Are there any special additives for digital printing?

Yes, digital printing (especially inkjet printing) requires a series of special additives to optimize printing effects, improve color fastness and improve fabric feel. The following are the key additive classifications and their functions:

Classification of special additives for digital printing

1. Pretreatment additives (pretreatment liquid)

Function: Treat the fabric before printing to ensure uniform ink penetration and prevent bleeding.

Common additives:

Ink absorbents (such as cationic modifiers): Improve ink fixation rate and increase color saturation.

Impurizers (such as sodium alginate, polyacrylate): Prevent ink diffusion and ensure pattern clarity.

Alkali agent/urea (for active ink): Promote the reaction between dye and fiber.

2. Ink matching additives

Function: Add directly to the ink to improve printing performance.

Common additives:

Moisturizers (such as glycerol, diethylene glycol): Prevent nozzle clogging and prolong ink stability.

Defoamer: Avoid bubbles causing line breakage during printing.

Surface tension regulator: optimize ink drop shape and improve printing accuracy.

3. Post-processing additives (fixing/soaping)

Function: improve color fastness and feel.

Common additives:

Steaming fixative (for active/acid ink): promote dye fixation during steaming.

Soaping agent: remove unfixed dyes and improve water washing fastness.

Softener: improve fabric feel (such as silicone oil, polyethylene emulsion).

Multifunctional auxiliaries:

Three-in-one pretreatment agent (ink absorption + anti-seepage + antibacterial).

Low temperature fixative (energy saving, suitable for heat-sensitive fibers).

High-precision auxiliaries:

Nano-level dispersant (to improve the color rendering of pigment ink).

Conductive auxiliaries (for electronic textile printing).

4. Customer selection suggestions

Matching ink type:

Acid/active/disperse/pigment inks need to correspond to different additive systems.

Equipment compatibility:

High-speed digital printheads require low-viscosity additives to avoid clogging.

Test verification:

Small test to evaluate color fastness (ISO 105-C06) and clarity (microscope observation of ink droplet diffusion).

5. Solutions to common problems

Problem 1: Blurred printing

→ Increase the concentration of anti-bleeding agent or replace high film-forming additives.

Problem 2: Dull color

→ Check the ink absorption of the pretreatment solution, or add a cationic charge enhancer.

Problem 3: Hard feel

→ Use silicone softener during finishing.