The use of a low-liquor ratio (1:10 or less) in the dyeing of wool has several economic and environmental benefits, such as lower energy usage and smaller quantity of auxiliaries are required ...compared to the traditional dyeing method. However, the reduction in liquor ratio increases the occurrence of agglomeration of dyes causing uneven dyeing. The aim of this study is to develop a low-liquor dyeing method for wool with acid dyes that could potentially be applied to larger scale industrial practices. In this work, the feasibility of application of several chemical auxiliaries to prevent the agglomeration of dyes in dyebaths and also for improving the dyeing uniformity in the low liquor ratio dyeing of wool fabric with three acid dyes, has been investigated. Optical microscopy was used to evaluate the performance of various auxiliaries to prevent the agglomeration of dyes in a dyebath. The dyeing uniformity was assessed by measuring the colour difference in various parts of the same dyed fabric by a hand-held reflectance spectrophotometer. It was found that Teric G12A6 showed the best results in terms of prevention from the agglomeration of dyes and the dyeing uniformity produced for all three acid dyes investigated. The low liquor ratio dyeing of wool fabrics with acid dyes using Teric G12A6 as a dye agglomeration preventer is equally efficient as the traditional high liquor ratio dyeing in terms of colour strength and uniformity in dyeing. The developed method could reduce dyeing cost and environmental footprint compared to the traditional dyeing of wool.
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•Low liquor ratio dyeing of wool with three acid dyes were investigated.•A range of dye agglomeration preventing agents were use in the dyebath.•Dye agglomeration was evaluated microscopically.•Teric G12A6 at 3 g/L produced level dyeing and inhibited agglomeration of dyes in dyebath.•The low liquor ratio dyeing method developed is as efficient as the traditional dyeing method.
A novel optimisation technique based on the differential evolution (DE) algorithm with dynamic parameter selection (DPS-DE) is proposed to develop a colour difference classification model for dyed ...fabrics, improve the classification accuracy, and optimise the output regularisation extreme learning machine (RELM). The technique proposed is known as DPS-DE-RELM and has three major differences compared with DE-ELM: (1) Considering that the traditional ELM provides an illness solution based on the output weights, DE is proposed to optimise the output of the RELM. (2) Considering the simple parameter setting of the traditional algorithm, the DE algorithm with DPS is adopted. (3) For DPS, an optimal range of parameters is chosen, and the efficiency of the algorithm is significantly improved. This study analyses the colour difference classification of fabric images captured under standard lighting based on the DPS-DE-RELM algorithm. First, the colour difference of the fabric images is calculated and six color-difference-related features extracted, and second the features are classified into five different levels based on the perception of humans. Finally, a colour difference classification model is built based on the DPS-DE-RELM algorithm, and then the optimal classification model suitable for this study is selected. The experimental results show that the output method with regularisation parameters can achieve a maximum classification accuracy of 98.87%, which is higher compared with the aforementioned optimised original ELM algorithm, which can achieve a maximum accuracy of 84.67%. Therefore, the method proposed has the advantages of greater convergence speed, high classification accuracy, and robustness.
Addressing fabric fading in the textile industry, this research investigates plasma treatments as a sustainable solution. The ambiguous relationship between plasma parameters such as air ...concentration, moisture content, and treatment duration with fading introduces uncertainty in the treatment process, necessitating optimization through precise prediction. Such precision not only curtails costs but also highlights the pivotal role of digital innovations in textile fabrication. Two predictive systems, Bayesian Regulated Neural Network (BRNN) and Gaussian Process Regression (GPR), were developed using tenfold cross-validation to accurately link these parameters to fading results. To handle prediction complexity and small samples, a modular approach was adopted. Four individual BRNN and GPR models predicted CIE L*, a*, b*, and K/S values and were integrated into a single system. The systems’ predictive capabilities were compared, revealing that GPR’s predictive accuracy generally surpassed that of the BRNN model, although its advantage lessened in the testing set, particularly for CIE a* predictions. Nevertheless, it is noteworthy that both GPR and BRNN models demonstrated significant prediction performance on the unseen dataset, with the colour prediction deviating from the actual colour within an acceptable range for industrial applications in most scenarios. Specifically, under a stricter standard of ∆E < 1, the GPR model's predictive accuracy was able to maintain between 79.17 and 87.5%. Thus, the application of the BRNN and GPR models might provide valuable digitalization insights for cotton processing, saving time and cost while efficiently predicting fading effects.
