With the advancements of textile technology and synthetic fibers, smart textiles now covers the fields of nanotechnology, material science, design and textile engineering. Emerged as a result of interdisciplinary researches in electronics and computer engineering and medicine, smart textiles started to occupy have begun to gain an important place in the textiles and ready-to-wear industries study such as medicine.
Starting its education services in 1966 as İzmir Textile Technical High School, today the Department of Textile Engineering boatsts to be one Turkey’s oldest, modern and comprehensive textile education institutions. Since its inception, it has been training problem-solving engineers for the Turkish textile industry, who are equipped with an up-to-date and high quality education, open to improve, creative, aware of responsibilities, and have a strong communication engineers.
We present to you as the Textile Technology Magazine, the informative interview we have made with Assoc. Prof. Deniz DURAN of the Department of Textile Engineering at Aegean University, on smart textiles and nonwoven surfaces.
Can you tell us about your studies in your laboratory, smart textiles and what innovations it has brought?
In our laboratory, researches are conducted on both smart textiles and nonwoven textiles. Our studies on smart textiles has mainly concentrated on the areas of conductive and electromagnetic protective textiles. Conductive textiles are textile structures that have the ability to transmit electrical charges unlike conventional textile structures. Demand for conductive fibers and textile structures is increasing every day. Researches on conducting polymers have become very important in the last 20 years,. One of the functions that the electrical conductivity brings to textiles is the electromagnetic protection
Why is it necessary to have electromagnetic protection and what is its importance for public health?
Radiation spread from the electromagnetic fields (EMF) in high tension lines, such as high voltage lines, is a social problem. The electrical and electronic devices we use in the daily lfie and in the professional area are emitting electromagnetic waves. There are reports about exposure to the electromagnetic field, causing people to have various health problems. For this reason, electromagnetic protection is an important issue for public health.
What kind of studies are you carrying out in the laboratory to provide electromagnetic shielding?
Our research in this area is carried out by undergraduate and graduate dissertations and the R&D projects supported by the Ministry of Industry and the Scientific and Technological research Council of Turkey.
Conductive and electromagnetic protective textiles are made with production of conductive yarns, woven and knitted fabrics, nonwoven production methods on conductive textiles and coating/lamination techniques. Electromagnetic shielding effectiveness measurements are tested in our laboratory with electromagnetic shielding effectiveness measurement system, which is produced in the frequency range of 30 MHz-6 GHz in a frequency range of 30 MHz-6 GHz, in accordance with EN50147-1 standard. In this way, the closest results are achieved.
Tests on electromagnetic shielding efficiency are conducted with electromagnetic shielding efficiency measurement system in our laboratory, by producing real electromagnetic waves in the frequency range of 30 MHz-6 GHz completely isolated from the environment with the anechoic chamber principle, in accordance with EN50147-1 standard and and applying them on textile materials. Thus, we achieve most real-time results.
This way, designing, production and performance tests on many finished textile products for both daily and professional use are carried out. Researches on the conditions in which healthcare staff who are intensively exposed to electromagnetic radiation in the workplace, and the sensitive products for white collar workers or pregnant women and children who should not be exposed to electromagnetic waves.
Which machines do you have in your laboratory and for what purposes do you use them?
We have a meltblown line, an automatic feeder line, an airlaid elbowsheet and binder fixture, a laboratory-type coating and laminating machine, a tufting machine and a recycling line for the nonwoven surfaces. Innovative product development and R&D studies are maintained by using these machines and relevant methods.
In the needling method, which allows processing of synthetic and natural fibers, fiber bundles are fed to the combs by air-flow after opening and blending. After carding, the cheesecloth are taken to the laying and folding band with the swan-neck apparatus and is laid on top according to the desired thickness. Needling is carried out throughout the thickness of the cheesecloth/padding which is formed by unfixed fibers. The notched needles move fibers from one face of the cheesecloth to the other side to form a complex structure, one part of the fibers which form the cover, which are loose during the needling, stick up to the needles and remain in place, and the fibers are pulled down with the needles reattached. This way, mechanical interlocking of the fibers is completed.
What is the Meltblown method?
The meltblown method is when thermoplastic raw material is melted in the extruder and sprayed in high-speed airflow through the rolls in the form of microfibers on the cylinder, and forms the final surface by self-bonding. In this method, the polymer material/melt dissolved in the extruder is sprayed through the nozzle holes, with a flow of hot air at high speed and the micro-sized fibers, cool and solidify as they move towards the collecting cylinder. The solidifying fibers are randomly orientated in the picking cylinder and form the nonwoven textile surface. The Meltblown method is a single step process, and is the shortest method fpr textile surface production as known currently.
