This study investigates the potential use of digital inkjet printing to produce uniform-colored textiles comparable to those dyed conventionally. The color uniformity of inkjet-printed block pattern using combined vacuum plasma treatment and inkjet printing of nano-pigment ink is studied. The surface properties of the plasma treated textiles were characterized using scanning electron microscopy (SEM) and absorption. The color performances, color uniformity and fastness properties of printed textiles were evaluated by color measurement, wash fastness, and abrasion tests respectively. The results showed that plasma treatment significantly enhances the color performance of printed polyethylene terephthalate (PET) and polyamide 66 (PA). The color strength increases with printing passes and the most significant enhancement was with two printing passes, thereafter it reaches saturation. It was found that plasma-treated fabrics absorbed the ink faster, therefore the colorants concentrated at the textile surface. Furthermore, the inks printed on plasma-treated samples showed better wash fastness and abrasion property for both PET and PA fabrics. Moreover, the color uniformity results showed that ΔECMC is distributed between 0.25 and 0.5 over the uniform-colored surface. This study demonstrates the feasibility of using resource-efficient textile processes, such as plasma treatment and inkjet printing, to produce uniform-colored textiles as alternative to conventional dyeing methods. 

One way of charting the way forward is to research potentials to educate through various options that today’s technology can offer. Virtual reality (VR) using 3D glasses is one example and we know from earlier research that learning in this way is experienced as joyful by students. In a European perspective, the use of technology in a pedagogical way to stimulate learning needs attention. Despite fairly common prerequisites in Europe, it is not obvious how technology can be used to not only be joyful but also enhance learning and develop the learning environment. In this specific study, the safe environment in a virtual reality lab (Tatli & Ayas, 2010) offers an alternative to the real physical lab when students in textile education are studying inkjet printing. The aim is to gain knowledge about how the learning of the inkjet printing process takes place in the traditional physical lab and in virtual reality lab. The research questions are: 

• What characterizes the learning conditions in a lab and VR environment respectively?
• What characterizes the learning through physical lab work and in VR respectively?
• What improvements do the students suggest for the VR app?
• What happens to learning when lab and VR experiences are combined in different sequences?

Closely related to the security that virtual environments offer is the joy that arises (De Vries & May, 2019; Makransky et al. 2019), for example, from students being able to repeat stages in a process as long as they want and need without risking destroying anything. The positive feelings increase students’ confidence in their own ability (Sarmouk et al., 2019) and thereby, motivation for learning is strengthened. Not least intrinsic motivation, based on Self Determination Theory, meaning that the driving force comes from the students themselves instead of, for example, parents or teachers, is desirable. The result in a study by Makransky et al. (2019) show that the use of VR provides increased internal motivation. Comparing VR and physical labs, the conclusion in most studies is drawn that VR constitutes a valuable complement to the physical lab (see for example Sarmouk et al., 2019; Vahdadikhaki et al., 2024). However, there are researchers claiming that VR labs in some cases are more effective than physical labs (Chan et al., 2021). Training in VR as preparation for students to handle the real lab better contributes to both cognitive and emotional aspects meaning that they increase their self-confidence (Sarmouk et al., 2019). Other researchers, for example Moozeh et al. (2020) show that VR is not only preparing students but also gives them an opportunity to integrate and apply knowledge from the physical lab in the VR context. Apart from the research showing that safety, joy and motivation through VR stimulate students' learning, there are no clear results about what characterizes learning in the virtual environment. Learning in areas such as processes, concepts, practical skills and analytical skills can according to some studies (for example Garcia Estrada & Prasolova-Førland, 2022) be facilitated by VR while other studies (for example Sarmouk et al., 2019) show that students can become accustomed to using the equipment through VR. However, it is not only the design of the specific VR app that is essential for learning. In addition, factors such as pursuit of realism (Vahdadikhaki et al., 2024), the implementation in terms of, for example, instructions, support (Chan et al., 2021) and adaptation to students' individual needs (Yang et al., 2023) also matters for learning.

