Direct Dyes on Cellulosic Fibers

RETARDER SD is a leveling agent for vat, sulfur and direct dyes on cellulosic fibers. 

Dye fixing agent for direct dyes on cellulosic fiber. Excellent wet fixation of dyes. 

The affinity (substantivity) of direct dyes for cellulose fibers depends on the type of chromophore and can be influenced by the choice of dyeing parameters (see Section 4.3.3). Chromophores are azo compounds (Sections 2.2 and 3.2), stil-... 

BORCODYE D-6-LF is multifunctional, eliminating the need for additional leveling agents when dyeing fiber blends. It as also an effective leveling agent for direct dyes on cellulosics. 

WARCOFIX 808 fixative reduces bleeding and staining of colors and improves washfastness of direct colors on cellulosic fibers. WARCOFIX 808 fixative can be applied in the finish mix or by exhaustion after the dyeing cycle. 

C-Profix NF. [Chemurgy Prods.] Poly-quatemary amine fixing agent improving wetfastness of direct and reactive dyes on cellulosic fibers ... 

Uses Wetfastness improver for dyeings and prints with direct and reactive dyes for exhaust and pad applic. fixing agent for fiber reactive dyes on cellulosic fibers fixing agent for direct dyes... 

Dyes for cellulose fiber include the direct, sulfur, vat, a2oic, and reactive dyes. R D activities of world dye manufacturers have been focused on the area of reactive dyes, because reactive dyes offer brighter shades and excellent wet-fastness and have been increasingly used for dyeing cotton. 

In contrast to some naturally occurring dyes like indigo or kermes, which must be vatted or mordanted to be applied in textile dyeing, direct or substantive dyes can be used on cellulosic fibers directly . Their use is widespread because of their easy handling. Today, direct dyes still account for ca. 10% of the world textile dye consumption. For use on paper, see Section 5.3. Recent research on direct dyes concentrated on the replacement of possibly carcinogenic benzidine dyes [44],... 

Speciai dyes have been developed to react directly with the substrate. Such dyes are reactive dyes applied within an alkaline dye bath. These dyes contain a reactive group, such as a haloheterocycle, which covalently bonds to hydroxyl groups on cellulosic fibers in particular. 

Uses Aftersoaping agent for direct and fiber reactive dyes, and other dye classes, on cellulosic fibers and their blends Closyl30 2089 [Boehme Filatex Canada ]... 

The simplest way of coloriog cellulosic fibers is with direct dyes. The dyeing mechanism follows exactly the outline just described where the addition of sail is used to allow dyestuff to be absorbed on the fiber. This is done carefully to ensure that level dyeing is achieved, especially during the early stages of dyeing. 

CASSOFIX TW is a cationic aftertreating agent that markedly improves the wet and perspiration fastness of direct colors (substantive dyes) on cotton, rayon, or other cellulosic fibers. 

The experiments reported here were formulated with the intention of uncovering, in as much detail as possible, the environment existing within a cellulosic fiber in contact with an ionic aqueous phase. Measurements were made at room temperature ( 25°C) and at 90°C. The salt used most extensively was NaaS04 and measurements were made on the uptake of both cation and anion as a function of the concentration of the bath at 25°C and 90°C and as a function of pH at 25°C. In addition, the uptake of the direct dye, Chrysophenine G, and the effect of the dye on the salt uptake were studied at 90°C. It was also necessary to perform some measurements relating to the stability of the fibers. Finally, some measurements were made on the uptake of the Br ion from NaBr solutions. 

Jute can be dyed with a wide range of dye stuffs. All those generally used for cellulosic fibers, such as direct, vat, and reactive dyes, can be used successfully on jute, but, in addition, jute has a strong affinity for both acid dyes and basic dyes, which normally have little or no dyeing capacity for cotton or rayon but are used extensively for wool. 

Direct dyes bind to cellulose at nonspecific dye sites on the surface of naturally occurring crystalline areas within the fiber. The binding mechanism is hydrogen bonding or van der Waals forces. This provides for fairly weak binding (typically 2 kcal/mol). As a result, these dyes wash off during end use unless fixatives are applied. These fixatives may be of several types, typically resinous dicyandiamide crosslinking materials. 

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