Cotton Knitted Fabrics Research Articles

Effect of the CO2 laser treatment on properties of 100% cotton knitted fabrics

In the textile and fashion industry, cotton knitted fabric is commonly used for making apparel. To achieve different functional effects of the cotton knitted fabric, chemical treatments are commonly used, but due to increased environmental restrictions, physical treatment, e.g., with a laser, has recently been introduced to the market as an environmentally friendly way to treat the surface of cotton fabric. Thus, the aim of the present study is to evaluate the impact of laser treatment on the physical and mechanical properties of 100% cotton single jersey knitted fabrics with different yarn counts. The fabrics had been treated using a carbon dioxide laser (CO2) with different levels of intensity in terms of the resolution and treatment time, i.e., the resolution (28, 32, 36, 40 dpi) and pixel time (100, 110, 120, 130 μs). The laser power density resulting from the different combinations of laser variables was measured. Various evaluation tests including scanning electron microscopy, fabric weight, fabric thickness and fabric bursting strength were used to study the effect of laser treatment on the knitted fabrics. Grooves and microcracks appeared on the fibers after laser treatment. With increasing resolution and pixel time, these changes became more distinct on the fiber surface. The highest number of pores was found on the yarn with a higher yarn count and lower yarn twist. According to the results of knitted fabrics treated with a laser, the largest difference was found for the aspects of weight, thickness and whiteness values of the fabric knitted with the thickest yarn. Furthermore, it was confirmed that not only the yarn count affects the change in weight and thickness, but also the fabric structure such as the number of courses affected the laser treatment result.

Study and application of an enzymatic pool in bioscouring of cotton knit fabric

AbstractGrey cotton contains between 4–12 % non‐cellulosic impurities. The removal of these impurities is generally carried out by alkaline washing at elevated temperatures which may cause damage to the cellulose fibre and generate an effluent with a high environmental impact. An alternative approach is the use of bioscouring, with enzymes specifically removing the impurities under mild conditions of pH and temperature. In this study, the effect of a commercial enzymatic pool (cellulase, lipase, and pectinase) on the bioscouring of 100 % cotton knit fabric was evaluated. The effect of each enzyme and the interaction between them were evaluated with the aid of an experimental design and the characterization of the treated fabric (weight loss, degree of whiteness, degree of pectin removal, and hydrophilicity) was performed. The combination of the three enzymes on bioscouring led to the best results in terms of degree of whiteness (25.0 °Berger), pectin removal (87 %), and hydrophilicity (14 s). A comparison between the enzymatic treatment and the scouring confirmed that bioscouring can be as effective as the conventional process, being more environmentally sustainable because it occurs at neutral pH and consumes less water and energy.

Dyeing of S/J Cotton Knit Fabric with Natural Dye Extracts from Green Walnut Shells: Assessment of Mordanting Effect on Fastness Properties

In this study, aqueous extraction method is used because of its high extraction ratio, light fastness and also functional properties. In 1st phase, for dyeing S/J cotton knit fabric with green walnut power ferrous sulfate is considered as a mordant. In this study, three different mordanting methods such as pre-, meta-, and post-mordanting are conveyed the dyeing process with the state of metallic mordant and without metallic salt mordants. In 2nd phase, in dyeing for fixation ferrous sulfate was considered as mordants. Furthermore, the analysis and evaluation of each colour dyed material was done through following two terms for instance CIELAB (L*, a*, and b*) and K/S values. According to AATCC test methods, colour fastness to washing, crocking, perspiration of the dyed samples is determined whereas according to the ISO standard, the colour fastness to light was estimated and tested. When dyeing was carried out on S/J cotton knit fabric through considering optimum parameter like at 80&degC for 60 min and at pH 4 which showed optimum results. From the results we can see, very good wash fastness was obtained while there is no fading of the colour, whereas the outstanding and moderate level of colour fastness to light and crocking is achieved.