Method

Descriptive phenomenology and specifically the approach Reflective Lifeworld Research (RLR) (Dahlberg et al., 2008; Giorgi, 1997) has been used to study how the learning of the inkjet printing process takes place in the traditional physical lab and in virtual reality lab respectively. The current phenomena, i.e. those that manifest themselves, are both learning that takes place in a physical lab and learning that takes place in VR. Within descriptive phenomenology, only basic theories on which phenomenology generally rests, for example life-world theory (Husserl, 1970/1936) are used. It is a conscious choice to avoid other theories with the aim of reinforcing that the lived experiences of the participants must be central in the search for new knowledge. Data collection was conducted via five focus group interviews with students, four of them at bachelor’s level and one group at master's level, a total of 12 participants. The participants were expected to experience learning through both lab and VR and therefore were offered both for ethical reasons. Informed consent had been collected previously. Lab and VR were scheduled in different orders and interviews at different times enabled variations in the participants' experiences. To avoid that the learning VR experience was prevented by novice equipment issues, all participants had an opportunity to try VR glasses with Demo app before using the specific app. In phenomenological research, many different contexts and variations are desirable in the data and in this study, variation was offered through schedule, different study levels, gender and ages. The variations enable examination of what, despite all the differences, are common characteristic features of the phenomena (Dahlberg et al., 2008). The analysis was conducted in several different steps, all of which are characterized by openness and reflection so that the researcher's previous knowledge of the phenomenon is bridled during the process (Dahlberg et al., 2008). After reading the data, meaning-bearing units, which can consist of words, sentences or whole paragraphs are marked (van Manen, 2014). Patterns, called clusters are then sought among the units so that the meaning of the phenomenon can eventually be formulated as a new whole on an abstract level.

Expected Outcomes

The result shows that learning in both physical and VR lab evoke emotions. The students experience joy in both labs but express their motivation more clearly based on the experience of using VR glasses. The physical lab is experienced as more serious based on all safety instructions, protective clothing and more. The VR lab is more playful and because mistakes have no consequences, a kind of trial-and-error behavior develops. The instructions in the physical lab were more detailed and were perceived as very clear and easy to follow. In addition, there was the possibility to always ask a teacher. In VR, the instructions were not that specific and disappeared after a while.The students also felt that they were left to fend for themselves without having anyone to ask. In VR lab, different parts of the process can be practiced again and again without any material being destroyed, which offers students opportunities for extensive training that might be too costly in physical labs. An advantage of the physical lab is that the students experienced the process with many different senses. They understood how the ink worked by observing how particles got stuck in the filter and by handling the ink with their own hands. Learning differs in the various labs and aspects such as being able to use one's senses are difficult to achieve via VR, but for example the perceived uncertainty through unclear instructions could be remedied without major efforts. There is thus good potential for learning through the virtual lab and regardless of order, students need both labs as they offer different kinds of learning.

Current immobiliza;on techniques oWen face significant challenges, including unevendistribu;on of enzymes, reduced enzyma;c ac;vity, and material waste, all of which can limitthe effec;veness of immobilized enzymes in industrial applica;ons. To address these issues,this study introduces a hydraulic spray automa;on system specifically designed for theimmobiliza;on of redox enzymes on tex;le substrates, providing a novel, resource-efficient,and con;nuous method for enzyme immobiliza;on. For this, glucose oxidase (GOx) waschosen as the model enzyme and was immobilized onto polyester tex;les (PET) using thehydraulic spray system. To op;mize the immobiliza;on process, several cri;cal parameters,including enzyme concentra;on, pickup percenatge, and the technique of layer-by-layerassembly of GOx was studied. Results revealed significant improvements in both the stabilityand ac;vity of the immobilized GOx, which are crucial for its effec;veness in industrialapplica;ons. Results showed that, the loading of GOx on PET had no influence on type of PET(ac;vated or pris;ne) used. However, surface ac;va;on offered be2er stability of GOxagainst rinse cycles. Results also showed that, with the increase of pickup percentage theac;vity of immobilized GOx increases un;l it reaches to the plateau. The results werepromising and demonstrated significance in uniformity and reduc;on in waste and ;meduring enzyme immobiliza;on. This immobiliza;on method not only minimizes resourceconsump;on by reducing waste but also facilitates large-scale produc;on, making itpar;cularly well-suited to meet the evolving demands of the industry. Ul;mately, this researchdemonstrates the poten;al of hydraulic spray automa;on technology to revolu;onize enzymeimmobiliza;on, paving the way for more sustainable and efficient industrial applica;ons.