Can you talk about your productions and what areas are they targeting?
In our melt blown laboratory, we conduct production of microfibrous nonwoven surfaces and our studies on this subject. We have some finished and ongoing projects in the fields of medicine and hygiene textiles, insulation, three dimensional sandwich nonwoven textiles, recycling and biodegradation, agricultural textiles, nonwoven-reinforced composites and automotive textiles. By producing surfaces with the combination of melt blowing and some other methods such as needle punching, we focus on nonwoven medical textile products, which speed up the treatment process, increase patient comfort during treatment and facilitate application to healthcare personnel. In addition to all these features, nonwoven surfaces, especially those with microfibers, increase the hygiene by exhibiting very good barrier features thanks to the enlarged surface area and small size pores. We countiue our researches on the meltblown surfaces to increase hygiene.
We have also carried out reserches on the biodegradable nonwoven surfaces for the agriculture field, which are destroyed in nature and do not harm the nature after having fulfilled the function expected of them.
Insulation materials are very important components in terms of both energy saving and enhancing the comfort of life, which are not noticed in the first place by the buyers in the construction and automotive industries. No doubt, nonwoven textile, especially three dimensional sandwich textures, are ideal materials for heat and sound insulation thanks to their random fiber orientation and hollow structure. In this context, we carry out studies in our laboratory to make insulation materials for the automotive and construction industries by combining meltblown, needling and other methods on structures achieved with the methods of needling and lamination.
Today’s most important issues for the automotive industry are energy saving, lightness and recycling, i.e. sustainability. For this reason, the share of textile materials in the automotive industry grows every day. To this end, we are working on nonwoven surface structures and mechanical engineering, which will both lighten the construction and provide insulation in the automotive industry as well as composites with reinforced nonwoven textiles. We also appreciate the use of natural fibers and recycled fibers in this area.
Can you tell us about your researches on recycling and the recycling process in your laboratory?
Sustainability, as it is known, is one of the most important issues in the textiles industry in recent years, as well as in many other industries. We also continue to work on this important issue in our laboratory. All kinds of textile waste are recycled into fibers in the guillotine and chiffon machines in our recycling line.
In the guillotine machine, fabrics, garments or textile wastes classified according to the raw material type or color are separated from the metal parts and fed to the conveyor band. A metal detector detects the metal alloys, which may be contained in the material fed to the conveyor belt, and if it detects any, it stops the band and sends a signal. The machine continues to operate after the metal part is removed. Cutting dimensions can be set by adjusting the speed of the conveyor belt with the frequency setting on the control panel. When it is conveyed with the material supply band, it is compressed in a certain position by the upper pressure rollers and fed regularly to the cutting outlet. The upper knife on the machine is mobile while the lower knife is fixed. The material, fed by the up and down movements of the upper blade is separated into small pieces.
Textile wastes separated into small pieces in the guillotine machine are fed to the chiffon machine. Then, the fiberized wastes taken from the chiffon machine can be used alone or in combination with non-recycled natural or synthetic fibers to produce nonwoven surfaces or as composite reinforcement material. In processing these fibers, needling and airless crimping methods yield good results.
What kind of collaborations have you been engaged in so far?
So far, we have been engaged in collaborations with various companies both in the fields of conductive and electromechanical protective textiles and nonwoven materials in the scope of projects by the Ministry of Industry and the Scientific and Technological research Council of Turkey. Within these projects, we have developed textile products for daily and professional use, which have electrical conductivity and other features of texture, use and comfort provided by conventional textiles. Designing, production and performance tests for these products are carried out within the companies and departments which we are in cooperation with. We also work together with different departments of our university, such as mechanical engineering, for interdisciplinary studies. We would also like to point out that we are always ready to cooperate with companies and other universities, which want to work with us on these issues.
What will be your new projects?
In our new projects, we plan to utilize our know-how and experience in the field of conductive and smart textiles for designing and production of specific products, to bring together different functions, and to cooperate with different sectors.
About nonwoven textiles, our studies will continue to intensify on medicine and hygiene, agricultural textiles, automotive textiles, insulation, recycling and sustainability. Because of the importance we attach on sustainability, biodegradable polymers and nonwoven textile production will continue to be our priorities. In the near future, we will also focus on filtration, for which we have already completed the preliminary works.