Coating steam-free discharge printing process (3)

2.4 Preparation of paint printing paste key issues
The key to the preparation of pastes is that the contents of the dye solvent oil fractions and aromatic hydrocarbons meet the requirements of the printing process. Strictly control the conditions such as emulsification, add the right amount of water at the right time, and quickly disperse the oil droplets into tiny one-microns or so fine. The oil droplets make it a narrow and uniform droplet of fine oil droplets. Only in this way can the pigment particles in the coating color paste be prevented from migrating with water. Here.

This new type of paint printing paste on fine mesh screens of high value textiles printed on the fine flower shape, can show a clear outline, the line interface is smooth and no oozing edges, bright color effect. With the appropriate additives and processes, double-sided fine floral prints can be obtained.

(1) Influence on the fabric's hand feeling The high value-added textiles printed with paint printing paste are soft and similar to the dye printing. Table 6 shows the printing effect.

(2) Relationship between water repellency and impermeability
The water-holding property of the paste is related to its structural viscosity and composition. In combination with the large viscosity, the cohesive water is more, but it is easily released to cause osmosis, but if an appropriate amount of slow-release component is added to the paste, it slows or stops Rapid release of water can prevent osmosis.

Bar filter paper with relatively poor water absorbency is inserted into the paste at an equal distance, and the height of the liquid to be measured is taken out after 30 minutes. The water holding data is shown in Table 7.

Table 7 Humidity test data

2.5 Preparation of New Type Coating Discharge Printing Paste
The first choice of high quality resistant adhesives should be film-forming transparent, high-brightness, excellent hand and fastness, acid resistance, alkali resistance, electrolyte resistance, high yellowing resistance, dry cleaning resistance, sun resistance, and other necessary properties. In short, there must be good chemical and physical stability. This is used as a base material to be mixed into the paint printing paste, and several kinds of special additive components are added at the same time for the paint discharge steaming process and the steam-free steaming process.

(1) Equipment
1000L stainless steel kettle with variable speed high speed emulsifier
(2) Formula

(3) Process flow
In the 1000L kettle, the following addition sequence was performed:

Coating printing paste + slow-release paste → stirring for 15-20 min at medium speed (500-600r/min) of emulsifier → adding PA synthetic latex → adjusting emulsifier speed 800-1000r/min condition emulsifying and dispersing 20-30min → adding Wet penetrants A and B → Stir with the same conditions for 20-30 min. → Add the dyestuff agent/softness modifier ■ Adjust the emulsifier speed to 1000-1400r/min and stir for about 30 minutes to achieve evenness and rheology. Paint discharge printing finished product → packaging.

There are two types of paint discharge printing pastes: steaming type and non-steaming type, to meet the needs of printing plants with different types of steaming conditions and steaming conditions. Firstly, the two kinds of brands (steaming process) of paint discharge printing paste are introduced as follows:

2.6 UN coating discharge printing paste range of application This product is suitable for: silk, wool, cotton, linen and other natural fiber and viscose fiber fabric whitening and color pull printing.

Physical and chemical properties:

Ingredients: acid and alkali and electrolyte binder, paint printing, special intermediates and stabilizers, etc. Appearance: white to milky white pourable slurries pH: Neutral Storage: Store in a cool dry place at 3-35°C More than six months of product characteristics 1, this product and a variety of commonly used discharge auxiliaries have a good compatibility, good stability of the prepared printing paste.
2, the application of a simple prescription, just add a suitable amount of moisturizing penetrant can be used for whitening, if you add the right amount of color coating can be used for color pull, very convenient.
3, pull the white pulp after steaming easy washing, color paste steaming, baking, washing the color fastness, soft, dye and pull very similar.
4. The fineness of the outline of the drawn fabric is good, which is suitable for high value-added textile printing and dyeing.
5, paint color pull because the pigment is more stable than the dye, hue is not easy to change, good reenactment, color paint colored flower-shaped light, resistant to oxygen bleach, chlorine bleach fastness.

Reference prescription


* The reducing agent should be selected according to the dye of the dyed fabric.

Reference process 1, pull-out printing → drying (100-105°C × 60s) → steaming (102-105°C × 8-10min) → washing (adding 2-3g/L soda to the bath) → soaping → warm water washing → Wash with cold water → dry.
2, color pull printing → process ibid, but need to be given after steaming 135-165 °C baking 1.5-3min, temperature and time depending on the thickness of the fabric and the sample to adjust their own requirements, if the color fastness requirements particularly high, can be Adding proper catalyst to the printing paste can reduce the baking temperature and increase the fastness.

Precautions Because the discharge printing is a printing method with important commercial value, the process is relatively complicated, and the production processes and links are numerous. A slight carelessness can cause irreversible losses. Therefore, before the batch production, you must first do a small test to avoid Necessary loss.

1, the discharge color is generally more black, dark blue, dark red, dyed ground color dye whether active (usually more use vinyl sulfone type), acid