Influence of Weave and Densities on Visual Appearance of Woven Fabrics Made From Two Colored Yarns

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

Multilayer cotton fabric porosity and its infl uence on permeability properties

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

Numerički i grafički prikaz i usporedba dvobojnih tkanina s različitim modelima boja

Cilj rada je istražiti mogućnost primjene nekih modela boje za numeričko i grafičko predstavljene optičkog miješanja na dvobojnim tkaninama. U tu su svrhu odabrane dvobojne tkane strukture koje su imale jednako obojadisanu osnovu i pet različito obojadisanih potkinih niti. Kao referentne su izrađene jednobojne tkanine na kojima su istraženi utjecaji teksture na spektrofotometrijske vrijednosti. Konstrukcijski parametri tkanih struktura su bili različiti, čime su postignuti različiti udjeli obojenih komponenata na površini strukture. Teoretske tristimulusne vrijednosti dvobojnih struktura, određene aditivnim postupkom pomoću spektralnih vrijednosti i udjela obojenih komponenata, služile su za prikaz linearnih položaja mješavina između položaja boje osnovinih i potkinih niti u modelima boja. Stvarne tristimulusne vrijednosti su bile izmjerene spektrofotometrijski. Teoretske i izmjerene vrijednosti refleksije i tristimulusne vrijednosti su uspoređene pomoću metode korelacije te grafičke usporedbe dvobojnih mješavina u xy i u u\u27v\u27 dijagramu te a+b+ ravnini. Izračunate su i vrijednosti ukupne razlike u boji. Pomoću rezultata istraživanja omogućena je kritična numerička i grafička analiza primjene različitih sustava boja pri vrednovanju dvobojnih površina, koja je pokazala prednosti i nedostatke svakog obrađenog sustava boja

Study of cotton woven fabrics with added polybutylene terephthalate yarns

U radu je prikazan razvoj novih tkanina pamučnog tipa povećane istezljivosti uz upotrebu teksturirane multifilamentne pređe od polibutilen tereftalata (PBT) po potki i primjenom odgovarajućeg postupka obrade. Za potrebe istraživanja izrađena je skupina referentnih uzoraka tkanina koje sadrže PBT pređu. Tkanine su se razlikovale po redoslijedu pamučnih i PBT pređa u smjeru potke. Kod nekih uzoraka upotrjebljena je bila udvojena nit PBT koja je simulirala upotrebu pređe dvaput veće duljinske mase. Ispitan je utjecaj udjela teksturirane PBT pređe na elastična svojstva tkanina od mješavine pamuka/PBT, nakon obrade u kipućoj vodi u vremenu od 30 min. Skupljanje tkanine u smjeru osnove i potke te utjecaj na gustoću tkanine (po osnovi i potki), debljinu, površinsku masu i prekidna svojstva određena su primjenom standardiziranih postupaka. Količina PBT uglavnom je utjecala na elastičnost tkanine u smjeru potke. Najveća elastičnost imala je dobru korelaciju s najvećom količinom PBT. Osim toga, minimalni udio PBT je učinkovito povećao prekidna svojstva obrađenih tkanina u oba smjera, što je važno, jer tkanine većinom zadržavaju svoj pamučni karakter. Upotreba PBT i odgovarajući postupak obrade za razvoj zahtijevanih povećanih elastičnih svojstava tkanina za bilo koje namjene mogla bi biti od značajne prednosti u pogledu cijene (u usporedbi s Lycra®) i vremena proizvodnje (priprema za tkanje i brzina tkanja).The aim of this work is a development of new products, i.e. cotton like woven fabrics with increased extensibility, using textured multifilament polybutylene terephthalate (PBT) yarn in a weft direction and a proper finishing procedure. For the research purpose, a set of referential samples of woven fabrics containing PBT was made. The fabrics differed in the sequences of cotton and PBT yarns in the weft direction. In some samples a doubled PBT yarn is inserted in as one weft, simulating double linear density. The influence of the textured PBT yarn quantity on the elastic properties of cotton/PBT woven fabrics, developed after the treatment in boiling water for 30 minutes, was studied. The contraction in warp and weft directions that affect warp and weft density, thickness, mass per unit area and tensile properties were measured using standardised methods. The quantity of PBT mainly influenced the elasticity in weft direction. The highest elasticity correlated well with the highest quantity of PBT. Furthermore, a minimum portion of PBT effectively improved the tensile properties of treated fabrics in both directions, this being important in such cases, as the fabrics mostly keep their cotton character. The use of PBT and proper finishing procedure for developing the required increased elastic properties of woven fabrics for any purposes could be of significant advantage in the terms of price (compared to Lycra®) and production time (preparation for weaving and speed of weaving)

Use of extended cover factor theory in UV protection of woven fabric

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$_R$), transmission (K$_T$), and absorption (K$_A$) 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

A New Simplified Model for Predicting the UV-Protective Properties of Monofilament PET Fabrics

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

Optical assessment of porosity parameters in transparent woven fabrics

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

Elongation properties of woven fabrics with incorporated PBT yarns

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