Numerical Simulation of the Condensing Effect of Different Suction Slots on Fiber Strands in a Compact Siro Spinning Machine with Lattice Apron
Compact-siro spun with lattice apron combines compact spinning and siro spinning, and is widely put into practice. In this paper, compact-siro spun models with the parallel shaped slots, oblique parallel shaped slots and V-shaped slots were simulated. Based on the airflow data in the condensing zone, the geometrical model of single fiber is built, and then the trajectory of single fiber can be got. The morphological changes and movement process of fiber strands in the flow field of condensing zone were verified by the comparison experiments of yarn morphology, hairiness, tensile and evenness properties. The results showed that the V-shaped slot achieved the optimal agglomeration effect and yarn performance. The theory analysis gives foundation and explanation for the experiment, and also provides a theoretical basis for optimizing the properties of compact-siro yarn in production practice.
Assumptions for the Fiber Movement Model in the Drawing Mechanism Field in Modified Regulation Systems
The paper presents assumptions for the fiber movement model in the drawing mechanism field, aiming at establishing a regulation equation with a modified operation algorithm of the short-term draft regulator of slivers made of staple fibers. The model takes into account the sliver retardation phenomena and makes it possible to increase the evenness of slivers feeding successive machines in the technological process. As a result of this, the evenness of yarn will be increased contributing to an improvement in the quality of flat textile fabrics. This model, despite simplifying assumptions, sufficiently precisely presents the phenomenon of reducing the effect of drawing waves on the distribution of the linear mass of the fiber stream.
Simulation of Reliability Prediction Based on Multiple Factors for Spinning Machine
Reliability prediction of spinning machines can result in a time-saving and cost-saving development process with high reliability. Based on an analysis of failure times among systems and subsystems, a simulation method for reliability prediction of spinning machines is proposed by using the Monte Carlo simulation model. Firstly, factor weights are determined according to the fuzzy scoring and analytic hierarchy process. According to the status of reliability growth, growth coefficients are proposed based on reliability influencing factor weights and fuzzy scoring. To achieve the prediction of reliability distribution law, reliability index, and fault frequency, the reliability prediction model is constituted by combining the reliability growth coefficient and the Monte Carlo simulation model. Simulation results for spinning machines are obtained via the model thus built, which are confirmed with a practical example.
Study on PLA/PA11 Bio-Based Toughening Melt-Blown Nonwovens
With aim to improve the mechanical and thermal properties of poly (lactic acid) (PLA) melt-blown nonwovens (MBs), polyamide 11 (PA11) was melt blended with PLA at the weight proportions of PLA/PA11 (95/5, 90/10, 85/15, 80/20), and the corresponding PLA/PA11 MBs were also manufactured. The crystallization, thermal and rheological behaviors of PLA/PA11 blends were investigated. PLA/PA11 MBs were also characterized by morphology and mechanical properties. The results indicated that PA11, as globular dispersed phases, formed confined crystals and could improve the thermal stability of PLA matrix. The viscosity of PLA/PA11 blends was slightly increased but the rheological behaviors of “shear-thinning” kept unchanged in comparison with PLA. The average diameter of PLA/PA11 MB fibers was slightly increased, whereas the toughness of PLA/PA11 MBs including the strength and elongation were efficiently enhanced compared with those of PLA MBs.
Structure–Property of Wet-Spun Alginate-Based Precursor Fibers Modified with Nanocarbons
The results of studies assessing the influence of the addition of carbon nanofillers, such as multiwalled carbon nanotubes (MWCNTs) and graphene oxide (GO) that differ in size and structure, on the molecular and supramolecular structure and properties of alginate fibers that might be prospective precursors for carbon fiber (PCF) industry are presented in this article. The investigation was carried out by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), and tension testing. In the frame of the current study, two types of alginate fibers were examined and compared: alginic acid and calcium alginate fibers. Alginic acid fibers were formed by chemical treatment of calcium alginate fibers with hydrochloric acid due to the fact that Ca2+ ions presented in the fibers were expected to adversely affect the prospective carbonization process. This investigation brought important conclusions about the influence of nanofillers on the physical properties of the final material. Understanding the link between the incorporation of carbon nanostructures and a possible influence on the formation of ordered carbon structures in the precursor fibers brings an important opportunity to get insights into the application of alginate fibers as a prospective base material for obtaining cost-efficient carbon fibers.
