Geometric Structures in Textile Design Made with 3D Printing

3D printing is a well-known technology for producing 3D objects by depositing successive layers of material. Among its many applications, the fashion industry has taken advantage of this technology to revolutionize its brands. Due to the unique properties of textiles, such as comfort, flexibility, etc., attempts have been made to create textile-like structures. Structures with different geometries were designed and printed using different materials ranging from rigid to flexible. In this study, three different basic geometric structures were designed using the Blender program (a free open-source 3D modelling software). Each geometric structure was designed in two different sizes with smaller and larger basic structural elements. In this case, six different models were created. The aim of this study was to compare the textile-like surfaces of different basic geometric shapes produced with 3D printers. It also aimed to investigate the use of surfaces designed with basic geometric shapes in the textile-like material for fashion industries. In the production phase, the fused deposition modelling (FDM) process was chosen, and ABS and TPU materials were used. Various tests were performed, such as weight tests, and tensile and flexural strength tests on models with different basic geometric shapes and sizes. An examination of the test results showed that the different geometric shapes of the various basic structures and the different materials used have an overall effect on the final properties of the structures. It was concluded that the obtained results can be used as a reference and could be helpful for researchers in the use of 3D printers in the textile-like material and fashion material industries

Influence of printing material and printing ink layer on RFID antenna operation

Radio Frequency Identification (RFID) enables non-contact quick and easy data transferring through electromagnetic waves in the radio frequency range. The technology of RFID tags in the clothing and the textile industry is not commonly used yet, however, it enables the tracing of materials or textile products from their creation to sale, the identification of textiles and their protection against theft. In the research, the possibility of using of functional screen printing technique with an electrically conductive printing ink based on silver particles for the printing of passive RFID tags on textile material is showed. For printing, the two textile materials; polyester woven fabric, lyocell nonwoven textile and comparatively paper were used. The suitability of the selected textile materials for the printing of electronic structures for working passive UHF-RFID tags was tested. As a reference printing material that enables a high-quality print of electrically conductive structures, paper was used. The electrical conductivity of conductive patterns printed on textile materials and paper was measured, the quality of the prints and their abrasion resistance were assessed and the read range of the RFID tags on different printing materials was checked. It was found out that the best electrical conductivity of the prints was achieved on paper and slightly less electrically conductive prints were on the lyocell nonwoven textile. The RFID antennas printed on lyocell had the same range of operation, i.e. 150 cm from the receiving antenna of the reader, as the prints on paper. On the polyester fabric, it was not formed such an uniform layer of electrically conductive printing ink as on the lyocell nonwoven textile, therefore the prints on polyester were less electrically conductive and the printed RFID antennas operated at a shorter distance, only 60 cm from the receiving antenna of the reader. The abrasion resistance of the surfaces of printed RFID antennas was poor on all printing materials, because the ink transferred from the prints to the rubbed samples; the worst surface-resistant were prints on the lyocell

Influence of Ink Curing in UV LED Inkjet Printing on Colour Differences, Ink Bleeding and Abrasion Resistance of Prints on Textile

Digital printing techniques are increasingly present in the field of textile printing. Particularly prominent is the inkjet printing technique using water-based inks, UV LED inkjet printing also increasingly being in use. UV LED inkjet is primarily not intended for direct clothing printing; however, it can be used especially as a hybrid solution in the soft signage market. It is a great option for the printers that are not engaged only in textile printing, and want a more versatile print portfolio, extending it to non-clothing textile products, e.g. soft signage and non-wearable products. As these types of products often require colour reproduction of logos, accurate colour reproduction, good ink adhesion and sharpness are important just like in other printing technologies. In order to evaluate the impact of UV LED radiation amount on colour differences, ink bleeding and abrasion resistance, six different fabric samples (five woven and one nonwoven) were printed using a UV LED inkjet printer. Based on the results of colour difference, it was established that a reduction of UV radiation (by half the manufacturer’s recommended amount) had no effect on this parameter. However, perceptible colour differences were observed with the use of different M measurement conditions defined by the international standard ISO 13655-2017. Reducing the amount of UV radiation had no effect on the adhesion and durability of the printed ink. Small differences detected in these two parameters were mainly a consequence of the properties of textile materials and not of decreased UV radiation

Problem of waste effluents in wood industry - the possibilities of biological treatment

Lesna industrija ni velik onesnaževalec voda, a s tem se ni tolažiti. Odpadne vode lesne industrije pogosto vsebujejo zelo visoke vrednosti nevarne in strupene substance - formaldehida, zato je nujno potrebno, da se prične s podrobnimi analizami odpadnih voda in z raziskavami o možnostih čiščenja. Statistične analize so pokazale, da se lesna industrija še vse premalo zaveda kako hitro lahko porušimo ekološko ravnotežje v naravi, saj so vrednosti o količini čiščenih odpadnih voda v lesni industriji izjemno nizke. Tako smo v seminarju podali nekaj smernic in možnosti odstranjevanja formaldehida iz odpadnih voda s poudarkom na sekundarnem postopku čiščenja - biološkem čiščenju odpadnih voda. Biološko čiščenje je lahko anaerobno ali aerobno, zato smo predstavili oba postopka. Večji poudarek in podrobnejši opis je podan za aerobni postopek biološkega čiščenja, na katerem sem opravila svoje raziskave v praktičnem delu diplomske naloge.Wood industry does not pollute waters to a great extend, nevertheless we must be aware that the problem still exists. Waste effluents in wood industry contain very high portion of dangerous and toxic substance - formaldehyde. That is why it is inevitably vital to start with detailed analysis of waste effluents and with studies of possibilities of decontamination. Statistical analysis are showing that wood industry are not well aware of the fact how quickly the ecological balance can be destroyed, since the quantitiesof treated waste effluents are extremely low. During the seminar some guidelines on how to extract formaldehyde from waste effluents were issued with the stress on secundar method of treatment - biological treatment of waste effluents. Biological treatment can be both, aerobic or anaerobic. During the seminar both methods were introduced with theemphasis on the aerobic procedure, which I was researching in the experimental part of my diploma work

