Document 06G2Gq1g5K1wgNqZb1LVXGY9J

NSW ADDITIVES INDUCE TEIXOTROFY. PROVIDE SAG AND VISCOSITY CONTROL John L. Myers Technical Superintendent \ Reprint of1 paper presented in May 1969 to the Western Coatings Technology Society Meetings in Denver, Los Angeles, San Francisco, Portland, Seattle, and Vancouver, B. C. UCC 014857 NEW ADDITIVES INDUCE THIXOTROPY, PROVIDE SAG AND VISCOSITY CONTROL About twelve years ago a Union Carbide exploration geologist was tramping through central California In search of nickel or other metallic mineral deposits which would be of value to the Corporation. Although neither of us realized it in 19S7, what he found is what I'm here to talk about this evening: GALIDRIA ASBESTOS The word "asbestos" is a comtarclal term applied to several fibrous silicate minerals which are fire-proof and capable of being processed into flexible fibers. Although there are six different varieties of asbestos, chrysotile Is by far the moat common and accounts for some 90% of world production. Canada produces 1% million tons per year, while in the United States small quantities are mined in Vermont, Arizona and California. California accounts for over 50% of U.S. production. There are certain characteristics which sre unique to chrysotile asbestos, and which make it the most-used variety: 1. A lower index of refraction, 1.51 to 1.55 2. Softest and moat flexible fibers 3. Positive or cationic surface charge 4. High tensile strength, up to 800,000 pal Figure 1 compares the physical properties of the six different types of asbestos, and you will note the major disadvantage of chrysotile is poor resistance to acid. However, in spite of this, it is estimated that chrysotile asbestos is found in over 3000 applications. UCC 014858 A07714 2 The Source of CALIDRIA Asbestos Is a unique deposit located In the southern part of the Diablo Mountain range, in Fresno and San Benito Counties (see Figure 2). It is In what Is known as the Hew Idris mining district, which has long been famous as the oldest producing mercury mine in the United States. All exploration activities were centered in the nearby town of Coalinga, and the deposits became known as Coallnga Asbestos. The Coallnga deposit Is unique far several reasons, not the least being that It la thought to be the largest single mineral deposit In the world. Rich asbestos ore has been found over an area of 40-50 square miles, and to depths of over 500 feet. Conservative estimates indicate that over one hundred million tons of Chrysotlle asbestos are available. Of course Union Carbide does not control all the claims and is not the only company mining the deposit. But, based on exhaustive drilling programs, we feel that we have the richest deposits and ample ore supply for up to one hundred years of operation. Although mine owners try to keep such information confidential, Canada's ore reserves have been estimated at leas than 50 million tona. Chrysotlle asbestos occurs only in serpentine, a fine-grained rock composed almost entirely of hydrous msgneslua silicate minerals similar to chrysotlla in composition. Figure 3 depicts its crystal structure. The Canadian and most other deposits of serpentina contain chrysotlle in cross-fiber veins that ere rarely more than half an inch thick. A typical ore contains only 6-10Z fiber, of random lengths and tightly bonded together in m parallel configuration, (see Figure 4). The Coallnga deposit bears little resemblance to other serpentine bodies found throughout the world since most of the mass has been highly sheared and pulverized. It consists of soft, friable sheets and clumps of asbestos fibers, and the only ocher known ore body of this type Is the Stragarl deposit UCC 014859 A 0 7 7 'I b la Yugoslavia. In contrast to the cross-fiber arrangement