SMI: Benefits of PCC

Benefits of Specialty Minerals Precipitated Calcium Carbonate (PCC)

Specialty Minerals (SMI) offers the papermaker a family of distinct precipitated calcium carbonates (PCCs) with unique properties and functionalities for optimizing graphic paper and paperboard. Our PCC is available in a number of configurations involving particle size, shape, size distributions, surface area and surface chemistries to address a number of paper making concerns. PCC, when used as an additive, can replace costly pulp, increase sheet brightness and opacity, produce more bulk, and enhance coating gloss, smoothness, and more.

When paper makers use PCC in their paper manufacturing operations, machine speed and productivity are likely to increase. The positively charged surface of the PCC particle helps its attraction to the wood fiber thereby increasing first pass retention. Further, precipitated calcium carbonates exhibit a sharply defined particle size distribution showing a lack of particles at the fine end. This characteristic also increases retention. Likewise, water drainage is improved and machine speed can be increased. More tons out the door mean lower manufacturing cost per ton.

When PCC or ground calcium carbonate (GCC) is used, the papermaking system must operate in a neutral or alkaline pH condition. Papers made under these environments are less prone to the degradation often seen as the yellowing and brittleness of acid made papers.

PCC adds gloss, whiteness and opacity to paper coatings. Often PCC or GCC are not used as the sole pigment but are incorporated as blends of themselves or with other minerals (e.g. kaolin). Opacarb^® coating PCC products have been used on high speed coating machinery around the world. The outstanding rheology of this PCC allows for excellent runnability.

Printers like papers coated with PCC. The ability to control coating layer pore size, (ideally 40 to 80 nanometers for print) and volume, allows for control of fountain solution acceptance, better ink trapping, controlled ink setting and reduced blister potential in drying. Precipitated calcium carbonate increases color intensity, brilliance, and resolution in high quality printing papers. Benefits include ease of handling and formulation, excellent runnability and exceptional print quality.

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