Transfer and Friction Characteristics of Sports Socks Fabrics Made of Synthetic Fibres in Different Structures

Sports socks fabrics produced from polyester, polypropylene, their modified forms Thermocool®, Polycolon®, in three different structures (single jersey, piquet, terry) were investigated for their skin-fabric friction, permeability (air and water vapour), liquid absorption and transfer (absorbency, immersion, absorption capacity, wetback and drying) properties. According to the results, the effect of structure is dominant for frictional characteristics but focusing on the material, polypropylene created a bulkier and lighter structure with lower friction coeffi¬cients, an advantage for sports socks. The effect of structure is greater than the material also for some thermal comfort parameters, e.g. air permeability and absorbency. Focusing on materials, besides their better liquid transfer characteristics, modified forms of both fibres had worse performances for air permeability and absor¬bency compared to their standard forms. Absorption capacity, wetback and drying performances were related to fabric density besides the polyester’s higher regain capacity. While Polycolon® had superiority for wetback performance against standard polypropylene, this was not the case for Thermocool®; however, both modified materials showed apparent superiority for drying periods. Piquet structures were advantageous for absorption capacity and wetback performances for polypropylene. For sports socks parts, specific needs can be met by changing the fabric structure. Considering the materials, polypropylene and Polycolon® can be recommended for both thermal and tactile aspects.

Thermo physiological comfort of single jersey knitted fabric derivatives

The main aim of this study is to determine the thermo-physiological comfort properties of single knit fabrics and their derivatives. As the Single Jersey knitted fabrics are the most widely used fabrics in the apparel sector, they have been selected for the analysis purpose. Derivatives of single jersey are developed and compared in order to understand the influence of structural variations. Physical properties e.g. thickness and areal density were evaluated for all knitted fabrics with 100% cotton yarn having three different yarn linear densities and after different stages of relaxation. Various thermo-physiological properties have been studied by changing the combed cotton yarn linear density as well as the structure of single knit fabric. Air permeability, thermal insulation and relative water vapor permeability of the fabrics were observed and investigated under wet relaxed states. It is determined that fabric physical properties are affected by changing yarn linear density and by the dry or wet relaxation stages. The percentage/number of tuck stitches (NTS), location of tuck stitches (LTS) and ratio of tuck to knit stitches (RTKS) have strong influence on physical and thermo-physiological properties of single knit fabrics, even though other knitting parameters remained the same.

Tribology of The Sock-Skin Interface – The Influence of Different Fabric Parameters On Sock Friction

The purpose of this parametric design of experiments was to identify and summarize how the influence of knit structure (single jersey vs. terry), fiber composition (polyester vs. cotton), fiber linear density (30/1 Ne vs. 18/1 Ne & 1/150/34 vs. 2/150/34), and yarn type (filament vs. spun) affected the frictional profile across the sock-skin interface, and then relate these factors to friction blister incidence. Friction testing trials were completed against both a polypropylene probe and a synthetic skin material (Lorica soft®) to determine if there was a difference in friction based on interface interaction. Friction testing was completed by sliding a probe across the inside bottom surface of the sock (the part that is usually in-contact with the bottom of the foot) while instantaneously measuring the frictional force every tenth of a second. For both trials (plastic probe and synthetic skin), in the dry condition, knit structure was found to be the most prominate fabric parameter affecting the frictional force experienced at the sock-skin interface. It was also determined that fiber linear density, and yarn type are tertiary factors affecting the frictional force measured at the sock-skin interface. Finally, in the dry state, it was determined that fiber composition had seemingly no effect on the frictional force experienced at the sock-skin interface.

DEVELOPMENT OF MULTIFUNCTIONAL YARN FROM THE FUNCTIONALIZATION OF ORGANIC RAW COTTON FIBERS WITH ZINC NANOPARTICLES

The emergence of increasingly contagious diseases in these days, such as COVID-19, increased the need to develop more effective personal protection equipment’s (PPEs). Therefore, the goal is to create textile materials capable to act against bacteria, virus or fungi, with a long-lasting performance but, at the same time, that could be comfortable and safe for their users. In this sense, based on the advantages of nanotechnology, the aim of this work was to functionalize organic raw cotton fibers with zinc nanoparticles (NPs) and previously tretated with NaOH, for the further production of multifunctional yarns with antimicrobial activity. Thereby, the fibers functionalization was tested using 1% w/w and 2% w/w of zinc NPs aqueous dispersion, being subsequently evaluated their distribution, chemical nature and zinc concentration by SEM/EDS and Atomic Absorption Spectroscopy, respectively. Subsequently, using the functionalized fibers, a yarn was spinned and their structural, mechanical and moisture management properties determined. Also, to assess the influence of the produced yarn on the properties of a fibrous structure, a single jersey knit sample was further produced and evaluated regarding their mechanical, moisture management and antibacterial properties. Based on the methodology used it was possible to develop a yarn with a tenacity 24% higher and a knit sample 28% more breathable and with a water evaporating ratio 37% higher than the one without any treatment or functionalization, but mainly with a strong antibacterial activity against both gram-negative (Klebsiella Pneumoniae) and gram-positive (Staphylococcus Aureus) bacteria, presenting therefore potential to be used in the production of effective PPEs.

