Microwave Technology of the Flax Processing
Development of Foundations of Microwave Technology for the Processing of Flax and Flax-Inclusive Materials into Products of Different Kinds
Tech Area / Field
- PHY-RAW/Radiofrequency Waves/Physics
- MAN-PDM/Plant Design and Maintenance/Manufacturing Technology
3 Approved without Funding
Russian Academy of Sciences / Institute of Radioengineering and Electronics, Russia, Moscow
- Central Scientific Research Institute for Integrated Automation of Light industry, Russia, Moscow
- Karolinska Institute / Microbiology and Tumor Biology Center, Sweden, Stockholm\nQueen's University of Belfast, UK, Belfast\nInstitute of Agricultural Engineering, Germany, Potsdam\nInstituto Nacional de Investigacao Agraria e das Pescas, Portugal, Lisbon\nUniversity of Maryland / Institute for Research in Electronics and Applied Physics, USA, MD, College Park
Project summaryThe aim of this project is a development of the new methods for processing of flax and flax-containing materials into products for different purposes with application of high-power electromagnetic pulses. The main attention in the process of implementation of this project will be focused on the investigation of the influence of high-power microwave pulses on the flax properties alteration for the improvement of consumer quality of the flax products.
The main object of the investigation is a bast fiber (flax and hemp fibers) that represents a very important source of cellulose for the Textile Industry. Flax and hemp are traditional world crops that relate to fiber crops. Flax is the only easy-reproductive natural cellulose-containing plant raw-material in Russia with unique properties. It can be cultivated on large areas according to the soil and climate conditions. The bast-fiber crops have the same stalk structure representing a number of concentric layers that can be pided into three main parts: cortex (bast), wood (shive) and core. The bast is the sourse of fiber, and the rest parts of the plant should be removed in the process of decortication.
The flax fiber has good consumer properties. The rate of the flax cellulose polymerization is 2-3 times higher than that of cotton. Therfore, flax is much stronger and has much higher sun-light and washing resistance. Flax is very hygroscopic. It absorbs moisture very well and at the same time returns moisture very fast and becomes dry. No static electrical charges form on the surface of the flax cloths. These and other properties make flax very health-giving for the humans and, in addition, the articles made of flax are very comfortable in use. Besides the fabrics for domestic purposes, there are also different industrial cloths made of flax. Recently, the interest to the problems of flax greatly increased due to the unique medical and biological properties of flax fiber investigated in Russia and other countries.
Unfortunately, at present, the linen fabrics are more expensive than the cotton ones because of very complicated and expensive technology for obtaining and processing flax as well as because of the great number of biological and chemical processes participating in the production. In addition, there are some difficulties in using the unique medicinal properties of the bast plant fibers: the difficulties of fiber separation from the stalk (imperfect decortication process); the complexity of preparation for spinning; the coarse properties of the obtained spun yarn; the necessity for the special preparation for weaving and especially for knitting; high wrinkle rate of fabrics.
Decortication is one of the main technological stage of the flax life cycle. It is a separation ability of the bast-fiber layer from the wood. The decortication ability of the flax straw determines the quality and quantity of the obtained flax fiber. The flax primary treatment is very expensive because of the very high labor and energy expenditure for drying the material. In this process, the fiber makes up only 20%, and other 80% are the wastes (wood). The new developed primary treatment methods of the straw on the base of chemical and chemical-physical processes make the treatment more expensive or deteriorate the quality of the obtained fiber.
The main problem in the linen processing consists in the fact that the linen is coarse. Therefore, it must be specially treated for making knitted fabric. The conducted investigations showed that the coarse rate of the linen is determined by the quality of its cellulose, namely, by the level of crystallinity and structural anisotropy. The brightening agents and paraffin are often applied for softening the linen, and they should be removed from the ready-made knitted fabric. All these processes include liquid treatments, they are characterized by very high labor and energy expenditure and therefore are accompanied by a lot of ecological problems.
All this requires to develop new methods and approaches for the processing of flax products. At present, the following three groups of the world tendencies in the field of textile materials’ dressing development can be conditionally distinguished by their methods of exposure: chemical, biological, and physical intensification.
The exposure of the textile materials’ dressing processes to the different physical fields is usually considered as a physical intensification. A new technology proposed by the Institute of Radioengineering and Electronics of Russian Academy of Science (IRE RAS) and Federal State Enterprise – the Central Scientific Research Institute for Integrated Automation of Light Industry (FSE – CSRIIALI) relates namely to this kind of intensification. It is a technology for alteration (modification) of the properties of flax and flax-containing materials for improving their characteristics on the basis of non-thermal exposure to the high-power electromagnetic pulses. This is an absolutely new method and there are no analogues in the world.
The electro-physical generators of high-power video and radio pulses consist the technological base of this newly developed method. The flax products are to be exposed to the high-power pulses at the initial stage of the finishing technological process. This technology provides the possibility to reduce or avoid the application of the strong chemical agents. This method can be easy applied at the existent production cycles because the pulse generators are the electric devices and they do not require any special conditions. This technology is environmentally appropriate because the used electromagnetic pulses have practically no influence upon the human health and environment. The exposure is performed by the pulses of 5-100 ns duration. The main peculiarity of the proposed method is the use of the electric field with very high electric intensity of about 105 V/cm. The radiant pulse energy at that is small, and its order amounts to mJ.