The change in reflectivity of Cu-Zn alloys was investigated with the modulation of Zn content. The reflectivity of the prepared alloys were compared with pure copper and divided into wavelength ...regions corresponding to blue, green, yellow, and red colors. As the amounts of Zn increased, the difference in reflectivity of the yellow region increased, and that of the red region decreased. To determine the color difference, the measured reflectivity of the alloys was transformed into a tristimulus value using the Reflectance-Tristimulus value converting equation. Then the tristmulus value was converted into the CIE L*a*b* color space. The color difference was calculated using the color difference formula of the converted L*a*b* values. When 5 at%Zn was added, the color difference value was 3.224, and it increased with increasing Zn content. As the difference in the reflectivity of the green and yellow regions increased, the b* value of the alloys increased and the a* value of the alloys decreased. In this study, the addition of Zn content to Cu alloy induced changes in the reflectivity of the green and yellow wavelength regions, which influences color differences of α-Cu solid solution alloys.
(Received November 1, 2017; Accepted December 27, 2017)
In the Water, Energy and Waste Directive, the European Commission provides for the use of household washing programmes with lower temperatures (30-40 °C) and lower water consumption. However, low ...washing temperatures and the absence of oxidising agents in the liquid detergents, and their reduced content in powder detergents, allow biofilm formation in washing machines and the development of an unpleasant odour, while the washed laundry can become a carrier of pathogenic bacteria, posing a risk to human health. The aim of the study was to determine whether the addition of hydrogen peroxide (HP) to liquid detergents in low-temperature household washing allows disinfection of the laundry without affecting the properties of the washed textiles even after several consecutive washes. Fabrics of different colours and of different raw material compositions were repeatedly washed in a household washing machine using a liquid detergent with the addition of 3% stabilised HP solution in the main wash, prewash or rinse. The results of the antimicrobial activity, soil removal activity, colour change and tensile strength confirmed the excellent disinfection activity of the 3% HP, but only if added in the main wash. Its presence did not discolour nor affect the tensile strength of the laundry, thus maintaining its overall appearance.
•Fruit growth of two commercial pomegranate cultivars were studied over two seasons.•Significant variations in fruit morphology, respiration and physico-textural properties of the fruit were ...found.•These findings would allow growers to have a tool to select and monitoring fruit maturation in other to meet export market requirements.
The time course and pattern of fruit growth and changes in physical, physiological properties and texture dynamics of pomegranate fruit (cvs. ‘Bhagwa’ and ‘Ruby’) along the days after full bloom (DAFB) were studied over two different year seasons. Significant variations in fruit growth, respiration rate and physico-textural properties of the fruit were found at five maturity stages (S1–S5). Fruit lineal dimensions (length and diameter) exhibited a linear growth pattern and the fruit weight followed a similar pattern. Both fruit cultivars showed a decline in respiration rate during fruit development, with the highest respiration rate measured in immature fruits (‘Bhagwa’, 66.83mLCO2kg−1h−1; ‘Ruby’, 51.17mLCO2kg−1h−1) and declining with maturity to minimum rates in fully ripe fruit (stage 5) (S5) (‘Bhagwa’, 23.84mLCO2kg−1h−1; ‘Ruby’, 19.16mLCO2kg−1h−1). No ethylene gas was detected throughout fruit development. Fruit pigmentation increased with advancing maturity and the lowest total colour difference (TCD) between fruit peel and arils was noted in immature fruit. Textural dynamics of aril revealed increasing trend in bioyield force and elasticity with advancing maturity. Overall, the study indicated that fruit reached mature stage between the 132–139 DAFB for ‘Ruby’ and 140–165 DAFB for ‘Bhagwa’. This period could be regarded as the physiological mature stage of the fruits that would present the optimum values of harvesting properties desirable in the investigated cultivars. This information could be used as a tool to assist growers in assessing fruit readiness for harvest.
