The paper presents an extension of existed cover factor theory more suitable for the evaluation of light penetration through a net woven fabrics structure. It also introduces a new simplified model ...of predicting the ultraviolet (UV) protective properties of woven fabrics assuming that the coefficient of reflection (K
), transmission (K
), and absorption (K
) of constitutive yarns are known. Since usually they are not, the procedure of preparation of simulation of proper woven fabric samples without interlacing and with known constructional parameters is also presented. The procedure finishes with a fast and cheap detection of missed coefficient for any type of yarns. There are differences between theoretical and measured results, which are not particularly significant in regard to the purpose and demands of investigation.
The subject of the paper focuses on the effect of weave architecture on microbial barrier properties of woven fabrics or more precisely on identifying crucial elements of weave architecture that ...dominantly influence bacteria penetration in dry condition. For that purpose, 12 samples of cotton fabrics were woven and examined. In their structure, all samples had the same yarns (36 tex) in warp and weft, same densities of warp (24 yarns/cm), two weft densities (24 and 20 yarns/cm) and six different basic weave structures. Microbial barrier permeability was determined according to a previously developed test method in cooperation with University Hospital Center Zagreb. Bacterial endospores of apathogenic species of the genus Bacillus: Geobacillus stearothermophilus and Bacillus atrophaeus were used. The effect of weave pattern on microbial barrier properties was significant. Weave patterns, decisively determined the number of influencing pores and its sizes in woven fabrics, as well as the yarn floating which jointly almost perfectly correlated with bacteria penetration through the woven fabric. Multiple linear regression of pore numbers and floating threads produced equations which correspond in 99% to the measuring results for densities 24/24 and 24/20, and more than 98% considering both densities of the set. Among compared weave patterns, satin weave had significantly lower permeability of microorganisms (six–seven times) than basket weave (the highest), for both densities.
This paper deals with the possibility of a fast and accurate assessment of the number, size, and distribution of pores in transparent woven fabrics based on light penetration. The procedure of ...analyzing the pore structure in the fabrics based on a digital image is presented in detail. Fabric pores are treated as image particles and analyzed with the Java-based image processing software ImageJ. The obtained data relate to the constructional parameters of the fabric that allow for further analysis, provide the possibility to compare structurally similar or different samples as well as double check the results generated by optical or other means. This paper describes work on plain and similar to plain weaves. The conducted analysis revealed several expected and some unexpected results. Among the former, we can list the range of pore sizes in the examined woven fabrics, the distribution of pores in regard to their similarity, and the effect of dents. Examples of the latter are the magnitude of the cumulative percentage of pores in regard to the weave and the degree to which they participate in the inter-yarn and inter-fiber pores.
Knowing the reflection, transmission, and absorption properties of the yarns from which the woven fabric is made, prediction of a fabric’s UV-protective properties is simple. Using the geometrical ...properties of monofilament yarns and fabrics, which were determined optically, and following the cover factor theory, we have determined the areas of fabrics covered with no yarns, only one yarn, and two yarns. From a special selected set of high-module polyethylene terephthalate (PET) monofilament materials (e.g., fabrics), we have elaborated a method for determining the reflection, transmission, and absorption of yarns. By first defining the differently covered areas of fabrics, we were able to use them in a mathematical model for calculating and predicting the UV-protective properties of the fabrics. The calculated and measured values of the UV-protective properties of the selected test fabrics were highly correlated, with a correlation coefficient >0.98.
The paper examines the effect of different factors, i.e. weft density, weave type and consequently agglomeration of the interlacing points of the same type, on the colour impression of a woven ...fabric. The experimental part is based on 60 weaved samples which differ in weave type (we used 10 different weave types in which the technical face and technical back are the same), colour of the warp (we used white and black warp) and weft density (we used yarns with densities 15, 20 and 25 yarns / cm). We measured the colour values of the woven samples. We arranged the measurements in different ways and tried to visually evaluate the effect of density, effect of weave type, also the effect of the size and shape of agglomerated interlacing points of the same type, on the colour impression of the woven fabric. The results of the colour measurements were sorted into tables and presented in graphs, which were used to find the samples within the observed groups of characteristics that showed the biggest colour differences, to calculate these colour differences and observe and explain the effect of the observed factors on the colour impression.
