Wybrane zagadnienia z metrologii użytkowej odzieży funkcjonalnej

Politechnika Łódzka. Wydział Technologii Materiałowych i Wzornictwa Tekstyliów. Katedra Materiałoznawstwa, Towaroznawstwa i Metrologii Włókienniczej.Lodz University of Technology. Faculty of Material Technologies and Textile Design. Department of Material and Commodity Sciences and Textile Metrology.Rozwój technologii nowych materiałów, sposobu ich przetwarzania i wykorzystywania, a także coraz lepsze poznanie mechanizmów zachodzących w organizmie człowieka sprzyjają rozwojowi odzieży specjalnego przeznaczenia. Odzież już nie stanowi wyłącznie bariery przed zimnem, ale również ma za zadanie stanowić barierę przed czynnikami szkodliwymi, skrajnymi warunkami termicznymi, a także wspomagać funkcjonowanie organizmu jej użytkownika w warunkach ekstremalnych. Obecnie coraz większą uwagę zwraca się na zachowanie optymalnych warunków, w jakich powinien żyć i pracować człowiek, ponieważ zostało potwierdzone, że manualne i intelektualne zdolności człowieka osiągają swoje optimum w warunkach komfortu cieplnego. W tym kontekście problem odzieży ochronnej zapewniającej optymalny komfort cieplny użytkownika nabiera szczególnego znaczenia.Prace badawcze do prezentowanej książki były współfinansowane z Projektu pt. „Optymalizacja struktury ubioru ochronnego dla noworodków urodzonych przedwcześnie przy zastosowaniu oryginalnych narzędzi wspomagających proces projektowania” UMO-2011/03/B/ST8/06275, finansowanego przez Narodowe Centrum Nauki i Projektu pt. „Nowoczesne ochrony osobiste służb ratowniczych KSRG w oparciu o potrzeby użytkowników końcowych”, O ROB 0014 01/ID14/1, finansowanego przez Narodowe Centrum Badań i Rozwoju oraz z prac statutowych Wydziału Technologii Materiałowych i Wzornictwa Tekstyliów, Politechniki Łódzkiej

Shaping Ability of ProTaper Next, Hyflex CM, and V-Taper 2H Nickel-Titanium Files in Mandibular Molars: A Micro-computed Tomographic Study

Introduction: Although micro-computed tomography (MCT) evaluation of the shaping ability of ProTaper Next (PTN) and Hyflex CM (HCM) files has been reported, to our knowledge, no study has assessed the performance of V-Taper 2H (VT) files. The aim of this study was to evaluate and compare the shaping ability of PTN, HCM, and VT systems in the mesial canals of mandibular molars using MCT. Methods and Materials:  Thirty extracted first and second mandibular molars were scanned using MCT and randomly assigned to HCM, PTN, and VT groups. Images obtained before and after preparation were evaluated for the increase in the root canal volume, untouched surface area, and amount of accumulated hard tissue debris. One-way analysis of variance (ANOVA) and Kruskal-Wallis test were used to compare the variables in the groups (α=5%). Results: There were no statistically significant between-group differences in the postoperative measurements (P>0.05). The canal volume increased in all three groups: PTN   (73.84%), VT (73.48%), and HCM (49.29%). The largest and smallest untouched areas were observed in the PTN (41.37%) and VT (30.85%) groups, respectively (P>0.05). The debris formed during canal preparation was 1.84%, 2.16%, and 2.42% in the VT, PTN, and HCM groups, respectively (P>0.05). Conclusions: Based on our in vitro study, the PTN, HCM, and VT systems showed similar shaping abilities. None of the tested canals were completely free from debris, while the untouched surface area was considerably large. The VT system had the most favorable results with the smallest untouched surface area and least debris were. We would recommend further trials to endorse these findings

Modeling of Air Permeability of Knitted Fabric Using the Computational Fluid Dynamics

This article concerns the widespread matter of biophysical comfort. In this work, 10 double-layer knitted fabrics with potential application in multilayer garments addressed to a specific group of users, such as newborns, were investigated. The materials were constructed with the following raw materials: cotton, polypropylene, polyester, polyamide, bamboo, and viscose. The textiles with a comparable geometrical structure and different composition were tested for their air permeability. In the experimental part, the materials were tested in specific constant ambient conditions using an air permeability tester. In the simulation part, 3D models of actual textiles were designed and air permeability based on the performed simulations using finite volume method was calculated. Both measurements and simulations yielded comparable results and showed that the air permeability of the knitted fabric strongly depends on the thickness and geometrical parameters of yarn

Assessment of the Impact of the Surface Modification Processes of Cotton and Polyester Fabrics with Various Techniques on Their Structural, Biophysical, Sensory, and Mechanical Properties

This article presents research on the assessment of the impact of surface modification of cotton and polyester fabrics using four techniques (flocking, layer by layer, screen printing and thermal-transfer printing) on their structural, mechanical, biophysical, and sensory properties. Depending on geometry and raw materials of the fabrics, the clothing made of them it is characterized by certain biophysical properties which are intended to protect the human body against external factors, but also against excessive sweating and overheating or cooling down. The aforementioned properties of the modified textiles were determined with: optical microscopy, microcomputed tomography, a tensile testing machine, sweating guarded-hotplate, air permeability tester, and the Kawabata evaluation system. Based on analysis of obtained results, it can be concluded that flocking reduces air permeability the most (−77% for cotton fabric and −99.7% for polyester fabric), and total hand value (−58% and −57%) and increases water vapor resistance the most (+769% and +612%) while the screen printing increases the thermal resistance the most (+119% and +156%) compared to unmodified textiles. It can be concluded that, when modifying textile substrates, the area of modification and their size on clothing products should be carefully selected so as not to adversely affect the feelings of potential wearers

