b'INNOVATIVE MINERAL SUPPLYCould mineral additives enable the next bigCalcium Carbonate is also known as limestone or marble and can be thing in tissue innovation? provided as a wet-ground product (GCC) that has a very broad particle By Leslie McLain, Technical Support Director and David Gittins PhD, Science & Technologysize distribution, or as a precipitated Director, Imerys Performance Minerals - Americas calcium carbonate (PCC) which is a chemically synthesized product with Kaolin, Calcium Carbonate,a narrow particle size distribution and Diatomaceous Earth Since thevery specific particle morphology.Due 1800s, these naturally occurringto the nature of production, PCC tends minerals have served as keyto be lower in abrasion and may be components in the manufacturedelivered as a low solids slurry or as a of graphic paper and paper board,higher solids cake, which requires some and are highly valued for theirhandling equipment installed at the mill ability to improve paper opacity andin addition to unloading, storage and brightness. Why arent these anddelivery infrastructure. While calcium other minerals more prevalent in thecarbonate delivers high brightness and manufacture of tissue products? Upoptical properties, it can also be lower until now, production limitations inin softness and more difficult to retain materials handling, retention andFigure 1. FiberLean made using precipitated calcium carbonate (left) and kaolin clay (right). relative to kaolin clays at similar particle water treatment have prevented theirsizes, due to the level of dispersants wide use; also, certain minerals hadMinerals have long been used in theand decrease in softness of the finalthat may be associated with the high gained a reputation for unfavorableproduction of printing and writingproduct. solids slurry (GCC more than PCC).end-product attributes, like decreasedpapers as well as various paperboard softness and increased density -grades. These minerals are cost- Recent developments in microAs previously mentioned, kaolin clays no-nos in the world of tissue. effective means of displacing morefibrillated cellulose/mineral compositeand calcium carbonates are the expensive cellulose fiber, but can alsoproducts have improved the ability topredominant minerals used in cellulose Todays mineral producers haveimpart functional attributes to enhanceretain mineral as well as offset strengthbased paper applications. These evolved well past the mine-to- optical, surface and printing propertiesissues typically associated with addingminerals, along with the FiberLean market offerings of days gone by.of the finished product; which, in turn,fillers. One example is FiberLean,technology can be used to replace fiber Now minerals are engineered tocan increase the value. a patented technology from Imerysand maintain quality. But, what about meet specific product requirements,which processes cellulose fiber in thethe potential for product development? and can even be provided asHowever, widespread use of mineralpresence of minerals to cost-effectivelyCan the intrinsic properties of specialty micro fibrillated cellulose/mineralfillers has not been adopted in tissueNowproduce a very high surface area microminerals offer additional value for tissue composites which significantlyand towel production for severalminerals arefibrillated cellulose (MFC) associatedproducers?improve strength, retention andreasons, mostly due to performanceengineered towith mineral fibers via hydrogen runnability issues that wereand operational efficiencies. Somemeet specificbonding. When added to a paperDiatomaceous earth (DE) is a problematic in the past. Could theseof the reasons cited for not usingproductmaking system, these products aresedimentary rock composed of pre-crystalline compounds spark the nextmineral fillers include disruption ofrequirementsretained more easily as the MFC lengthhistoric skeletal remains of single-wave of tissue product innovation?fiber-to-fiber bonding resulting inCould thesebridges over traditional cellulose fibers.cell aquatic plants called diatoms. This article will take a look at somelower strength characteristics for verycrystallineIn almost all cases, use of FiberLeanThe shapes and structures of these of the more promising minerallightweight tissue grades, chemicalcompoundsimproves the z-directional strengthchemically inert particles are not only technologies, their properties, andcosts required to retain mineral,spark theof paper and paperboard, even atbeautiful, but they are efficient at oil the functionality they could bring tointerference with Yankee drier coatingsnext wave ofincreased filler levels. In essence, theabsorption as well as improving filtration an industry in search of the next bigresulting in increased downtime duetissue productfiller is cemented into the sheet as partprocesses. Historically used either in thing.to contamination, higher abrasion,innovation? of the composite FiberLean product. friction paper or for stickies control,88 TISSUE TECHNOLOGY INTERNATIONAL'