Owing to growing demand for comfortable clothes, elastane filament yarns are being used in fabrics for several garments. In this study, core spun yarns were produced with cotton fibres and ...PBT/elastane filament yarns (cotton as sheath material, PBT yarn and elastane as core yarns). Twill woven (1/3 Z) fabrics were produced by using core spun yarns (30 tex) and cotton yarns (30 tex) as weft, and 100% cotton yarn (59 tex) as warp yarns. The fabrics consisting of PBT were washed at 100°C for 30 minutes to gain the elasticity. The woven fabrics’ weight, thickness, elongation, permanent elongation, dimensional stability, air permeability, thermal conductivity, thermal absorptivity characteristics were tested and statistically evaluated. According to the results, the fabrics containing PBT and elastane filaments had similar elongation and shrinkage values. PBT filament yarns have a great potential to produce lightweight elastic fabrics.
Apart from their soft feel and good water absorbency, cotton fabrics are also characterised by good heat conductivity, air permeability and breathing. By increasing the open surface of one-layer ...fabrics, their air and water vapour permeability, and heat conductivity should increase as well, whereas the protection against UV rays, on the other hand, which is especially important for summer clothes, decreases. The aim of the research was to establish the influence of multilayer cotton fabric constructions on the properties connected with porosity, i.e. thermal resistance, water vapour resistance, UV-light permeability and air permeability. One-layer, two-weft and double cotton fabric constructions were woven from white, blue and black yarn with fineness 8 × 2 tex, warp density 40 ends/cm and weft density 60 picks/cm, taking into consideration the colour distribution of yarns in the fabrics as well. The research results showed that the most optimal construction characterises multilayer two-weft and double fabrics. Among the studied fabrics, a positive correlation was established between the porosity of fabrics and their air permeability or ultraviolet protection factor (UPF), respectively, and a negative correlation between the porosity of fabrics and their heat or water vapour permeability, respectively. The correlation between the calculated number of pores of individual samples, as an important factor in porosity, and the studied permeability resistance properties (i.e. heat resistance, water vapour resistance, UV-light permeability and air permeability resistance) was higher than the correlation between the porosity of samples and the abovementioned permeability properties.
Air permeability is one of the fundamental textile properties influencing the design of comfortable clothes. In particular, it is very important in the field of technical textiles. Air permeability ...depends mainly on the fabric structure, which can be described by yarn linear density, type of yarn, warp/weft density and weave.
The purpose of our study was to identify a small number of parameters that have the strongest influence on air permeability of cotton fabrics and enable its good prediction. Rather than focusing on the constructional parameters, we decided to include a composite parameter known from the theory of fluids, hydraulic diameter of pores, which treats rectangular-shaped pores as circular ones. In addition to the hydraulic diameter of pores, two other parameters were used for the prediction of air permeability: the number of macro pores and the total porosity of woven fabrics.
36 woven fabric samples were produced using nine frequently implemented weave types together with two warp densities (29.3 and 22 ends/cm) and two weft densities (15 and 20 picks/cm), resulting in four different densities of woven fabrics. The yarns had the same linear density and material in warp and weft directions. Air permeability measurements were performed with the Air Permeability tester FX 3300 Labotester III (Textest Instruments) according to the ISO 9237:1995 (E) standard.
Principal components analysis revealed that the four investigated plain weave specimens behave differently than the other samples, which might be explained by weave structure. This multivariate statistical method also confirmed the appropriateness of the three selected parameters for air permeability prediction which was done using multiple linear regression. The high adjusted coefficient of determination (R2) value of 0.94 indicates that the model explains variability in the air permeability to a large extent.
In this article, the breaking elongation properties of woven fabrics with incorporated PBT yarns are presented. Different polybutylene terephthalate (PBT) yarns (multifilament PBT yarn, cotton core ...yarn and twisted viscose yarn, both with PBT in the core) were used. Textured PBT yarns have latent elastic properties, which become visible after the thermal treatment by the finishing process. The aim was to determine which of the constructional parameters is most important in analysing the shrinkage of fabrics after treatment, breaking elongation properties of all tested fabrics, and breaking elongation properties of woven fabrics before and after treatment. A multivariate statistical method ANOVA was used for the analysis. The results show that treatment was by far the most influential factor in the study of breaking elongation of all tested fabrics. When analysing the fabrics separately before and after treatment, the construction of the PBT yarn and the weave were found to be statistically significant parameters.
PDF