Study on antibacterial and comfort performances of cotton fabric finished by chitosan-silver for intimate apparel

The fabric used for intimate apparel is widely required to have excellent antibacterial and comfort performances. In order to improve its antibacterial ability, this paper studied chitosan-silver finishing on the cotton knitted fabric. The study indicates that the chitosan-silver attached to the fabric exhibits excellent antibacterial action against the typical bacteria of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureu). The anti-bacterial mechanism of chitosan-silver against E. coli and S. aureu were investigated. To guarantee its prominent comfort performance, measurements were made on the finished fabric of its air permeability, water vapor transmission, hydrophily, surface friction and bending ability against the control fabric, which is currently used for intimate apparel. The antibacterial and comfort performances were compared between the tested fabrics. The results show that the air permeability and the hydrophily of the finished cotton fabric are significantly better than the control one, while the water vapor transmission, the surface friction and the adjustable rate remain similar to each other. The bending rigidity of the finished fabric is slightly better due to the attachment of chitosan within accepted threshold. The dual compounding theory of chitosan-silver proves to be useful for a higher synergistic effect of anti-bacteria, lower whiteness degradation and overall optimization of comfort performance. This dual compounding theory of chitosan-silver is valuable for improving antibacterial and comfort performances of intimate apparel.

Fuzzy Knowledge Based Expert System for Prediction of Color Strength of Cotton Knitted Fabrics

The present study is intended to develop an intelligent model for the prediction of color strength of cotton knitted fabrics using fuzzy knowledge based expert system (FKBES). The factors chosen for developing the prediction model are dye concentration, dyeing time and process temperature. Besides, such factors are nonlinear and have mutual interactions among them; so it is not easy to create an exact correlation between the inputs variables and color strength using mathematical or statistical methods. In contrast, artificial neural network and neural-fuzzy models require massive amounts of experimental data for model parameters optimization which are challenging to collect from the dyeing industries. In this context, fuzzy knowledge based expert system is the most efficient modeling tool which performs exceptionally well in a non-linear complex domain with lowest amount of trial data like human experts. In this study, laboratory scale experiments were conducted for three types of cotton knitted fabrics to verify the developed fuzzy model. It was found that actual and predicted values of color strength of the knitted fabrics were in good agreement with each other with less than 5% absolute error.

Designing a composition formulation of surface active substances for the pretreatment of knitted fabric

The process of pretreatment of knitted fabrics for dyeing is the most important technological operation. As a result of the pretreatment, fabrics acquire capability to wet evenly, which contributes to the uniform putting of the solutions of dyes and other decoration substances. Based on the analysis of the washing and wetting capacity of different classes of surface active substances, we determined those preparations, which ensure the optimal capillary properties of knitted fabric. A mathematical model by the wetting and washing capacities was obtained by the method of mathematical planning of the experiment – the Scheffe’s simplex lattice plan of the second order. Based on the obtained results, the Authors carried out optimization of the models “composition­property” and determined the optimal formulation of the composition for pretreatment of cotton knitted fabric for dyeing, g/l: SAS1=3,40; SAS2=2,75; SAS3=0,90; SAS4=2,90. It was found that the application of the proposed composition of SAS of the concentration 1,2 g/l for the technology of pretreatment of knitted fabric leads to a significant increase in the capillarity of knitted fabric (by 3 times) and the degree of fixation of active dye (by 7,5 %).

Low temperature bleaching for reactive dyeing and top white knitted cotton fabric

This study aims at setting an example for reducing customer complaints and energy costs in dyehouses. For cotton knitted fabric to be dyed and gain top white quality, the commercial non-ionic bleaching system with activators at low temperature (60 °C) was compared with the conventional system with stabilizers (98 °C). According to the test results, it is possible to obtain a product with high capillarity and dyeability, sufficient whiteness degree, less decrease in bursting strength, less weight loss and even less burdened waste liquid.

Sensitivity Analysis Of Vynyl Sulphone And BisMonochlorotriazine Reactive Groups Of Reactive Dyes

Reactive dyes contain different types of reactive groups which have different levels of sensitivity. Reactive dyeing is carried out by exhaust method on cotton knit fabric. A trichromatic combination is chosen containing vinylsulphone and bis-monochlorotriazine reactive groups. Dyeing of fabric is carried out with standard condition and variation of the conditions (electrolyte concentration, pH, exhaustion time, fixation time and M:L). Colorimetric data (DE*) is produced by comparing the difference between standard shade and the resulting shades by using spectrophotometer. Between the investigated reactive groups of reactive dye bismonochlorotriazine shows lower sensitivity in other terms higher robustness than vinyl sulphone.

