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Sodium alginate used in the textile dyeing

(A) for reactive dye printing paste

Theoretically speaking, the starch molecules in the hydroxyl OH easily with a reactive dye active groups bonded, resulting in poor fastness to pale, in case of bleeding and the formation of water droplets easily scrub Lase other shortcomings. So any hydroxyl containing a large amount of carbohydrates, such as starch, gum dragon, yellow dextrin and gum, etc. A bit of Peter, are not used as a reactive dye printing paste. Ideal for reactive dye printing paste, sodium alginate when pushed, because it not only has a good performance and no chemical reaction occurs with reactive dyes functional groups.

Note: 1, although sodium alginate structure also contains a hydroxyl group, a hydroxyl group but seq:. CHOH form, the reaction is less lively, very low affinity for reactive dyes.

2. Some people think that sodium alginate is not the beginning of a hydroxyl .CH2OH, only carboxyl .COONa, .COO- negatively charged carboxyl ions, sodium alginate itself so negative for the Netherlands, while reactive dyes also have female sexual charge (reactive dyes Dutch female parent having water-soluble groups such as carboxyl group, a sulfonic acid group, a sulfonic? group and the like, they are in the water ionization and charge of a female), and therefore the electrostatic repulsion occurs, thereby preventing the reactive dyes binding paste, promoted dyeing dye.

3. It must be noted, in case of hard water, sodium alginate, calcium ions Ca ++ and other metal ions will generate a calcium alginate or other heavy metals were precipitated, this precipitate carboxylated ionic charge loss. Thus, sodium alginate paste secondary hydroxyl group = CHOH it is possible to work with the dye, both damaged paste performance, but also easy to make color caused by unstable color, but also affect the color fastness, especially active Tsui blue KN5G. Therefore, in the preparation of the original paste, you must add sodium hexametaphosphate to complex heavy metal ions, can improve the permeability of good printing paste, to ensure proper color fastness. Water softener B envelope force is too strong, certain reactive dyes containing complex metal ions affected, it is generally not.

4. Preparation of sodium alginate paste formulation warm water (50 ~ 60 ℃) 80 Gongjin

Hexametaphosphate 0.6 to 0.8 kg

0.2 to 0.6 kg of soda ash

5 to 8 kg sodium alginate

Formaldehyde (37.5%) of 1 to 2 liters

Synthesis of water 100 kg

Action: First warm water into the barrel, adding sodium hexametaphosphate, under constant stirring to the sodium alginate slowly into warm water, stir until evenly without granular paste, add water to the total amount of soda ash and then adjusted to pH 7-8, followed by addition of formaldehyde, the standby. When pasting without boiling, generally should not exceed 60 ℃, otherwise it would decrease the viscosity, the role of sodium alginate paste light-hydrolysis occurs, a sharp decline in viscosity, and therefore should be placed in the dark during storage. It is 6 ~ 11 was stable at pH values, the case of acids, alkalis are a gel. Heavy metal ions can cause gel formation, can be used to prevent sodium hexametaphosphate, the general concentration of carved white powder, insurance powder, sodium chlorate, etc., at room temperature, it has no effect.

(B) as Indy losartan dye printing paste Indy Montreal losartan dyes for printing large, starch paste modulation printing paste, starch paste due to poor permeability, often to produce uneven color phenomenon. Modulation using sodium alginate paste printing paste, and textured with carving Montreal spendthrift printing can improve the dye to color uniformity. Bleach sodium alginate shall, when pasting, plus the amount of sodium thiosulfate dechlorination, because most of the dyes as well as some Hindi losartan dye, such as blue O4B, black and IB, etc. are not resistant to chlorine, otherwise for printing paste will affect their hair color.

(C) for the tension azole Phi Phi pull printing paste black Seoul Seoul azole black (commonly known as the black pull or pull-membered) printing, the general pattern of available wheat starch paste, but the fine line printing, in order to ensure good permeability, too color uniform, smooth lines, usually sodium alginate paste, and add some triethanolamine, increase stability and prevent sodium alginate paste condensation. Printing with sodium alginate paste, hot YORK perishable, or add a small amount of a preservative such as formaldehyde, but note that the addition of sodium alginate formaldehyde should not be used to pull the black Phi azole Seoul.

(D)When  for printing paste condensation condensation turquoise turquoise I5G printing, no special requirements on the paste, starch, sodium alginate, synthetic rubber and other dragon can be used. What kind of paste is based on its performance printing with the dye may be: when mixed colors and dyes, sodium alginate paste can be used, and is not reactive dyes mixed colors available dragon starch paste or synthetic rubber.