Document QJRbv1GQNowbVJgkZz5RYxwgR

Cross Ref; Punch Card Index 621 Line Pigments Georgia Marble Co. Anil! ID MARSHALL MEMORANDUM REPORT NO. M-*H4 CC; Stuart Graves, Lab. Iji j'l K. C. Lamport, Lab. I. L. McGinnis, Lab. | 100AD]/ MARSHALL LABORATORY LIUHWll January 10, 1952 USE OF "CALWHITE" IN FLAT WALL PAINT! An evaluation of Georgia Marble Company's "Calwhite" (calcium carbonate) as a replacement for Gilders Whiting (W~90) in flat wall paints, has been completed. The results Indicate that there is no real advantage to be gained by using "Calwhite" to replace W-90* "Calwhite" seems to duplicate the performance of W-90 in every respect except that some evidence indicates the use of "Calwhite" yields marginal improvement in whiteness or brightness. This improvement is of such low order, and is so beclouded by Inherent batch-to-rbatch variation and other errors that it cannot be demonstrated statistically. Details of this evaluation are attached hereto. MARSHALL LABORATORY P. F. ROSBACH PFRtBLM l/T/52 N35436 2- - TABLE I 621-847 and Analogs (1) 2-100-U~5122 and P-10C-U-5178 controls Batches Code Name pounds/Cfal RS-315 (RS-7001) W~4l Zinc Oxide XX-55 .1971 RS-2987 (#2274) W-92 "Ti-Cal" R-31 5-7487 . RS-929 (#3027) W-90 Gilders Whiting .3942 #6981 (RS-339) W-44 Celite #110 .8869 #7228. (#6890) VI-88 Silversheen Mica . .2956 Batches shown in Brackets used in p-100-0-5178. (2) P-100-U-5132 and p-100-U"5i88 containing "Calwhites" Batches Code Kame pounds/cal. RS-315 (RS7001) W-4l Zinc oxide XX-55 .1971 RS-2987(#227^) W-92 "Ti-Calrt R-31 5.7487 DS20256(DS22962) - "Calwhite" .3942 #6981 (RS339) w-44 Celite #110 .8869 #7228 (#6890) W-88 Silversheen Mica .2956 Batches shown in brackets used in P-10Q-U-5188. (3) P-lOO-W-SlSS and P-100-U-5184 containing W-73. Batches Code Name . Pounds/Gal RS-7001 (RS315) w-4i Zinc oxide XX-55 .1971 #2274 (RS2987) VI-92 "Ti-Cal" R-31 5.7487 #1849 (#l848) W-73 "Surfex - CaCO^ .3942 RS-339 (#6981) W-44 Celite #110 .8869 #6890 (#7928) w-88 Silversheen Mica .2956 Batches shown in bracks used in p-100-W"5l84,, DUP030003320 -3- ' >:v> 1 TABLE II T, & C. FLAT (P-621-R-84784) AND ANALOGS (1) P-100~U-5130 and P-100-U-5180 controls. Batches Code Name pounds/Gal. RS-315 (RS-7001) W-4l Zinc Oxide XX-55 .3962 #2588 (#2237) -49 "Ti-Cal" R-30 5.1846 DS-22473 (DS22473) KW-3867 Celite #201 1.2226 HS-929 (#3027) -90 Gilders Whiting 1.3018 Batches shown in brackets wed in P-100-U-5l8c>. (2) P-lOO-U-5154 and P-100-U-5190 containing "Calwhite" Batches Code Name pounds/Gal. RS-315 (RS-7001) W-41 Zinc Oxide XX-55 .3962 #2588 (#2337) W-49 "Ti-Cal" R-30 5.1846 BS-224-73 (DS224735 ICW-3867 Celite #281 1.2226 DS-20256 (DS22962) "Calwhite" 1.3018 Batches shown in brackets used in P-lpO-B-5190. (35 P-100-0-5146 and P-lOO-U-5186 containing -73 Batches Code Name pounds/Gal. RS-315 (RS-7001) W-4l Zinc Oxide XX-55 .3962 #2588 (#2337) -49 "Ti-Cal" R-30 5.1846 DS-22473 (DS22473) KW-3867 Celite #281 1.2226 #3184 -73 "Surfex" - CaC03 1.3018 Batches shown in brackets used in P-lOO-U-5186. DU P030003321 -4- Experimental Details (1) Calwhite was evaluated as a pound-for-pound replace ment for V/-90 In "47" Plat (621-847) and in the improved T. & C, Plat (P-621~R~84784) . por purposes of comparison, W-73 