Document y9xJ7vgbV4kXeQE5Ed6ezqMX

4: D bestoswas used to replace a similar amount of day. Then the TiOj additions were reduced from 8%. to 6.8%. This resulted in an ash retention increase during the production run from 38.4% to 40.6% across the wire and from 68.1% to 71.8% overall. (Data on this analysis throughout an 11-hour period are shown in figure S.) But despite the reduction in TiOj, the ash and titania contents of the paper at the couch remained about the same as- before the trial. The TiOj content averaged 6.26% with asbestos compared to 6.12% before, and opacity and brightness were therefore kept at 92% and 81.5%, respectively.. As at the other mills, tray.water and saveall efflu ent solids were markedly reduced: What all this data point up. Carbide hopes, is something the company has claimed over the past few years -- that asbestos isn't as foreign an aid to papermaking as its industrial history would seem to imply. AVERAGE ASH ANALYSIS IN PAPERMAKING SYSTEM, PER CENT 40-LB. GOVERNMENT OFFSET BEFORE TRIAL Total solids, lbs./lOOO gallons No With asbestos asbestos Tray-water 30.3 25.5 Saveall influent 22.0 19.2 Saveall effluent 11.7 8.9 From the figures, the mill estimates that traywater solids were reduced by over 15% while losses from the saveall were slashed by 24%. Saveall re coveries improved from 47.0% to 53.7% with asbestos in the system. Asbestos' contributions apparently have not been limited to paper. Board producers also report signif icant improvements in retention by using the highpurity variety. One mill producing 28-35 pt. white vatlined chipboard increased the. retention of pigments in both the topliner and underliner, as measured by the decrease in solids in the white water. In the topliner system, 1.9% asbestos was added to the furnish without any other change in the furnish components. White-water solids were sharply reduced from 20.5 lbs./1000 gallons to 3.8 lbs./1000 gallons. As for the underliner, a 1.4% asbestos addition meant a reduction in white-water solids from 17.7 lbs./1000 gallons to 4.9 lbs./lOOO gallons. Clay addition was then cut from 3.8% to 2.5%, further reducing whitewater solids to 4.1 lbs./lOOO gallons. Besides obtain ing an improvement in pigment retention, mill per sonnel reported better smoothness with asbestos pres ent in the liner -- an improvement that could lead to better printability. MACHINE CHEST HEAD BOX REEL TRAY WATER Figure 4. Carbide's high-purfty asbestos does well also. This furnish held 2.2% of the fiber, enough to raise ash retention by 10% across the wire and 30% overall. AVERAGE ASH ANALYSIS IN PAPERMAKING SYSTEM, PER CENT 40-LB. WHITE OPAQUE STUFF BOX HEAD BOX COUCH TRAY WATER Figure 5. Paper formed during this production run con tained 3% high-purity asbestos and maintained its ash content despite a reduction in TiO, and clay additions. JULY 1966 |