Basic Performance of Inkjet Inks

Inkjet printing technology, with its flexibility, high efficiency, and strong adaptability, has been widely applied in home, office, commercial printing, and even industrial manufacturing. As one of the core consumables of this technology, the quality and characteristics of inkjet inks directly determine the overall performance of the printing system and the final output results. The physicochemical composition of the ink plays a crucial—sometimes decisive—role in droplet formation mechanisms, jetting accuracy and stability, the visual quality of printed images (such as color, sharpness, and uniformity), and the long-term reliability of equipment operation (including printhead lifetime and maintenance frequency).

Basic Performance Requirements of Inkjet Inks

① Excellent Image Quality and Durability

Inks must be capable of producing high-resolution images with vivid colors, rich tonal gradation, and uniform appearance.
Key durability requirements include:

• Lightfastness: Printed output should resist fading or color change under light exposure (especially ultraviolet light), maintaining long-term color stability. This is critical for outdoor applications, fine art reproduction, and archival documents.
  
  

• Weather Resistance: The ability to withstand environmental factors such as temperature and humidity fluctuations, ozone, and pollutants, preventing image degradation.
  
  

• Dry/Wet Rub Resistance: After drying or when exposed to moisture, images should withstand a certain degree of physical abrasion without peeling or smearing, ensuring integrity during transportation and use. This is especially important for packaging, labels, and frequently handled documents.
  
  

② Excellent Jetting Stability and Anti-Clogging Performance

The physical properties of the ink (such as viscosity and surface tension) must precisely match the design requirements of the inkjet printhead to ensure stable and consistent droplet formation and ejection.
Core requirements: The ink composition must be clean and free from large molecules that are highly volatile or prone to crystallization, impurity particles, or components that easily precipitate. Any factor that may cause micro-particle precipitation, scaling, or drying crust formation poses a clogging risk, which can severely affect printing continuity and printhead lifespan.

③ Good Physical and Chemical Stability (Long-Term Storage Stability)

During storage and transportation, inks must maintain compositional uniformity, which means:

• Resistance to Phase Separation: Pigments/dyes should remain stably dispersed in the solvent/water, and resins or other additives should remain dissolved, without sedimentation, floating, or phase separation even after long-term storage (months or longer). Phase separation leads to inconsistent performance or complete ink failure.
  
  

• Resistance to Agglomeration/Flocculation: Dispersed colorant particles should remain discrete and avoid aggregation into larger particles.
  
  

④ Chemical Compatibility with Printhead Materials

Ink formulations must be fully compatible with all materials used in inkjet printheads—especially precision nozzle plates and internal fluid channels—including metals, silicon, polymers, adhesives, and sealing materials.
Strict prohibition: The ink must not cause corrosion, swelling, dissolution, or any chemical reaction with printhead materials. Even minor chemical interactions can damage printhead structures, degrade performance, or cause complete failure, resulting in costly repairs or replacements.

⑤ Excellent Color Strength and Color Stability

• High Color Strength / Saturation: Achieving the required color density and intensity with less ink consumption helps improve efficiency and reduce costs.
  
  

• Color Stability / Consistency: Colors must remain consistent within the same batch and across different batches. During storage and after printing, ink colors should remain stable and not change significantly over time or due to environmental factors. This is essential for brand color management, fine art reproduction, and high-quality image output.
  
  

⑥ Fast Drying / Curing Performance

After being jetted onto the substrate (media), the ink should dry or cure as quickly as possible.

Importance: Prevents adjacent droplets from spreading or merging before drying (ink bleeding), which would reduce sharpness and resolution; improves production efficiency (e.g., high-speed printing and immediate post-processing); and avoids smudging or set-off during stacking or rewinding of printed materials.

While drying mechanisms vary by ink type (water-based, solvent-based, UV-curable, latex, etc.), the goal of rapid fixation remains the same.

⑦ Broad Media Compatibility (Especially Plain Paper)

Although inkjet printing can be applied to many specialized media (such as photo paper, films, textiles, metals, and plastics), a key and widely required capability is that inks must deliver good print quality on plain office paper and copier paper.

Challenges and requirements: Achieving fast penetration while controlling ink spread to avoid feathering and edge fuzziness; maintaining sufficient color density and sharpness on fibrous, uncoated papers; rapid penetration and drying to reduce smudge risk; and ensuring good paper flatness to avoid excessive curling.