Starch is widely used as a sizing agent, being readily available, relatively cheap and based on natural, sustainable raw materials. Spinning spinning is the process which converts raw fibre into yarn or thread. Scouring is an essential prerequisite before other finishing processes such as bleaching, dying, printing of the fabric. Caustic soda dissolves starch and form layer, can be separated. Utpal mondal west bengal university of technology govt. Short and efficient desizing and scouring process of.
To achieve a high degree of whiteness with minimum damage to cellulose, a twostage process is. The cloth is impregnated with the dilute acid solution in a twobowl or three bowl padding mangle and then stored for 8 12 hours in a closed concrete pit. Sustainable processes for pretreatment of cotton fabric core. Here, the desizing bath is made of a desizing agent peroxydisulphate and an oxidationresistant, watersoluble dispersing agent. Use of ultrasonic energy in the enzymatic desizing of. The % fabric weight loss, the tegeva rating on the desized fabric, the effect of desizing bath ph and the molarity of the alkalis to the desizing results, and the starch removal rate of the treatments was studied. In the direct method, the flame contacts the freeguided fabric at. Our experiments showed that by use of a mixture of two appropriate enzymes, a glucoamylase multifect. Integrated desizingbleaching reactive dyeing process for cotton towel. Combined onebath desizingscouringdepilling enzymatic. Enzymatic desizing for effective processing processing. Sizing or size is a substance that is applied to, or incorporated into, other materialsespecially papers and textilesto act as a protective filler or glaze. The aim of this lab is to scour the already desized cotton fabric to determine any differences in appearance between the scoured.
Enzymes are complex organic, soluble biocatalysts, formed by living organisms, that catalyze chemical reaction in biological processes. During bioscouring, the significant weight loss is observed when chelating and wetting agents are combined with xylanase. Enzymatic onebath desizing bleaching dyeing process for. During oxidative desizing process, oxidative degradation of cellulose is unavoidable. Textbooks in consumer textiles often stress the more aesthetic areas of textiles, whereas textbooks in textile chemistry and textile physics present a highly rigorous approach to the field. The alkali desizing of woven cotton fabrics emerald insight.
To enlarge the economic use of these enzymes, cotton fabric was desized and scoured in a one step and single bath. Sizing agents are selected on the basis of type of fabric, environmental friendliness, ease of re. The desized fabrics were then subjected to dyeing using reactive dyes. Desizing of a grey fabric can also be done by using alkali and oxidising agents. Pdf onestep process for enzymatic desizing and bioscouring of. Feasibility study of integrated desizing, scouring and. Cotton as a natural product is made up of its main. Enzymatic onebath desizing bleaching dyeing process. Desizing process the desizing was carried out in in rota dyer laboratory machine at ph 7 at 60 c for material liquor ratio 1. Novel oxidative desizing agent consisting essentially of from 10 to 80, preferably 50 to 80% by weight of a surfactant and from 20 to 90, preferably 20 to 50% by weight of potassium persulfate. May 03, 2014 a process to remove the sizing material from the fabric is called desizing. Combined pretreatment and causticization of cotton fabric.
In this case, similar amounts of residual pva in fabrics were detected in comparison with the conventional desizing process which uses hot water 80c, 30 min. Enzymatic desizing is the classical desizing process of degrading starch size on cotton fabrics using enzymes. A process to remove the sizing material from the fabric is called desizing. A solar energy accelerated process for combined desizing. Cotton dhoti, in general, and polyester cotton dhoti, in particular, are very popular as the traditional dress in rural and semiurban areas in india and in some countries in asia and africa. The effects of ozone bleaching and ozone desizing method. Short and efficient desizing and scouring process of cotton. Sound is a form of energy, just like electricity and light. Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials sizing is used for oilbased surface preparation for gilding sometimes called mordant in this context. The first reason is to use ozonation process for desizing pretreatment of a terry fabric. To enlarge the economic use of these enzymes, cotton fabric was desized and scoured in a one.
To overcome this problem, a novel method has been suggested by kothe and angstmann2. The effects of the ozone desizing and combined conventional. The alkali metal hydroxides lioh, naoh and koh have been studied in the desizing of woven cotton fabrics under different treatment conditions. College of engineering and textile technology berhampore, murshidabad, india email. This process is used on woven fabrics but not on knitted fabrics. Chemical technology in the pretreatment processes of. Pdf desizing of untreated cotton fabric with the conventional and.
