Helmbrechts, and Textilchemie Dr. Petry, Reutlingen – were able for the first time to establish biotechnological processes in raw material extraction and finishing that have proven to be compatible with all textile processes. So far, this is a unique selling point in the finishing of textiles. “We have all recognized the great potential of chitosan for efficient hydrophobization and as a functional carrier. And, thanks to the good cooperation, we were able to successfully establish techniques for tailor-made functionalization of textiles,” adds Dr. Thomas Hahn, who conducts research in the innovation field of Industrial Biotechnology at the IGB. “In addition, other fields of application for the biopolymer are very promising. That is why we initiated the follow-up project ExpandChi immediately after HydroFichi, in which together with our partners techniques are to be developed to use biobased chitosan as a functional carrier to replace other synthetic polymers, for example for a special anti-wrinkle or flame-retardant coating. The textile industry is very interested in utilizing such a sustainable biomolecule as quickly as possible.“

The “HydroFichi” project was funded by the German Federal Ministry of Education and Research (BMBF) under promotional reference 031B0341A; the follow-up project “ExpandChi”, which began in February 2021, is funded under promotional reference 031B1047A.

TREND REPORT

• Winter sports trends for 2020/2021
• The winter sports industry is increasingly focusing on sustainability
• ISPO Munich (January 26 to 29) to showcase next season’s products

Health will be one of the next decade’s megatrends. The sports industry is, for its part, one of the growth drivers, not least because society now views fitness as a synonym for health. In the future, athleticism will have an ever greater bearing on our everyday lives.

“Medical fitness” refers to ensuring both a sporty lifestyle and the right medical care tailored to the individual needs. Winter sports are also set to assume a challenging yet important role in the future as a vehicle for teaching values within society. Veit Senner, Professor of Sports Equipment and Sports Materials at the Technical University of Munich, says: “Sports must be used as an emotional Trojan Horse for teaching skills and in particular for teaching values.”

There are also other challenges that will need to be faced in the next few years: Children and adolescents need to be encouraged to lead more active lifestyles and our aging population needs to be kept fit and mobile for as long as possible. Senner believes that winter sports could hold the key for today’s youth: “We need to demonstrate the kinds of educational content and values that can be taught through sports.” Attractive products and services therefore need to be created for children. The latest winter sports trends and pro ducts will be showcased at ISPO Munich from January 26 to 29.

Textile manufacturers are giving the winter sports industry an eco-boost
Swedish label Klättermusen impressed the ISPO Award jury so much with its first fully compostable down jacket “Farbaute” that they named it the Gold Winner in the Outdoor category and the winner of the ISPO Sustainability Award.

The first 100% biodegradable down jacket biologically decomposes on the compost heap after around three months (all apart from the zippers and a few snap fasteners which can be removed and reused).

When washed it does not release any microplastics into the environment. Norwegian clothing manufacturer Helly Hansen is launching a new membrane technology for winter 2020/2021 which can be produced without any additional chemicals. The microporous Lifa Infinity membrane is made using a solvent-free process and, together with a water-repellent Lifa outer material, provides extremely impressive protection from the elements. Helly Hansen’s new Lifa Infinity Pro technology also uses the spinning jet dyeing process whereby the color pigments are already injected during the fiber production process. This can save up to 75% water. What’s more, no harmful wastewater is produced.

The winter sports industry is increasingly focusing on sustainability
“The really big trend is for biopolymer fabrics and materials,” says Senner. “The idea is to replace the many different types of plastics that are used in the sports industry with biopolymers.” Together with his team, he is working hard to conduct in-depth research in both areas. This is a trend which French ski brand Rossignol has also identified, whereby it has focused on the use of raw and recycled materials for the production of its new Black Ops Freeride skis. The Black Ops Sender TI model was crowned the winner in its category by the ISPO Award jury.

Alpina Sports is also exploring new ecological avenues and launching a completely sustainable back protector made from 100% sheep’s wool, obtained exclusively from sheep in Switzerland and Norway. The back protector, which consists of three layers of pressed sheep’s wool, meets the standards for protection class 1 and boasts all the impressive properties that the natural material has to offer: In icy temperatures it remains supple, can both warm and cool the wearer, and is odorless. The ISPO Award jury chose Alpina Sports’ “Prolan Vest” as the “Product of the Year”* in the Snowsports Hardware category.