of conventional ores, the Coallnga deposit occurs as a swirling mash of disoriented fibers (see Figure 5). Each fiber or fiber bundle is only in point contact with its neighbor. The "fiber assay" of the ore we process ranges from 50-60% and is all classed as short fiber, similar to a Canadian Grade 7. As mentioned before typical Canadian deposits yield varying fiber lengths, ranging from several inches down to several microns. These are designated by Canadian standards from Grade 3 (spinning fibers) to Grade 7 (shorts and floats). In addition to removing large quantities of rock from asbestos fibers, the fibers must also be classified by length. Conventional Canadian processing methods include blasting, crushing, grinding, and air classifying. Figure 6 shows the result of processing coalings ore by the very beat dry methods. Fiber bundles ara still very much in evidence and the full potential of the fiber cannot be utilized. We mine the asbestos ore by conventional open pit methods. After scraping off 10 to 20 feat of overburden, ripper-equipped bulldozers and self- propelled scrapers are used to remove the ore from the deposit. The ore is loaded into bottom-dump trailers through a 3/4-inch screen and hauled to the mill site. Because of the high production rates obtainable with a minimum amount of equipment, the mine is operated only during the suamer season. Inclement weather and poor road conditions preclude efficient operations during other parts of the year. Now let me sumaarize the unusual characteristics of the Coallnga deposit: 1. All chrysotile 2. All short-fiber 3. Random-orlentad fibers 4. Over 50% fiber content 5. About 20% moisture content A077 1 6 UCC 014860 -4 To take advantage of the unique features of the Coalings deposit, Union Carbide developed a hydraulic beneflclatlon process to provide the product shown In Figure 7. Conventional mineral processing techniques such as wet screening and grinding, are utilized; but the process is proprietary and I cannot describe it in detail. I can say that it consists primarily of three systems: rock-fiber separation, refining, and special treatment. This provides us with three basic product categories: fiber, colloidal and modified. Lets taka a close look at the fiber before we proceed to a discussion of particular grades and their various applications. It Is this individual fiber. Its purity and liberation, which makes CALIDRIA Asbestos different from any other asbestos product available today. \ You will remember from Figure 3, depleting the crystal structure of chrysotlle asbestos, that there Is a slight curvature in the configuration. This rep resents the tubular form of the fibers, which consist of about ten concentric layers of bruclte (magnesium hydroxide) and silica. The tubes have an external diameter of 26q and an Intarnal diameter of 110&. Electron micro graphs, recently made In Japan of the ends of the fibers, have proven the tubular- theory. The length of the fibers varies greatly, probably from 100 to 1000 times the diameter; but we feel that the average L/D ratio la sbout 200. This means that tha average fiber length is about 5 microns; and, from this, we have estimated that there ere 1014 fibrils in one gram of CALIDRIA 1 Asbestos. (For mathematic buffs this means thee if all the fibers in one gram were placed end to end they would stretch out 300,000 miles). But let's look at some more practical and measurable numbers and physical characteristics. From strictly geometrical considerations, an assemblage of closely packed hollow tubes with the diameters mentioned previously UCC 014861 4077 1 7 would have a surface area of 105 square maters per gram (35m2/g Internal and 70m2/g external). Based on BET-nitrogen tests, our asbestos products have surface areas of 60 