Effect of hollow polyester fibres on mechanical properties of knitted wool/polyester fabrics

The physical and mechanical characteristics of hollow polyester fibres were compared with solid polyester fibres in order to establish their processing behaviour and performance characteristics. The effects of hollow fibres on fabric properties were investigated by using microscopy and tests of tensile and bursting strength, pilling, abrasion resistance, water vapour permeability, and handle. The results show that tensile strength of hollow polyester fibres and yarns are negatively affected by the cavity inside the fibre. Hollow fibres also have higher stiffness and resistance to bending at relaxed state. Fabrics made from hollow polyester/wool blends and pure wool fabrics show three distinguishable steps in pilling. During pilling, hollow fibres break before being pulled fully out of the structure, leading to shorter protruding fibres. Microscopy studies showed that the breakdown of hollow fibres started during entanglement by splitting along the helical lines between fibrils. KES results showed that the friction between fibres and the fibre shape are the most important parameters that determine the fabric low stress mechanical properties. However, in some aspects, the hollow structure of the fibre does not have a significant effect.     

Preparation of nano disperse dyes from nanoemulsions and their dyeing properties on ultramicrofiber polyester

Six nano disperse dyes were prepared using corresponding O/W nanoemulsions which were obtained with sodium laurylsulphate and caprylic triglyceride. The average particle size of the dyes prepared were in the range of 110–130 nm. Exhaust dyeing using nano dyes resulted in low exhaustion yields of 17–26 % on regular polyester fiber and 28–38 % on ultramicrofiber polyester. The observed low exhaustion yields of nano disperse dye can be explained by the solubilization of dye particles into surfactant micelles as well as the high stability of the nanoemulsions, these might reduce the capacity of dye uptake onto the fibers. However, higher K/S values of dyeings with nano dyes on ultramicrofiber sites compared to those on regular polyester sites suggested their potential to be more efficient dyes for finer denier microfiber polyesters.     

The effect of blend ratio and process parameters on tensile properties of polyester/viscose blended needle-punched nonwovens

In this study, the tensile strength and elongation of polyester/viscose blended needle-punched nonwovens were analyzed. For this purpose, five different blend ratios of polyester/viscose webs were produced, cross-lapped and needled in four different mass per unit areas and three different needling/punching densities. The tensile properties of the nonwovens were determined by performing the standard test methods and the data obtained from tests were statistically analyzed in Design Expert software. In addition, a mixture process crossed regression model with two mixture components (polyester and viscose blend ratios) and two process variables (fabric mass per unit area and needling density) was developed to analyze the tensile strength and elongation of polyester/viscose blended needled nonwovens. In conclusion, the regression model indicated that the tensile strength of the needle-punched nonwovens decreases with the increase of polyester proportion in the mixture and increases with the increase in mass per unit area and punching density.     

Effects of deposition parameters of electroless copper plating on polyester fabric

Properties of electroless copper-plated polyester fabric mainly depend on the plating bath constituents/conditions. The nickel serves to catalyze the copper deposition when hypophosphite is used as a reducing agent. In this study, the effects of deposition parameters including additive NiSO₄ concentration and pH on microstructure and properties of the electroless copper plating on polyester fabric using hypophosphite as a reducing agent were investigated. The results show that at a higher NiSO₄ concentration, the copper content present in the coating decreases whereas the nickel content increases slightly. On the other hand, the copper content present in the coating increases, whereas the nickel content and phosphorus decreases with respect to the rise of pH. The morphology of the copper deposits show that the particle size increase with respect to the rise of NiSO₄ concentration and pH. The XRD patterns indicate that the copper-plated polyester fabrics are crystalline. In addition, there is a decrease in the surface resistance and an increase in the electromagnetic interference (EMI) shielding effectiveness (SE) with respect to the rise of Ni²⁺ concentration and pH of the solution as a result of gaining a greater weight in the deposits. The results suggest that the copper-plated polyester fabrics have a great potential application as an EMI shielding material.     

Self-cleaning and handle properties of TiO2-modified textiles

Self-cleaning surfaces based on photocatalysis are an extremely promising nano-technological field of extensive research and development. Recently comprehensive research work has been performed to evaluate the optical, photocatalytic and antimicrobial properties of TiO₂ nano-particles and composites thereof. The aim of this study was to obtain self-cleaning properties for regenerate cellulose surfaces by nano-modification, using TiO₂ nano-coating and to define the impact of the modification on fabrics end-use properties. Two different modified fabrics with self-cleaning effect were prepared and analysed, i.e. the modification efficiency was determined. In addition, the influence of fibre modification on several textile properties was determined. However, a soft handle, good appearance and some other surface properties accompanied by appropriate mechanical properties represent the basis for a high quality fabric therefore the influence of the modification procedure on textiles handle was studied.     