Wet‐driven shape‐memory behaviors and thermal adaptability of cotton knitted fabrics containing crosslinked poly(ethylene glycol) moieties

ABSTRACTCotton knitted fabrics were treated with poly(ethylene glycol) (PEG) in the presence of polyhydric alcohol etherified dimethylol dihydroxy ethylene urea as the crosslinker and magnesium chloride hexahydrate as the catalyst. In wet–dry cycles, the fabrics treated with 30% PEG1500 in the presence of 15% crosslinker and 3% catalyst showed obvious wet‐driven shape‐memory behaviors in terms of a 12% shrinkage rate in the wet state and a 80% shrinkage‐recovery rate in the dry state. The results of weight gain, morphological structures, Fourier transform infrared spectra, and X‐ray diffraction pattern tests confirmed PEG deposits on the surface of the treated fabrics, demonstrated the crosslinking of cotton cellulose with PEG and crosslinker, and also explained the wet‐driven shape‐memory mechanism. The results from differential scanning calorimetry show that the treated fabrics with wet‐driven shape‐memory behaviors had a phase‐change enthalpy and heat‐storage capacity. The crosslinking of cotton cellulose with PEG had a strong influence on the mechanical performance and air permeability of the cotton knitted fabrics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43473.

Engineering of Knitted Cotton Fabrics for Optimum Comfort in a Hot Climate

Cotton knitted fabrics are popular for summer-wear and outer-wear due to their comfort. The typical porous structure of knitted fabrics, however, increases the risk of exposure of human skin to UV rays, resulting in skin cancer. Therefore a trade-off is required between the comfort and UV ray resistance of the fabric. In this study, an attempt was made to engineer single jersey and 1×1 rib knitted fabrics with optimum comfort and desired UV resistance. It was found that 1×1 rib knitted fabrics could provide better comfort and UV protection with respect to single jersey fabrics manufactured on the same gauge knitting machine.

An Artificial Neural Network Model for Prediction of Colour Properties of Knitted Fabrics Induced by Laser Engraving

In this paper, we propose an artificial neural network (ANN) model for prediction of color properties, including color yield (in terms of K/S value) and CIE L, a and b values of 1005 cotton knitted fabrics under the effect of laser engraving process with different process parameters. Fabric factors to be examined in the ANN model included fiber composition, fabric density, mass of fabric, fabric thickness, linear density of yarn, yarn twist, direction of yarn twist and crimp. After obtaining the ANN model, its performance was compared with linear regression model. It is noted that the ANN model produced superior results in prediction of color properties of laser engraved 100 % cotton knitted fabrics. The relative importance of the examined factors influencing color properties was also investigated.

Ultrasound energy to accelerate dye uptake and dye–fiber interaction of reactive dye on knitted cotton fabric at low temperatures

Acoustic cavitation formed due to propagation of ultrasound wave inside a dye bath was successfully used to dye cotton fabric with a reactive dye at lower temperatures. The energy input to the system during sonication was 0.7W/cm2. This was within the energy range that contributes towards forming cavitation during ultra-sonication. The influence of ultrasound treatment on dye particle size and fiber morphology is discussed. Particle size analysis of the dye bath revealed ultra-sonication energy was capable of de-agglomeration of hydrolyzed dye molecules during dyeing. SEM micrograph and AFM topographical image of the fiber surface revealed fiber morphology remains unchanged after the sonication. The study was extended in understanding the contribution of ultrasound method of dyeing towards achieving good color strength on the fabric, compared to the normal heating method of dyeing. Study showed color strength obtained using ultra sound method of dyeing is higher compared to normal heating dyeing. Ultrasound energy was able to achieve the good color strength on cotton fabric at very low temperature such as 30°C, which was approximately 230% more than the color strength achieved in normal heating method of dyeing. This indicates that energy input to the system using ultrasound was capable of acting as an effective alternative method of dyeing knitted cotton fabrics with reactive dye.

Antimicrobial controlled release systems for the knitted cotton fabrics based on natural substances

Materials with antibacterial properties, that can be used as barrier materials, hygiene products, plasters or bandages, have been obtained by applying some systems consisting of essential oils incorporated in beeswax and beeswax/chitosan. The influence of oil, wax and chitosan amounts on emultion stability has been analyzed by optical microscopy. The controlled release of essential oils of Eucalyptus (EEO), Tea Tree (TTEO) and Sage (SEO) incorporated in beeswax and beeswax/chitosan from the treated material was estimated through UV/Visible spectrophotometric analyses. The antibacterial effect of the emulsions and of the materials obtained by treating them with these emulsions have been investigated against the Staphylococcus aureus ATCC 29213 and Escherichia Coli ATCC 25922 bacteria. Comfort performances (air and vapor permeability and hygroscopicity) for the treated materials have also been evaluated. The best antimicrobial activity and the highest amount of essential oil released in vitro were obtained for the treatment variants that contain 7.14 % beeswax and 26.67 % essential oil, and respectively 26.67 % essential oil, 3.33 % beeswax and 3.33 % chitosan.