to 80m2/g. This compares to 10 to 30m2/g for average Canadian asbestos, and verifies the electron microscope observations Chat there la little or no foreign material between the fibers* Also, since we use a wet process, the tube Interiors are probably cleaned out to some extant. Some interesting values are shown In Figure 8 and should facilitate a comparison between asbestos and materials with which you are more familiar. To sumaarlze, CALIDRIA chrysotlle asbestos fibers heve the following Important characteristics: 1* High surface area, 60-80m2/g 2. High tensile strength, up to 800,000 pal 3. Cationic surface charge 4. Colloidal form, average L/O of 200 5. Extremely high purity, 90-991 fiber 6. Essentially Inert 7. High temperature stability to about 700C. 8. Low refractive index, 1.51-1.55 As I mentioned previously Canadian asbestos Is classified by fiber length into Grades 3 through 7, described as follows: Grade 3 - Spinning fibre 4 Shingle fibre 5 - Paper fibre 6 - Vaste 7 - Shorts Grade 7 is divided into numerous sub-grades, such as: 70, 7M, 7R, 7T, etc.; which have slightly different characteristics. Figure 9 compares the A077 i 8 UCC 014862 ''average" Canadian Grade 7 with CALIDRIA products. Figure 10 shows all the CALIDRIA products and their major market applications. The discussion which follows, to the best of my ability, will be about products and applications of direct Interest to you. I don't know if the tape joint, or drywall industry is considered to be in the coatings field; if not, it is certainly a related area. Figure 11 shows a typical ready-mix tape joint compound utilizing CALIDRIA S-G 210. The important factor to note is that the S-G 210 content Is only one half the usual amount of asbestos used in such a formulation. Mineral content and water demand are maintained constant by increasing the inexpensive limestone > addition. Textured coatings utilize two other products: S-G 130, a coarser grind than S-G 210, and T-135, a tttanated asbestos produce. To digress just a moment, T-135 is colloidal, or High Purity Asbastos co flocculated with enetaae Tl(>2 It was the first of our modified products. Figure 12 is an electron micrograph which shows how the TIO2 particles are dispersed along the fibers. They are bound together by their opposite electrical charge and cannot be separated by mechanical energy. T-135, in Che paper industry, usually replaces TIO2 on a pound-for-pound basis with no lose in brightness or opacity. This is dua to the efficient dis persion of the TIO2 by the asbestos fibers. T-135 is just being Introduced to the texture coating fonmilators and is showing very good promise as a valuable additive. Good body and high brightness can be achieved with a single product. The potential for an asbestos/rutile product is obvious and we are working toward that end. Even though CALIDRIA fiber is very small, the particle size is presently too large for widespread application in finish coatings, UCC 014863 A0771.9 especially Interior. An application where the particle size has been adequately small to really offer some advantages is in asphalt compounds. CALIDRIA Resin Grade 110 was developed for this application, especially in automobile undercoatings, and has proved to be quite valuable. Figure 13 shows the improved thicken ing efficiency of R-G 110 in a coal tar residue (CP-524). Besides offering i good bodying at low concentrations, R-G 110 is essentially non-abrasive and meets the demanding performance of airless spray applications. Vlacoaity and thixotropy are two very important words used when talking about liquid resin systems. Viscosity, of course, is a measure of a material's resistance to flow; or, as Webster so aptly puts it: "the state of being viscous". (You can check this when you get home, but