Effect of heat setting parameters on some properties of PLA knitted fabric

This article reports the outcome of a study conducted for examining the effect of heat setting parameters on some properties of PLA knitted fabric. Three heat setting parameters, namely, treatment time, treatment temperature, and tension, were considered for optimizing the heat setting process with fabric shrinkage after dyeing and color yield as the evaluation factors. Experimental results revealed that lower shrinkage and higher color yield can be achieved when: (i) heat setting time = 60 s; heat setting temperature=130 oC; and tension=0%. After that, the PLA knitted fabric was treated under the optimum heat setting condition and was dyed with 1% depth disperse dye, which produced a better dyeing result. However, the handle of the heat set PLA knitted fabric, as measured by Kawabata Evaluation System for Fabric (KES-F), became stiffer and more resistant to shearing movement and had worse drape and bending recovery ability, while the appearance became fluffier and rougher.     

Antibacterial properties and color fastness of silk fabric dyed with turmeric extract

The use of non-toxic and eco-friendly natural dyes on textiles has received much attention due to the increased environmental awareness in order to avoid some hazardous synthetic dyes. In the present study, an eco-friendly approach was developed to impart color and antibacterial properties to silk fabrics dyed with turmeric extract as a non-toxic natural colorant. The natural colorant was extracted from Curcuma Longa rhizome. Copper sulfate, ferrous sulfate and potassium aluminium sulfate were applied in a pre-metallization process as mordanting agents. Antibacterial properties of treated fabrics were evaluated against common pathogenic bacteria, Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). The effects of dye concentration and mordant types on the obtained color hues, antibacterial efficiency and color fastness of the fabrics were investigated. The results indicated that mordanted and dyed fabrics possessed desirable antibacterial properties. Complete antibacterial activity of the treated fabrics was obtained with 3 %owf (on weight of the fabric) copper sulfate. It was also shown that increasing the dye concentration could lead to a more efficient antibacterial activity on the mordanted dyed fabrics. An optimum level of the antibacterial activity was observed in the sample treated with 30 %owf of turmeric. Furthermore, the results of CIE L*, a*, b* values, FTIR, washing, light and rubbing fastnesses of the dyed fabrics were reported. The mordanted dyed silk fabrics exhibited desirable color fastness properties. These studies proved a direct relationship between the degree of antibacterial activity of the fabrics treated with turmeric and the metals ion concentration.     

Dyeing properties and colour fastness of wool dyed with indicaxanthin natural dye

This research work involves the dyeing of wool with indicaxanthin, a natural dye extracted from fruits of Opuntia ficus-indica. The optimal conditions for dye extraction were to mix 50 g of Juice from cactus pears with 100 mL of 80% aqueous ethanol as solvent for dye extraction. Liquid chromatography was applied for the separation. Two main dyes were obtained, which were identified as indicaxanthin (75 mg per 50 g) and betanin (5 mg per 50 g). The effect of dye bath pH, salt concentration, dyeing time and temperature were studied. The optimal conditions for wool dyeing with indicaxanthin dye were carried out at 70 °C for 90 min with the pre-treatment of various metal salts as mordant. The colour yields of the dye on the wool were found to be highly dependent of the pH, optimum results being obtained at pH 4. The K/S of wool increased in the order of the dyeing using KAl (SO₄)₂ > MnSO₄ > CoSO₄ > FeSO₄ > none > ZnSO₄ > CuSO₄. Un-mordanted samples have good properties of water and washing fastness. Mordants KAl (SO₄)₂ and CoSO₄ were found to give good light fastness (rating 5).     

The study of coloration and antibacterial efficiency of corona activated dyed polyamide and polyester fabrics loaded with Ag nanoparticles

The aim of this study was to examine the influence of dyeing on antibacterial efficiency of corona activated polyamide and polyester fabrics loaded with colloidal Ag nanoparticles as well as the influence of the presence of Ag nanoparticles on the color change of dyed fabrics. C.I. Acid Green 25 and C.I. Disperse Blue 3 were used for dyeing of polyamide fabrics and C.I. disperse violet 8 for polyester fabrics. The color change of polyamide fabrics depends on the dye type, which was generally lower compared to polyester fabrics. Antibacterial efficiency of Ag loaded fabrics was tested against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli. Corona activated polyester and polyamide fabrics showed excellent antibacterial efficiency independently of order of dyeing and Ag loading. The morphology of fibers loaded with Ag nanoparticles was assessed by SEM and atomic absorption spectroscopy for elemental analysis.     