Study on the Trajectory of Free-End Fiber in Jet Vortex Spinning Based on the Elastic Thin-Rod Finite Element Model of Flexible Fiber
During the air flow twisting process of jet vortex spinning, the moving characteristics of flexible free-end fiber are complex. In this paper, the finite element model of the fiber is established based on elastic thin rod element. According to the air pressure and velocity distribution in the airflow twisting chamber of jet vortex spinning, this paper analyzes the undetermined coefficients of the finite element kinetic differential equation of the free-end fiber following the principle of mechanical equilibrium, energy conservation, mass conservation and momentum conservation. Based on numerical simulation, this paper gets the trajectory of the free-end fiber. Finally, the theoretical result of the free-end fiber trajectory by finite element simulating is tested by an experimental method. This paper has proposed a new method to study the movement of the fiber and learn about the process and principle of jet vortex spinning.
Analysis of Stress and Strain to Determine the Pressure Changes in Tight-Fitting Garment
Based on the mechanical properties of stretch fabrics and Laplace’s law, the mathematical models have been developed enabling one to determine the values of the relationship between the fabric strain and the circumferential stress depending on pressure and diameter of the body. The results obtained refer to the values of the parameters assessed for the initial phase of their exploitation, which allow us to preliminarily predict the values of these parameters.
Anthropometry and Size Groups in the Clothing Industry
It appears that from generation to generation the anthropometric dimensions of the human population are changing. The aim of this paper was to examine the extent of these changes and the need for generating updated measurements for the clothing industry. The clothing industry uses mannequins and avatars to represent the modal group of the population. The industry tends to use three different categories for the human body shape (endomorphic, mesomorphic, and ectomorphic). The clothing industry should focus on specific measurements of the body rather than general categories and create more body shapes to satisfy customer needs. The paper also aimed at showing the problems faced by clothing designers. The traditional way of measuring takes into account only selected dimensions of the human body; this does not reflect the “true” overall body shape. The dimension tables used by the apparel industry are based on the fourth anthropometric photograph taken between 1987 and 1989. These tables are still in the use currently; however, after 30 years they are outdated and should be revised for the young contemporary generation. This study can be used for the development of new dimension tables as well as defining methods aimed at improving the quality of measurements for clothing engineering purposes. This is an important issue, because the National Institute of Anthropometry does not deal with such problems (the measurements are conducted mainly for understanding the human body shape rather than any other application), which means that anthropometric measurements are not ideally suited to applications of clothes fitting.
Mechanism of Electrical Conductivity in Metallic Fiber-Based Yarns
We explore the conductive mechanism of yarns made from metallic fibers and/or traditional textile fibers. It has been proposed for the first time, to our knowledge, that probe span length plays a great role in the conductivity of metallic fiber-based yarns, which is determined by the probability and number of conductive fibers appearing on a cross section and their connecting on two neighboring sections in a yarn’s longitudinal direction. The results demonstrate that yarn conductivity is negatively influenced to a large extent by its length when metallic fibers are blended with other nonconductive materials, which is beyond the scope of conductivity theory for metal conductors. In addition, wicking and wetting performances, which interfere with fiber distribution and conductive paths between fibers, have been shown to have a negative influence on the conductivity of metallic fiber-based yarns with various structures and composed of different fiber materials. Such dependence of the conductivity on the probe span length, as well as on the moisture from air and human body, should get attention during investigation of the conductivity of metallic fiber-based composites in use, especially in cases in which conductive yarns are fabricated into flexible circuit boards, antennas, textile electrodes, and sensors.