he defines VISCOUS as "having viscosity".) Webster, at least in his Collegiate Edition, avoids thixotropy completely; but it is a property which is required in a coating, so we can't ignore it. A thixotropic resin Is one which is "thin" when energy is applied, such as pimping or sprsying; but "thick" under static conditions. You might think of catsup ss thixotropic: thick In the bottle, but when you apply energy to the bottom--look out! A better example might be DuPont's Lucits paint, or approved equal, which spreads easily with just the energy from s brush stroke; although, in the can, it looks like paste. Resin-Grade 144 la a particularly effective thlxotrope and vlacoslty control agent for epoxy resin systems. Figure 14 depicts some of Its typical physical characteristics. It disperses readily In liquid rsslns and hardeners with s Cowles Dissolver or similar high-shear mixar, and over-mixing does not destroy its effect. Epoxy systems containing R-G 144 have excellent aging characteristics; and, up to 2 or 3 phr, are amazingly clear. UCC 014864 A0772C 8 Resin stability is the main reason that R-g 144 has been included as the thixotrope in the California Division of Highways specification for adhesives used in applying lane markers. Formulations for both Standard-Set and Rapid-Set adhesives are shown in Figure 15. At storage temperatures o which sometimes reach 115 F., adhesive components containing pyrogenic silica were subject to drastic changes in thixotropy and viscosity. The state found that not only did R-G 144 provide a stable resin, but it also did not detract from adhesion or strength properties. Processing advantages, including reduced cost, are also realized. Unlike some other thixotropes, R-G 144 Is effective with amine hardeners; and no amine salts are required for viscosity build or thixotropic stability. The thickening effect of different thixotropes is shown in Figures 16 & 17. Figures 18 & 19 depict the thixotropic effect of R-G 144 and two other thixotropes in epoxy and hardener respectively. With epoxy/hardener systems, each loaded with 47L R-G 144, 70 mil thicknesses can be held et room temperature; and up to 40 mil thicknesses can be held, sag-free, at 80C. Figure 20 shows the results of some of these tests. The value of R-G 144 as a thixotrope Is not limited to epoxy resin systems, as it performs equally well in many other organic systems. It is being used as a thickener for greases, bituminous mastics and sealers, butyl rubber end polysulfide sealants, heat curable vinyl plastisols, casein and phenolic adhesives, etc. In addition to viscosity control and thixotropy, R-G 144 also provides some measure of reinforcement. The first single-crystal whiskers used by man were asbestos fibers. As mentioned earlier, the tensile strength of asbestos fibrils has been A0772 1 UCC 014865 9 measured at more than 300,000 psi, as strong as the strongest filaments. But so far, strengths achieved in composites do not go beyond those achieved with glass-mat reinforcements. We have found good whisker rein forcement with R-G 144 in rigid vinyls (with excellent see-through up to 30 phr loading), nylon molding compounds, polysulfones and others. The whisker theory says that above some critical volume loading, dis continuous short fibers reinforce a given matrix as well as a continuous one of the same material. This is true because the many short fibers are in such close proximity that the central load bearing portions can transfer an applied load from one to the other without the fiber ends becoming Involved. The basic requirement for most resin systems is that the 4D ' ratio be at least 90. The R-G fiber, at 200:1, is well above the minimum; and Figure 21 depicts the superior reinforcement of VYNS (a FVC-FVA copolymer) with