was also tried as an equal weight substitute for W~90 in these formulas. Duplicate batches of these paints and their controls were prepared using, in most cases, different lots of pigments. All twelve paints were made by the same operator, in random order, a period of eight weeks, * (2) Previously unpainted, smooth wallboard panels, approxi mately 1-1/2} x 4-1/24, were given two coats of primer Sealer. Then, two horizontal strips (approximately 2 inches wide) were painted on each panel with plat Black (474-4248), and allowed to dry thoroughly. The twelve paints were then applied in random order to the test panels, with five minute laps and at the storraer viscosities shown in Table HI. These panels were compared for hiding, flow, leveling, flashing, sbinners at laps, sheen or flatness, and general overall appearance. Hiding was checked qualitatively by visual inspection of the paints ability to mask the black strips on the brushout panels. ov (3) Drawdowns were made in random order of these same paints with a 10 mil. doctor blade over white sections of standard hiding power charts, After overnight dry, Beckman reflectance values were determined and the color difference values relative to MgO were calculated. These values, and the results of a visual rating under a Macbeth lamp are recorded in Table III, Results (1) " Calwhite" shows marginal brightness or whiteness improvement over W-90 in the T. & C. Flat formula. However, these results probably reflect batch-to-batch variation and other errors of the test method, rather than any statistically reliable improve ment. (2) At application viscosity, all analogs appear to have about the same hiding power and show approximately the same degree of flashing or shinners at laps. The application properties of paints made with "Calwhite" appear to be identical with those containing w-90. (3) Leveling characteristics, pigment settling or separation, and general can stability appear to be unchanged when "Calwhite" is u; in place of W-90. Paints containing W-73 show somewhat higher sheen and slightly better leveling. "Calwhite" does not change the sheen. (4) Philadelphia replacement cost for W-90 is $.0067 per poundj for "Calwhite" the replacement cost is $.0111 per pound. (5) References Experiment A-117 and A-128, notebook #5337. DUP030003322 5bJ:J* -- TABLE III "47'' Plats AB CD E P-lOO-U-5122 621-847 control 1 2 78 2 3.22 P-1O0-U-5178 " " 5 4 74 3 3.17 p-lOO-U-5132 "Calwhi'te" replaced W90 8 9 76 5 3 *89 P-1CO-U-5188 ", " " 12 12 78 3 3.13 P-lOO-V-5182 W-73 replaces W-90 4 5 78 4 3.17 P-100-U5l84 " " " 7 7 So 1 2.92 T. & C. Flats P-100-0-5130 P-621-R~84?84 control 11 8 78 5 3-56 p-ioo-u-5180 " " 10 1 78 2 3.20 P-lOO-U-5134 "Calwhite11 replaces W-90 3 3 78 2 3.12 p-lOO-U-5190 " " "6 10 76 1 2.94 P-100-tJ-5146 W-73 replaces W-90 9 6 78 1 2.91 P-lOO-U-5186 W-73 " W-90 2 11 80 1 .2.64 A Order of* brushouts B " " drawdowns C Stormer viscosity when brushed D Visual rating for whiteness (lebestj 5worst) E Color difference calculated from Beckman reflectance values relative to MgO. (A difference of 0.2 units is usually apparent by visual inspection and the lower the figure the better the whiteness. On this scale the whiteness of MgQ Is sera). DUP030003323