The Impact of Particle Size of Water-Based Flexographic Inks on Print Quality

Date: Jan 21 2025 From: Star Color

In the field of flexographic printing, the particle size of water-based inks serves as a critical indicator with comprehensive and profound effects on print quality. Let's delve into the various aspects of how the particle size of water-based flexographic inks correlates with print quality.

Impact on Ink Transfer Performance

Dot Replication Accuracy: Flexographic printing relies on anilox rolls for ink transfer, with precise dot replication being the foundation of print quality. When the particle size of water-based inks is smaller, meaning the pigment particles are fine and evenly distributed, the ink can more smoothly fill the cells of the anilox roll and accurately transfer to the substrate surface to form dots when the plate comes into contact with the substrate. For example, in high-precision label printing, only inks with good particle size can ensure clear and sharp dot edges, with dot sizes highly matching the designed dimensions, thereby achieving delicate image reproduction. Conversely, poor ink particle size can lead to larger pigment particles blocking the anilox roll cells, resulting in incomplete dot transfer, dot enlargement, reduction, or absence, severely affecting image clarity and depth.

Solid Printing Uniformity: In solid printing areas, the particle size of the ink determines its spreading and leveling performance on the substrate surface. Inks with high particle fineness have pigment particles that are easy to disperse, enabling uniform coverage of the substrate surface during the printing process, resulting in smooth and even ink films. This makes solid printed areas color-saturated with no obvious color differences.
The Impact of Particle Size of Water-Based Flexographic Inks on Print Quality

Impact on Color Performance

Color Saturation: The particle size of the ink directly affects its light absorption and reflection characteristics, thereby determining color saturation. Fine and evenly distributed pigment particles can more effectively absorb specific wavelengths of light, enhancing color purity and saturation. When printing vivid color patterns, water-based inks with good particle size can make reds more vibrant and blues more intense, bringing a lively visual experience to printed materials. Larger pigment particles, however, increase light scattering, reducing color purity and making printed materials appear dull and unable to achieve the expected color effect.

Color Accuracy: Precise color reproduction is one of the key requirements for print quality. Inks with high particle fineness, due to the uniformity of pigment particles, maintain relatively stable optical properties under different printing conditions, ensuring color accuracy. When color matching, inks with good particle size are easier to adjust to match standard color samples.

Impact on Print Gloss

Ink Film Surface Smoothness: The smoothness of the ink film surface formed after flexographic printing is closely related to gloss. Water-based inks with good particle size can form a smooth and flat ink film surface during the drying process, as the pigment particles arrange tightly. This flat surface reflects light like a mirror, giving printed materials high gloss. Especially in high-end cosmetic packaging printing, high-gloss printing effects can enhance the premium feel of the product.

Drying Process Impact: The particle size of the ink also affects its drying process, indirectly influencing gloss. Inks with good particle fineness, due to the uniform dispersion of pigment particles, have a relatively consistent drying speed, forming a uniform dried ink film structure conducive to maintaining high gloss.

Impact on Printability

Affinity with the Plate: Good affinity between ink and plate is an important condition for smooth printing. Water-based inks with good particle size, having fine pigment particles, can better interact with the microstructure of the plate surface, enhancing ink adhesion to the plate. This makes ink transfer on the plate more stable, reducing ink accumulation or shedding on the plate, and improving the stability and reliability of the printing process.

Drying Speed and Clogging Risk: The particle size of the ink has a certain impact on drying speed. Generally, inks with finer particle sizes have better dispersion of pigment particles, with more uniform water evaporation and a more stable drying speed. At the same time, fine pigment particles are less likely to accumulate on components such as anilox rolls, plates, or doctor blades, reducing the risk of clogging and ensuring printing process continuity. Poor particle size inks, with pigment particle agglomeration, can hinder water evaporation, prolong drying time, and agglomerated particles are more prone to accumulation on printing components, causing clogging, affecting print quality, and even damaging printing equipment.
The Impact of Particle Size of Water-Based Flexographic Inks on Print Quality

In summary, the particle size of water-based flexographic inks plays a crucial role in print quality. From ink transfer, color performance, gloss, to printability, every aspect is closely linked to ink particle size.

Zhongzhixing water-based inks excel in particle size control, utilizing advanced grinding and dispersion technology, along with a strict quality inspection system, to ensure their particle size is less than or equal to 10 micrometers. Such fine particle size makes the pigment particles in the ink fine and evenly distributed, laying a solid foundation for improving print quality.