Alder wood (Alnus glutinosa L.) was steamed with a saturated steam-air mixture at a temperature of t = 95 °C, or saturated steam at t = 115 °C and t = 135 °C to obtain a pale brown colour, a light ...red-brown colour and a dark brown-grey colour. Subsequently, samples of unsteamed and steamed alder wood were irradiated with a UV lamp in a Xenotest Q-SUN Xe-3-HS after drying in order to test the colour stability of steamed alder wood. The colour change of the wood surface was evaluated by means of measured values on the coordinates of the colour space CIE L*a*b*. The results show that the surface of unsteamed alder wood as well as steamed alder wood with a steam-air mixture at t = 95 °C and saturated steam at t = 115 °C darkened and browned due to photochemical reactions caused by UV radiation. The opposite tendency was recorded at the surface of alder wood steamed with saturated steam with a temperature of t = 135 °C, where the deep dark-brown-grey colour lightened to a brown-reddish colour shade under the influence of UV radiation. The analysis of the changes in the coordinates of the colour space CIE L*a*b* shows that the greater the darkening and browning of the alder wood by steaming, the smaller the changes in the values of ΔL*, Δa*, Δb* of the steamed alder wood caused by UV radiation. The positive effect of steaming on UV resistance is evidenced by the decrease in the overall colour difference ΔE*. While the value of the total colour difference of unsteamed alder wood caused by UV radiation is ΔE* = 10.9, it decreased to ΔE* = 8.7 for alder wood steamed with steam-air mixture at t = 95 °C, which is a decrease of 20.2 %; for alder wood steamed at t = 115 °C it decreased to ΔE* = 6.5, which is a decrease of 40.3 %; and for alder wood steamed with saturated water steam with the temperature t = 135 °C it decreased to ΔE* = 5.7, which is a decrease of 47.7 %.
Za potrebe ispitivanja drvo johe (Alnus glutinosa L.) pareno je smjesom zasićene pare i zraka na 95 °C odnosno zasićenom parom na 115 i 135 °C kako bi se dobila blijedosmeđa, svijetla crvenosmeđa i tamna smeđosiva boja. Nepareni i pareni uzorci drva johe nakon sušenja su ozračeni UV lampom u uređaju Xenotest Q-SUN Xe-3-HS kako bi se ispitala stabilnost boje parenog drva. Promjena boje površine drva procijenjena je uz pomoć vrijednosti izmjerenih u koordinatnom sustavu boja CIE L*a*b*. Rezultati su pokazali da je površina neparenog drva johe i drva johe parenog smjesom pare i zraka na 95 °C te drva parenog zasićenom parom na 115 °C zbog fotokemijskih reakcija uzrokovanih UV zračenjem potamnjela i posmeđila. Suprotna je promjena zabilježena na površini drva johe parenoga zasićenom parom na 135 °C, na kojemu je tamna smeđosiva boja pod utjecajem UV zračenja posvijetlila i poprimila smeđocrvenkasti ton. Analiza promjena u koordinatnom sustavu boja CIE L*a*b* pokazuje da UV zračenje uzrokuje niže vrijednosti ΔL*, Δa*, Δb* parenog drva johe što je tamnjenje i smeđenje drva johe zbog parenja jače. Pozitivan učinak parenja na otpornost prema UV zračenju vidljiv je po smanjenju ukupne promjene boje E*. Tako je vrijednost ukupne promjene boje neparenog drva johe nakon UV zračenja parenjem smjesom pare i zraka na 95 °C smanjena s E* = 10,9 na E* = 8,7 (smanjenje od 20,2 %), parenjem zasićenom parom na 115 °C smanjena je na E* = 6,5 (smanjenje od 40,3 %), a parenjem zasićenom parom na 135 °C zabilježeno je smanjenje od E* = 5,7 (smanjenje je iznosilo 47,7 %).
Water is the ultimate and mostly used media during textile materials processing, especially in colouration. This study investigated the possibilities of using seawater for cotton and polyester ...fabrics dyeing. Single jersey fabrics made of 100 percent cotton and polyester were dyed using a standard recipe and two separate water source as dyeing mediums. It has been focused on the assessment of colour fastness to wash, perspiration, saliva, rubbing, water, light and colour difference value due to compare the efficiency of dyeing media. The results revealed that the cotton fabric dyed with seawater showed lighter shade than that of ground water sample. But for polyester fabric darker shade was obtained compared to ground water. The cotton sample dyed with sea water carried about 15% higher colour strength than ground water dyed sample but for polyester it was very negligible, only 3%. Moreover, the results of colour fastness to wash, perspiration, saliva, rubbing, water and light for seawater dyed samples of cotton and polyester were shown satisfactory outcomes having the grading of 4–5 in most of the cases. This exploration established that commercial dyeing processes were robust and can be practically transferable into the seawater medium for cotton and polyester fabrics.
Colour fastness, Ground water, Seawater, Water consumption, Colour difference.
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