Pdf the objective of this study was to develop a new process to desize, bleach, and dye starchsized cotton fabrics in one bath using enzymes. Lye caustic soda desizing in this method fabric containing starch would be expanded under the hot solution of sodium hydroxide caustic soda naoh. Sustainability assessment of cottonbased textile wet processing. Onestep desizing, scouring and bleaching of cotton fabric. These higher rates of desizing plasma pre treated fabric can save time, energy and water. Oct 22, 2016 aly as, sayed sm, zahran mk 2010 onestep process for enzymatic desizing and bioscouring of cotton fabrics. Combination of multiples processes or reduction of process steps singlestage desizingscouringbleaching favors economic production. Abstract enzyme process and ultrasound power are the two important clean technologies which have potential use in the textile industry like desizing, scouring, dyeing and so on. Pollution due to disposal of chemicals is a major threat for environment in textile processing.
Pdf combined desizing, scouring and bleaching of cotton. A simple hot box type solar collector has been used to achieve simultaneous desizing, scouring, and bleaching of cotton fabrics using a padbatch method. Pdf textile desizing techniques abdul azeem academia. Polyester cotton blend fabrics are normally bleached with sodium hypochlorite, followed by sodium chlorite. Application of ultrasound in the preparation of cotton and. After conducting desizing with atmospheric pressure plasma treatment, the cotton denim fabric was subjected to an enzymatic colour fading process. Fabric is simultaneously desized, scoured and bleached by a process in which it is first impregnated at room temperature with an aqueous solution containing hydrogen peroxide in an amount corresponding to a content of 2. Singeing is the process of passing a yarn or fabric rapidly through a heat source. I used exhaust method to desize the cotton fabric in which enzymes and wetting agent were used simultaneously for desizing of cotton fabric. Sizing may be done by hand, or in a sizing machine. Pdf onestep process for enzymatic desizing and bioscouring.
The sizing liquor is applied on warp yarn with a warp sizing machine. Jul 29, 2015 acid desizing dilute sulphuric acid or hydrochloric acid may be used to hydrolyse the starch from the sized fabric. Jul, 2012 in addition, the desizing effect induced by atmospheric pressure plasma treatment was compared with conventional enzyme desizing treatment. Conventionally, enzymes are drained after completion of process. Commercial desizing enzyme, a amyloglucosidase 186 unitsg, pullanase 395 unitsg. To observe the effect of ph on enzyme desizing of 100%. Use of ultrasonic energy in the enzymatic desizing of cotton.
To observe the effect of ph on enzyme desizing of 100% cotton. Starch sized 100% cotton woven fabrics need desizing, scouring and. The presence of impurities in the raw fibres, additives present in the yarn and fabrics also intervene during the plasma processing. In this article, the performance of atmospheric pressure plasma treatment in the desizing of grey cotton denim fabric followed by an enzymatic colour fading process was studied. Desizing is a process of removing the sizing agents covering the warp yarns prior to the finishing process because the sizing agents will lead to uneven dyeing, printing or finishing due to the sizing agents ability to act as waterproofrepellent barrier. Cotton textile processing the national cotton council. Effect of atmospheric pressure plasma treatment on the. An attempt has been made to desi ze, scour and bleach grey cotton fabric simultaneously using ozone. This desizing agent may optionally also contain from 5 to 25% by weight of a solubilizer with a simultaneous reduction of the surfactant and persulfate portions. Cold solutions of dilute sulphuric or hydrochloric acids are used to hydrolyze the starch. Desizing on a jigger is a simple method where the fabric from one roll is processed in a bath and rewound on another roll. Chakraborty, in fundamentals and practices in colouration of textiles, 2010 12. The presence of sizing ingredients in the fabric hinders processes, such as dy. Jun 06, 2014 enzymatic desizing of cotton fabrics is most efficient at 60c and at ph 7.
The objective of this study was to develop a new process to desize, bleach, and dye starchsized cotton fabrics in one bath using enzymes. Every enzyme has particular effect on grey fabric at a particular ph. For cotton woven fabric and its blends with synthetic fibres, a threestage pretreatment process has been the standard procedure for many years, comprising. Desizing bleaching dyeing process for cotton fabrics. Above all it has to be stated that the acid consumption of untreated cotton fabrics table 1. Novel oxidative desizing agent consisting essentially of from 10 to 80, preferably 50 to 80% by weight of a surfactant and from 20 to 90, preferably 20 to 50% by weight of potassium. Developments in grey preparatory processes of cotton textile materials. The optimum conditions for the enzymatic desizing process embraced were am concentration 3. Us4654043a desizing cotton and cottoncontaining fabrics. First, the sized fabric is washed in hot water 80 95c to gelatinize the starch.