In-Vitro Analysis of the Effect of Constructional Parameters and Dye Class on the UV Protection Property of Cotton Knitted Fabrics.

Cotton knitted fabrics were manufactured with different yarn types (conventional ring spun yarn and torque-free ring spun yarn) with different fibre types (combed cotton and combed Supima cotton) and yarn fineness (Ne30 and Ne40). These fabrics were then dyed with three types of dye (reactive, direct and sulphur dye) with three dye concentrations (0.1%, 1.0% and 5.0% on-weight of fabric (owf)) in three colours (red, yellow and blue). This study examined the impact of constructional parameters and dyeing on ultraviolet (UV) protection properties of cotton knitted fabric. In-vitro test with spectrophotometer was used for evaluating the UV protection property of dyed cotton knitted fabrics. Among the six parameters investigated, fineness of yarn and dye concentration were the most significant factors affecting UPF while the color effect is the least significant. Experimental results revealed that the UPF value of dyed fabrics made from combed cotton is generally higher than the combed Supima cotton since combed cotton is composed of shorter fibres which facilitate the blocking or absorption of UV radiation. Second, fabrics made with twist yarn (i.e. ring spun yarn) have higher UPF value than the corresponding ESTex one (i.e. torque-free yarn) in general since fabrics made with ring spun yarn tend to shrink during wet processing and so it is more compact. Third, the UPF value of fabrics made with 30Ne yarn was higher than the 40Ne one since it is thicker and has lower fabric porosity. Fourth, fabrics dyed with lower concentration of dye gave the lowest UPF. Fifth, the sulphur dyed samples performed worse than the reactive and direct dyed samples in terms of UV protection property. Sixth, there is no significant difference in UPF for red, yellow and blue coloured fabrics. Seventh, this study also demonstrated that lightness of fabric is negatively related to UV protection property.

Design carboxymethyl cotton knitted fabrics for wound dressing applications: Solvent effects

Abstract Carboxymethyl cotton knitted fabrics (CM-CKFs) for wound dressings were fabricated with different solvents: water, ethanol–water, and isopropanol–water. The FTIR analysis showed that carboxymethylation reaction in the CM-CKFs occurred with the different solvents. With the water, ethanol–water and isopropanol–water order and the decrease of water ratio in the mixed solution, the degree of substitution (DS) increased, the crystallinity index of the CM-CKFs decreased, crystal structure of cellulose changed from type I to II, and appreciable increased in fiber diameter and gel formation. The water absorbency and water retention of the CM-CKFs increased with DS. The water absorbency of the CM-CKFs treated in water, ethanol–water (v/v = 3/1), and isopropanol–water (v/v = 3/1) was 1.86, 6.95, and 14.86 g/g, respectively. The breaking force of the CM-CKFs was lower than that of cotton knitted fabrics, but the breaking force increased with the DS, so did the breaking elongation. The water vapor permeability and water diffusibility decreased with the DS. The results demonstrated that the carboxymethylation of CM-CKFs occurring in isopropanol–water was most effective and uniform. The findings have theoretical and practical significance for the industrial uses of carboxymethyl cellulose dressing.

An investigation of the relationship between blend ratio, linear density and loop length on geometrical and air permeability properties of bamboo cotton-knitted fabrics

Air permeability is one of the most important aspects of clothing. This study presents the geometrical and air permeability properties of single-jersey-knitted fabric structures made from cotton, bamboo and cotton–bamboo-blended yarns. The objective was to determine the influence of blend ratio, yarn linear density and stitch length on geometrical and air permeability properties of bamboo cotton-knitted fabrics. Yarns with linear densities of 19.6, 23.6, 29.5 tex and with the same twist level were used to construct the fabrics of single-jersey structure with loose, medium and tight structures. The air permeability of the fabrics was observed to increase with an increase in bamboo fibre content. The anticipated increase in air permeability with a decrease in yarn linear density (tex) and an increase in stitch length was observed. Bamboo fibre in the fabric causes a reduction in fabric thickness and mass/unit area for all linear densities of yarn.