This study introduces hydraulic spray (HS) atomizing system as new resource-efficient continuous dyeing-finishing method for wool fabric. Here, wool fabric was dyed and finished by using commercial dyes and finishes through either one-step or two-steps HS method. Results obtained from color strength (K/S), color difference (ΔECMC) and color fastness analysis presented the apprehension of HS method in dyeing of wool fabric with different GSM and dyes. Finishing performance of wool fabric was measured through water contact angle analysis. Analysis shows that, the finishing performance of HS method were substantial to reach water contact angle as high as 145° while maintaining high fastness to wash and abrasion. Between one-step and two-steps HS method, one-step method showed better performance with high resource efficiency compared to two-steps method. Results from statistical analysis shows no statistical significance of fabric weight, type of dyes, and finishes to the performance of new HS method which is crucial for true-scale industrial implementation and scaling up of this process. The findings of this report are of great importance as it presents a greener alternative to the conventional resource-intensive dyeing-finishing methods of wool fabric.

Although resource-efficient processes like inkjet printing have a large potential to foster the development of smart and functional textiles, one bottleneck still is the development of functional inks. To make inkjet printing and UV curing given production techniques for smart and functional specialty products, e.g. photochromic textiles, deepened knowledge about the development, rheological behavior and jetting behavior of functional ink is needed. This paper focuses on the formulation and performance of UV-responsive and UV-curable inkjet inks, which are based on photochromic dyes and their application to produce UV-responsive textiles. Two commercial photochromic dyes—Reversacol Ruby Red (RR) and Sea Green (SG), which represent dyes of the naphthopyran and spirooxazine class, respectively, have been used to develop the inks. The photochromic inks are characterized according to their physical–chemical and rheological properties in respect to temperature. The influence of temperature on the drop formation of the inks in an industrial print head is analyzed using a high-speed camera, which reveals important information regarding challenges in ink jettability. It was found that the dye structure and type used in the ink can influence the jetting behavior of photochromic UV-curable ink. More pronounced temperature sensitivity of dyes can increase the temperature-related effects of drop formation as was observed for SG ink. The printability of the RR and SG inks is framed and underpinned by theoretical calculations of the Z number. Discrepancies are observed and discussed between existing theory of ink jettability and visual evaluation of the photochromic ink.

Smart textiles have been a hot topic in research for several decades; however, comparatively few products can be found on the market. Resource-efficient processes can boost the breakthrough of smart and functional textiles, which often necessitate high-cost materials and only require small batches.

This thesis provides a technology-driven approach with resource-efficient solutions for the production of UV-sensing textiles, while pointing out the challenges of the new materials, which are created when novel production processes are used. The performance of UV-sensing textiles produced by ink jetting and UV curing of ink with commercial photochromic dyes is primarily explored. Several steps in the development of a UV-sensing textile are covered in thesis; development and jetting performance of the photochromic UV-curable inkjet ink, optimization of the color performance of photochromic prints using production process parameters by tuning color kinetics, and evaluation of the durability and textile character of photochromic textiles. Other focuses included in the thesis are dyeing of photochromic textiles with supercritical carbon dioxide (scCO2), novel ways of stabilizing photochromic prints and ink jetting of functional ink for sports and work wear.

It was shown that physical properties of the ink and temperature affected the jetting behavior of the ink. A discrepancy between the drop formation of UV-curable photochromic ink and existing models for jetting of inkjet ink was highlighted. Reversibly color-changing textiles can be produced with inkjet printing and UV curing of photochromic inks. The combination of the resource-efficient processes with the photochromic material required the introduction of an extended kinetic model to describe the coloration reaction of prints. An essential finding was that the kinetics of photochromic dyes in UV-curable ink applied on polyester fabric could be tuned using fabrication parameters during printing and curing in a continuous resource-efficient production process. By changing fabrication parameters during production, the prints’ crosslinking density is influenced and hence dye kinetics can be modified as a result of matrix rigidity of the UV ink. Furthermore, fabrication parameters influence and can be used to improve print durability as of abrasion and washing. Also, printing with photochromic UV-curable ink did not affect the fabric properties significantly in regards to flexibility and surface morphology. With the results obtained, photochromic textiles can be produced resource-efficiently using inkjet printing and UV curing, as well as scCO2 dyeing to boost the cost-effective and flexible production of smart textile UV sensors.

