Examinando por Autor "Ruiz-Calleja, Tamara"

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Analysis of the influence of graphene and phase change microcapsules on thermal behavior of cellulosic fabrics
(Elsevier, 2020-12) Ruiz-Calleja, Tamara; Bonet-Aracil, Marilés; Gisbert-Payá, Jaime; Bou-Belda, Eva
Thermal management is a critical factor in several areas, such as architecture, computing, and transportation. Improving thermal regulation effectiveness is a challenging materials engineers. New materials can be used as thermoregulators sucha as graphene or Phase Change Materials (PCM). Textile engineering is also concerned and researchers are developing numerous advances for effective thermal control. In this investigation, we focus on finding new approaches for thermal regulation of cellulosic fabrics combining both technologies, phase change materials and graphene. For this purpose, we compare the thermal behavior of a cellulosic fabric when applying a coating paste containing graphene or phase change materials individually, finding that their performances are similar during heating. Likewise, the synergy produced by using both materials in the same coating paste is studied, proving that the action of graphene and PCM simultaneously allows the dissipation of more heat energy than when acting individually. These results open new paths of research on thermoregulation that may be useful in numerous applications beyond textiles.
Characterization of conductive particle dispersion in textile coatings through Joule’s effect monitoring analysis
(Sage, 2024-03-14) Ruiz-Calleja, Tamara; Jiménez-Suárez, Alberto; Calderón-Villajos, Rocío; Prolongo, Silvia G
Achieving proper dispersion of pigments, dyes, or other additives, such as microcapsules or nanoparticles, within printing pastes or textile coatings is crucial for obtaining a homogeneous result. In certain specialized applications, such as coloration technology, it is possible to use colorimetry tools, visual examination, and even artificial vision to identify defects. However, none of these techniques comprehensively map the specific additive distribution. This paper proposes a novel approach: monitoring the distribution of conductive particles (graphene nanoplatelets, referred to as GNP) within an acrylic coating paste using Joule’s effect. Four different dispersion systems (ultrasound mixer, blender, toroidal agitation, and three-roll mill) are employed. Thermographic images provide an accurate view of how conductive particles are distributed. This complements data from numerical values like maximum and average temperatures recorded for each sample. In certain cases, relying solely on numerical values can be inadequate or insufficient, hence the novelty of this article emphasizing the significance of using Joule’s effect to assess the distribution of conductive particles. Concerning the mixing systems, optimal dispersion of GNP in distilled water is most effectively achieved using an ultrasound mixer, with enhanced uniformity as dispersion time increases. For mixing the components of the coating paste, the toroidal agitation method yields the best result. Employing the three-roll mill is discouraged for this application due to its propensity to induce phase separation.
Effect of calendering on the performance of 100% recycled polyester weft-knitted fabrics
(Sage, 2024-03-27) Ruiz-Calleja, Tamara; Jiménez-Suárez, Alberto; Sainz-de-Robles, Federico; Cristóbal-Ruiz, Paula
Government policies focus on the textile sector to follow a tendency towards sustainability and circular economy, thus, raising the use of recycled textiles which require further performance improvement to be completely competitive with other textile products while using secondary treatments that are also environmentally friendly. In this study, a 100% recycled polyester weft-knitted fabric, currently used by commercial brands in the apparel and sport textile industry, is calendered and its properties are examined before and after such treatment. This research investigates variations in the physical (appearance and thickness), mechanical (tensile strength and elastic recovery), and physiological (water vapour resistance, spray test, and wettability) characteristics of the samples. The calendering treatment reduces water vapour resistance up to 23%, which is particularly interesting for garments used in sports. Additionally, the contact angle is increased by the calendering process which translates in poorer wettability. Novel findings of this work include that, whereas in the original fabric sweat marks are visible, sweat stains do not appear on the calendered fabric and moisture management improves, while mechanical properties do not undergo significant changes. These results have not been previosly found in the literature, giving a particular interest to a conventional process in this type of recycled fiber that can contribute to the advancement of knowledge in the textile industry and enhance the performance of treated fabrics. All these aspects make the treatment particularly interesting to improve the technical performance of the textile material while using an economic treatment with low effect on the environment.