Free enzyme, treatment time, and ultrasound brings about a significant increase in the starchsize removal. The sizing material present on the warp yarns can act as a resist towards dyes and chemicals in textile wet processing. Abstract in this experiment 100% cotton fabric was desized. Alternative ecofriendly desizing agents are available in the market in the form of enzymes. Therefore, desizing the removal of warp size becomes.
Us5980581a process for desizing and cleaning woven fabrics and. For cotton woven fabrics, a separate enzymatic desizing process has been carried out traditionally to remove starchbased sizes added on warp yarns about 15% of the yarn weight in weaving 6 while synthetic sizes applied to manmade fibers are generally water. Acid desizing dilute sulphuric acid or hydrochloric acid may be used to hydrolyse the starch from the sized fabric. Dec 01, 2011 in this study, the possibility of simultaneous acid. We discuss the design and efficiency of the solar oven and the results of the experiments done in it. Title to observe the effect of ph on enzyme desizing of 100% cotton fabric. Integrated enzymatic and chemical treatment for singlestage. Enzyme types and desizing recipes recommended by manufacturers. Chapter 11 combined pretreatment processes of textiles. They are 1 terry fabric samples 2 ozone application. The results indicate that ultrasonic power value and.
Addition of edta a strong metal complexing agent results in higher weight losses of cotton fabrics. Onestep process for enzymatic desizing and bioscouring of cotton fabrics. The process basically consists of boiling the cotton fabric with strong alkali and detergent at high temperature. A process for desizing cotton and cotton containing fabrics in a strongly alkaline aqueous solution with an alkali metal hypochorite, wherein from 0. Enzymes an alternative for wet processing of denim. Read article about the desizing procedure of cotton textile materials depends on the type of size so that required to know what type of size is on the fabric before desizing. The resultant performance properties were also compared. Enzymes are quite specific in their action on a particular substance. Process of cotton textile materials desizing different. Sustainable processes for pretreatment of cotton fabric. Mar 11, 2016 reuse of scouring and bleaching process water for desizing. After the weaving process the fabric is desized washed. For woven fabrics, the size applied to the warp yarns during weaving can interfere with the penetration and fixation of print color. In the present work, the feasibility of introducing ultrasonic energy in enzymatic desizing process of cotton to improve the desizing efficiency is investigated.
Jan 01, 1999 in this process, the desized and washed cotton fabric is treated in open kier boiling for 4 h with a liquor containing hydro gen peroxide 1%, emulsified solvent 0. Among all the chemical processes of textile materials, the grey preparatory process has been the most neglected area. Us4309298a oxidative desizing agent and process for. Padding the fabric in alkali and stacked under 60 80 for 6 to 12 hours, the desizing process.
Cotton and cotton containing fabrics are desized in strongly alkaline aqueous solution with an alkali metal hypochlorite by a process in which from 0. Developments in grey preparatory processes of cotton textile. A clean fabric will ensure that the next wet process can be done without interference from unwanted residual components. Coldpadbatch biopretreatment of cotton woven fabrics. Desizing was performed with an amyloglucosidasepullanase enzyme dextrozyme dx, manufactured by novozymes instead of a conventional amylase enzyme in order to hydrolyze starch into single glucose units. Desizing is the process of removing the size material from the warp yarns in wov en fabrics. Cotton fabric is padded with this solution for 7580% expression, dried or covered with polyethylene sheet to avoid oxidation of selvedge and developed in a boiling solution of naoh 40 gl and na 2 co 3 20 gl for 30 min, aired, washed in cold and hot water, treated with na 2 sio 3. The process in turning cotton fiber into fabric is complicated. After recycling the scouring and bleaching process water three times, the baths still contain 55 % alkali and 67. Padding the fabric in alkali and stacked under 60 80 for 6 to 12 hours, the desizing process can be finished. Material and method material the materials used in this study are four grouped under heading. Pdf enzymatic onebath desizing bleaching dyeing process.
Cotton based woven fabric encompasses desizing of the sizing elements starch, polyvinyl alcohol etc are usually applied on warp yarns to avoid breakages during weaving process, alkali scouring to take out the natural impurities such as fats and waxes, pectines and proteins followed by a hypochlorite or hydrogen peroxide bleaching process. Materials and methods fabric the lyocell cotton 40. Denim fabric is made from yarns in which the warp yarn has been dyed with indigo andor sulfur dye. Developments in grey preparatory processes of cotton. The geometrical properties of the fabric are given. Desizing is the process of removal of size material applied on warp threads of a fabric to facilitate the process of weaving. Application of ultrasound in the preparation of cotton and silk fabric. Enzymatic desizing of polyvinyl alcohol from cotton fabrics.
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