Traditionally, paper made in North America was made in an acidic manufacturing environment, involving the use of a variety of chemicals including alum, rosin sizing and clays. Beginning in the mid to late 1980's a revolution took place as paper manufacturers began switching to an alkaline-based environment. One of the primary advantages to making this adjustment was the introduction of precipitated calcium carbonate (PCC). The primary use of PCC is as a filler when constructing the paper, providing a number of advantages. These advantages include brighter paper, better opacity, improved printability, increased thickness, and most importantly, a reduction in the amount of wood fiber required to make paper.
Another important advantage of PCC is that it is generally less expensive than the clay-fillers it has replaced. This is because the raw materials used to make PCC are lime (calcium oxide or CaO) and carbon dioxide (CO2) emitted by the mills.
Graymont has played a major role in the development of the PCC market. In addition to supplying a number of production facilities with the high quality of quicklime required for this exacting process, Graymont owns and operates two PCC plants on the west coast. Graymont has also invested in innovative transportation systems to better supply customer requirements. This includes the use of four specialized barges specifically designed for transporting PCC.