Bleached Fabric Research Articles

The Flame Retardant Coating of Linen Fabrics

In this research an effect of a flame-retardant coating with antimony trioxide (Sb2O3), commercial printing pastes Printperfec EX-TS, Tubvinyl 235MC and a pigment Bezaprint ROT KF onto a raw linen fabric and a bleached linen fabric has investigated. After the coating 5 washing cycles were applied to half of the fabrics. The burning test of the raw and the bleached linen fabrics and those coated with commercial printing pastes and antimony trioxide, as well as the washed fabrics was accomplished. The results of the test show, that the raw and the bleached linen fabric burns completely. The flame extinction was observed for coated fabrics and coated washed fabrics.

Application of Multifunctional Scouring Agent for Cotton Fabric Bleaching

Multi-functional scouring agent (M.F.S.A.) successfully can replace caustic soda, soda ash, scouring agent and H2O2 –bleach stabilizer. It has strong properties of washing, dispersing, emulsifying and chelating, particularly applicable to bleach bath. In this experiment three processes like desizing, scouring and bleaching were done by single stage. Grey fabrics (woven) were treated by using various concentrations of M.F.S.A. and H2O2 at different temperature variation. The maximum value of whiteness of treated fabric were found at 80°C by using the concentration of M.F.S.A. and H2O2 (3.0 g/L and 3.0 g/L respectively). Also minimize required number of chemical used for bleaching process; here only two chemicals used for whole process. No additional chemicals used for water treatment and washing of treated fabric. After process only cold wash were done. Finally by using less concentration of both M.F.S.A. and H2O2 have got comparatively better result for whiteness and tensile strength.

Simultaneous sonosynthesis and sonofabrication of N-doped ZnO/TiO2 core–shell nanocomposite on wool fabric: Introducing various properties specially nano photo bleaching

In this study, N-doped ZnO/TiO2 core–shell nanocomposite was successfully sonosynthesized and sonofabricated on wool fabric through a facile one-step method under ambient pressure and low temperature (75–80°C) as a novel photo-catalyst nanocomposite on textile material. The differences between crystalline phase transformation of conventional and ultrasound synthesized N-ZnO/TiO2 has been compared. The influence of different zinc acetate and titanium isopropoxide precursors in the formation of nanocomposite was studied and optimized through response surface methodology. The photocatalytic activity of the sonofabricated catalyst on the wool fabric surface was evaluated through decomposition of Methylene Blue as a model compound under sunlight irradiation. Also, N-doped ZnO/TiO2 nanocomposite sonosynthesized on wool fabric led to photo bleaching of wool fabric due to decomposition of the naturally occurred pigments under daylight irradiation. Further, yellowness index, antibacterial and antifungal activity against Escherichia coli, Staphylococcus aureus and Candida albicans, cell viability, char residual, alkali solubility, mechanical properties and water drop absorption time on the treated wool fabrics were evaluated. Also, the acid solubility of the synthesized nanopowder obtained from sonobath after treatment was characterized in acetic acid indicating higher acid resistance on N-doped ZnO/TiO2 nanocomposite.

Catalases as biocatalysts in technical applications: current state and perspectives.

Catalases represent a class of enzymes which has found its place among industrially relevant biocatalysts due to their exceptional catalytic rate and high stability. Textile bleaching prior to the dyeing process is the main application and has been performed on a large scale for the past few decades. Their limited substrate scope has not prevented the development of various other catalase-based applications. Newly developed approaches continue to exploit their excellent catalytic potential to degrade hydrogen peroxide while (per)oxidase activity of catalases is opening a new range of possibilities as well. This review provides an overview of applications that involve heme-containing catalases that have been demonstrated in recent years.

Effect of Silicone Nano, Nano/Micro and Nano/Macro‐Emulsion Softeners on Color Yield and Physical Characteristics of Dyed Cotton Fabric