Swedish label Spektrum uses plant-based polymers made from castor oil as well as corn and recycled polyester for its ski and snowboard goggles. The ISPO Award jury was extremely impressed with both the ecological aspects and the execution and named the “Östra Medium” model the Gold Winner.

• Good chances for synthetic fibers and functional textiles

Bangkok (GTAI) - Thailand's textile industry is in transition and is increasingly positioning itself in new markets with higher added value. Synthetic fibers became an important foothold on the basis of innovative raw materials, while functional textiles are grateful to customers in a dozen sectors. In addition, there is the traditional silk craft, which can be marketed by international design and attractive fashion shows - and this at top prices.

The Thai textile industry is changing. As a part of the long-term national development strategy “Thailand 4.0” , new technologies are designed to help innovative products breakthrough in key emerging markets, backed by concerted efforts in design, fashion and marketing. The industrial foundation ensures the availability of a complete value chain from fiber production, yarn spinning, fabric weaving and processing to the production of clothing.
The long-term strategy has been outlined by the Thailand Textile Institute (THTI) in its "Thailand Textile and Fashion Industries Development Strategy 2015-2030". Three phases are planned from the regional center for textile and fashion retail, to the development of creative products for international brands, and finally the breakthrough as the global market leader in fashion design, including Thai components. The concrete catalog of measures includes an industrial fashion zone, a pilot fiber plant, a development center for yarn, fabrics and fashion products as well as a regional fashion academy.

Broad spectrum for innovations
A diversified petrochemical industry with high-quality downstream products provides a rich foundation for a wide variety of synthetic fibers. The main products are polyester, nylon, rayon and acrylic polymers. The range of applications is quite broad, including apparel, medical technique, hygiene and automotive manufacturing. For polyester, Thailand ranks ninth in the world with an annual production of 621,000 tons, the larger producers include Indorama Polyester, Teijin Polyester or Thai Toray.

Increased research and development efforts with both artificial and natural textile fibers are paving the way for functional textiles. There are a dozen applications in this broad future market: Agrotex, Mobiltex, Medtex, Hometex, Oekotex, Packtex, Buildtex, Clothtex, Indutex, Geotex, Protex and Sportex. The leaders in this branch are companies such as Asahi Kasei, Perma, Saha Seiren, PJ Garment or TP Corporation. Thailand also wants to play an active role in shaping the future market of "smart fabrics" - such as fabrics with UV protection or antibacterial and fire-resistant properties.

Renaissance of the silk
On elegant paths also the traditional over generations grown art of silk crafts is moving. Thanks to the rich raw material base, the kingdom is considered to be the world's fourth largest silk producer. In the preference of visitors from abroad, silk products are at the eighth place in the souvenir statistics 2015 with USD 149 mio.
The origins of silk were characterized by the craftsmanship weaving with regional origin characteristics such as at the Lumphun Broocade Thai Silk, the Phu Thai Praewa Silk or the Surin Hole Silk. The change to innovative products took place with the growing demands of customers. New technologies produced goods of higher value, which were also became promoted with new stronger marketing ideas.

Jim Thompson and Passaya are considered two major pioneers of world-class luxury silk brands. Jim Thompson generates USD 72 mio thanks to modern design and premium products. Passaya won international awards for outstanding innovations in design as well as in the production process. Public support has been provided by promotional events such as "Proud Pastra", which recently completed USD 1.5 mio  in trade surplus. The Ministry of Commerce also intends to establish a silk center in the northeastern Korat under the state-sponsored so-called OTOP scheme (One Tambon One Product).

The entire industry has currently  4,700 textile and garment manufacturers with over 500,000 workers, including 730 textile companies for technical textiles. The export value amounted to USD 6.45 billion in 2016, which represented about 3 percent of total exports. The national retail sector recorded steady growth rates averaging 3.5 percent per year over the period 2011-2016.

In addition to production, Thailand also tries to profile itself as a fashion hub for regional and international fashion shows. The most important events are the "Bangkok International Couture Fashion Week", "Elle Bangkok Fashion Week" and the "Bangkok International Fashion Fair". The first national designer brands have already made their debuts on the catwalk, such as Sretsis, Naraya, Dry Clean Only or Disaya. Sretsis, founded by three sisters, became successfully supported by some big names such as Beyoncé, Paris Hilton, January Jones and Zooey Deschanel.