R-G 144 compared to two Canadian asbestos products. These data represent the first work done In this area and show the dlatinct advantages of a high purity, fully-liberated fiber product which contains 99% asbestos rather than the 60% normally contained in competitive asbestos products. Only modest Improvements are effected in several of the low cost, high volume replns such as styrenes and polyethylenes. However, very impressive results have been achieved In polymers derived from polar monomers, such as phenoxy, polysulfone and nylon. These data are tabulated In Figure 22. Dramatic increases in tensile, flexural, and impact strength are effected Mlhh additions of 15-307. R-G 144. In Nylon-6, R-G 144 imparts improvements very similar to chopped glass, at considerably less cost. Similar improve ments have also been found in Nylon 6/10 and 6/6. Although R-G 144, at high loadings, is effective in Chickling polyester A07722 UCC 014866 10 resin systems, it was apparent chat this product could not compete with existing thixotropes In such applications. Through the efforts of Dr. Steve Chwastiak of our Niagara Falls R & D staff, another "new" asbestos product vas developed. R-G 244 is a chemically modified fiber developed to provide maximum thickening efficiency and thixotropy in polyester spray-up and hand lay-up laminating resins. Figure 23 compares the thickening efficiency of R-G 244 and pyrogenic silica In a typical polyester resin. It is also a very effective thickener in vinyl resin sealants and for organosols and plastlsols used in a wide variety of adhesives, coatings, mastics and sealants. Figure 24 depicts a suggested heat-curable vinyl sealant formulation in which R-G 244 imparts a high degree of sag control and promotes adhesion. In most systems R-G 244 does not contribute color or opacity. Optimum efficiency, greatest stability, and lowest cost are obtained through Che use of sonic dispersers and high energy mixers. However, especially at low viscosity levels, R-G 244 can be incorporated with low sheer, propeller-type stirrers. Since R-G 244 imparts little, if any, color. It is being rapidly accepted as a thixotrope for polyester gel coats. The thixotropic effect which R-G 244 Imparts to a polyester resin is depicted in Figure 25. Here you will note that a high shear, where a resin would be sprayed, the viscosity Is lower than with pyrogenic silica; and at low shear, whera the resin would come to rest on a surface, extremely high viscosity is developed. This prevents sagging and facilitates the maintenance of a smooth uniform coating. You no doubt have noted during my discussion that In almost every application, UCC 014867 A07723 sag or viscosity control has been an important factor. This physical characteristic is required In almost all liquid systems, aqueous, or resinous and Including coatings, adhesives, sealants, laminates, and molding compounds And the secret to the success of CALIDRIA Asbestos la related directly to its ultimate purity and fiber liberation. X hope that through this paper X have conveyed the idea that CALIDRIA Asbestos fiber is different and that Its range of applications is limited only by your imagination. UCC 014868 A07724 . HI H to Pig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Pig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Pig. 11 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Pig. 17 Fig. 18 Fig. 19 Fig. 20 Pig. 21 List of Figures Physical Properties of Asbestos Minerals Location of Union Carbide's CALIDRIA Asbestos operation Crystal structure of ehrysotlle asbestos Electron Micrograph of Canadian Asbestos Ore Electron Micrograph of Coalings Asbestos Ore Electron Micrograph of Dry-processed Coalings Asbestos Ore Electron Micrograph of CALIDRIA Asbestos Fibers Comparative