Bioscouring of cotton fabrics using pectinase enzyme its optimization and comparison with conventional scouring process

The conventional scouring process involving the harsh environment is slowly being replaced with environment friendly approach using enzymes. These enzymes remove the non cellulosic impurities present in the fabric. Such a process would enhance the absorbency of the fabric without appreciable strength loss and also would help in the proper dyeing and finishing of the fabric. In the present work pectinase enzyme was isolated from Fusariumn sp. and was optimized under different cultural conditions. The partially purified pectinase enzyme was used in the scouring of cotton fabric. The efficiency of the bioscoured cotton fabric was compared with that of the conventionally scoured fabric. It was found that the water absorbing character of the bioscoured fabric was found to be considerably higher than that of the conventionally scoured fabric. Also, the tensile strength of the cotton fabric was found to be higher for the sample treated using pectinase enzyme than the sample treated conventionally. The results of FTIR confer that the pectin and wax impurities were removed from the cotton surface in both the conventionally scoured and bioscoured fabrics.     

草本纤维生物提取菌株产果胶酶的组分研究

为了系统研究草本纤维生物提取菌株的果胶酶组分及其表达量,采用DNS法、C=C光吸收法和酸碱滴定法系统地测定菌株P1、P2和P3表达的果胶解聚酶、果胶酯酶和果胶裂解酶活力。结果表明：3个目标菌株均能同时表达果胶解聚酶、果胶酯酶和果胶裂解酶,其中菌株P1表达的胞外果胶解聚酶活力最高达71.66 IU/mL;菌株P2表达的胞外果胶酯酶活力最高为76.7 IU/mL;菌株P3表达的胞内果胶裂解酶活力最高达210.7 IU/mL。3个菌株表达的果胶酶组分及其活力存在明显差异,其结果可以为进一步探讨草本纤维原料中非纤维素生物降解机理和开发菌株新用途提供科学依据。     

Effects of sodium hydroxide treatment on microstructure and mechanical properties of lotus fibers

Lotus fibers were prepared from lotus stems through being treated with sodium hydroxide. The lotus fibers were characterized by scanning electron microscopy (SEM), fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and thermal analysis (TG and DTA). The results indicate that the length of lotus fibers ranges from 3.52 cm to 5.80 cm and the width of lotus fibers ranges from 50 μm to 90 μm. Lotus fibers belong to celluloses fiber with cellulose I structure and the crystallinity of lotus fibers is 48.50 %. The lotus fibers consist of cellulose, lignin, hemicellulose, pectin, lipid and water-soluble substances. The effect of concentration of sodium hydroxide, time and temperature of treatment on removal of impurities, fineness and breaking strength of lotus fibers were investigated. The results suggest that the removal of impurities and breaking strength increase with the rise of concentration of the sodium hydroxide, time and temperature of treatment, respectively. However, the fineness of lotus fibers decreases with an increase in concentration of the sodium hydroxide, time and temperature of treatment. The results are expected to provide valuable guidance for preparation of lotus fibers through simple treatment with sodium hydroxide, which can be applied in textile industry.     

汉(大)麻与其它纤维素纤维染色性能研究

本文在汉麻纤维化学组分分析的基础上,利用中温活性染料,对多种纤维素纤维的染色性能进行了测定。研究了不同组成成分对汉麻纤维染色性能的影响,比较了汉麻纤维与其它纤维素纤维的上染百分率和上染速率的差异。结果表明,果胶和木质素的含量对汉麻纤维的染色性能均有不同程度的影响,但果胶的影响较木质素更为明显,汉麻纤维的染色性能与苎麻接近,但比棉纤维要差,更低于再生纤维素纤维。     

The combining process for bio-preparation of starch-sized cotton fabrics at high temperature

α-amylase and pectinase showed good compatibility. A desizing ratio of 95.4 %, a pectin removal rate of 80.4 % and a capillary effect height of 7.1 cm for cotton fabrics treated with α-amylase and pectinase were obtained by a one-bath for bio-desizing and bio-scouring process under the condition of 90 °C for 30 min. After the treatment of the nonionic surfactant Peregal O at 100 °C for 20 min, these important properties for the cotton fabrics were further improved to 98.7 %, 96.8 %, and 18.4 cm separately. The capillary effect height of desized cotton fabrics was improved from 0.2 cm to 6.4 cm by the removal of waxes because its hydrophobic nature of the cotton fabrics. The whole time for this new combining process with high temperature treatment was significantly shortened and it only took about 55 minutes.     