Grain and milling characteristics and their relationship with selected mixogram parameters in hard red bread wheat

Breeders in South Africa are faced with the problem that quality testing is only done in advanced phases of the bread wheat breeding programme when enough seed is available. This means that lines not meeting quality requirements of the South African industry for cultivar release are only discarded during the advanced breeding phases. The aim of this study was to determine relationships between grain and milling characteristics and mixogram parameters and to determine whether these characteristics can be used for selection of acceptable mixogram parameters and vice versa. A mixograph with Mixsmart software was used to analyse 10 bread wheat cultivars, in four replications at three different locations. Thirteen mixogram parameters were used to determine correlations with important grain and milling characteristics. Highly significant correlations were observed between mixogram parameters and grain as well as milling characteristics, although not with hectolitre mass, thousand kernel mass, vitreous kernels, falling number or flour colour. Multiple coefficient of determination was low to moderate for grain characteristics and low for milling characteristics as independent variables in explaining the variation in several mixogram parameters. In spite of the highly significant correlations, grain and milling characteristics explained little of the variation in mixogram parameters in this study.     

Influence of deposition parameters and kinetics of electroless Ni-P plating on polyester fiber

The electroless nickel-phosphorous (Ni-P) plating on polyester fiber using sodium hypophosphite as a reducing agent in alkaline medium was studied. The effects of plating parameters including concentrations, pH and bath temperature of the plating bath on deposition rate of the electroless Ni-P plating were investigated. The results reveal that the deposition rates increase with the increase in the concentration of nickel sulfate, sodium hypophosphite, pH and bath temperature, respectively. However, it is determined that the deposition rates decrease with the rise of sodium citrate. The kinetics of the deposition reaction was investigated and an empirical rate equation for electroless Ni-P plating on polyester fiber was developed.     

Surface properties studies of MPCMs containing fabrics for thermo-regulating textiles

This paper reports the effect of microencapsulated phase change materials (MPCMs) and silicon carbide (SiC) by a direct composite coating on outdoor winter fabrics by examining the changes in the mechanical and physical properties that occur before and after the composite coating. Pretreated waterproof breathable nylon was coated with PCMs 20 wt% (20PCM) and PCMs 20 wt%/SiC 20 wt% (SC-20PCM). The far-infrared (FIR) emissivity was measured using a Fourier transform infrared spectroradiometer. The cross-section morphology, mechanical properties and changes in pore size were examined by scanning electron microscopy (SEM), a Kawabata evaluation system for fabrics (KES-F) and porometry, respectively. SEM revealed the successful embedding of MPCMs and SiC into the coating layer. The KES-F system showed that the application of coating additives onto the fabrics made them stiffer and slightly heavier but decreased their pore size. The FIR emissivity was only marginally improved from 0.88 to 0.9.     

Antimicrobial activity of textiles with selected dyes and finishing agents used in the textile industry

It is shown in this paper that cationic dyes and chemical finishing agents for textiles exhibit antimicrobial properties both in solution and when present on textile products. The dye Maxilon Navy 2RM has particularly high antimicrobial activity — its values of the minimum concentration inhibiting the growth of the studied microorganisms (MIC and MBC) are very low, in the range 0.0003–0.06 %. The tested dyes display mainly fungistatic action, while the fiber softener Sapamine OC and the dyeing fixative wet fastness improver Albafix WFF were more active against bacteria. The paper presents sensitivity series of microorganisms with respect to the tested dyes and finishing agents. Fabrics to which the substances had been applied showed reductions in microorganism numbers by 16 % to 99.9 %, depending on the type of substance and the microorganism. The studies showed that in some cases the use of a typical (justified technologically) quantity of dye or finishing agent imparts high antimicrobial activity to the textile materials, with bacteria or fungi reduced by more than 99 %.     

Prediction of selected rheological characteristics of wheat based on Glutopeak test parameters

The GlutoPeak®-Test, a new rapid small-scale technique, was proposed as an alternative method for evaluation of wheat grain and tool for predicting the wheat flour quality. Samples obtained from an industrial mill were analyzed by a GlutoPeak test (whole grain flours) as well as by farinograph and extensograph tests (refined flours). Firstly, linear correlation coefficients between water absorption, dough stability, dough energy and defined parameters of GlutoPeak were calculated. Next, a sequential multiple quadratic regression analysis (backward, forward and stepwise), a logistic regression analysis and a PLSR analysis were applied. The correlation between the flour water absorption and most of the parameters obtained from the GlutoPeak test were strong (r ≥ 0.74, p < 0.001). For stability, the r value was 0.40, while for energy it was 0.44. Based on the obtained results it could be state that in the case of water absorption, the best fit was the sequential regression model, for dough stability sequential regression model and the PLSR model had the best fit, whereas logistic regression model was the best fitted to the energy. Unfortunately, after cross validation it was found that the last model is not good enough for energy prediction.     

