n coating formulation systems, talcum powder ranks among the most widely used functional fillers. It can partially replace titanium dioxide and resin to cut production costs, as well as optimize the mechanical, rheological and weather‑resistant properties of paint films. Besides whiteness, purity and silicon‑magnesium content, the width of particle‑size distribution serves as a critical quality indicator of talcum powder, which determines the stability, workability and film appearance of finished coatings. Compared with conventional talcum powder with broad particle‑size distribution, narrow‑distribution talcum powder features concentrated and uniform particle sizes, free of coarse particles and excessive ultrafine dust. It delivers all‑round advantages in coating production, construction and finished‑product performance, making it a preferred filler for high‑grade latex paints, industrial coatings, floor paints and wood coatings. This paper systematically illustrates the positive effects and functional mechanisms of narrow particle‑size distribution talcum powder on various coating properties.

It refers to the energy absorbed per unit cross‑sectional area when a test specimen fractures or breaks under impact load, with the unit of KJ/㎡. Impact strength is used to evaluate a material’s impact‑resistance capacity or determine its brittleness and toughness; hence, it is also known as impact toughness.

Talc is a typical natural layered hydrous magnesium silicate mineral. As a core variety of non‑metallic mineral resources, it is widely applied in coatings, plastics, ceramics, cosmetics, new materials and many other fields owing to its unique chemical structure and stable physicochemical properties. The chemical type of talc directly determines its purity, whiteness, stability, processing performance and industrial application scenarios. The chemical classification, structural differences and compositional characteristics of talc constitute the fundamental basis for ore selection, quality inspection and deep‑processing applications.

This study takes anatase nano-titanium dioxide (D50≈0.25 μm), a widely used material in the papermaking industry, as the research object to explore the influence mechanism of the lamellar structure of high-purity talc powder (D50≈0.5 μm) on its agglomeration behavior.

In the previous two issues, we clarified the mineral mechanism of talc abrasion and the quantitative relationship between grade and abrasion value. This issue focuses on the production side, analyzing the specific damage caused by high-abrasion talc to forming fabrics, paper cutting knives and refining equipment. Combined with research findings, a full set of engineering suggestions on talc selection, quality control and production optimization are put forward.

In the previous chapter, we analyzed that magnesite impurities are the fundamental cause of abrasion generated by talc from the perspectives of mineral structure, hardness and paragenetic characteristics. In this chapter, combined with measured data from Liaoning Xinda Talc Group, we quantitatively analyze the variation law of abrasion value of talc powder with different grades, and unpack the structure-activity relationship among the three factors: talc content, magnesite proportion and abrasion value.

Talc powder is a core functional filler in the papermaking industry, widely applied in cultural paper, packaging paper and specialty paper, normally accounting for 10% to 30% of the paper’s dry weight. As the operating speed of modern paper machines exceeds 1500 meters per minute and papermaking equipment becomes increasingly sophisticated, the abrasion characteristic of fillers has become a critical factor affecting paper machine operational stability, equipment service life and production costs.

The papermaking process is the core procedure of converting pulp obtained from the pulping stage into finished paper on paper machines, mainly including web forming, press dewatering, drying, calendering and other processes.