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  • Author: Izabella Krucińska x
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Abstract

In this study, the new tool for measuring thermal insulating power of garments for premature babies under coupled heat and moisture transport was developed. The thermal mannequin corresponds to the body weight and size of a premature baby born in the thirty fourth week of pregnancy. The mannequin surface temperature can be set at various levels, while the heat loss is measured in W/m2. The mannequin is divided into eleven independent heating zones and seven independent zones of moisture evolution. The study also presents the test results of heat insulating power obtained for the newly developed garment set with commercially available garment set for babies, conducted under different climatic conditions. The results exhibit the advantage of the new material construction of the garment over the commercially available one.

Abstract

Sound absorbing materials used to provide optimal conditions in rooms can be applied in the form of textiles with a special structure such as nonwovens or fibre-containing composites. Nonwovens can be successfully used to make thermoplastic composites by thermal pressing. This paper presents the comparison of the sound absorbing properties of needled nonwovens and composites made from them. Composites with various densities can be made of nonwovens with various percentage contents of filling and matrix fibres. The sound absorption by composites with similar thickness, about several millimetres, is slightly lower than that by the laminar nonwoven packs used for their making. The optimal content of the filling fibres in the composite, when its sound absorption coefficient reaches the highest values, is at the level of 10 wt.%. With the increase in the content of filling fibres the composite density decreases. In the case of the composite with 10 wt.% of filling fibres, its density is the highest among the composites investigated, and the increase in absorption of high-frequency sounds is the highest. Imparting a relief with a protrusion diameter over 10 mm to the composite surface, we can increase the sound absorption of that composite.

Abstract

The study presents the manufacturing of nanofibrous structures as osteoconductive, osteoinductive materials for osseous tissue regeneration. The fibrous structures were obtained by electrospinning of poly(l-lactide-coglicolide) (PLGA) with addition of hydroxyapatite (HAp) and of a blend of PLGA with polyhydroxybutyrate with HAp added. The polymers used in the experiment were synthesised by an innovative method with a zirconium catalyst. First, the optimal electrospinning process parameters were selected. For the characterisation of the obtained osseous tissue reconstruction materials, the physical, macroscopic, functional, mechanical and thermal properties as well as crystallinity index were studied. The study of the radiation sterilisation influence on average molar mass, thermal and mechanical properties was made in order to analyse the degradation effect.

Abstract

This study presents the results of research concerning fabrication of nonwovens from biodegradable polymer blends using the melt-blown method. The experiments performed within the framework of the research confirmed the possibility of obtaining polymer composites based on polylactide (PLA) with poly(hydroxyalkanoates) (PHA) and another aliphatic-aromatic copolyester. The obtained products were subjected to the analyses of chemical structure using the Fourier Transform Infrared Spectroscopy(FTIR) Attenuated Total Reflectance(ATR) method. The physical and mechanical properties of the fabricated nonwoven layers were also tested, which confirmed a wide spectrum of their applicability, depending on the polymer composition used in production.

Abstract

Head is the most sensitive body part of neonate. Head that is considerably uncovered causes the significant heat and moisture loss from the skin to the surrounding areas. The main goal is to optimise the thickness of a multilayer composite textile bonnet to secure the optimal skin parameters. Problem is solved using both sensitivity analysis and material derivative concept. An arbitrary objective functional is introduced, its first-order sensitivity is formulated by means of a direct approach. Numerical application is the thickness optimisation of a composite bonnet made of different textile materials.

Abstract

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.

Abstract

The main goal of the current work is to analyse the three-dimensional approach for modelling knitted fabric structures for future analysis of physical properties and thermal phenomena. The introduced model assumes some simplification of morphology. First, fibres in knitted fabrics are described as monofilaments characterized by isotropic thermal properties. The current form of the considered knitted fabric is determined by morphological properties of the used monofilament and simplification of the stitch shape. This simplification was based on a particular technology for the knitting process that introduces both geometric parameters and physical material properties. Detailed descriptions of heat transfer phenomena can also be considered. A sensitivity analysis of the temperature field with respect to selected structural parameters was also performed.

Abstract

The aim of this work was to visualise liquid transport in textiles. Knowledge of the transport phenomena allows for the design of textiles for various applications, e.g., comfortable to wear filtration and wound dressing. To visualise liquid transport through textiles, three test methods were explored. The first one was the high spatial resolution magnetic resonance imaging (MRI) technique (also referred to as nuclear magnetic resonance (NMR) microscopy). It allowed the observation of the pathways of liquid flow through textiles. In the second method, a thermographic camera was used to record temperature changes and assess the liquid flow in the textile. The third method was using a high-speed video camera to observe the liquid transport within the textile. Two types of textiles were studied: a double-layer knitted fabric and a woven fabric, both made from hydrophilic and hydrophobic fibres (cotton, viscose and polypropylene). The knitted fabrics were tested as a new type of wound dressing, which trans

Abstract

The aim of the work was to obtain nano fibrous structures from biodegradable polymer with the addition of hydroxyapatite using electrospinning technique. Research was conducted with two types of solvent: dichloromethane and 50:50 mixture of dimethyl sulfoxide and dichloromethane. As a polymer a copolymer of L-lactide and glycolide (PLGA), commercial product with trade name Resomer®LG 824, was used. The preliminary electrospinning tests enabled to match optimal polymer solution concentration of tested samples. Rheological properties of all tested polymer solutions has been determined. Influence of electrospinning conditions and the type of solvent on macroscopic structure has been investigated.

Abstract

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.