Preparation of adsorbent based on cotton fiber for removal of dyes

Synthetic dyes are used extensively in modern industries, which are toxic and harmful to environment and human. Cotton fiber is a kind of abundant, renewable and eco-friendly cellulose fiber in nature, however, the adsorption capacity of raw cellulose for pollutants was often low. Therefore, an efficient adsorbent for removal of dyes was successfully prepared by grafting beta-cyclodextrin (β-CD) and amino-terminated hyperbranched polymer (NH₂-HBP) onto cotton fibers in this study, which was effective to anionic dyes and cationic dyes. The adsorbent were characterized using FTIR, SEM and XPS analysis. The results of adsorption experiments showed that the adsorbent based on cotton fiber exhibited better adsorption performance for Congo red(CR) and methylene blue(MB). The experimental results revealed that the pH value had a great influence on the adsorption capacity.     

Adsorption and dyeing characteristics of reactive dyes onto cotton fiber in nonionic Triton X-100 reverse micelles

The nonionic reverse micelles used for dyeing cotton fiber were prepared with a non-ionic surfactant Triton X-100 (TX-100) by injecting small amount of reactive dye aqueous solution. The adsorption capacity of three water-soluble anionic azo dyes including Reactive Blue 222, Reactive Red 195 and Reactive Yellow 145 onto cotton fiber was investigated. The Langmuir and Freundlich isothermals were employed to model the adsorption data. In addition, the color strength and fixation rate of cotton fabrics dyed in the reverse micelles and bulk water were examined and compared. The salt and alkali as influencing factors were also discussed. The FT-IR spectra were employed to study the polarity of water added in reverse micelles. The results indicated that the adsorption of the dyes onto cotton showed better agreement with Langmuir model. The adsorption process was monolayer adsorption. Reactive Yellow 145 with lower negative charge and higher hydrophilicity exhibited the higher adsorption capacity. The fixation percentage and color strength of the cotton fiber dyed in TX-100 reverse micelles was higher than those in bulk water. The polarity of water in TX-100 reverse micelles was lower than that in bulk water.     

The bioscouring efficiency and activity of alkaline pectinase for cotton fabric

Alkaline pectinases could be applied in the bioscouring for cotton textiles to improve the wettability of the fabric. In order to evaluate the bioscouring effect of cotton fabrics directly and simply, the relationship between the amount of products degraded by alkaline pectinase and the wettability of the fabric was established with spectrophotometry. The results showed that products degraded by an alkaline pectinase Bioprep 3000L exhibited one characteristic absorption peak at 239 nm, which indicated that unsaturated degradation products were yielded. During the bioscouring of the cotton fabrics, the increase of the amount of both unsaturated degradation products and reducing sugars released from the pectins existing in raw cotton fiber was consistent with the improvement of wetting property of the cotton fabrics with prolonging the treatment time.     

Influence of chemically modified short hemp fiber structure on biosorption process of Zn2+ ions from waste water

Short hemp fibers, acquired as a waste from textile industry, were used as an efficient biosorbent for removal of zinc ions from polluted water. In order to obtain the material with better sorption properties, short hemp fibers were subjected to oxidative and alkali treatment. The following factors that may influence the sorption properties of short hemp fibers were examined: fiber structure and morphology were characterized by iodine sorption, water retention and scanning electron microscopy, while specific surface area was determined by BET method. Additionally, the amount of carboxyl groups was determined by calcium-acetate method, and the point of zero charge of the short hemp fibers samples was determined by the solid addition method. Biosorption of zinc ions was evaluated through the total uptake capacity, equilibrium and kinetic data. Obtained data were analyzed by nonlinear Langmuir and Freundlich isotherms, as well as pseudo-first and pseudo-second order kinetic models, and the best fitting model was chosen using Akaike information criterion. Chemical modification, used in this work, leads to structural and morphological changes of short hemp fibers, and improvement of their sorption properties. It was found that sorption properties of short hemp fibers are predominantly influenced by surface acidity and the amount of functional groups, while fiber structure and specific surface area have a secondary role in the biosorption of zinc ions. Akakike information criterion values showed that biosorption of zinc ions on all tested hemp fiber samples obey the pseudo-second order adsorption kinetics, while experimental isotherm data fit better with Langmuir model. Biosorption of zinc ions on the hemp fibers is a predominantly chemical process, which mainly follows the mechanism of ion exchange on acidic functional groups, and occurs through the fast surface adsorption, intraparticle diffusion and final equilibrium stage.     

