Despite obtaining good dispersion results in the lab, the challenge of unstable quality upon mass production occurs in many settings. The main cause of this is that the dispersion conditions are not replicated due to differences in scale. In lab equipment, the smaller size leads to higher energy density, making shear and flow more uniform, while in mass production equipment, the larger scale often results in insufficient dispersion energy at the same rotational speed and processing time. Additionally, differences in equipment structure and flow patterns can cause variations in the shear history and residence time experienced by particles, leading to differences in the dispersion state. Furthermore, simple scale-up does not ensure that critical parameters such as flow rate, residence time, and shear intensity match, making it difficult to reproduce the same results as in the lab. To address these challenges, it is essential to focus on process design based on dispersion energy density and flow conditions rather than merely increasing equipment size. By designing the system so that particles pass through the processing area under consistent conditions, it is possible to achieve reproducible dispersion quality even when the scale changes, as seen in inline continuous processing.

In dispersion processes, the occurrence of agglomerates (clumps) during powder addition, which cannot be resolved in subsequent dispersion stages, is a common issue in many settings. The cause of this is that the powder does not wet uniformly in the liquid, leading to the formation of localized high-concentration areas. These agglomerates are also referred to as "fisheyes," and due to their internal unwetted structure, they are difficult to break apart. Once an agglomerate forms during powder addition, liquid has difficulty penetrating its interior, resulting in only the outer layer being wetted, which makes it hard for the internal particles to be disintegrated. Additionally, depending on the addition position and speed, the powder may float on the liquid surface or remain stagnant without following the flow within the equipment, promoting the formation of agglomerates. Particularly under conditions of high viscosity or high solid content, the low fluidity makes it challenging to achieve uniformity in the initial dispersion stage, leading to a higher likelihood of agglomerates remaining. Such agglomerates may not be completely resolved even with strong shear in subsequent processes, causing variations in the quality of the final product and introducing foreign substances. To prevent the formation of agglomerates, it is crucial to improve wettability during powder addition, ensure appropriate addition positions and flow design, and optimize the initial dispersion. By performing shear and mixing simultaneously right after addition, as in inline powder addition and simultaneous dispersion, it is possible to suppress the formation of agglomerates and achieve stable dispersion quality.