The primary constituent of calcium sulfate whiskers is calcium sulfate (CaSO₄); in mainstream commercial products, the CaSO₄ content is typically 98% or higher.
Based on the content of water of crystallization, they are classified into three distinct types:
Anhydrous calcium sulfate whiskers: Composed of CaSO₄; these offer the greatest structural and performance stability and are the most common type used in industrial applications.
Hemihydrate calcium sulfate whiskers: Composed of CaSO₄·0.5H₂O; these exhibit excellent toughness, thermal stability, and ease of processing.
Dihydrate calcium sulfate whiskers: Composed of CaSO₄·2H₂O; these see less widespread application compared to the other two types.
These whiskers are inorganic fibrous single crystals produced from raw materials such as natural gypsum, phosphogypsum, and desulfurization gypsum. Overall, they are classified as non-toxic, eco-friendly inorganic materials and are virtually free of harmful impurities.