咖啡湿法发酵中使用果胶酶对脱胶时间与杯品质量的影响

以云南阿拉比卡咖啡为原料,在咖啡湿法发酵环节中加入Pectinex Ultra SP-L果胶酶进行脱胶,并对加工出的咖啡豆进行理化及感官分析。结果表明：与自然发酵脱胶相比,果胶酶脱胶能缩短脱胶时间,有效快速脱除咖啡果胶。其脱胶时间与果胶酶的浓度、脱胶温度、鲜果成熟度呈正相关。与自然发酵脱胶相比,果胶酶脱胶所得咖啡豆的内含物质无显著差异,杯品质量干净稳定。就咖啡豆的杯品质量而言,0.01%果胶酶添加量脱胶处理要高于自然发酵脱胶,而添加量为1.00%、0.10%果胶酶脱胶处理略低于自然发酵脱胶。综上所述,果胶酶脱胶能保证咖啡品质的稳定性及提高咖啡加工效率,具有应用前景。     

Controlling supermolecular structures and improving colorfastness in cotton fibers

A new discovery was made in which commercially available triethanolamine could reduce the lattice volume of the supermolecular structure of cotton from the periphery of the lattice by moving cellulose chains on the surface of the crystallites to the amorphous regions, thereby decreasing the close-packed crystallization volume and leading to an increased free volume of the amorphous regions. Subsequently, several supermolecular structures for cotton fibers were successfully controlled to improve the colorfastness in cotton fibers at the molecular level. With the decrease in the degree of crystallinity, more unfixed dyes could be removed by washing reagents, whereas the remaining dyes were mostly fixed to the cotton by covalent bonds, causing a stronger colorfastness, with the best wet rubbing fastness reaching a relatively permanent grade 4. Moreover, the effect mechanism revealed that the unfixed dyes were detached from the cotton fibers according to the reverse process of the adsorption models and that there were additional methods for the unfixed dyes in the fibers to be removed in the presence of triethanolamine than when using pure water. In addition, the binding forces of dye adsorption in the cotton fibers decreased, while the entropy of dye adsorption was higher than that measured when using pure water. Thus, the results suggested that controlling the supermolecular structures of the cotton fibers promoted the removal of unfixed dyes from the fibers and achieved improved colorfastness.     

Water and oil-repellent coatings of perfluoro-polyacrylate resins on cotton fibers: UV curing in comparison with thermal polymerization

UV curing of perfluoro-alkyl-polyacrylate resins able to impart water as well as oil-repellency to cotton fabrics was studied in comparison with conventional thermal polymerization. The process was assessed through weight gain and gel content measurements while the properties conferred to cotton fabrics were determined in terms of water and oil contact angles, moisture adsorption, and water vapor permeability. The polymerization yields were of the same order (>80 %) of those obtained with thermal curing as well as the high contact angles with water (>127°) and oil (>118°) even at low resin add-on (3 %). UV cured resins yielded oil contact angles mostly higher than 120° denoting super oil-repellent surfaces. Moreover the water and oil-repellency was adequately maintained after washing. The moisture adsorption of finished fabrics was lower than that of untreated cotton, but slightly higher for UV cured than thermally treated fabrics. Water vapor transmission rate showed that the finish treatment, thermal as well as by UV curing, does not reduce the breathability of the original cotton. DSC analysis demonstrated that the fiber pyrolysis is affected by the polymer add-on, while FTIR-ATR spectra of all finished fabrics showed typical peaks of ester and C-F groups. XPS analysis showed small differences between thermal and UV curing coatings with each resin, while coatings with the lowest percentage of fluorine groups did not affect the water and oil-repellency.     

