thailand is a regional hub for the plastics industry, and at the heart of this industry is the masterbatch sector. masterbatch is a concentrated mixture of pigments and additives encapsulated in a carrier resin, which is then used to color or impart properties to raw plastic during manufacturing. A critical component in many masterbatches, particularly white and filler masterbatches, is calcium carbonate. To serve this sophisticated and demanding market, a specialist calcium grinding mill has been established in the rayong province, at the center of thailand's eastern economic corridor.
this facility is designed for the production of ultra-fine calcium carbonate specifically for the masterbatch industry. the calcium grinding mill at its core is a ultrafine classifier mill, capable of producing particles at the very low end of the size spectrum. with a production capacity of six tonnes per hour, it is a dedicated line focused on quality over quantity. The raw material is premium white marble from thailand's own petchabun province, known for its exceptional brightness and purity, which is essential for producing bright white masterbatches and for ensuring that the filler does not impart any unwanted color or impurities to the final plastic product.
for high-quality masterbatch production, the fineness of the calcium carbonate is absolutely critical. this mill is configured to produce a d97 of four micrometres. at this ultrafine particle size, the calcium carbonate can be incorporated into the masterbatch at high loading levels without negatively affecting the mechanical properties of the final plastic product. It disperses perfectly within the polymer matrix, ensuring that films are smooth, fibers are strong, and molded parts have a flawless finish. The plant also has the capability to coat this ultra-fine powder to enhance its dispersibility in different polymer systems.
the production process at this thai facility is a masterclass in precision engineering. the raw marble is fed into the classifier mill, where it is ground between rotating pins and a stationary liner. The integrated high-speed classifier, spinning at several thousand revolutions per minute, creates a powerful centrifugal force that separates the particles. Only the finest particles, below four micrometres, make it through to the collection system. This requires immense precision and control, with the plant's operators constantly monitoring the system parameters. The final product is so fine it feels like face powder and is handled in a completely sealed system to prevent loss.
