Introduction To Dyeing Methods And Precautions Of Garment Coatings

General, coating It is dispersed into particles of 1 micron in size, and about 108 moles of pigment molecules contained in one particle are all attached to the fiber. The dye is dyed with 1 mole of molecular unit (several moles of association state according to different situations), so we can understand the difference between paint and dye here.

The coating does not have the ability to diffuse to the inside of the fiber, so it is physically attached to the fiber surface. It is fixed on the fiber surface by using the resin component called adhesive. If the adhesive is used to make it completely fixed on the fiber surface, the pigment will not fall off easily and the color fastness will be good. However, due to the influence of the resin contained in the adhesive, there is a disadvantage that the hand feels hard.

Pigment printing or pigment pad dyeing is to force the coating to physically adhere to the fiber surface. As the adhesive is used for fixation, even if the coating itself has no affinity for the fiber, it can also be dyed. The paint must be firmly fixed on the fiber surface when using the absorption method for dyeing clothing paint.

When exhaustion dyeing is used, cationic polymers are attached to the fiber surface in the pretreatment process (for example, compounds used as dye fixatives and the like). Generally, coatings are dispersed by anionic interfacial activator, and the coatings are absorbed by the fiber surface through the ionic combination of the cationic group of the pretreatment agent and the anionic group of the anionic activator on the coating surface.

This is not the combination of coating and fiber, so it is not firm. After the coating is adsorbed, the resin is adsorbed on the fiber, and the coating on the fiber surface is bonded with the fiber through the resin. The dyeing process is as follows:

[Example of paint dyeing process] Degumming → hot water washing → cationic agent pretreatment (60~70 ℃ × 20~30min) → paint dyeing (70~100 ℃ × 30min) → adhesive exhaustion (30~60 ℃) → drying? Curing (adhesive fixation, 90~130 ℃ × 10min) (recently, the surface was positive, and new coating products that can be exempted from pretreatment have appeared)

In the above Dyeing method The main pigments used in are the paints with the following chemical structures. Compared with ordinary dyes, the color itself has excellent fastness

Yellow: Acetoacetate aniline yellow paint

Red: azo paint

Blue green: phthalocyanine paint

Black: carbon black paint

White: titanium white paint. However, the above dyeing method is to use adhesives to combine fibers without affinity with pigments. For this reason, color fastness is related to the bonding degree of adhesive based coatings and fibers.

Generally, in pigment printing, the pigment is fixed to the printing part by a large amount of adhesive, so it feels hard, but the fastness is good.

There are many cases in which a large amount of adhesive should not be used in the suction method. For example, due to the great importance attached to hand feel and popularity during garment pigment dyeing, the dosage of adhesive needs to be reduced, so the following problems often occur in color fastness:

·Light fastness (discoloration), fading (caused by incomplete combination of paint, coagulation, migration, etc.)

·Rubbing fastness (wet), abrasion pollution (caused by incomplete dye binding on the coating surface)

·Washing resistance, color shedding (caused by solvent resistance of adhesive) Textile It is common that the color fastness does not meet the standard. It is necessary to develop new products after fully mastering these conditions.