DALLAS, TX,
Sept. 14, 2011
(Press Release) -
Paper brightness and whiteness can be influenced by the type of binder used in its coating formulations, according to a whitepaper released by Celanese. The information is significant to papermakers seeking new approaches for the cost-efficient manufacture of high brightness, high opacity paper without relying solely on titanium dioxide.
According to Phil Confalone, technical manager for the Americas, titanium dioxide will always be an important part of paper coatings formulated to impart brightness and opacity, but as its costs rise, new strategies are necessary. "One way to achieve both of these goals is to boost what is known as the void volume within the dried coating layer," Confalone said. "Hard binders such as polyvinyl acetate (PVAc) will not deform as easily as soft binders such as SBR upon calendering, thus maintaining the higher void volume necessary for maximum brightness and opacity."
Research Findings
Application scientists at Celanese conducted tests on lightweight coated paper with PVAc and SBR binders, separately and in combination with each other. The PVAc containing samples performed better in the areas of TAPPI brightness, opacity, whiteness (CIE) and yellowness (Hunter b), allowing chemists the possibility of reducing their level of TiO2 in the coatings formula. "With TiO2 becoming more expensive, paper coatings formulators are looking at PVAc as a way to curb costs and satisfy optical performance," said Confalone.
Reformulation of Paper Coatings
Celanese application chemists offer formulators of paper coatings technical assistance to optimize optical performance by using hard polymers such as PVAc latex. Specialists at Celanese Emulsion Polymers provide coating expertise on paper products ranging from lightweight coated paper to coated paperboards. For more information, request the white paper entitled "Curb Rising Titanium Dioxide Costs with Celanese Polyvinyl Acetate Paper Coatings Binders to Achieve Brightness and Opacity" by contacting a Celanese Emulsions' technical specialist at EmulsionsTechService@celanese.com or learn more about vinyl-based emulsions for paper use at www.Celanese.com/BriteCoat .
