DEVELOPMENT OF POLYMERIC OPTICAL FIBRE FABRICS AS ILLUMINATION ELEMENTS AND TEXTILE DISPLAYS
Polymeric optical fibre (POF) is used for simple light guide and illumination applications. The polymer optical fibre materials can be utilised in flexible lighting elements which can be combined with textile structures. The POF woven fabrics are introduced as a flexible alternative to lighting elements.
Various light-emitting woven fabric and light emission theories has been discussed. Simple poly-methyl-metacrylate PMMA and polycarbonate PC fibres have been produced experimentally through single-screw and conical extrusion. The fibre is integrated in woven structures by means of handloom, narrow fabric weaving and Jacquard technology. The manufacturing technology suitable for light-emitting textile applications and its opportunities in textile integration is discussed.
NUMERICAL INVESTIGATIONS FOR CUTTING OF WIRES AND THREADS
Strengthening threads or strings are incorporated in technical textiles for example to protect against vandalism. Among other things, the resistance to mechanical destruction (e.g. cut) depends on the material, the cross-section of the strengthening threads and the support points in the base fabric. An essential criterion for durability is the maximum size of the cutting force, which increases with the decrease in the span. In preceding investigations with spring steel wire, it was shown that an optimum apparently exists for this span. The purpose of the investigations was the development of methods for ascertaining the maximum cutter strengths on the basis of standardised experiments (tensile test) and the proof of the existence of a span optimum. The investigations will be focused on monofilament wire.
COMPUTER MODELLING OF THE LYOCELL FIBRE SPINNING PROCESS
The cellulose Lyocell fibre spinning process can be divided into two processes, a dry spinning process in the air gap, and a wet spinning process in the coagulation bath. In order to simulate the process in the air gap, the heat capacity Cp, the density ?, and the elongational viscosity ? were measured by experiments carried out as a function of temperature and concentration of cellulose. The calculated diameters and temperature profiles along the spinning path were compared with the experimental results. The concentration of N-methyl-morpholine-N-oxide (NMMO) in the fibre (in the coagulation bath) was also measured during the experiments, and the diffusion coefficient was then calculated. Using the data obtained, the time during which the NMMO content in the fibre reaches the equilibrium state in the coagulation bath can be predicted.
YARN TENSION IN THE PROCESS OF ROTOR SPINNING
Yarn tension is a phenomenon of fundamental importance for rotor yarn formation. The problem of dynamic tensions during spinning is of essential importance, as it may result in the possible decrease in yarn quality parameters, such as irregularity of linear density, elongation, tenacity, and the number of faults. We analysed the parameter dependencies which characterise sliver feeding the spinning machine, as well as the dependencies of linear density of the product manufactured on the tension which appears during the process of rotor spinning. This research fragment, on the basis of which the influence of the yarn's linear density on the tension estimated, is discussed in this paper. The measuring method and equipment used is presented.
ANALYSIS OF YARN TWIST FROM THE POINT OF VIEW OF CURRENT KNOWLEDGE
An analysis of models (presented in available world literature) for the twist of multi-folded threads consisting of two component fibre streams (doubled thread, doubled yarn) is discussed. The possibility of forecasting the twist value of the component streams for an accepted twist value of the multi-folded thread is considered.
ASPECTS REGARDING FINISHING OF LYOCELL WOVEN FABRICS
Lyocell fibres have made a special impact on the worldwide textile market since their appearance. The trends in the field of textile fibres and the necessity of increasing the competitiveness of textile articles motivated an analysis of lyocell fibres' potential for the garment sector, and especially for fashion. To this end, some different finishing experiments on lyocell woven fabrics have been conducted.
The technological experiments had the primary fibrillation effect-enzymatic defibrillation-secondary fibrillation in view. For obtaining these effects, rope finishing with/without woven fabrics causticising was carried out, followed by defibrillation (biopolish treatment) before or after dyeing, using different cellulasic enzymes such as Bactosol CA (Clariant), Perizym 2000 and Perizym LYO (Textil Chemie GmbH Dr. Petry).
The experiments considered the evidence of the influence of these technological stages on the surface modification that appears in finishing lyocell textile materials.
BIOACTIVE SURGICAL SUTURES
Investigations carried out into the development of bioactive surgical sutures and radioactive fibres are presented. Anti-microbial surgical sutures, which for a long period provide the wound with the antibiotics settled in their structure, can be of considerable use for precautions and treatment of surgical sepsis. Simultaneously the hydrolytic influence of proteolytic enzymes on the necrotising tissues, which serve as a nutrient medium for microbes, is desirable. The anaesthetic and anticancerous properties of sutures are also of such importance. Antibiotics (such as clindamycin, gentamycin, lincomycin etc.), proteolytic enzymes (such as tripsin and pepsin), anaesthetics (such as lidocaine, novocaine, trimecaine, and pyrocaine), and anti-tumour medicaments (such as prospydin, 5-fluorocyl, sarcolysin etc.) were fixed by us separately or in different combinations onto cation-exchanging polypropylene fibres with the help of ion-exchanging bonds.
A principally new type of biologically active surgical fibres is radioactive fibres which exhibit their action by the emanation of ionising radiation from radioactive isotopes fixed in the fibres' structure. Sulphur-35 isotopes emanating soft beta-rays, and phosphorus-32 isotopes emanating much harder electrons were fixed by us onto polypropylene, polyethylene terephthalate, polyamide, and polyvinyl alcohol fibres by firm covalent bonds.
Biological, medical and clinical tests showed the high effectiveness of the biological active sutures developed by us, as well as that of the radioactive surgical fibres used in different forms.