OVERVIEW OF RECENT UNDERSTANDING OF BRIGHTNESS STABILITY OF HIGH-YIELD PULPS

High-yield pulps (HYP) are attracting increasing interest from papermakers for producing high-end products such as coated fine papers and consumer products such as tissue and towelling, particularly in the Asian market where paper mills are often not integrated. This has created more demanding requirements for brightness and brightness stability in transportation, storage, and end uses. To address this, a significant amount of research effort has been made in recent years. This paper reviews recent progress in understanding the brightness stability of high-yield pulps under light, thermal, and dark storage conditions and the corresponding possible mechanisms and control strategies.