Application of fiber loading technology to improve paper strength and optical properties of lightwieght, high opacity printing and copy paper.

摘要

Fiber Loading is a method for manufacturing precipitated calcium carbonate (PCC) directly within the pulp processing portion of papermaking by treating a fiber slurry with hydrated lime (calcium hydroxide, Ca(OH)₂) and then reacting it with a gas (carbon dioxide, CO₂) during a mixing process. PCC is a filler normally precipitated in a separate manufacturing process and added during pulp processing to reduce fiber use and create higher optical properties of the final product.; Fiber loading, PCC crystallization and its influence on papermaking were researched, especially in regards to refining and how pulp and paper properties will be affected by this process. The impact of Fiber Loading on paper manufacturing and printing processes was also investigated, including any resulting environmental effects. A commercial Fiber Loading process was developed during this research, including a study of the economic feasibility of a mill changing it's process.; The results of this research showed that precipitated calcium carbonate crystals with the Fiber Loading process have rhombohedral structure when processed below 50°C and scalenohedral structure when processed above. Fiber Loading will have a positive impact on most aspects of paper production. Fiber Loading can save 50% of refining energy if used before the refining process. It allows equal or better mechanical and optical paper properties of paper at the same filler to fiber ratio if conventional PCC and GCC are replaced with fiber loaded PCC. Because fibers are equally coated, an improved printing process is expected. Papermakers can increase paper machine performance because fiber loaded pulp has high water retention, which requires less drying energy. Fiber Loading decreases process water contamination, resulting in cleaner water systems, improved runnability, less contamination and less wear of paper mills' manufacturing equipment. This research also helped determine the best commercial manufacturing method to implement this process, allowing a high return of investments far exceeding the industry investors' expectation of 10 to 15%.