Starch-modified fillers for linerboard and paper grades: A perspective review

High-filler-content paper is a growing research and development opportunity in papermaking. These new products must address traditional paper product properties while providing papermakers with distinct product platform benefits. Over the past decade, a research team involving researchers from the Institute of Paper Science and Technology at Georgia Institute of Technology and from Imerys have significantly advanced the application of starch-encapsulated papermaking fillers. This review summarizes these accomplishments from initial laboratory studies to mill trials. Laboratory results have illustrated that starch-encapsulated fillers can facilitate a near-doubling of filler content over conventional levels at equal tensile and z-direction tensile (ZDT) values. Equally important is that the use of starch-encapsulated kaolin (SEK) filler has been shown to facilitate a doubling of filler addition rate without any detrimental impact on ring crush compared with control studies with filler. Pilot-plant and mill trials have shown that SEK can function as a fiber extender, reduce steam demand for drying by 10%, and increase papermaking speeds and production rates.