The use of the developed technology for the flax materials’ processing in the textile industry will provide for the decrease and even for the elimination in some cases the utilization of the dangerous chemicals. This will improve the environmental safety of the textile industry. In addition, the improvement of the quality and properties of the flax products will reduce the price of their production due to the low power consumption of the electro-technological equipment. Therefore, the industrial implementation of the technology proposed in the present project will provide for the significant total benefit.
The whole cycle of research work on the influence of the high-power electromagnetic pulses upon the flax straw and yarn was performed in IRE RAS and FSE- CSRIIALI. The influence on the flax straw made it possible to significantly increase its decortication ability. The microscopic anatomic analysis revealed the breaks on the parenchyma tissue and cambial layer. The influence on the wet spun yarn can reduce its coarse rate by 20-30%. The influence of the high-power pulses is different for different technological process. In the case of decortication, the influence is determined by the conductivity of the fibers. In the case of exposure of the flax yarn and fabric, the effect of treatment is determined by the chemical structure of cellulose. The efficiency of the treatment is also determined by different parameters of pulses (amplitude, duration, frequency, etc.).
The complete scope of the investigation will be the result of the combined efforts of all the project participants. The highly qualified scientific specialists of IRE RAS and FSE-CSRIIALI are engaged in the implementation of this project. All the products of the linen industry including the crops, straw, fiber, yarn and fabric are the objects of the exposure and investigation. At the first stage, the electro-physical characteristics, structure and peculiar properties of the flax products will be investigated. This task is an auxiliary one in the certain sense. The results of the exposure to the high-power electromagnetic pulses (the change of the physical, mechanical and technological characteristics of the linen and fabric) will be analyzed thereafter.
The following tasks will be realized in the course of the project implementation:
- the determination and investigation of the electro-physical characteristics of the flax fiber using the modern experimental equipment and methods of analysis;
- the experimental investigations of the influence of high-power pulses with different parameters upon the flax products;
- the determination, analysis and investigation of the physical and technological changes taking place in the flax fiber and linen under the exposure to the high-power pulses;
- the determination of the high-power pulses parameters that are optimal by their influence upon the different flax products;
- the development and production of the experimental models of the powerful high-voltage generators that will be used for the demonstration of the possibility of the developed technology application in the working conditions;
- the performance of the experimental investigations in order to obtain the flax materials with new medico-biologic properties and their products (flax-wool, bulky dressings) that are characterized by the compatibility with the human organism.
The highly qualified scientific specialists of IRE RAS and FSE-CSRIIALI are engaged in the implementation of this project.
The works on the development and creation of the high-power electromagnetic pulse generators on the base of the heavy-current accelerators as well as the works on application of these generators for different purposes have been performed in IRE RAS for a long time already. A great experience on the application of the electromagnetic radiation generators for investigation of non-thermal affect of the high-power microwave pulses on the different natural and artificial media is accumulated in the institute. At present, in IRE RAS, it is possible to carry out experimental and theoretical investigations of the flax products’ characteristics using modern analytical methods including the X-ray structure analysis and optical and electron microscopy.
FSE-CSRIIALI holds the full range of knowledge on all technological stages of the flax processing and is engaged in research of the flax properties and development of the new articles made of flax. FSE-CSRIIALI is a leading organization in the Federal Target Program “Development of the Flax Complex in Russia”. It accumulates an abundant scientific and practical experience in the development of new consumer materials and non-traditional articles for the medical practice made of domestically produced flax-containing raw materials.
The following results are expected at the project implementation:
- a fundamentally new technology of the flax straw decortication that allow for the significant decrease of the expenses required for the preparation of the source starting material will be developed;
- a new method of the linen and flax cloth modification (the change of rigidity, cloth dyeability) characterized by the decrease of brightening preparation consumption will be developed;
- flax materials with new medico-biologic properties and their products (flax-wool, bulky dressings) that are characterized by the compatibility with the human organism will be obtained.
The closing statement with the recommendations for the implementation of the developed microwave technology at the light industry enterprises will be published after the project termination. The recommendations for the use of the proposed method in the processing of some other textile materials will also be analyzed and published.
Russian specialists working over the problems related to generation of the high-power electromagnetic pulses and their influence upon different media as well as the specialists in the domain of the textile materials’ dressing are expected to participate in collaboration with the foreign participants in the framework of the scientific and technical researches. The regular information exchange concerning the problem under consideration as well as the discussion of the obtained results, the co-ordination of the engineering factors of the designed equipment and suggestions concerning the developed technology implementation are planned. The co-authorship publications and participation in the scientific seminars and conferences are also expected.
The project accomplishment answers the purposes of ISTC to promote the military projects’ conversion and to involve the Russian scientists and specialists into the international scientific and technological society. Research officers and engineers of IRE RAS that participated earlier in the development of the powerful accelerating machinery will be engaged in the work over the project.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.