Invisible threshold of quality control: Guide to detailed control of metal pigment dispersant inspection

Invisible threshold of quality control: Guide to detailed control of metal pigment dispersant inspection

Metal pigment dispersants play an important role in various industrial applications, and their correct use has a direct impact on product quality and performance.

1. Choose the right type of dispersant

Understand the characteristics of dispersants: Different types of dispersants have different chemical structures and mechanisms of action. For example, anionic dispersants stabilize pigment particles through electrostatic repulsion, while non-ionic dispersants rely on steric hindrance effects. When selecting a dispersant, it is necessary to comprehensively consider the type of metal pigment (such as aluminum powder, copper powder, zinc powder, etc.), the properties of the base material (such as water-based, solvent-based, powder coatings, etc.) and the application requirements (such as gloss, weather resistance, chemical resistance, etc.).

Consider compatibility: Ensure that the selected dispersant has good compatibility with other components in the system (such as resins, solvents, additives, etc.) to avoid stratification, flocculation and other problems caused by incompatibility.

2. Optimize the dispersion process

Pre-dispersion treatment: Before adding metal pigments to the system, pre-dispersion treatment can be performed first. For example, mixing the pigment with a small amount of dispersant and solvent, pre-dispersing it through high-speed stirring or grinding equipment, making the pigment particles initially dispersed evenly, and then adding it to the main system will help improve the overall dispersion effect.

Controlling dispersion conditions: The stirring speed, time, temperature and other conditions during the dispersion process will affect the dispersion effect. Generally speaking, appropriately increasing the stirring speed and extending the dispersion time will help the pigment particles to be fully dispersed, but too high a speed and too long a time may cause the pigment particles to break or the dispersant to fail. At the same time, control the dispersion temperature within an appropriate range to avoid excessive temperature causing the dispersant to decompose or the pigment to discolor.

3. Determine the appropriate addition amount

Conduct a small test experiment: Due to the complexity and differences of different systems, it is difficult to accurately predict the optimal addition amount of the dispersant. Therefore, it is recommended to conduct a small test experiment first, by changing the amount of dispersant added, observing the dispersion effect of the system (such as viscosity changes, pigment sedimentation, gloss, etc.), and determine the optimal addition amount range.

Consider synergistic effects: In some cases, the coordinated use of two or more dispersants may produce better dispersion effects. For example, using a dispersant with electrostatic repulsion in combination with a dispersant with steric hindrance can stabilize pigment particles from two aspects at the same time. However, when using synergistic dispersants, more experiments are needed to determine the optimal ratio and addition amount.

4. Pay attention to the storage and use environment of dispersants

Storage conditions: Dispersants should be stored in a cool, dry, well-ventilated place, avoiding direct sunlight and high temperature environment. At the same time, it should be sealed to prevent moisture, impurities, etc. from entering and affecting the performance of the dispersant.

Use environment: When using dispersants, the working environment should be kept clean to avoid dust, impurities, etc. from mixing into the system. In addition, pay attention to operational safety, operate according to the safety instructions of the dispersant, and wear necessary protective equipment.

5. Evaluation and adjustment

Regular evaluation: During the product production process, the dispersion effect should be evaluated regularly. The use effect of the dispersant can be judged by testing the viscosity, stability, glossiness and other indicators of the system, or observing the appearance quality of the product.

Timely adjustment: If the dispersion effect is found to be unsatisfactory, the cause should be analyzed in time, and the type, addition amount or dispersion process of the dispersant and other parameters should be adjusted. For example, if it is found that the pigment settles quickly, it may be that the amount of dispersant added is insufficient or the dispersion effect is not good. You can appropriately increase the amount of dispersant added or optimize the dispersion process.