On December 21, 2025, Guangdong Zhangdao Technology released a professional analysis, focusing on the key value of Particle Size Distribution (PSD) in coating research and development. It breaks the traditional perception that "the smaller the particle size, the better the performance" and points out that the overall distribution curve of PSD is the core determining coating performance. PSD is not simply defined by values such as D10, D50, and D90. Its core lies in the coexistence state of particles of different sizes in the system, including unimodal or multimodal distribution, width degree, and the presence of "tail particles". These directly affect the rheological behavior, gloss, stability, and film-forming quality of coatings. For instance, narrow-distribution PSD results in low low-shear viscosity and good leveling of coatings but weak anti-sagging performance; wide-distribution, on the other hand, increases low-shear viscosity and broadens the construction window by filling the gaps between large particles with small particles. In the film-forming process, emulsion PSD is particularly crucial: emulsions with a single particle size form dense films but are prone to cracking, while bimodal or multimodal emulsions can achieve continuous film formation and uniform stress release through the supplementary positioning of small particles. Zhangdao Technology emphasizes that PSD is an "engineering parameter" rather than a "laboratory parameter", determining the upper limit of coating formulation space. When problems such as ineffective matting powder addition, instability caused by raw material batch replacement, and failure to scale up laboratory results occur, 90% of them are related to PSD. Engineers need to comprehensively consider factors such as system distribution requirements, tolerance for "tail particles", and complementarity between emulsion and pigment/filler PSD, transforming PSD from a testing item into a design tool to facilitate the research and development of high-performance coatings.

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