AbstractThe study of silicone nano‐emulsions and softeners to alter physical properties of undyed cotton fabric has recently gained a substantial interest. However, systematic investigation of silicon nano‐emulsion softeners on dyed cotton fabric has not so far been conducted. This paper deals with the application of silicone nano‐, micro‐, and macro‐emulsion softeners, and combinations of nano/micro and nano/macro, on dyed cotton fabric. We report the effect of silicon nano/micro‐ and nano/macro‐emulsion softeners on color yield and physical characteristics of dyed cotton fabric. All bleached fabrics were dyed with CI Reactive Black 5 and then treated with known concentrations of silicone softeners by the pad‐dry method. The silicone nano‐emulsion was combined with micro‐ and macro‐emulsion softeners using blending ratios of nano/micro (1:1) and nano/macro (1:1). Treated fabrics were compared in terms of physical properties such as fabric handling, wrinkle recovery angle, bending length, abrasion resistance and tensile strength. The color changes were evaluated by color yield (K/S) values and total color difference (ΔEcmc). The results revealed that the silicon nano‐emulsion had better physical properties than micro‐, macro‐ and combination nano/micro‐ and nano/macro‐emulsion softeners. Among all treated samples, nano‐emulsion softeners showed better ΔEcmc values. Scanning electron microscopy analysis suggests that the fiber morphology of treated fabrics was very smooth and uniform.

Microwave-Assisted Bleaching of Wool Fabrics

Microwave irradiation was used to reduce consumption of energy and time during bleaching of wool fabrics with hydrogen peroxide. The effect of some reaction conditions; viz. hydrogen peroxide concentration, treatment time, presence of stabilizer, on degree of whiteness imparted to bleached wool, was studied systematically. Comparative study between bleaching of wool using microwave irradiation and conventional heating was undergone. The effect of bleaching of wool on its morphological structure was assigned by scanning electron microscopy. The change in some chemical and physicomechanical characteristics of bleached wool was monitored; namely whiteness index, alkali solubility, wettability, critical surface area, tensile strength, and elongation at break, of the treated as well as untreated fabrics were measured. The microwave-assisted bleaching of wool resulted in improved degree of whiteness comparable to that is obtained using conventional heating method. However, the microwave-assisted bleached wool shows lower degree of deterioration than that of conventionally bleached wool. The COD and BOD of the wool bleaching effluents were determined.

A Pilot-Scale Application of Ozone to Bleach Raw Cotton Fabric Using Various Additives

The influence of various additives on the efficiency of optimized ozone bleaching process at pilot scale has been discussed in this study. The results reveal that the best whiteness (63.79) and strength of bleached fabric is achieved with the addition of surfactant (2 g/L) at an ozone dose of 50 g/h, pH 5, and ozone treatment time of 45 min at room temperature. The dyeing quality of ozone-bleached and hydrogen peroxide-bleached fabric samples is almost identical. The analysis of variance of the experimental data validates that the process parameters have significantly affected the efficiency of ozone bleaching process.

A facile energy and water-conserving process for cotton dyeing

Nowadays, all research efforts in the field of wet processing of textiles are directed towards shortening and simplification of the processing sequence. To minimise water and energy consumption, it has become necessary to combine several textile processing stages to reduce the number of operations or shorten the process time. An attempt was made to combine the pre-treatment and dyeing processes with optimal quantities of textile auxiliaries in single bath. In this process, individual stages of pre-treatment like desizing, scouring and bleaching followed by dyeing using direct dyes were carried out in a single bath without the usual intermediate washings. This process was carried out without replacing the liquor bath until the end of dyeing. An attempt was also made to dye a woven fabric at different stages, viz., grey, desizing and scouring. These efforts were made to conserve water and energy required for that particular pre-treatment process. The depth of dyeing and the colour fastness properties of all these dyed fabrics were then compared with a bleached fabric which was dyed with conventional method. The properties were at par with the conventional method. Moreover, the combined process saved 83.1 % water, 88.6 % energy (thermal) and 79.3 % time than the conventional processes. Thus, the process has been shown to be ecological, economical and energy conserving.

Effect of γ (Gamma)-radiation on the physico-mechanical properties of grafted jute fabric reinforced polypropylene (PP) composites

The bleached jute fabric (BJF) reinforced polypropylene (PP) composites with various contents of acrylic acid (AA)-treated BJF and un-AA-treated BJF were fabricated by compression moulding method at 190 °C. The AA-grafted BJF reinforced PP composites were then irradiated by γ-ray at various doses. The mechanical properties of neat PP (N-P), ungrafted-BJF and PP composites (UG-BJFPC), AA-grafted-BJF and PP composites (AA-BJFPC) and γ-ray cum AA-grafted-BJF and PP composites (γAA-BJFPC) show maximum tensile strength (TS) of 30, 46, 47 and 51 MPa, maximum flexural strength (FS) of 34, 49, 50 and 54 MPa and maximum Young’s modulus (E) of 280, 428, 436, and 680 MPa, respectively. The increase of TS, FS and E from UG-BJFPC are 2 %, 2 %, and 2 % for AA-BJFPC and 11 %, 10 % and 59 % for γAA-BJFPC. The TS, FS and E are found to increase with radiation dose up to 500Krad and then decrease. The water absorption (WA) for UG-BJFPC, AA-BJFPC and γAA-BJFPC is respectively about 14, 10 and 9 %, indicating a gradual development of hydrophobic character of the composites first by AA-treatment and then by γ-ray-treatment. AA treatment on jute fabric and gamma irradiation on composite result in significant change of morphology of the jute fabric composites surface and better mechanical bonding between fabric and polymer matrix, as a result improved mechanical properties are found.