physical Properties of Well-Known Fibers Physical Properties of Chrysotile Asbestos CALIDRIA Asbestos Market Applications > TJC Ready-Mix Electron Micrograph of Tltanated Asbestos, CALIDRIA Type- T-135 Comparative Thickening Performance of Various Materials in coal Tar Residua Typical Physical Characteristics - CALIDRIA R-G 144 Epoxy Adhesives for Pavement Markers Effect on Viscosity of Various Thickeners in Bakelite Epoxy Resin ERL-2774 Effect on Viscosity of Varioua Thickeners in Bakelite Resin Hardener ZZL-0814 Effect on Thixotropy of Various Thlckners in Bakelite Epoxy Resin ERL-2774 Effect on Thixotropy of Various Thlckners in Bakelite Resin Hardener ZZL-0814 Thickening of Blsphenol-Based Resin with R-G 144 & Thickening of Amine Hardeners with R-G 144 Asbestos Reinforce VYHS-CompressIon Molded UCC 014869 A0772S Fig. 22 Fig. 23 Fig. 24 Fig. 25 Mechanical Properties of Injection Molded Samples Comparison of Thickening Efficiency of Resin* Grade 244 Asbestos with that of Colloidal Silica in Polyester Resin Typical Heat-Curable Vinyl Sealant Formulation Comparative Thixotropic Characteristics CALIDRIA R-G 244 Vs Pyrogenic Silica UCC 014870 A07726 N 8 3 <? B* Jf O h to Q js 1 g * O >r*s ttoo j09 * i* 11 Um jt ---< Qm 0 M 4 0 a 2 ato 1 a 1 s dw 4 S t u O<0 U 0ha 1 3 I'*' f HI S l 4 {0J3 to* *4 00 tj5o: i*0b Jpt(ot04o ^* 0C Jtf 3 S5 IS" 8U u09 .t9o0 :i v 43* to to 3^to -0> n .0 0u 4 w. to t* a JJ 3 r* 5 I Xw N & o Ob (0 m II c Hi * 2a ?] 900 i l< tXut1lAoobtt#o*So*9Ho---9r*tgEiottgo*f to i 2 4ttW^9Xoot'p--X>*m0 lato & ttoo H V 4 3 nb S tmo au n 9 i3 4 to J0t 9 4* 3 5& S0t*o 3900 to 4ttoo 1 5 3 4to 4 Sa s a 4 I m.teo+ S to &g 4^ ** 0 11 (O r* t1*o t**o $ 5 -B l 9 u 3* S to a ttt3toooo 1t90o t9too to to to 0 to to to to 4to 4" .to 0 to to 11 to 0 n2 01 1 1# 0to 4 0* 4 5 14 to S s d &0t 0to 2to S >i ttoo 0 to J5 2ZS * 830 0 tJ9t^0ooS4 ttp00|oo4| t0o to Aa 0 r0 5 pu99al tt00oo 4 ttoo 31 t4o v* <to A300 f9 5 tdo t039o 0M to.4to to Mto 0 009 *t^o*050 S54 m09 4m 0 44 8 *N0 ' M H t9o t0o titnoo- to 9 ? 4s t>o to 1 tt0oo 3149 1s1i 13M & ttt05S0SIooo* t<owo0tfoo*l uuttt0oo0o 0 3t0o 9U 3 jf t>o0C jt0aHort -009Qt0o 4 ttgoo ttK>oo |S 0 ttS9oo 1to to 1 4M t0tdoo ato, *aw a U0 1? 38 H tM3o 3 a 5* 30 -03to 134 445 tttooo* t0o Hai 0 .t0oK0 ttoo ttoo t0o 111 2 MO UCC 014871 AQ7727 Location of Union Carbide's CALIDRIA Asbestos operation Fig. 2 A07728 UCC 014872 FIGURE 3. C rysta l s tru c tu re o f chrysotH e asbestos. t UJ o oo x o <7> o s >xo<r CO zUJ Q > X o< 2 UCC 014873 A 0 7729 T UCC 014874 UCC 014875 Fig. 6 ' Electron Micrograph of dry processed asbestos fibe^isQ ~f 3 ^ UCC 014876 Fig. 7 - Electron Micrograph of vet processed Calidria asbestos fibrils A07733 UCC 014877 CO0 ' oo ooo ooo * o o* * o o 0* o CN GO IT) t1 o o f-- I--* o o 4% o o CO o u & 3 as 4J u <8 01 00 Lfc* g 1 o 1--*t O'*! o u CDO rs <* O t o CO 1 o *0 COMPARATIVE PHYSICAL PROPERTIES OP WELL-KNOWN FIBERS FiR o o u 41 o oCJ 3o o M 01 M s u a* _o c fl 1 o0 co w w (0 co AUJ 0 c el >s 0 w u :* z Cb. UCC 014878 tfl Q H CO W ca to < s as a M 5 *0773-4 PHYSICAL PROPERTIES OF CHRYSOTILE ASBESTOS >* ~H o <r o r*. o Ow CO <T r*- vO w >- X 1 i XX o o l 1. * 'T a Ok yQ rs. V w O o <N CN gs a tm4 r") r* o (* o CO cn CN CM wu m CN *4 V ta V) o* o** u< o N. CM oo CM g *5 Es ss tSoU>EAU-r X uC6 < 8 fi w a< oA* j m hzU M3 * 12 8z B MH t V) 5 5 3 9 UCC 014879 ^0773 CALIDRIA PRODUCT DESIGNATION S-G 100 S-G 144 S-G 130 S-G 210 HPP HPO T-135-P T-135-0 R-G 110 R-G 144 R-G 244 APPLICATION Vinyl asbestos and asphalt floor tile || II If M II t| Texture coatings, acoustic compounds Tape Joint compounds Pulp and Paper Industry \ PSP, waste treatment, pollution control PSP PSP, textured coatings Asphalt compounds, polyester pre-mix Thixotropic thickener, resin systems " " , polyester resins CALIDRIA