Direct dyes in the water solubility of size mainly depends on the type and quantity of water-soluble groups in the dye molecules, which contain water-soluble groups, solubility in water. Outdoor Flags For Advertising To raise the temperature, but also make the dye solubility increases. Direct dyes dissolved in water, the formation of dye anion in solution. However, due to the general water contains more metal calcium, magnesium, calcium or magnesium combined with the dye anion and the formation of insoluble precipitate, is not conducive to the conduct of staining in the actual production, Custom Feather Flags and dyeing water must be softened . More convenient in the dyeing of the water by adding soda ash or sodium hexametaphosphate. Of soda ash can increase the solubility of the dye, but too much will make the dye on the dye slowly. Outdoor Flags For Advertising
Direct dye is in solution form of the dye anion, a small amount of soda ash solution to promote cellulose anion dissociation was negatively charged dye anions and fiber anion with each other have a greater repulsion and difficult to close to each other, thereby affecting the dye on fiber dyeing, soda ash by adding dye has played an increase in the solubility of the dye and reduces the affinity of the dye on the fiber and play a role in retarding But the addition of inorganic neutral salts in solution, it will cause this phenomenon to change. Inorganic neutral salt is added to the solution, Personalized Yard Flags Personalized Yard Flags these salts dissociate into cations (Na +) and the corresponding anion. Constitution smaller inorganic cations in aqueous solution, more lively, Outdoor Flags For Advertising easily absorbed around the fiber macromolecules, thereby reducing the fiber molecular surface of the anionic dye and fiber repulsion decreases, the relative increase in the dye anion and cellulose molecules between the adsorption capacity, to promote the effect of dye. Therefore, when the neutral salt can increase too much as an accelerant, but when the salts will dye colloidal state destruction, resulting in partial condensation to produce precipitation.
The direct dyes are anionic dyes, which, with cationic surfactants resin combining the generation of insoluble compounds. Therefore, in order to improve the washing of direct dyes, light fastness, often take advantage of this principle, the use of cationic fixing agent for fixing. Outdoor Flags For Advertising
(B) direct dye application performance according to the temperature, salt and the dye uptake on the dyeing properties of direct dyes, direct dye application performance is divided into three categories: Garden House Flags Wholesale
(1) Group A: This type of dye molecules structure is relatively simple, rapid uptake rate, the dyeing performance is very good, about 70 ~
(2) (B): This type of dye molecular structure is complex, with more water-soluble gene, the uptake rate is slow, poor performance of dyeing, salt promote dyeing effect of these dyes is very significant to good control of salt by adding amount, to control the rate of dyeing and levelness. If the salt by adding too early, it will make the dye uptake is too fast to cause uneven dyeing.
(3) Category C: These large and complex molecular structure, have a greater binding capacity of fiber, salt it to promote dyeing effect is very small, but the temperature of its influence. Backpack Flagstaff Such dyes in the beginning of dyeing temperature can not be too high, otherwise too fast, because the dye affect the dyeing. Outdoor Flags For Advertising
Mixed colors, pay attention to appropriate selection of performance close to the similar dye.
(C) direct dyes direct dye staining method is simple, to jigger mainly, due to the dye solubility and uptake rate constraints, the pad is limited to light in color. Staining generally selected in the neutral or weakly alkaline medium, Custom Made Decorative Flags in acidic solution is not used for dyeing cotton, dyed silk in acid medium. Direct dye jigger process is as follows.
Reel → Juanran → washed (solid color processing) → cold water volume.
Prescription and process are shown in Table 2-1.
Table 2-1 direct dye jigger prescription and process
Projects a light-colored in the color dark
Dye prescription dye (fabric weight%)
Soda ash (g / L),
Salt (g / L) 0.2 the following
0.5 to 1
– 0.2 to 1 Outdoor Flags For Advertising
1 to 1.5
More than 71
1.5 to 2
7 to 15
Fixing fluid prescription fixing agent Y or M (fabric weight%) 0.8 1.2
30% acetic acid (fabric weight%) 0.6 to 1 Advertising Feather Flags
Process conditions of the
On the shaft –
6 to 12
100 to 150
– 60 to 70
At room temperature
Room temperature, -60
At room temperature
Note for each axis fabric weight according to the specifications of the different fabrics.
3 jigger Handling Precautions Outdoor Flags For Advertising
(1) The dye is first dissolved in hot soft water and mix thoroughly, and some dyes are advised to add some wetting agent first tune into a paste, then add hot water soluble dye that when dissolved filter by adding the dye vat.