Photochromic molecules are well-established colourants in the manufacturing of niche products, providing reversible colour change effects when irradiated with ultraviolet (UV) light. The high material cost of such speciality dyes along with the general high carbon footprint and extensive water consumption of textile products necessitates resource-efficient production processes. The use of supercritical CO2 (scCO(2)) dyeing technique enables the economic production of textile high-end products, where a uniform through colouration is desired. This study investigates the potential application of two commercial photochromic dyes based on spirooxazine (Sea Green - SO-SG) and naphthopyran (Ruby Red - NP-RR) to polyester fabric using scCO(2) dyeing technique and examines their photochromic behaviour. The dyeing was carried out at 120 degrees C and 25 MPa for 1 h. The photochromic performance was evaluated using a specially designed online colour measurement system capable of simultaneous UV irradiation and continuous measurement of photochromic colour change even after the shutdown of the UV source. The colour yields (K/S values), photoswitching rates and durability against washing were the main parameters examined. The results showed that scCO(2) dyed photochromic polyester fabrics exhibited reversible colour changing properties upon UV exposure and removal. The samples dyed with SO-SG demonstrated a comparable degree of photo-colouration, lower background colour, faster colouration and decolouration speeds, but inferior wash fastness compared with NP-RR dyed samples. Particularly, the same class of dyes applied by scCO(2) dyeing showed faster fading rates compared with conventionally dyed and screen printed samples. This study shows that scCO(2) dyeing method is a potential alternative to develop uniformly coloured photochromic textiles providing excellent photochromic performance with additional economic and environmental benefits.

The development and design of novel functional and smart textile materials such as textile sensors and multicolored systems based on photochromic dyes necessitate controls of color intensities, switching speeds, and material durability. Precise control and synchronization of dye kinetics are important for multi-colored photochromic applications especially. However, durability towards abrasion and washing should not be compromised on if we aim to design reliable future textile products. In this study, two different commercial photochromic dyes — a naphthopyran and a spirooxazine-based dye — have been applied on PET fabric by inkjet printing and UV-LED curing. The photochromic textiles’ color behavior, fastness to abrasion and washing, and handle are evaluated using spectrophotometry, scanning electron microscopy, and Kawabata evaluation system. Despite a decrease in color performance after washing, the photochromic inkjet print is effective and barely influences the textile structure. Reduced rigidity of the host matrix promoted higher color yields and faster dye kinetics, but also improved durability towards abrasion and washing. In order to synchronize kinetics of the different dye types for multi-colored applications, distinct curing conditions are preferable, which, however, result in varying print durability. In the design of multi-colored photochromic textiles, dye kinetics, and durability have to be balanced.

Photochromic textiles are of considerable interest for smart and functional textile applications due to their remarkable dynamic colour changing effect when irradiated with light of a certain wavelength. The use of resource efficient processes, such as digital inkjet printing and supercritical carbon dioxide (scCO₂) dyeing techniques enables an economic production of those high-end functional products with high material costs. In this study, photochromic polyester fabric has been prepared by applying two commercially important photochromic dyes from spirooxazine (SO) and naphthopyran (NP) dye classes using scCO₂-dyeing technique. The properties of scCO₂ dyed photochromic fabrics were compared with the properties of the same dyes in a non-polar solvent, hexane. UV-Vis spectroscopy and a specially designed online colour measurement system capable of simultaneous UV irradiation and colour measurement were used to evaluate the photochromic colour behaviour. Both photochromic dye types embedded in textile as well as in solution showed significant reversible colour changing properties when exposed to UV light and revert to their original non-coloured form when the UV light is removed. The scCO₂ dyed polyester fabrics exhibited similar trends of colour build-up as in solution, while contrasting behaviour was observed in terms of colour changing rates compared to their behaviour in solution.

The complexity and challenges of higher education (HE) in recent times have been widely discussed in HE literature, as have concomitant demands on university teachers and their professional learning needs. Much attention has been paid to new academics in these conversations, but less so to international PhD and post-doctoral researchers, who are often asked to teach, yet can be precluded from attending foundational pedagogical courses. This paper discusses an interpretive-hermeneutic study based on a pedagogical course developed for new academics in this very situation. Our discussion focuses on professional growth experienced by the course participants in terms of pedagogical understanding and self-confidence, and what enabled that growth from the participants’ perspectives. On the basis of analysis of interviews, questionnaires and qualitative course evaluations, we consider the value of such purpose-built courses and offer insights into what may need to be considered by course developers to ensure that their impact is optimal.