Trends in bio-processing of textiles: A review

This review highlights the use of enzymes in textile industry. Amylases have been used for desizing since the middle of the last century. The industrial use of biotechnology is bringing about new products and processes aimed at the use of renewable resources, as well as the application of green technologies with low energy consumption and environmentally acceptable processes. Textile processing is a growing industry that has traditionally used a lot of water, energy and harsh chemicals. Due to the ever growing costs of water and energy worldwide, the investigations are carried out to substitute conventional chemical textile processes by environmentally friendly and economically attractive bioprocesses using enzymes. The application of cellulases for denim finishing and laccases for decolourization of textile effluents, and textile bleaching are most recent commercial advances. New developments rely on the modifica­tion of natural and synthetic fibres. This work represents a review of enzyme applications in textile processes. The described bio-processings were accom­panied by a significantly lower consumption of energy, water, chemicals, time and costs. So it has advantages as well as in terms of ecology as in economy.

Study on H2O2/TAED and H2O2/TBCC bleaching mechanism related to hydroxyl radical with a fluorescent probe

The generation of hydroxyl radical (HO) in H2O2/TAED and H2O2/TBCC systems for cotton fabric bleaching was proved and detected with a novel fluorescent probe benzenepentacarboxylic acid (BA). Effect of HO generation on the cotton fabric bleaching performances was further discussed. The results show that HO yield in H2O2/TAED and H2O2/TBCC systems was respectively about 11 and 15 times higher than that in H2O2 system without activators under the same alkali condition. Meanwhile, TAED and TBCC apparently promoted fabric whiteness and H2O2 decomposition rate. As the addition of HO scavenger dimethylsulfoxide (DMSO), fabric whiteness decreased while tensile strength increased. It proves that HO played a significant role in H2O2/TAED and H2O2/TBCC bleaching. Two main bleaching routes were suggested. The present work brought new insight into H2O2/TAED and H2O2/TBCC bleaching mechanism. It is quite instructive to develop efficient and ecological bleaching processes.

Novel Method for Fast Bleaching of Cellulose Acetate Fabric by Using H2O2 Aided by Ultrasonic Waves

This research focuses on the use of ultrasonic waves to aid ultrasonic aided hydrogen peroxide (H2O2) bleaching (UAB) of cellulose acetate fabrics. UAB is studied under different conditions and based on the results obtained, the following conditions are established: H2O2 concentration, 10g/l; reaction temperature, 30°C; reaction time, 3 min; and pH, 9.0. The bleaching effect is expressed in terms of acetyl content, loss in fabric weight, whiteness index, roughness degree, tensile strength and elongation at break when the cellulose acetate fabrics are bleached per the UAB method as well as the conventional method. A comparison between the two methods with regards to these properties reveal the superiority of the UAB method with its novelty and fast inducing bleaching under the influence of cavitations and extra energy generated thereof; the cavitations are caused by the high frequency of the ultrasonic waves. Electron scanning microscopies of the UAB bleached fabric display a smooth and partially swollen surface morphology opposite those of conventionally bleached fabric in which the surfaces are irregular, rough and scratched bleached. In addition, UAB bleached fabric displays a significantly higher dyeability towards disperse dyes than the untreated fabric and fabric bleached by using the conventional method.

Application of ozone in cotton bleaching with multiple reuse of a water bath

This paper discusses the effect of ozone bleaching on the quality of cotton fabric in terms of whiteness, dye pick-up, copper number and degree of polymerization (DP). The process parameters (pH, ozone dose and treatment time) were optimized, and the best whiteness (60–62) and quality of bleached fabric was obtained at pH 5, 45 min treatment time and room temperature. A strongly acidic environment and longer ozonation time decreased the quality of fabric by producing a higher copper number (0.18) and DP loss (51.5%). Statistical analysis of the experimental data using analysis of variance confirmed that process parameters significantly affected the bleaching efficiency. The process was then applied to bleach 20 different samples of cotton fabric re-using the same water bath, and the whiteness of ozone-bleached samples did not decrease, even after the 20th reuse of the water bath.

