TWO-STEP CROSSLINKING OF PVP/GEL NANOFIBERS

In this study, it was achieved that crosslinking of PVP/GEL nanofibers with two-steps. Crosslinking is a process highly important for water-soluble polymers in terms of application areas and mechanical properties. Firstly, crosslinking of PVP polymers experimental studies were carried out via heat treatment at different temperatures and times. Then, GEL polymers were crosslinked with GTA vapour at different times. Morphological analysis was carried out via SEM images and chemical characteristics were determined via FT-IR analysis. Moreover, after the crosslinking process, SD and WL values were calculated. All results showed that before crosslinking of SEM images, nanofibers were smooth, fine and without beads. The average fiber diameter is 196 nm and the fiber diameter distribution is quite uniform. After crosslinking of SEM images, it is expected that all nanowebs will turn from fibrous surfaces to membranous. Generally, SD and WL values decrease with crosslinking time increase. According to all of the SEM images, SD and WL values, optimum conditions were determined for PVP as 4 hours at 180oC and for GEL as 24 hours. Lastly, the presence of PVP and GEL polymers in the nanofiber structure was verified chemically with FT-IR analysis.

CARBON FIBRE ALIGNMENT FOR REINFORCED COMPOSITES USING EMBROIDERY TECHNOLOGY

Composites are materials formed by the combination of two or more components that acquire better properties than the ones obtained by each component on its own. Composites have been widely used in the industry due to its light weight and good mechanical properties. To improve these properties several layers of reinforced material (e.g., carbon fibre) are overlapped which produce an increase in the fibre consumption. In this sense Tailored Fibre Placement (TFP) embroidery can offer good opportunity to reduce the consumption of reinforced fibre while improving the mechanical properties due to the alignment of the fibres in the effort direction. This study analyzes the performance of carbon fibre reinforced composites with Polyester resin made with TFP embroidery technology against flexural strength efforts and without using plain woven fabrics to demonstrate that the use of reinforcement fabrics in composites can be optimized by a curved alignment of the fibers. Two different structures were embroidered with TFP technology, one simulating a woven fabric with straight unidirectional alignment of fibres in horizontal and vertical direction, and a second structure made with curvilinear alignment of carbon fibers. After the study of the flexural mechanical properties an improvement of 18% was obtained in maximum flexural strength.

DEGRADATION OF NONWOVEN FABRICS SUITABLE FOR WET WIPES BURIED IN SOIL

In this research, biodegradation behaviour of nonwoven fabrics suitable for wet wipes having different fibre types such as regenerated cellulose (viscose and Tencel), polyethylene terephthalate (PET) and their blends were investigated. Each nonwoven fabric was buried in soil and test samples were controlled in regular periods. Visual appearance was reported and examined by photographs and microscopic views. According to the changes in visual appearance and weight loss, biodegradation was examined in a systematic way. It has been observed that regenerated cellulose nonwoven fabrics and the PET nonwoven fabrics show big difference under the same degradation conditions. PET fibre content delays biodegradation in the soil and degradation behaviour is similar the content of PET fibre in fabric structure. The higher PET, lower degradation, and the higher cellulosic fibre, the higher degradation was determined for nonwoven fabrics suitable for wet wipes.

DESIGN OF GARMENTS USING ADAPTABLE DIGITAL BODY MODELS

In recent years, the 3D design software has been mostly used to improve the garment design process by generating virtual 3D garment prototypes. Many researchers have been working on the development of 3D virtual garment prototypes using 3D body models and involving the 3D human body scanning in different postures. The focus of research in this field today relies on generating a kinematic 3D body model for the purposes of developing the individualized garments, the exploration of which is presented in this paper. The discussed area is also implemented in the Erasmus+ project OptimTex - Software tools for textile creatives, which is fully aligned with the new trends propelled by the digitization of the whole textile sector. The Slovenian module focuses on presenting the needs of digitization for the development of individualized garments by using different software tools: 3D Sense, PotPlayer, Meshroom, MeshLab, Blender and OptiTex. The module provides four examples: 3D human body scanning using 3D photogrammetry, 3D human body modelling and reconstruction, construction of a kinematic 3D body model and 3D virtual prototyping of individualized smart garments, and thus displays the entire process for the needs of 3D virtual prototyping of individualized garments. In the OptimTex project, the 3D software Blender was used to demonstrate and teach students how to construct the "armature" of the human body as an object for rigging or the virtual skeleton for a 3D kinematic body model, using the knee as an example.

DEVELOPMENT OF MULTILAYER TEXTILE STRUCTURES FOR FILTERING APPLICATIONS – A NEW SURGICAL MASK APPROACH

Universal mask use has emerged as one of the main strategies for reducing community transmission of the SARS-COV-2 virus. Due to the scarcity of material to produce disposable surgical masks, the governmental strategy was oriented to the community masks, even though performance levels were still not the same. This study intended to develop a new generation of surgical masks with different warp knit structures, evaluating the potential of multilayer gradient performance. The assembling methodology was also considered by modifying flat-bed calendering process parameters and manipulating final structures into a new origami design concept, and the overall mask filtration performance was reviewed. The overlapping of monolayers increased the substrate resistance to air and water vapour permeability, also influencing the water molecule's adhesion. The introduction of the web allowed a better layer assembling during the flat-bad process. Moreover, the breathability and water vapour diffusion are compromised since the adhesive web with temperature tends to merge and occupy the empty spaces between the layers. Moving forward, calendared structures without a web proved to be the best approach, meeting the certification criteria for surgical masks level I and II.

