Sodium Feldspar and Calcium Carbonate: What You Need to Know About the Plastics Industry

In the plastics industry, the choice of filler is crucial to product performance, cost and processing characteristics. Calcium carbonate and sodium feldspar are two common inorganic fillers, each with its own characteristics and showing different advantages in different application scenarios. This article will compare these two fillers and focus on analyzing the advantages of sodium feldspar over calcium carbonate.

The main difference between calcium carbonate and sodium feldspar

Chemical composition

Calcium carbonate: The main component is CaCO₃, which is a carbonate mineral.

Sodium feldspar: The main component is NaAlSi₃O₈, which is a silicate mineral containing sodium oxide (Na₂O), aluminum oxide (Al₂O₃) and silicon dioxide (SiO₂).

Thermal stability and processing performance

Calcium carbonate: It is easy to decompose into CaO and CO₂ at high temperatures (such as over 400°C), which may produce bubbles or affect the quality of products during high-temperature processing.

Sodium feldspar: It has excellent thermal stability and is not easy to decompose at high temperatures. It is suitable for plastic products that require high-temperature processing.

Optical and appearance effects

Calcium carbonate: It has high whiteness and is often used in plastic products that need to be whitened or opaque.

Sodium feldspar: Its whiteness is slightly inferior to that of calcium carbonate, but it can provide better surface gloss and transparency control, and is suitable for products with high appearance requirements.

Impact on mechanical properties

Calcium carbonate: It can effectively improve the rigidity and hardness of plastics, but excessive addition may reduce toughness and impact strength.

Sodium feldspar: Due to its higher hardness and more regular particle shape, it can significantly improve the tensile strength, wear resistance and dimensional stability of plastics, while having little effect on toughness.

Advantages of sodium feldspar over calcium carbonate

Improve the heat resistance and wear resistance of plastics

The heat resistance of sodium feldspar is better than that of calcium carbonate and it is not easy to decompose, so it is suitable for high-temperature processing of plastics, such as engineering plastics (PA, PBT, etc.). In addition, its higher hardness helps to improve the wear resistance of plastic products, such as automotive interiors, pipes and other products with high wear resistance requirements.

Improve the mechanical properties of plastic products

Because sodium feldspar contains SiO₂ and Al₂O₃, it is better than calcium carbonate in enhancing the rigidity and strength of plastics. In particular, it has advantages in enhancing the bending strength and impact resistance of plastics.

Better chemical stability

Sodium feldspar is not easily affected by acidic environments, so it has advantages over calcium carbonate in some chemically resistant plastic products (such as chemical storage tanks, pipes, etc.).

Reduce the density of plastic products

Because the specific gravity of sodium feldspar is slightly lower than that of calcium carbonate, it can effectively reduce the density of plastic products at the same filling amount, which helps to reduce product weight and improve fuel economy (especially important in automotive plastic parts).

Henan Ankai New Materials Co., Ltd. focuses on providing high-quality sodium feldspar fillers. Its products excel in improving the durability, processing stability and appearance quality of plastic products. Although sodium feldspar is more expensive, its comprehensive advantages are significantly better than calcium carbonate in certain high-end applications. When choosing a filler, it is necessary to weigh it according to specific needs and budget. The sodium feldspar of Henan Ankai New Materials Co., Ltd. is undoubtedly an ideal choice for customers who pursue quality.