Combination of Ozonation and Hydrogen Peroxide Bleaching for Linen Fabrics: Optimization of the Process Using Experimental Design Technique

It is well known that ozone can be used as a bleaching agent for cellulosic textile materials. In the context of this study, investigations were undertaken to optimize bleaching of linen fabrics using Box-Behnken Experimental Design. The bleaching process involved two distinct steps where linen fabrics were ozonated under different treatment times then the latter in a subsequent step were subjected to hydrogen peroxide bleaching under a variety of conditions. As a result of study, three optimum recipes were achieved and pretreatment with ozone for 15 min before peroxide bleaching supplies time and chemical savings.

Characterization of ligno-cellulosic materials bleached with oxo-diperoxo-molybdates

A newly effective system was used to bleach ligno-cellulosic textile materials. This system is based on two different newly synthesized natrium oxo-diperoxo molybdates, Na2[MoO (O2)2(C2O4)] and Na2[MoO (O2)2(C6H6O7)].These two compounds were characterized by means of cyclic voltammetry, and the bleached fabrics were fully characterized by measuring their whiteness index, percent loss in fabric weight and the content of lignin in the fabric. The obtained results revealed that good whiteness index of the bleached linen-cotton fabrics (50% linen and 50% cotton) and low content of lignin could be obtained by soaking the fabric for 55min at 90°C in a solution containing 3.5% of molybdate complex and 3.5% H2O2.

Mass-size distribution of PM10 and its characterization of ionic species in fine (PM2.5) and coarse (PM10−2.5) mode, New Delhi, India

Size distribution of PM10 mass aerosols and its ionic characteristics were studied for 2 years from January 2006 to December 2007 at central Delhi by employing an 8-stage Andersen Cascade Impactor sampler. The mass of fine (PM2.5) and coarse (PM10−2.5) mode particles were integrated from particle mass determined in different stages. Average concentrations of mass PM10 and PM2.5 were observed to be 306 ± 182 and 136 ± 84 μg m−3, respectively, which are far in excess of annual averages stipulated by the Indian National Ambient Air Quality Standards (PM10: 60 μg m−3 and PM2.5: 40 μg m−3). The highest concentrations of PM10−2.5 (coarse) and PM2.5 (fine) were observed 505 ± 44 and 368 ± 61 μg m−3, respectively, during summer (June 2006) period, whereas the lower concentrations of PM10−2.5 (35 ± 9 μg m−3) and PM2.5 (29 ± 13 μg m−3) were observed during monsoon (September 2007). In summer, because of frequent dust storms, coarse particles are more dominant than fine particles during study period. However, during winter, the PM2.5 contribution became more pronounced as compared to summer probably due to enhanced emissions from anthropogenic activities, burning of biofuels/biomass and other human activities. A high ratio (0.58) of PM2.5/PM10 was observed during winter and low (0.24) during monsoon. A strong correlation between PM10 and PM2.5 (r2 = 0.93) was observed, indicating that variation in PM10 mass is governed by the variation in PM2.5. Major cations (NH4+, Na+, K+, Ca2+ and Mg2+) and anions (F−, Cl−, SO42− and NO3−) were analyzed along with pH. Average concentrations of SO42− and NO3− were observed to be 12.93 ± 0.98 and 10.33 ± 1.10 μg m−3, respectively. Significant correlation between SO42− and NO3− in PM1.0 was observed indicating the major sources of secondary aerosol which may be from thermal power plants located in the southeast and incomplete combustion by vehicular exhaust. A good correlation among secondary species (NH+, NO3− and SO42−) suggests that most of NH4+ is in the form of ammonium sulfate and ammonium nitrate in the atmosphere. During winter, the concentration of Ca2+ was also higher; it may be due to entrainment of roadside dust particles, traffic activities and low temperature. The molar ratio (1.39) between Cl− and Na+ was observed to be close to that of seawater (1.16). The presence of higher Cl− during winter is due to western disturbances and probably local emission of Cl− due to fabric bleaching activity in a number of export garment factories in the proximity of the sampling site.