ELECTROSPINNING OF ANTIBACTERIAL POLYURETHANE/ZnO NANOFIBERS

In this study, it is aimed to produce and characterize antibacterial polyurethane (PU)/Zinc oxide (ZnO) nanofibers by electrospinning method. Firstly, polymer solutions were prepared at various ZnO concentrations such as 0, 0.2, 0.4, 0.6, 0.8, 1. Then solution properties (conductivity, viscosity, surface tension) were determined and analysed the effects of ZnO concentration on the solution properties. PU/ZnO nanofibers produced via electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate and atmospheric conditions). Finally, the nanofibers were characterized in terms of fibre morphology, thermal stability, permeability and antibacterial activity using SEM-EDS, DSC-TGA, water vapour permeability and disk diffusion methods. According to the solution results; it was observed that conductivity and surface tension decrease significantly with ZnO addition. On the other hand, solution viscosity increases as the ZnO concentration increases. From the SEM images, it has been seen clearly that average fibre diameter increases with ZnO concentration and incorporation of ZnO particles to the fibre structure was verified by SEM-EDS. According to the thermal analyse result, nanofibers begin to degrade between 271.94 ºC and 298.73 ºC. In addition, water vapour permeability increases as the ZnO concentration increase. Lastly antibacterial activity against gram negative (E.coli) and gram positive (S. aureus) was determined with specific zone diameter.

CLOTHES DEVELOPMENT BASED ON METHODS OF HANDLING OF PREMATURE BABIES IN THE INTENSIVE CARE UNIT

The health of children born prematurely remains a significant challenge, but clothing products designed considering medical requirements and handling methods used in the intensive care unit, may contribute to the reduction of neonatal mortality. Assistants in the therapy unit implement practices based on the needs of vulnerable infants, from the very first second of life. This pilot clinical study was conducted in a specialised on neonatal intensive care unit, at the IMSP Municipal Clinical Hospital Gheorghe Paladi from Chisinau. Informed consent of parents and/or careers was required. All users (nurses and doctors) were informed about the product and instructed regarding dressing and undressing process. This controlled study was conducted under the supervision of doctors and nurses. As the study was exploratory in nature, aspects of grounded theory have been used for qualitative data collection. The sample studied consists of preterm infants less than 30 weeks GA, admitted by UTIN in 2018. The population eligible for qualitative data collection was made up of neonatology nurses from the clinic. To obtain a heterogeneous sample, aspects such as age, work experience, environment, and education were considered. The method of observation and subsequent testing used of the newly designed products and every manipulation under medical conditions was intensely studied. Local reactions, if any, due to the texture and quality of the textile material that come into contact with the baby's skin, were also carefully monitored. The process of dressing and stripping off the products, carrying out medical manipulations (in case of neonatal emergencies), were also carefully observed for developing ease of use clothes.

OPTIMIZATION OF SOME WEAVING MACHINE PARTS DESIGN. THEORETICAL APPROACH

The factors of increasing productivity, reducing the cost and the quality improvement are the most important research concerns in weaving machinery. Increasing the effectiveness and productivity of production were achieved by increasing the operating time and efficiency of weaving looms. Thus, the manufacturers of weaving equipment attempt to minimize factors that limit production speed and production conditions. Heald frame is one of the known parts of the weaving machine that causes vibrations and noise which are important factors that influence high-speed development of looms. In this research work, study of mechanical factors (stresses and vibration) has been investigated for heald shaft. Finite element model of the heald frame was constructed to simulate different type of material. Then some important natural frequencies and vibration modes are calculated and the results. Results show a major improvement with the usage of these different material. As well as the failure of heald shaft is mainly due to friction and vibration and not due to the stresses or weight.

ACCESSIBILITY AND USABILITY OF THE LEARNING TOOLS TO ACCELERATE INNOVATION IN THE FIELD OF SMART MATERIALS DEVELOPMENT

This work presents the general aspects concerning the accessibility and usability of the learning tools existent for smart materials development using eco-design in the context of the circular economy. These learning tools will be used in part and some of them developed in the framework of the Erasmus+ project DigiTEX and will cover also the aspects of digital learning technologies capable to accelerate innovation in the field of healthcare and protective systems based on electroconductive materials. In DigiTEX Erasmus+ project will be developed solution-based software technologies, database development and creative methods for coaching the innovative ideas from design, development and production management in the context of circular economy and sustainable development with reduced environmental impact. This paper is structured in 5 sections such as introduction, smart materials overview, eco-design for smart materials, circular economy approach and conclusions.

ELECTROSPINNING OF ST. JOHN'S WORT OIL LOADED MICROCAPSULES BASED PVA NANOFIBERS

In this study, it was achieved that the production of St. John's Wort oil loadad Eudragit RS 100/PVA microcapsules by emulsion/solvent evaporation method and the microcapsules were embedded in PVA nanofibers. Morphological analysis was carried out with SEM images of both microcapsules and nanofibers. The presence of St. John's Wort oil, PVA and Eudragit RS 100 polymers were confirmed in the chemical structure of microcapsules and nanofibers by FT-IR. According to experimental studies, microcapsules were produced to have a smooth surface, a spherical shape and a uniform particle size. The PVA concentration was kept constant at 10% wt and microcapsule concentrations were applied as 1, 3, 5, 7, and 9 wt %. Then, polymer solution properties were measured, such as conductivity, viscosity, and surface tension. It was determined that viscosity and surface tension values increased with microcapsule concentration increase, while conductivity did not change significantly. Nanofiber production was realized via the electrospinning method under the optimum process parameters. According to the SEM images and histogram, nanowebs have a fine fiber diameter, smooth surface, high quality and no bead structure. In addition, the average microcapsule size is 30 μm, average fiber diameter is 430 nm and the fiber diameter uniformity coefficient is 1,014. It is thought that this nanofiber surface containing microcapsules embedded in St. John's Wort has the potential to be used as a wound dressing.