Colour Fastness to Various Agents and Dynamic Mechanical Characteristics of Biocomposite Filaments and 3D Printed Samples

The aim of the study was to analyse the colour fastness of 3D printed samples that could be used as decorative or household items. Such items are often fabricated with 3D printing. The colour of filaments affects not only the mechanical properties, but also the appearance and user satisfaction. Samples of biocomposite filaments (PLA and PLA with added wood and hemp fibres) were used. First, the morphological properties of the filaments and 3D printed samples were analysed and then, the colour fastness against different agents was tested (water, oil, detergent, light and elevated temperature). Finally, the dynamic mechanical properties of the filaments and 3D printed samples were determined. The differences in the morphology of the filaments and 3D printed samples were identified with SEM analysis. The most obvious differences were observed in the samples with wood fibres. All printed samples showed good resistance to water and detergents, but poorer resistance to oil. The sample printed with filaments with added wood fibres showed the lowest colour fastness against light and elevated temperatures. Compared to the filaments, the glass transition of the printed samples increased, while their stiffness decreased significantly. The lowest elasticity was observed in the samples with wood fibres. The filaments to which hemp fibres were added showed the reinforcement effect. Without the influence on their elasticity, the printed samples can be safely used between 60 and 65 °C

Effect of printing process parameters on the shape transformation capability of 3D printed structures

The aim of our research was to investigate and optimise the main 3D printing process parameters that directly or indirectly affect the shape transformation capability and to determine the optimal transformation conditions to achieve predicted extent, and accurate and reproducible transformations of 3D printed, shape-changing two-material structures based on PLA and TPU. The shape-changing structures were printed using the FDM technology. The influence of each printing parameter that affects the final printability of shape-changing structures is presented and studied. After optimising the 3D printing process parameters, the extent, accuracy and reproducibility of the shape transformation performance for four-layer structures were analysed. The shape transformation was performed in hot water at different activation temperatures. Through a careful selection of 3D printing process parameters and transformation conditions, the predicted extent, accuracy and good reproducibility of shape transformation for 3D printed structures were achieved. The accurate deposition of filaments in the layers was achieved by adjusting the printing speed, flow rate and cooling conditions of extruded filaments. The shape transformation capability of 3D printed structures with a defined shape and defined active segment dimensions was influenced by the relaxation of compressive and tensile residual stresses in deposited filaments in the printed layers of the active material and different activation temperatures of the transformation

Colour fastness to various agents and dynamic mechanical characteristics of biocomposite filaments and 3D printed samples

The aim of the study was to analyse the colour fastness of 3D printed samples that could be used as decorative or household items. Such items are often fabricated with 3D printing. The colour of filaments affects not only the mechanical properties, but also the appearance and user satisfaction. Samples of biocomposite filaments (PLA and PLA with added wood and hemp fibres) were used. First, the morphological properties of the filaments and 3D printed samples were analysed and then, the colour fastness against different agents was tested (water, oil, detergent, light and elevated temperature). Finally, the dynamic mechanical properties of the filaments and 3D printed samples were determined. The differences in the morphology of the filaments and 3D printed samples were identified with SEM analysis. The most obvious differences were observed in the samples with wood fibres. All printed samples showed good resistance to water and detergents, but poorer resistance to oil. The sample printed with filaments with added wood fibres showed the lowest colour fastness against light and elevated temperatures. Compared to the filaments, the glass transition of the printed samples increased, while their stiffness decreased significantly. The lowest elasticity was observed in the samples with wood fibres. The filaments to which hemp fibres were added showed the reinforcement effect. Without the influence on their elasticity, the printed samples can be safely used between 60 and 65 °C

3D Digital Preservation, Presentation, and Interpretation of Wooden Cultural Heritage on the Example of Sculptures of the FormaViva Kostanjevica Na Krki Collection

The paper presents an interdisciplinary approach to the treatment of the FormaViva collection of wooden sculptures exhibited outdoors in a natural environment near the Božidar Jakac Art Museum in Kostanjevica na Krki in Slovenia. The study focuses on 3D graphic representations of sculptures created with photogrammetry and 3D modelling. The results are photorealistic renderings, interactive presentations, 3D printed reproductions, jewellery, and interpretive animations. The research results show that graphic documentation techniques on 3D models allow for a more detailed investigation of the original structural identity of the sculpture. By incorporating 3D and interactive technologies, we are expanding the usability of cultural heritage objects. By using interpretive techniques that have led to jewellery and interpretive animations in our research, we not only breathe new life into the sculptures, but also enrich the stories of the sculptures with our own experiences of the sculptural work