Kaolin vs. Calcined Kaolin: Which is Right for Your Application?
Kaolin, also known as China clay, exists in both hydrous and calcined forms, each offering distinct advantages for different industrial applications. Understanding these differences is crucial for formulators seeking to optimize their products. NINGBO INNO PHARMCHEM CO.,LTD., as a leading supplier in China, provides both forms, enabling our clients to make informed choices.
Hydrous kaolin retains its chemically bound water within its crystal structure. This gives it plasticity and a plate-like particle morphology. In paints and coatings, hydrous kaolin is often preferred for gloss and semi-gloss finishes due to its transparency and smaller particle size, which minimally impacts gloss levels. It's also used as an easy-to-disperse filler in transparent coatings. The selection of hydrous kaolin is often driven by the need for specific rheological properties and its cost-effectiveness as a general-purpose filler.
Calcined kaolin, on the other hand, has undergone a high-temperature process that removes its chemically bound water. This calcination results in a material with increased hardness, whiteness, and opacity. The particle structure becomes more irregular and often contains internal air voids. In paints, calcined kaolin excels in matt and eggshell finishes, contributing to dry hiding and gloss reduction. Its harder particles also improve scrub resistance and durability. For applications requiring enhanced opacity and cost-effective TiO2 extension, calcined kaolin is the preferred choice.
In ceramics, the choice between the two is also critical. Hydrous kaolin provides plasticity, which is essential for shaping ceramic bodies. However, as it dries and fires, it shrinks. Calcined kaolin, having already undergone shrinkage during its production, offers dimensional stability in ceramic formulations, preventing cracking and warping during firing. It also contributes to higher fired strength and whiteness.
The paper industry utilizes both forms, with hydrous kaolin often used for its coating and filling properties, while calcined kaolin can offer enhanced brightness and opacity. In rubber and plastics, calcined kaolin's reinforcing properties and fire resistance often make it the superior choice.
NINGBO INNO PHARMCHEM CO.,LTD. understands that the optimal choice depends on the specific performance requirements of your application. Whether you need the plasticity of hydrous kaolin or the enhanced properties of calcined kaolin, we are a reliable manufacturer in China committed to supplying materials that meet your exact needs. By partnering with us, you gain access to expert advice and a consistent supply of high-quality kaolin products to buy.
Hydrous kaolin retains its chemically bound water within its crystal structure. This gives it plasticity and a plate-like particle morphology. In paints and coatings, hydrous kaolin is often preferred for gloss and semi-gloss finishes due to its transparency and smaller particle size, which minimally impacts gloss levels. It's also used as an easy-to-disperse filler in transparent coatings. The selection of hydrous kaolin is often driven by the need for specific rheological properties and its cost-effectiveness as a general-purpose filler.
Calcined kaolin, on the other hand, has undergone a high-temperature process that removes its chemically bound water. This calcination results in a material with increased hardness, whiteness, and opacity. The particle structure becomes more irregular and often contains internal air voids. In paints, calcined kaolin excels in matt and eggshell finishes, contributing to dry hiding and gloss reduction. Its harder particles also improve scrub resistance and durability. For applications requiring enhanced opacity and cost-effective TiO2 extension, calcined kaolin is the preferred choice.
In ceramics, the choice between the two is also critical. Hydrous kaolin provides plasticity, which is essential for shaping ceramic bodies. However, as it dries and fires, it shrinks. Calcined kaolin, having already undergone shrinkage during its production, offers dimensional stability in ceramic formulations, preventing cracking and warping during firing. It also contributes to higher fired strength and whiteness.
The paper industry utilizes both forms, with hydrous kaolin often used for its coating and filling properties, while calcined kaolin can offer enhanced brightness and opacity. In rubber and plastics, calcined kaolin's reinforcing properties and fire resistance often make it the superior choice.
NINGBO INNO PHARMCHEM CO.,LTD. understands that the optimal choice depends on the specific performance requirements of your application. Whether you need the plasticity of hydrous kaolin or the enhanced properties of calcined kaolin, we are a reliable manufacturer in China committed to supplying materials that meet your exact needs. By partnering with us, you gain access to expert advice and a consistent supply of high-quality kaolin products to buy.
Perspectives & Insights
Molecule Vision 7
“The selection of hydrous kaolin is often driven by the need for specific rheological properties and its cost-effectiveness as a general-purpose filler.”
Alpha Origin 24
“Calcined kaolin, on the other hand, has undergone a high-temperature process that removes its chemically bound water.”
Future Analyst X
“This calcination results in a material with increased hardness, whiteness, and opacity.”