UV protective properties of cotton fabric treated with plasma,UV absorber,and reactive dye

The influence of water vapor plasma on the adsorption of UV absorber during the reactive dyeing of bleached and mercerized cotton fabric was examined. Exhaust dyeing of untreated and plasma-treated cotton was performed using a reactive dye Cibarcon Deep Red S-B and a commercial UV absorber Tinofast CEL. Blank dyeing was performed as a control experiment. Fourier transform infrared spectroscopy (FTIR) was used to identify the presence of the UV absorber on the cotton fabric, whereas scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze surface changes of untreated and plasma-treated dyed samples. The CIELAB color values and ultraviolet protection factor (UPF) of the samples were determined spectrophotometrically. Wash and light fastness of samples was performed also. The results reveal that the UPF of cotton increases after UV absorber treatment and that plasma treatment increases the adsorption of UV absorber during dyeing process, especially at higher dye concentrations. The enhanced adsorption of UV absorber onto plasma-treated cotton is the result of the increased concentration of oxygen containing functional groups on the cotton surface after plasma treatment, confirmed by XPS. The UPF of plasma-treated cotton samples is decreased after washing and increased after exposure to xenon light.     

Mechanical properties of wool fiber in the stretch breaking process

Short wool fibers obtained by the stretch breaking process can be blended with cotton fibers and processed in a cotton spinning system, which has a high production rate. For the structural property of the wool fiber after stretch breaking, the diameter and length of the wool fiber were measured as a function of time. The diameter of the broken fibers was finer than the diameter of untreated fibers. The fiber diameter at the break point was the finest and was more irregular than the original fiber. The broken fiber showed mechanical properties of increased modulus, decreased breaking strain, and increased breaking strength.     

Development of Superhydrophobic Microfibers for Bandage Coatings

In this research work, a fabricated composite fiber is proposed to protect wound surfaces from infectious organisms present in water. The composite fiber comprising PMMA, ZnO, and zinc stearate was developed using an electrospinning technique. The fiber surface was scientifically studied using scanning electron microscope, Energy dispersive analysis of X-rays, powder X-ray diffraction analysis and Fourier transform Infra-Red analysis. The pores present in between perpendicularly aligned fibers serves as an excellent medium for vapor transport to a wound surface. The maximum water contact angle of the developed fiber surface was approximately 151 degrees. A commercial cotton bandage after coated with this composite layer behaves as a perfect barrier to the entry of infectious water towards the wound. The pores in the fiber surface support rich supply of environmental oxygen and transport of exudate vapor from the wound. This fiber when coated over a cotton bandage cloth on one side served as an excellent wound protecting bandage against the penetration of external microbial water and also it admits the air, water vapor etc., towards the interior. Water penetration ability of hydrophilic cotton bandage and the water arresting ability of superhydrophobic fiber coated bandage were evaluated using a facile technique. Furthermore, antimicrobial activity of test samples was evaluated against gram positive and gram negative microorganism. Also, a bacterial infiltration test supports the blocking capability of superhydrophobic fiber to water-borne bacteria. The results obtained through this experiment may be used in future as wound healing bandages in an efficient manner.     

Influence of oxygen plasma pre-treatment on the water repellency of cotton fibers coated with perfluoroalkyl-functionalized polysilsesquioxane

