Specialty Minerals Products for Plastics

Plastic products are everywhere—in our homes, our cars, our workplaces, and where we have fun. Resin manufacturers have developed whole ranges of polymers with ever increasing performance and/or economy which have helped plastics replace more traditional materials such as wood, metal and glass.

Minerals in Plastics: Functions
Minerals such as talc and calcium carbonates, are often used in these plastic products. These minerals can provide functionalities, increasing the performance of the resin, adding impact strength, flexural modulus (stiffness), faster molding cycles, dimensional stability with less warpage, sound deadening, surface finish, sandability, and thickening. These minerals are also used as cost-reducing fillers by extending or replacing the more expensive resins and making the finished products more affordable for the consumer.

Different minerals play different functions in plastics, so the decision of which mineral to use in a new plastic product depends on which performance enhancements are required.


On this Specialty Minerals Inc. (SMI) web site, there are pages that give a general introduction to the fundamentals of some of these important mineral functions: antiblocking, impact strength, stiffness/flexural modulus and polymer nucleation.

Minerals in Plastics: Resin Types
Some minerals are more commonly used in a given polymer system than others—based on performance, cost, and compatibility. This table indicates which minerals are typically used for their functionalities and which are used as cost-reducing fillers or extenders.


Specialty Minerals Products for Plastics
SMI offers a variety of mineral products for the plastics industry to enhance the performance of plastic products and composites: 

  • Precipitated Calcium Carbonate (PCC) products including ultrafine particles in the nano range, are highly functional additives that provide superior impact strength in rigid or unplasticized PVC resin systems. Their uses include window profiles, fencing, siding, thermoforming, calendared stock and foamed PVC. They are also useful as thickening and gloss-producing minerals in unsaturated polyesters.

  • Antiblock Talcs are used in polyolefin and other film applications where the talc and talc-based antiblocks confer excellent anti-blocking with low haze and high clarity. 

  • Reinforcing Talcs are fine and ultrafine talcs used in reinforced polyolefins, thermoplastic olefins (TPOs), and engineering resins for superior stiffness (flexural modulus).

  • Ground Calcium Carbonates (GCCs) and Ground Dolomites  offer resin extension and economy.