Effect of the atmospheric plasma treatment parameters on surface and mechanical properties of jute fabric

Plasma treatment is a kind of environmentally friendly surface modification technology, which has been widely used to modify various materials in many industries. Plasma treatment improves the fiber-matrix adhesion largely by roughening the surface of fibers to increase mechanical interlocking between the fiber and the matrix. For this aim, the effect of atmospheric air plasma treatment on jute fabrics has been discussed in this study. The plasma treatment has been employed at different powers and time intervals. The effects of plasma treatment on fiber properties were revealed by wickability, surface roughness, fiber tensile test and pull-out tests. The effect of plasma treatment on functional groups of jute fibers was observed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Scanning electron microscopy (SEM) images showed the etching effect of plasma treatment on the surface. It can be concluded that plasma treatment is an effective method to improve the surface and mechanical properties of jute fabrics to be used for composite materials.     

Effect of chelating agent in disperse dye dyeing on polyester fabric

In this study, mild acid based chelating agents (glycolic acid, gluconic acid, ethylenediaminetetraacetic acid, and citric acid) were used for the dyeing of polyester fabrics with metal sensitive disperse dye in closed dyeing process. The chelating and pH adjustment efficiencies were compared in disperse dyeing condition. In the comparative analysis with different chelating agents, glycolic acid showed a higher chelation efficiency and consequently showed higher dye bath exhaustion and color strength. Slight differences in the color fastness of the dyed samples obtained by employing four different chelating agents were observed.     

Effect of polyester fabric through electroless Ni-P plating

Process for electroless nickel-phosphorous (Ni-P) plating has been investigated as a metallizing treatment technology on polyester fabric. The microstructure and mechanical performance of Ni-P-plated polyester fabric are investigated in this study. Surface modifications of Ni-P-plated polyester fiber were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The changes in weight and thickness of the Ni-P-plated polyester fabric were determined through direct measurements. Systematic investigations, including bending rigidity, tearing strength, tensile strength, elongation at break, air permeability, wettability and absorbency, and anti-static property were conducted on untreated and metallized polyester fabrics. A thorough discussion and quantitative report were made on the specific performance of the Ni-P-plated polyester fabric.     

Plasma-assisted surface modification of polyester fabric for developing halochromic properties

In the field of textiles, introducing pH-sensitive dyes onto fibrous materials is a promising approach for the development of flexible sensor. In this study, poly(ethylene terephthalate) (PET) textile surface with halochromic properties was fabricated by plasma-assisted sol-gel coating, followed by immobilization of two different azo pH-indicator dyes; namely Brilliant yellow and Congo red by conventional printing technique of fabrics. 3-aminopropyltriethoxysilane (APTES) was used as a coupling agent for attaching the pH-sensitive dyes through its terminal amines. The surface immobilization of APTES on PET fabric was conducted by the pad-dry-cure method. Moreover, the influence of oxygen plasma pre-treatment and the method of post-treatment either by oxygen plasma or by thermal treatment on the stability of sol-gel based matrix was investigated. The morphology and chemistry of 3-aminopropyltriethoxysilane coated PET surfaces were examined by using surface sensitive methods including electrokinetic and time-dependent contact angle measurements as well as X-ray photoelectron spectroscopy (XPS). In addition, fastness tests of the printed fabrics and color strength were carried out to assess the effectiveness of the fabric surface modification. Results indicate that sol-gel matrix exhibited a more stability by thermal post-treatment at 150 C for 5 min. Also, the results revealed that the printed fabrics with halochromic properties demonstrated sufficient stability against leaching by washing. The current work opens up a novel opportunity to develop flexible sensors based on fibrous materials, which have the potential to be employed in variable industrial applications.     

Effect of the low and radio frequency oxygen plasma treatment of jute fiber on mechanical properties of jute fiber/polyester composite

We investigated the surface modification of jute fiber by oxygen plasma treatments. Jute fibers were treated in different plasma reactors (radio frequency “RF” and low frequency “LF” plasma reactors) using O₂ for different plasma powers to increase the interface adhesion between jute fiber and polyester matrix. The influence of various plasma reactors on mechanical properties of jute fiber-reinforced polyester composites was reported. Tensile, flexure, short beam shear tests were used to determine the mechanical properties of the composites. The interlaminar shear strength increased from 11.5 MPa for the untreated jute fiber/polyester composite to 19.8 and 26.3 MPa for LF and RF oxygen plasma treated jute fiber/polyester composites, respectively. O₂ plasma treatment also improved the tensile and flexural strengths of jute fiber/ polyester composites for both plasma systems. It is clear that O₂ plasma treatment of jute fibers by using RF plasma system instead of using LF plasma system brings about greater improvement on the mechanical properties of jute/polyester composites.