Oxygen plasma pre-treatment was applied to cotton fabric with the aim of improving the water repellency performance of an inorganic-organic hybrid sol-gel perfluoroalkyl-functionalized polysilsesquioxane coating. Cotton fabric was pre-treated with low-pressure oxygen plasma for different treatment times and operating powers. Afterward, 1H,1H,2H,2H-perfluorooctyltriethoxysilane (SiF) was applied to the cotton fabric samples using the pad-dry-cure method. The surfaces of the untreated and modified cotton fibers were characterised using Fourier transform infrared spectroscopy, Xray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. The water repellency of the SiF-coated fabric samples was evaluated using static and sliding contact angle measurements with water. The results show that the plasma treatment with the shortest treatment time (10 s) and the lowest operating current (0.3 A) increased the atomic oxygen/carbon ratio of the cotton fiber surface from 0.6 to 0.8 and induced the formation of a nano-sized grainy surface. Increasing the plasma treatment time and/or operating current did not intensify the surface changes of the cotton fibers. Such saturation effects were explained by the large influence of reactive oxygen atoms during the plasma treatment. The measured static water contact angles on the surface of the untreated and plasma pre-treated and SiF-coated cotton fabrics showed that the oxygen plasma pre-treatment enabled the increase of the water contact angle from 135° to ≈150°, regardless of the applied plasma treatment time and discharge power. This improvement in the hydrophobicity of the SiF coating was followed by a decrease in the sliding angle of water droplets by more than 10° compared to the plasma untreated and SiF-coated sample characterized by a water sliding angle of 45°. Additionally, measurements of the water sliding angle revealed that the increase of the static contact angle from 149° to 150° corresponded to a drop of the water sliding angle from 33 to 24°, which suggests that the plasma pre-treatment of 20 s at an operating current of 0.3 A produced the best water-repellent performance of the SiF-coated cotton fabric.     

Effects of spinning processes on HVI fiber characteristics and spun yarn properties

The effects of opening, carding, and repeated drawings on single fiber and bundle cotton characteristics were studied by employing Mantis®, AFIS® and HVI Testers. Some of the significant changes in single fiber properties were found to be due to process parameters as well as the changes in the fiber crimps, parallelness of fibers within HVI beards, and the actual changes in the tensile properties of the fibers. The study showed that the HVI test data taken just prior to spinning had the highest correlation with the yarn tensile properties. Based on the study results, we point out the potential of HVI for future quality and process control in spinning by recommending a set of expanded HVI output that is more scientific and comprehensive for the future control needs.     

A study on processing of natural fibers by underwater shock wave treatment and its characteristics

Fiber quality is very important for all the steps of the textile area. Underwater shock wave has been utilized for metal, wood, food processing and medical applications and renewed and increased application during the last decade. The main object of this study, is to demonostrate underwater shock wave as a surface treatment of natural fibers such as jute and cotton in form of yarn and to report characterized properties of the treated fibers. The underwater shock wave was generated by the explosion of the detonation fuse in the water tank. The process of bubble generation and expansion inside the water results in the formation of shock wave. Natural fibers were exposed to shock wave treatment depending on the different pressures and detonatinon fuse separation distance. After shock-loading, fibers were selected for physicomechanical and physicochemical tests such as Scaning Elecron Microscopy (SEM) analysis, breaking strength, moisture behavior, permeability and wicking test. The maximum effect with improved moisture content, permeabilty and wicking properties were observed from 100 MPa. The treated fiber showed high performance necessary for use in woven and non woven purpose.     

Influence of temperature on corona discharge treatment of cotton fibers

In this study, corona discharge treatment was applied to modify the surface of cotton fibers at various temperatures. The fiber surface was roughened during this treatment and the surface oxygen content increased at a considerably low temperature, and then declined when temperature increased. Weight loss rate showed the treatment was fiercer as treated temperature increased. The breaking strength and surface adhesion property of the fabric treated with starch sizing increased to a certain extent and then decreased. These results suggest that the treated temperature plays a great role in the surface properties of cotton fiber when treated via corona discharge.     

Macro-micro structure,antibacterial activity,and physico-mechanical properties of the mulberry bast fibers

In this paper, the mulberry fibers were successfully obtained by a new pretreatment named alkali-assisted microwave plus biological enzymatic technique (AMBET). The morphology, microstructure, physico-mechanical and antibacterial properties of the mulberry bast fibers were investigated by means of scanning electron microscope (SEM), Fourier Transform-Infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), instron tensile tester and antibacterial testing. The results showed that impurities of the bast fibers could be removed by AMBET treatment. AMBET treated mulberry fiber was even, smooth and fine, and typical cellulose I in the mulberry fibers was confirmed by FTIR and XRD analysis. The crystallinity of the AMBET treated fibers was higher than that of the raw mulberry and chemical treated mulberry fibers. Thermal analysis indicated that the mulberry fibers had a good thermal stability. Moreover, the AMBET treated mulberry fibers showed excellent antimicrobial activities against S.aureus. The physical properties of the mulberry fibers indicated the AMBET treated mulberry fibers were ideal candidates for new textile materials.