Improving of Sewability Properties of Various Knitted Fabrics with the Softeners

Sewing damage is one of the most troublesome problems for the knitted fabrics and this damage is caused by the resistance of fabric to the penetration of needle during sewing operation. Such resistance comes from the fact that the spaces in fabric (between the fibers or the yarns). Finishing treatments directly affect these spaces and so, the sewability and the sewing conditions of fabrics are affected. The aim of this study is; to research the effect of the parameters, such as knitting structure, softeners type and chemical concentration to the sewability and seam puckering in apparel on cotton knitted fabrics. For this purpose, five various softeners with two concentration were applied to the pre-treated 100% of cotton single jersey, interlock and fleece fabrics. After applications, the sewability and the seam puckering of all fabrics were measured and the obtain results were statistically evaluated. The softening treatments improved the sewability and seam puckering markedly. Especially, macro silicone emulsion had the lowest needle penetration force value. After softening treatment, seam puckering increased nearly 1.5-2 grades. The lower concentration is sufficient to get same effect.

Influence of reactive dyes on ultraviolet protection of cotton knitted fabrics with different fabric constructions

The influence of coloration on ultraviolet (UV) protection of cotton knitted fabrics with different knit structures incorporated with the three major stitch types, namely knit, tuck and miss stitches, are studied in four approaches. The effects of color depth and knit structures on the ultraviolet protection factor (UPF) of fabrics are investigated. The influences of hue and color depth on the UPF of fabrics are also compared. Since UV protection offered by dyes mainly depends on their chemical structures, the UPF and color strength of fabrics colored by reactive dyes that varied in reactive groups, such as mono-functional and bi-functional reactive dyes, are examined. The correlations between UPF and the CIELAB color coordinates, color strength ( K/ Ssum), are analyzed. The results show that light-colored fabrics with compact structures achieve similar or even better UV protection than the dark-colored fabrics with loose structures. This implies that color property might not be a reliable indicator for UV protection of knitted fabrics and the effect of coloration on UV protection is affected by fabric construction. The results also denote that the chemical structure of reactive dyes affects the UV protection of fabrics in a qualitative approach that depends on the unique ultraviolet radiation blocking ability of the chemical constituents. Among the color coordinates investigated, only lightness ( L*) and K/ Ssum are found to be correlated with the UPF of the fabrics, but the strength of correlations is not very strong. This is because the fabric characteristics that have significant impacts of UV protection are mostly not involved in the measurement of color properties.

Effect of direct dyes on the UV protection property of 100% cotton knitted fabric

In this study, 100 % cotton knitted fabrics were dyed with direct dye with different colour depths. The colour properties such as CIE L*a*b* values as well as dyeing levelness of the dyed fabrics were measured. The relationship between colour properties and the ultraviolet (UV) protection property were investigated. Experimental results revealed that the colour depth and dye concentration are the most important factors influencing the UV protection property of cotton knitted fabrics. In addition, only CIE L* values have a significant relationship with UV protection factor (UPF). The CIE a* and CIE b* values did not have significant correlation with UPF values but the dyeing levelness would affect the UV protection property of coloured 100 % cotton knitted fabric.

Deep‐colour vat dyeing of cotton knit fabric on a modified jet dyeing machine

To improve the vat dyeing of cotton knit fabric with Indanthren Black RB Coll. (CI Vat Black 9), the basic parameters of dyeing, including the concentrations of chemicals, the dyeing temperature and duration, and the apparent diffusion coefficient of the dye, were obtained by test dyeing with a stoppered Erlenmeyer flask and the cellophane film roll method. A stable vat dyeing process has been developed on a modified jet dyeing machine for the first time without using nitrogen to purge oxygen. Modifications were made to improve the airtightness of the machine and the equipment in the liquor circulating system, with a water inlet and outlet for the gentle oxidation of dyed fabric, and with monitoring by means of a sensor inserted in the liquor circulating system for in situ measurements of the redox potential and the pH of the dyeing liquors. These measurements made it possible to follow to their completion the process of dyeing and the process of gentle oxidation by overflow washing with water and final oxidation. Optimal conditions with regard to the amount of reducing agent, the dyeing temperature (80 °C), and oxidising processes were established with this machine. It was found that, by using the modified machine and process conditions, dyeing proceeded stably and reproducibly (at 80 °C) to yield grade A dyed fabric. Visual inspection confirmed that faultless deep‐colour dyeing of the fabric was attained. Production has been proceeding successfully for the past 2 years. Owing to its insolubility, complete removal of the dye from the wastewater has been possible.