Surface activation of dyed fabric for cellulase treatment (original) (raw)
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NNOVATIVE technology for preparation of multifunctionalized ….. cotton fabrics with high technical performance was established. The innovation entailed the following consecutive sequence: cotton fabrics were subjected to cellulase biotreatment followed by reactive dyeing then easy care finishing treatment. pH was adjusted at 7 before commencing dyeing and finishing. No washing or drying was involved in the sequence. The so obtained fabrics displayed high technical performance as monitored by color strength, wrinkle recovery angle, retained strength in addition to softness and smoothness. Anchoring the enzyme to the cotton fabric ought to be taken as one of the reasons accounting for such high performance. It is believed that the enzyme protein molecules are fixed and immobilized within the molecules structure of cotton via their attachment to the cellulose hydroxyls by the finish molecules. The latter acts as bridges connecting the protein molecules of the enzyme with the cellulose macromolecules of the cotton fabric.
2. Processing of cellulosic textile materials with cellulases
Despite of the amazingly grown interest in cellulases due to their importance for biomass hydrolysis, their main industrial use is still related to textiles. The main application of cellulases are the removal of surface fibre fibrils from cellulosic fabrics to avoid pilling and improve fabric appearance and the ageing of indigo-dyed denim garments. Cellulolytic enzymes are also used in detergents to aid in the removal of fibre encrusted dirt and soil and to increase colour brightness of the washed garments and may be used for the treatment or recovery of cellulosic textile waste. The following chapter gives a short overview about cellulosic textile substrates and cellulose deconstructing enzymes and a detailed insight in the mechanism and the application of cellulases in textile processes.
The effect of cellulase treatment in textile washing processes
Journal of The Society of Dyers and Colourists, 2008
An attempt has been made to understand the interaction between cellulase hydrolysis and mechanical agitation by separating them into two sequential steps. Cotton fabrics were treated with cellulase mixtures of different compositions, and then washed in a process involving a high level of mechanical agitation. The cellulosic material removed during washing had different amounts of reducing ends depending on the cellulase composition used in the initial treatment. The fibre surface did not change significantly after cellulase treatment, but after washing the surface properties were completely different depending on whether the fabric had been previously treated with an endoglucanase– or a cellobiohydrolase–rich preparation. When denim fabrics were subjected to similar processing, it was verified that an increase in colour loss occurred in enzyme–treated fabrics, and that there was an interaction between different cellulase activities and backstaining.
Egyptian Journal of Chemistry
B IORemeDIAtION using enzymes is an important tool in textile industry; therefore the goal of the present study is to subrogate the pretreatment of natural (cotton) and recovered (viscose) cellulosic fabrics with microbial acidothermophilic cellulase produced by the native egyptian fungus Aspergillus terreus RS2. the produced enzyme was examined at two activity levels (10 and 20U/mL) in order to reduce the effluent load that was produced from scouring and bleaching processes and to upgrade a naturally adequate transaction for water and power economy. the effectiveness of the enzymatic pretreatment under the optimum conditions on raw, scoured and bleached cellulosic fabrics has been proved as the results indicated an increase in the color intensity of the treated fabrics in compare to the untreated one for different classes of reactive dyes based on Anthraquinones and Double azo. the fastness properties of the pretreated dyed fabrics were implemented. the contact angle for the pretreated cellulosic fabrics, tensile strength, Scanning electron microscopy and FtIR analyses were performed.
Applied Biochemistry and Biotechnology, 1998
A model microassay system was developed to measure indigo backstaining on cotton fabrics in the presence of enzymes on a small laboratory scale. Backstaining indexes for 11 cellulase samples were measured, and the enzymes were ranked from lower to higher backstaining. Two multienzyme cellulase preparations were separated into fractions using chromatofocusing on a Mono P column. Adsorption ability and backstaining properties of purified enzyme fractions were studied. Evidence was obtained that protein adsorption on cotton fabrics is a crucial parameter causing backstaining (both for crude cellulase samples and purified enzyme components).
A new approach for natural dyeing and functional finishing of cotton cellulose
Carbohydrate Polymers, 2010
A new approach for upgrading the dyeing properties of cotton knits with natural dyes as well as to enhance both the UV-protection and antimicrobial functions of the obtained dyeings was investigated. Factors affecting the dyeing and multifunctional properties of the treated substrates such as fabric structure, type and concentration of mordant, kind and percent of natural dye extract as well as dyeing regime were studied. In situ deposition of the mordant as a metal oxide onto and/or within the fabric structure followed by dyeing results in a dramatic improvement in the color strength as well as the fastness properties, in addition to an outstanding enhancement in both the UV-protection, against the harmful UV-radiation and the antibacterial activity against the hazardous G+ve and G−ve bacteria. The extent of improvement in the aforementioned properties follows the descending order: pre-mordanting followed by dyeing > dyeing only > none, and is determined by type and content of metal, physical state/chemical structure as well as extent of dye interaction and fixation, along with the fabric construction. The UV-protection properties as well as the antibacterial activities of the obtained dyeings are maintained even after 20 washing cycles.