The viscosity and pH value of water-based flexographic ink

Date: Feb 10 2025 From: Star Color

The global packaging printing industry is increasingly emphasizing environmental protection. As an industry closely linked to daily life, the printing industry is undergoing profound green transformations. Water-based flexographic inks have emerged as a star among many ink categories due to their unparalleled environmental advantages, such as low VOC emissions, degradability, and excellent adaptability to various printing needs, making them the preferred choice for many companies on the path to green printing. However, to maximize the performance of water-based flexographic inks during the printing process, precisely controlling their viscosity and pH value, the two key elements, is undoubtedly the password to improving printing quality.

1. Viscosity: The "Invisible Commander" of Printing Effects

Ink viscosity, this seemingly simple physical indicator, actually plays the role of a behind-the-scenes core decision-maker in the field of printing. At the microscopic level, high-viscosity ink has strong intermolecular forces and poor fluidity, like thick syrup, making it difficult to spread evenly on the printing plate surface. When printing, this unevenness can lead to blurred edges of printed patterns and abnormal enlargement of dots, instantly losing the sharpness of the originally delicate patterns and becoming blurred, seriously impairing the visual effect and commercial value of the printed materials.

If the ink viscosity is too low, the intermolecular forces are weak, and the fluidity is excessive. During the printing process, high-speed equipment can cause the ink to splash everywhere due to a lack of sufficient cohesion, resulting in ink misting. This not only severely pollutes the production workshop environment but also causes a significant waste of ink, directly increasing production costs. More crucially, ink misting leads to uneven distribution of ink on the substrate, greatly reducing printing quality and causing issues such as inconsistent colors and incomplete patterns.

Different types of printing equipment have their unique requirements for ink viscosity due to differences in their working principles and operating speeds. For example, high-speed rotary printing presses, which can reach printing speeds of hundreds of meters per minute, require ink with low viscosity to quickly and evenly transfer from the printing plate to the substrate within a very short time, achieving efficient and stable production. For some flexographic printing equipment used for printing materials such as corrugated cardboard with rough and porous surfaces, higher viscosity ink is needed to provide sufficient adhesion to ensure effective penetration and firm attachment of the ink to the material surface.
The viscosity and pH value of water-based flexographic ink

2. pH Value: The "Stabilizer" of Ink Performance

The pH value, as a key indicator measuring the acidity and alkalinity of water-based flexographic inks, has a comprehensive impact on ink performance. Scientific research shows that when the pH value of water-based flexographic inks is within the ideal range of 8.5 to 9.5, the various chemical components in the ink maintain the best balance, and their performance is most stable.

Once the pH value exceeds this range, the ink's performance will fluctuate significantly. When the pH value is too high, the alkaline components in the ink increase, inhibiting the drying and curing reaction of resin and other film-forming substances in the ink, resulting in a significant slowdown in the drying speed of the ink. This can cause serious problems in actual production, as newly printed products with incompletely dried ink can easily become smeared during subsequent stacking and transportation, destroying the carefully printed patterns and rendering all previous efforts futile.

When the pH value is too low, the ink becomes acidic, disrupting the chemical stability among the components in the ink. This can lead to aggregation and precipitation of pigment particles in the ink, causing the ink to clump and be unable to normally pass through the pipes and nozzles of the printing equipment, severely affecting production continuity. Additionally, the pH value is closely related to the color performance of the ink. A suitable pH value enables uniform dispersion of pigment particles in the ink, optimizing the scattering and absorption of light on the pigment particles, thereby achieving the best levels of color saturation and gloss of the ink, with printed patterns appearing vibrant, lifelike, and providing a strong visual impact.

3. Zhongzhixing Attribute Inks: Professional Leadership and Exceptional Quality

In the highly competitive market for water-based flexographic inks, Zhongzhixing Attribute Inks stand out with their exceptional quality and professional service, becoming the trusted choice of many printing enterprises.
Zhongzhixing has a professional R&D team composed of senior industry experts and top scientific research talents. They conduct in-depth research into the complex relationship between ink viscosity, pH value, and printing effects, utilizing advanced materials science and chemical engineering technologies to precisely control the ink formulation. Through numerous experiments and actual production verifications, they continuously optimize the formulation to ensure that each batch of ink has highly stable performance.

In terms of production processes, Zhongzhixing adopts internationally leading production equipment and a strict quality management system. From raw material procurement to product delivery, every step undergoes rigorous testing and monitoring to ensure that only products meeting high-quality standards enter the market. Zhongzhixing insists on using high-quality raw materials, which are not only reliably sourced but also carefully selected and pretreated, guaranteeing the stability and environmental friendliness of the inks.

Zhongzhixing's products have a wide range of applicability, meeting the diverse needs of different printing equipment and substrates. Whether it's high-speed printing presses or low-speed printing presses, whether the substrate is paper, plastic film, or aluminum foil, Zhongzhixing water-based flexographic inks can demonstrate outstanding printing performance. Additionally, for customers' specific requirements, such as special color needs or special printing process requirements, Zhongzhixing also provides customized solutions, tailoring the most suitable ink products for customers.
The viscosity and pH value of water-based flexographic ink

In addition to high-quality products, Zhongzhixing also provides comprehensive technical support and after-sales service to customers. The company has a professional technical service team ready to provide on-site technical guidance and training to help customers solve various problems encountered during use. Whether it's ink formulation, printing equipment adjustment, or printing quality optimization, Zhongzhixing's technical personnel can provide timely and effective solutions based on their rich experience and professional knowledge, ensuring smooth printing production processes.