Assessment of Thermal Performance of Phase-Change Material-Based Multilayer Protective Clothing Exposed to Contact and Radiant Heat

The research presented in this article concerns the thermal properties of multilayer protective clothing, specifically, the impact of phase-change material (PCM) incorporation on the occurring heat transfer. Multilayer textile assemblies with PCM inserts (macrocapsules containing n-octadecane) and reference assemblies with PP inserts (macrogranules from polypropylene) with very similar geometry and the same textile layers were tested. The spatial geometry of tested assemblies was examined using high-resolution X-ray microtomography (micro-CT). The heating process of the assemblies was examined under the conditions of exposure to contact heat (using thermography) and radiant heat (using a copper plate calorimeter, according to EN ISO 6942). PCM-containing assemblies achieved a temperature rise of 12 °C in a longer period than the reference assemblies; for the contact heat method, the time was longer by 11 and 14 min, and for the radiant heat method by 1.7 and 2.1 min

Analysis of the Thermal Insulation of Textiles Using Thermography and CFD Simulation Based on Micro-CT Models

The article presents the results of an attempt to use high-resolution X-ray micro-computed tomography (micro-CT) to model the thermal insulation of clothing as one of the most important parameters affecting the heat balance between a human and his/her surroundings. Cotton knitted fabric applied in functional clothing for newborns and aramid woven fabric used in multilayer protective clothing for firefighters were the tested materials. The 3D models of real textiles based on micro-CT images were developed. Next, the models were applied to heat transfer simulations using the finite volume method. The usefulness of the models was experimentally verified using thermography with real textiles. The simulation results were consistent with the measurement results and confirmed the relationship between the thermal insulation and geometry of the textiles on the one hand and the physical parameters of the raw materials from which they were made on the other hand

Assessment of Impact of the Surface Modification Techniques on Structural, Biophysical, and Electrically Conductive Properties of Different Fabrics

This article presents studies on the evaluation of the impact of surface modification of cotton, viscose, and polyester fabrics using three techniques (flocking, layer by layer, and screen printing) with materials with electrically conductive properties on their structural, biophysical, and conductive properties. Each tested fabric is characterized by specific biophysical properties. which can be disturbed by various modification methods, therefore, the following tests were carried out in the article: optical microscopy, micro-computed tomography, guarded perspiration heating plate, air permeability, sorption and electrical conductivity tester. The use of screen printing increased the thermal resistance of the cotton woven fabric by 119%, the polyester woven fabric by 156%, and the viscose fabric by 261%. The smallest changes in thermal resistance compared to unmodified textiles were observed in layer by layer modified fabrics and are as follows: −15% (cotton woven fabric), +77% (PES woven fabric), and +80% (viscose woven fabric)

Assessment of the Impact of Ionizing Radiation Absorption on the Structural, Mechanical and Biophysical Properties of Textiles Used in Multilayer Space Suit

The article presents research on ergonomics, biophysical comfort and safety of protective clothing. The resistance of the structural, thermal and mechanical properties of five fabrics (CBXS400, GG200T, Twaron CT736, Dyneema HB26 and T1790C), differing in geometry and raw material composition used in space suits, to dangerous ionizing radiation (β and γ) occurring in space was tested. For both types of radiation, four identical one-time doses in the range of 25–100 kGy were used. The effect of the applied absorbed doses of β and γ radiation on the parameters of textiles influencing ergonomics and safety of the cosmonaut’s work was verified by structural tests (micro-computed tomography and optical microcopy), thermal resistance tests (sweating guarded-hotplate) and strength tests (tensile testing machine). Experimental studies of thermal properties are supplemented with heat transport simulations using the finite volume method performed with 3D models of real textiles. The greatest reduction of thermal resistance for Twaron CT736 (−0.0667 m2·°C·W−1 for 100 kGy of β-radiation) and Dyneema HB26 (−0.0347 m2·°C·W−1 for 50 kGy of β-radiation) is observed. Strength tests have shown that all tested textiles are resistant to both types of radiation. Three textiles were selected to create a three-layer assembly with potential application in a cosmonaut’s glove (Extravehicular Activity—EVA)

Influence of the La3+, Eu3+, and Er3+ Doping on Structural, Optical, and Electrical Properties of BiFeO3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method

In this study, nanocrystalline (18–28 nm) perovskite-like bismuth ferrite rare earth-doped powders (Bi0.9RE0.1FeO3, where RE = La (BLaFO), Eu (BEuFO), and Er (BErFO)) were obtained by microwave-assisted modification of solution combustion synthesis (SCS). The influence of high load La3+, Eu3+, and Er3+ doping on structural, optical, and electrical properties of BiFeO3 was investigated. It was found that rare earth doping along with fast phase formation and quenching significantly distorts the crystal cells of the obtained materials, which results in the formation of mixed rhombohedral- (R3c-) orthorhombic (Pbnm) crystal structures with decreased lengths of Bi-O and Fe-O bonds along with a decreasing radius size of doping ions. This promotes reduction of the optical band gap energy and suppression of ionic polarization at high frequencies and results in enhanced dielectric permittivity of the materials at 1 MHz