Influence of fabric structure on electrical resistance of graphene-coated textiles
(Sage, 2022-09-07) Ruiz-Calleja, Tamara; Bonet-Aracil, Marilés; Gisbert-Paya, Jaime; Bou-Belda, Eva; Montava, Ignacio; Calderón-Villajos, Rocío
Coating is a widespread technique in the textile industry for different purposes, mainly in coloring and functional finishes. Graphene is usually applied to fabrics using coating techniques to provide such fabrics with properties like thermal or electrical conductivity. All woven fabrics have peaks and valleys in their structure, generated by the warp and weft threads interlacing. When spreading the graphene coating, the paste is placed in the fabric's interstices, and the connection between conductive particles is only produced when the height of the coating is sufficient to connect the different areas where it is deposited. This article analyzes three types of satin weave with three interlacing coefficients (0.4, 0.25, 0.17) and two sets of weft yarns each (20 and 71.43 tex). For a blade gap of 1.5 mm, the electrical resistance of samples with weft yarn count of 20 tex and interlacing coefficient of 0.4 is 534.33 Ω, while for IC = 0.25 electrical resistance is 36.8% higher and for IC = 0.17 this parameter increases 249.3%. For samples with weft yarn count of 71.43, the sample with IC = 0.40 exhibits an electrical resistance of 1053 Ω, for IC = 0.25 this value rises to 33.9% and for IC = 0.17 the electrical resistance value increases a total of 78.9%. This finding can be of interest for coatings where continuity is crucial, and for the application of substances that need to be protected from external factors, for which fabrics with deep interstices can be designed to house said products.
Performance of Resins for Stereolithography Printers in Jewelry Casting Applications: A Qualitative Assessment
(Springer, 2024-08-19) Ferrufino-Rojas, Juan-Manuel; Ruiz-Calleja, Tamara
This research analyzes the technical feasibility of manufacturing jewelry castings using the lost wax technique, substituting wax by the use of resins within the framework of 3D stereolithography printers (SLA). To achieve this goal, a pair of distinct 3D ring designs have been crafted: a robust signet ring and an intricate filigree ring. The purpose behind this decision is to determine whether the unique features of these two different designs have any noticeable effect on the result. Five different commercial resins have been utilized, with one of them explicitly formulated for casting purposes. Non-castable resins generate a unique, weathered appearance, due to the variability in ash residue within the mold after resin combustion, yielding unpredictable outcomes and diverse sample characteristics such as grainy texture, cracks, and corroded effect. Examining the castable resin reveals its optimal performance for smaller elements like the filigree ring, showcasing remnants of supports or layers originating from the resin's printer curing process. On the contrary, larger resin-abundant objects like the signet ring result in notable flaws, attributed to gas accumulation within the mold, exerting internal pressure and causing mold rupture, leading to metal leakage.
Thermoelectrical properties of graphene knife-coated cellulosic fabrics for defect monitoring in Joule-heated textiles
(Sage, 2022-01-05) Ruiz-Calleja, Tamara; Calderón-Villajos, Rocío; Bonet-Aracil, Marilés; Bou-Belda, Eva; Gisbert-Payá, Jaime; Jiménez-Suárez, Alberto; Prolongo, Silvia G
Knife-coating can confer new properties on different textile substrates efficiently by integrating various compounds into the coating paste. Graphene nanoplatelets (GNP) is one of the most used elements for the functionalization of fabrics in recent years, providing electrical and thermal conductivity to fabrics, later used to develop products such as sensors or heated garments. This paper reports thermoelectrically conductive textiles fabrication through knife-coating of cellulosic fabrics with a GNP load from 0.4 to 2 wt% within an acrylic coating paste. The fabric doped with the highest GNP content reaches a temperature increase of 100 ºC in few seconds. Besides, it is found out that the thermographic images obtained during the electrical voltage application provide maps of irregularities in the dispersion of conductive particles of the coating and defects produced throughout their useful life. Therefore, the application of a low voltage on the coated fabrics allows fast and effective heating by Joule’s effect, whose thermographic images, in turn, can be used as structural maps to check the quality of the GNP doped coating. The temperature values and the heating rate obtained make these fabrics suitable for heating devices, anti-ice and deice systems, and protective equipment, which would be of great interest for industrial applications.