Effect of Lycra Weight Percent and Loop Length on Thermo-physiological Properties of Elastic Single Jersey Knitted Fabric

The aim of this work is to estimate the effect of loop length and Lycra weight percent (Lwp) on the geometrical and thermo-physiological comfort of elastic plain knitted fabric. Fifty single jersey knitted fabric samples were produced at five levels of Lycra weight percent (Lwp) (4%, 5%, 6%, 7%, and 8%) and loop length (2.7 mm, 2.9 mm, 3.1 mm, 3.3 mm, and 3.4 mm) with full plaited (fp) and half plaited (hp) of bare Lycra. The thermo-physiological comfort properties (thermal conductivity, absorptivity, and water vapor permeability), air permeability, and geometrical properties were measured at standard of each one. The results showed that the elastic single jersey knitted fabric thickness ranged between 3.12 times and 4.2 times of the yarn diameter (d). The fabric thickness increased when loop length is increased and decreased when Lwp is increased. The thermal conductivity, absorptivity, and water vapor resistance (WVR) decreased with Lwp increasing.

Structural Impact on Some Common Physical Properties of Single Jersey Weft Knit Fabric

Single jersey weft knit fabrics include a large portion of knitted products. These fabrics are made using different types of stitches. In this study, several single jersey weft knit fabric samples containing four courses and two wales in the repeating unit of the fabric structure were made by introducing and gradually increasing the number of tuck stitches in the structure, to find out the effect of this stitch on fabric properties. Results showed that tuck stitches could positively affect the areal density, width, and tensile properties of the fabric. For some comfort-related properties, tuck stitches were found to improve wicking and drying properties, reduce water vapor transmission rate, and affect fabric smoothness. The position of tuck stitches in the structure also had some effect, but was not as significant as when the number of tuck stitches was varied.

Thermal comfort properties of cotton/spandex single jersey knitted fabric

Knitted fabrics are characterized by comfort compared to woven fabrics due to their high extensibility and airpermeability, but they have lower dimensional stability after repeated washing especially single jersey knitted fabric(SJKF). Therefore, the spandex (Lycra) core-spun yarns are used to maintain the dimensions of knitted fabrics duringuse and after repeated stresses. In this study, nine elastic SJKF samples were produced at three levels of loop lengthand spandex percent using yarn linear density 30/1 Ne. For comparison, three 100% cotton knitted samples wereproduced with the same levels of loop length and yarn count. The dimensional and thermal comfort properties of thelong-stretch samples were compared with the short-stretch cotton knitted fabric. The thermal comfort properties (thermalconductivity, resistance, absorptivity, and water vapour permeability), air permeability, and dimensional properties weremeasured and compared to 100% cotton samples. The results showed that the stitch density, fabric density, fabricthickness, and thermal resistance increased, whereas the air, water vapour permeability, and spirality angle decreasedin cotton/spandex samples.

Flexible Theoretical Calculation of Loop Length and Area Density of Weft-Knitted Structures: Part I

This work presents a simple and flexible method for theoretical calculation of the main structural parameter of weft-knitted fabrics’—the loop length and one of the main characteristics of textile fabrics—area density, which combines physical and economical aspects. It helps to predict many physical properties and the mechanical behaviour, which is especially important for protective textiles, and allows predicting potential yarn consumption for knitting of one square meter of the fabric. The main idea of the proposed method, based on Čiukas geometrical model, is to calculate different parts of the knitted loop separately, which gives a great flexibility of such modelling. The proposed theoretical formulas can be used for various weft-knitted structures, give very low errors to empirical calculations, and are easy to use. It is a big advantage because known geometric models only allow a loop length of some particular pattern to be calculated, usually of single jersey or rib 1 × 1.

Calculation of interlock, 1 × 1 rib, and single jersey knitted fabrics shrinkage during the dyeing process after determining loop shape

This study investigated existing dimensional variations in knitted fabrics produced by weft-knitting technology for knitting and dry relaxation, dyed and dry relaxation, and dyed and wash relaxation for the interlock, 1 × 1 rib, and single jersey structures. This paper demonstrates that once the structure has been knitted, the shape that the loop takes in the fabric, and loop length and loop width, for each relaxation state will be the main factor responsible for dimensional variations in cotton knitted fabrics. It also shows how loop length affects knitted fabric dimensions when knitting machine parameters are modified by varying the use of feeders, and obtaining more loosely or more tightly knitted fabrics. In this study a model to predict the longitudinal and transversal shrinkage of interlock, 1 × 1 rib, and single jersey fabrics after the dyeing process is presented. This avoids following the conventional analysis procedure according to Standard UNE-EN ISO 6330 of September 2012 and, thus, avoids investing relatively long calculation times, which speeds up the production process by avoiding product lots being stopped. These results are important for textile industry technicians as they substantially simplify production calculations in weft-knitted fabrics companies. This work offers an effective method for predicting the longitudinal and transversal shrinkage and width of knitting fabrics after the dyeing process from the loop dimension after the knitting process. The application of the study results may help businesses to significantly save time and, consequently, imply an intermediate product stock investment saving.