In this study, the possibility of using modern AM technologies to produce designed heels for personalized orthopedic footwear with a medium heel was explored. Seven variants of heels were produced using three 3D printing methods and polymeric materials with different natures: PA12 heels made using the SLS method, photopolymer heels made using the SLA method, and PLA, TPC, ABS, PETG, and PA (NYLON) heels made using the FDM method. A theoretical simulation with forces of 1000 N, 2000 N, and 3000 N was performed in order to evaluate possible human weight loads and possible pressure during orthopedic shoe production. The compression test of the 3D-printed prototypes of the designed heels showed that it is possible to replace the traditional wooden heels of hand-made personalized orthopedic footwear with good-quality PA12 and photopolymer heels made using the SLS and SLA methods, but also with PLA, ABS, and PA (NYLON) heels printed using a cheaper FDM 3D printing method. All of the heels made using these variants withstood loads of more than 15,000 N without damage. It was determined that TPC is not suitable for a product of this design and purpose. Due to its greater brittleness, the possibility of using PETG for orthopedic shoe heels must be verified by additional experiments.
A study of altering the conductive properties of wool fibers by applying copper selenide is presented. The researched modification of wool fibers was based on a two-stage adsorption-diffusion process. X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectrum, and Fourier transform infrared spectroscopy were performed to evaluate the morphological and physical characteristics of all CuxSe-coated wool fibers. X-ray diffraction (XRD) data showed a single, Cu0.87Se (klockmannite), crystalline phase present, while Atomic Absorption Spectroscopy (AAS) and Energy Dispersive X-ray (EDX) analyses showed that the concentrations of Cu and Se in copper selenide coatings depend on the number of wool fiber treatment cycles. It was determined that a dense layer of CuxSe grows through a nucleation mechanism followed by particle growth to fill out the complete surface. It was found that the conductivity of the coated wool fibers depends on the quality and density of the copper selenide coating, thus the resistance of electrically impermeable wool fibers can be reduced to 100 Ω by increasing the number of treatment cycles.
In this study, we analyzed the impact of the dyeing and the digital printing processes of linen/silk fabric (70% linen/30% silk) on its color fastness and shrinkage in the directions of warp and weft. This is a highly relevant topic because a single fabric combines two natural fibers of different origins—silk, a protein, is animal-based, whereas linen is derived from cellulose and is, thus, plant-based. Therefore, the different natures of the two fibers determine distinctive chemical properties. As a result, selecting the optimal technological course of processing for blended yarn fabrics and their yarn is a challenging task. The quality of the conducted finishing is determined by the physical properties of fabrics, such as color fastness to perspiration; soap; dry friction and wet friction; the pH of the fabric after finishing; and the shrinkage of the fabric in the directions of warp and weft. Here, color fastness was assigned the top grade with respect to all potentially harmful factors, except for wet friction. The evaluation proves that the technological regimes employed for digital printing and dyeing in the production item’s fabrics were properly selected.
11 May 2020 in Journal of Physics and Chemistry of Solids
Textile materials modified with copper-containing particles have antibacterial and antiviral properties that have prospects for use in healthcare. In the study, textile materials were saturated with copper-containing particles in their entire material volume by the absorption/diffusion method. The antibacterial properties of modified textile materials were confirmed by their inhibitory effect on Staphylococcus aureus, a Gram-positive bacterium that spreads predominantly through the respiratory tract. For the modification, ordinary textile materials of various origins and fiber structures were used. Technological conditions and compositions of modifying solutions were established, as well as the most suitable textile materials for modification. To assess the morphological and physical characteristics of copper-containing particles and the textile materials themselves, X-ray diffraction, a scanning electron microscope, and an energy-dispersive X-ray spectrum were used. In modified textile samples, XRD data showed the presence of crystalline phases of copper (Cu) and copper (I) oxide (Cu2O). On the grounds of the SEM/EDS analysis, the saturation of textile materials with copper-containing particles depends on the structure of the textile materials and the origins of the fibers included in their composition, as well as the modification conditions and the copper precursor.