New Development for Combined Bioscouring and Bleaching of Cotton-Based Fabrics

A thorough investigation into conditions appropriate for effecting combined eco-friendly scouring and bleaching of cotton based fabrics was undertaken. Loomstate cotton and blend fabrics were desized by α-amylase enzyme. Fabrics were the target for bioscouring using alkaline pectinase enzyme, bleaching by in-situ formed peracetic acid using TAED and H2O2 as well as concurrent bioscouring and bleaching which is considered by all means a new development. Also, practiced were the conventional scouring using NaOH followed by bleaching using H2O2 and other bleaching processes vis-à-vis the new current development. The comparison reveals unequivocally that the environmentally sound technology brought about by current development is by far the best. The new development involves a single-stage process for proper purification / preparation of cotton and blend fabrics . through removal of noncellulosic impurities and colouring matters . by padding the fabrics in a bath containing alkaline pectinase enzyme, TAED, H2O2, nonionic wetting agent and sodium silicate. In addition to the advantages related to major technical fabric properties, the new development is eco-friendly and reproducible, which advocates the new development for mill trials.

Characterization of the Alkaline Laccase Ssl1 from Streptomyces sviceus with Unusual Properties Discovered by Genome Mining

Fungal laccases are well investigated enzymes with high potential in diverse applications like bleaching of waste waters and textiles, cellulose delignification, and organic synthesis. However, they are limited to acidic reaction conditions and require eukaryotic expression systems. This raises a demand for novel laccases without these constraints. We have taken advantage of the laccase engineering database LccED derived from genome mining to identify and clone the laccase Ssl1 from Streptomyces sviceus which can circumvent the limitations of fungal laccases. Ssl1 belongs to the family of small laccases that contains only few characterized enzymes. After removal of the twin-arginine signal peptide Ssl1 was readily expressed in E. coli. Ssl1 is a small laccase with 32.5 kDa, consists of only two cupredoxin-like domains, and forms trimers in solution. Ssl1 oxidizes 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and phenolic substrates like 2,6-dimethoxy phenol, guaiacol, and syringaldazine. The kcat value for ABTS oxidation was at least 20 times higher than for other substrates. The optimal pH for oxidation reactions is substrate dependent: for phenolic substrates the highest activities were detected at alkaline conditions (pH 9.0 for 2,6-dimethoxy phenol and guaiacol and pH 8.0 for syringaldazine), while the highest reaction rates with ABTS were observed at pH 4.0. Though originating from a mesophilic organism, Ssl demonstrates remarkable stability at elevated temperatures (T1/2,60°C = 88 min) and in a wide pH range (pH 5.0 to 11.0). Notably, the enzyme retained 80% residual activity after 5 days of incubation at pH 11. Detergents and organic co-solvents do not affect Ssl1 stability. The described robustness makes Ssl1 a potential candidate for industrial applications, preferably in processes that require alkaline reaction conditions.

Low‐temperature bleaching of cotton fabric with a binuclear manganese complex of 1,4,7‐trimethyl‐1,4,7‐triazacyclononane as catalyst for hydrogen peroxide

Bleaching of cellulose fabric with hydrogen peroxide is traditionally conducted under alkaline conditions at high temperature, which leads to greater energy consumption and fibre damage. In this study, a binuclear manganese complex of the ligand 1,4,7‐trimethyl‐1,4,7‐triazacyclononane as the catalyst for hydrogen peroxide bleaching was synthesised via a simplified method. Low‐temperature bleaching of cotton fabric with the manganese complex and the effect of key bleaching variables on the bleaching performance were investigated. Hydrogen peroxide could be catalysed to bleach cotton knitted fabric at a temperature as low as 60 °C by incorporating the complex in the bleaching solution. The whiteness index of the fabric bleached at low temperature was lower than that of fabric bleached at high temperature, but the bursting strength retention is much better for the fabric bleached at low temperature. The low temperature is energy‐saving and has environment‐friendly advantages over the traditional high‐temperature method.

An effective redox system for bleaching cotton cellulose

An effective sodium chlorite/potassium permanganate bleaching system was used to bleach cotton fabric without severe loss in the fabric's mechanical properties. The bleaching process based on depositing MnIII on the fabric surface followed by treating the fabric with sodium chlorite solution. Parameters governing the bleaching efficiency, like potassium permanganate concentration, sodium chlorite concentration and bleaching bath temperature were studied. The bleached fabrics were fully characterized by measuring their whiteness index, carboxyl and carbonyl contents, percent loss in fabric weight and tensile strength. The obtained results reveal that bleached cotton fabric with satisfactory whiteness index and reasonable tensile strength can be obtained by soaking the fabric, at 50°C in potassium permanganate solution (0.01N), using material to liquor ratio of 1:10. The fabric is then rinsed with distilled water, squeezed and introduced to bleaching bath containing 5g/l sodium chlorite and 1g/l non-ionic wetting agent using a material to liquor ratio of 1:10.