Influence of Modified Cationic Starch in a Mixed Poly(Vinyl Alcohol)/Cationic Starch Solution on the Electrospinning Process and Web Structure
Nanofibers were electrospun from bicomponent poly(vinyl alcohol) (PVA) and modified cationic starch (CS) mixed solution PVA/CS with different mass ratios (75/25, 50/50 and 35/65) at a total concentration of 12 wt% for all polymer compositions. For comparison, pure PVA solution was used. Electrospinning technique Nanospider (Elmarco, Czech Republic) with a rotating electrode with tines was used to obtain nanofibrous web. The influence of prepared polymer solution compositions on the structure and morphology of nanofibers and webs were investigated. Analyzing the structure and morphology of the formed nanofiber webs, it was noticed that the fineness nanofibers were formed from the PVA/CS solution with a mass ratio of 50/50. This ratio of solution also lets us to obtain the nanofibrous web with less sticked nanofibers on spunbond. The increase in the CS ratio by more than 50/50 had a negative influence on the diameter of nanofibers and the structure of nanofibrous web.
Impact of Whip Roller Parameters on Warp Dynamic Loads for 3D Fabrics Made on a Four-Comb Warp-Knitting Machine
The most advantageous geometry of the warp feeding system was determined from the viewpoint of compensating temporary changes in the warp length during the technological cycle of a four-comb warp-knitting machine. Dynamic simulations of the feeding system were carried out for 3 different lengths of the shift of the slider with a guide bar – designating variants (series) of the cross-sectional sizes of the 3D knitted fabrics. The courses of instantaneous warp tensions during the operating cycle of the warp-knitting machine were presented. Limit dynamic loads of the warp were determined and presented as a function of natural frequency of the whip roller. Based on the criterion of the smallest dynamic loads of the warp, the optimum natural frequencies of the whip roller were determined. In the analyzed range of the whip roller parameters, they are 3–6 times greater than the operation frequency of the warp-knitting machine.
Producing Multifunctional Cotton Fabrics Using Nano CeO2 Doped with Nano TiO2 and ZnO
Cross-link method has been used to load nano CeO2, ZnO, and TiO2 on the surface of cotton fabric. Three types of nanocomposite fabrics are prepared (cotton/CeO2, cotton/CeO2/ZnO, and cotton/CeO2/TiO2) and their properties were investigated. Field emission scanning electron microscopic (FESEM) images of the samples showed good distribution of nanomaterial, and energy dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) samples proved the usage of amount of nanomaterials. On the other hand, elemental mapping was used to study the distribution of each nanomaterial separately. Antibacterial property of the samples showed excellent results against both Gram-negative and Gram-positive bacteria. Also ultraviolet (UV)-blocking of treated samples showed that all samples have very low transmission when exposed to UV irradiation.
Structural Constructs and Ease Reduction Treatment Interface Related to Cling Fit
Garment cling fit is a proximal fit that emphasizes close clinging contour lines of the apparel maintained by it on the human body in regular postures and while performing primary movements. To understand the nature of interface between ease reduction treatments and structural constructs, three-dimensional (3D) modeling of human body using body mapping concept and ease reduction treatment’s role in explaining the garment strain patterns in cling fit conditions were investigated. We report the impact of ease reduction treatment that defines the proportions and measurements of the cling fit pattern with reference to human body surface profile.
A System for Personalized Clothing Production as a Model for Supporting the Competitiveness of SMEs on the Example of Lodz Province
Poland’s accession to the European Union has given many opportunities both in terms of access to the EU economy and European funds. Owing to the set sustainable development goals, the business sphere faces the challenge of their implementation through, among others, activities in the area of social and human capital, and environmental protection. It is important to model solutions that enable sustainable production and consumption. The introduction of innovative product and process technologies may contribute to increasing the competitiveness of SMEs in the Textile and Clothing sector, which in consequence should also contribute to the implementation of objectives of the Regional Smart Specializations for Lodz Province. An example of such solutions is the system for personalized production of clothes presented in the article. The aim of the article is to determine the current situation of the Polish clothing industry in trade with the European Union by analyzing comparative advantages for CN 61 and 62 (related to the clothing industry) and presenting the level of innovation of Lodz Province against the background of Poland as a region specializing in the production of clothing under the adopted Regional Smart Specializations for Lodz Province. It is assumed that the presented system for the personalized production of clothing may affect the competitiveness of this industry and the region.