Coating: hollow pigments, higher solids: new technology using high solids hollow spheres with a binder can help increase solids levels in coating formulations.Industry studies indicate that higher solids levels in coating formulations offer many advantages, including faster operating rates and improved gloss and opacity Refers to being "opaque," which means to prevent light from shining through. For example, in an image editing program, the opacity level for some function might range from completely transparent (0) to completely opaque (100). . These advantages result from several factors. Faster operating rates. With higher solids levels, drying is easier. Paper mills can operate their coaters at higher speeds while maintaining target moisture, since there is less moisture to remove from the formulation. Mills can produce additional tonnage without spending more capital. (Figure 1 shows how much impact an increase in formulation solids can have on sheet moisture and ultimately line speeds.) [FIGURE 1 OMITTED] Improved gloss and opacity, with higher solids levels, paper mills receive better coating holdout hold·out n. One that withholds agreement or consent upon which progress is contingent. Noun 1. holdout - a negotiator who hopes to gain concessions by refusing to come to terms; "their star pitcher was a holdout for six , which can lead to increased sheet gloss. This improved coating holdout can also give papermakers the flexibility to calender CALENDER. An almanac. Julius Caesar ordained that the Roman year should consist of 365 days, except every fourth year, which should contain 366, the additional day to be reckoned by counting the twenty-fourth day of February (which was the 6th of the calends of March) twice. with less pressure, which improves opacity. (Figures 2 and 3 show examples of how a 2% increase in formulation solids can allow papermakers to calendar less to reach a target gloss, and how this can translate into an improvement in opacity.) [FIGURES 2 & 3 OMITTED] One way to increase solids levels in coating formulations is to use hollow plastic pigments. For example, Dow Chemical's new HSB (Hue Saturation Brightness) A color space that is similar to the way an artist mixes colors by adding black and white to pure pigments. The pigments are the hues (H), measured in a circle from 0 to 359 degrees (0=red, 60=yellow, 120=green, 180=cyan, 240=blue, 3042NA high solids hollow pigment (applied with a binder product) is produced at 42% solids level, a 6% higher solids level than could be obtained with a simple blend of hollow and latex products. The actual solids increase in coating formulations depends on the level of plastic pigment papermakers use in their formulations. Overall, papermakers can expect to achieve about 2% higher solids levels in formulations. Dow developed HSB 3042NA using its hollow sphere technology and its S/B S/B Should Be S/B Seen By (UK medical reporting) S/B Standby S/B swing/by S/B Signal to Background (ratio) S/B Switch Board S/B Sand Blast S/B Soil/Bentonite Latex technology. The S/B-type binder is included in the product to help obtain higher solids levels. The hollow plastic pigment contributes to a smoother and glossier coated sheet. The pigment is also ammonia-free, which is particularly desirable where low odor levels are necessary. Note: More information about higher solids coating formulations is available from Dow at the TAPPI TAPPI Technical Association of the Pulp and Paper Industry Coating Conference, May 11-14, 2003 in Chicago, Illinois, USA. About the author: David Wolfe  The of this article or section may be compromised by "weasel words".You can help Wikipedia by removing weasel words. is application development leader, Emulsion Polymers business, The Dow Chemical Co., Midland, Michigan, USA. Contact him by email at dlwolfe@dow.com, or by phone at +1 989 636-9124. |
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