Asbestos Market Applications Fig. 10 UCC 014880 A07736 3 a 3 o<K gooo P. C-- bi XM a i Qaups 8Hj --o1 HW O (4 oz w S CO tSn x dX X00 45 04 O o a I u03 04 >o o \ C X s 0 0 X QO .44 ce ia i <a S >* d uu d 00 a 1o I 04 4 o dO o O 44 * Mf so O CO >> 04 cm <r 1-- d d4 3 4 x(0 -o 3 4 a 4 Q. d 4 Co o4 o oo a. * o >9 o 00 H o -j00 o sO pH o 'X M3 -JCM H 4 d 5 a 00 Xto 3 0 d d 0 4a x d4 a* mo 4 U 4J Ori CQ 3 a -H c 4O 0 4 X X cr> x 4 pH UH >h U d Q 4a>N, 4OJ 44 aa J^oOo d4 XCO > 4J ->CC4DO >d jO >> A X dX>i *1 |1 4XCO CoOM ^aa3QH CQ 9Mf*4l X -4CS4O 2 ^d d4X3 4 **+M otoA S >, -i? X4* > X4a a4 pX3H ooo C0O C yd--h ppXCo4X4 44 oCM* O X4 pH sO Mo3* o JVh3P* ppHH o o 3 oO w4? Ja4CaC40030SO OXB nOO* ^0 ooi-4 XX43 X XX34XaX d CO Xo pp>HHs dd3 ofooHo ocn* o vooor oCoPMH oO . o X oo ^oH o o soo CM o pH sO -JCaXX443XHSlL 3 pftOHHi fHd0t0 d ocO u oo ^XxU4X00uOUXhdS5>.d-d4aCOCCHLxOud40DL* al x X XX XXXdX4 pH X d i d0 s d. 4X 3 4 a o 4 X4 00 4 > O x 4 X X B U4 4 CL Xa 4 . 4c4 X 4*J4 ^4J ^H X X4 4X O a* x x dX ^4 ' .a 4 Xo 4 r* dx x 4 *-44 j4: * o -Q X X4 XO 4 -32 e o x y-V x W 4w 33 3 3A e u-- oo 4 44 44 * w c c ON 4 Q d X u ^H X u d X hi $>4 LA 44 -- 4 x d -4 3 c tA w dX X od d X 0 0 O 04 3 d JS x < a Unv^ d -< ja 4 * CJ ** -- 3 9 ; u -- 0 Mm 44 o X d 44 < 3 3 -a hi <9 O U 44 >s 44 0 O o 0 O X A <9 0 X 4 4 z -- sc C* d 3 i z U a -- za - c o2 4 o o Xx 4 od y -- 3 --. o * is'4 hi s e C 4 pH x4 5 e -- a >* dd e4 4x Li CJ a z m < - jS 44 U 93 -- M 09 4a >d * dm 44 Q. 0 r-l i* X H 4 a) 3 X -- >< X h4 4 N-f d cr W s4^* eg X 4W X xO 4 Q U 91 < 4 3 hi pH V <9 00 u caJ c 4 Mw 00 4 CX X4 pJ hJ W 44 5 09 4 0 < 4 --u a 3 (23 ft* 3 b. Te5 v .a 4 1-4 H H mh 4 44 -d d << ai -- A U 9 U g 4 dV 2 --4 a 4 4 d 6 4 P--s M dd ao c H4 o2 f-4 CM C 1 u4 o4 X W5 X 4 as c d4 s X d X * pH i9-*h d a x 1 ohj o 2 0) l t0ot4 0 0* < XV (0 4 d ?s 4S 4 (0 < 0 X Xdo .U0a 2o00CoLf X-- aa X d46Ol 2HC5aL p JXX03 X --heM931i a o CXM XXo dX0X B Xd * i a hi jXX0a=0 xjX0r 0> ^3 ^>\ d* X X0 040x Xdd0 ax Q CM dd d Xhdi 4 Xd dd 0 fl XXd0 XXXdO o \oD -- # -X04 dd0c0C2 so 00u aos a zo h3i O. X hi X (9 19 <9 <9 91 BO U 99 hi hi BO 41 0 0 d d pH a B e* d X jS X X o ao z <s9 o A U o- 0 >X O A d X d 0 0 0X d Xdi X >X d 000 HP X X c 0 d dX as o C<J9 0 0X e H Xs 3 y d a 0O Oo 0 X X 9d* d d M *w X 0 0 od X VS d c rs a c < <9 CJ ** H d *p* 33 -3 M .* pH CM , cn * M3 P-9 9 2 Os O-- ---- S' Z UCC 014881 A07737 ---------------------------------------------M Fig. 12 - Electron Micrograph of. Titanated Asbestos, CALIDRIA Type T-135 A n n ~7 UCC 014882 comparative thickening performance Viscosity at 2 Rpm., cps. Thickener Added, % By Wt. Fig. 13 UCC 014883 A07739 CALIDRIA R-G 144 Typical Physical Characteristics Specific Gravity Moisture Content, 7. by Wt. Surface Area, Sq. meters per gram Reflectance, G.S. Brightness Nature of Surface Charge pH in Water (2T slurry) Bulking Value, gal./lOO lb. Oil Absorption (DOF) lb./lOO lb. Refractive Index, 25C. Aspect Ratio (Average L/D) Tensile Strength, pal* Tensile Modulus, pal* Dry Bulk Density, lb./cu. ft. (fully aerated) 2.45 2.0 max. ' 60 approx. 72-76 Electropositive (Cationic) 9.0 4.8 120 1.54-1.56 200:1 824.000 max. (281,000-436,000) 23.2 x 10 4 *1968 Modern Plastics Encyclopedia, p. 594 Fig. 14 UCC 014884 A0774C EPOXY ADHESIVES FOR PAVEMENT MARKERS RAPID SET TYPE: Package A: Epoxy Resin RESIN-GRADE ASBESTOS Titanium Dioxide Package B: Polymercaptan Hardener 2,4,6-Tri(dimethy1aminomethy1)pheno1 Alkyl Subs, polynnclear Aromatic Oil 2-Ethyl Hexanolc Acid Carbon Black RESIN-GRADE ASBESTOS Glaaa Spheres STANDARD SET TYPE; Package A: Epoxy Resin Titanium Dioxide RESIN-GRADE ASBESTOS Talc Package B: N-Amlnoethyl Piperazine Nonylphenol Carbon Black Talc RESIN-GRADE ASBESTOS Parts by Wt 100 7(56 3.00 1.62 60.00 6.00 15.00 0.20 0.05 2.00 36.36 100.00 7.31 5.00 37.64 23.16 52.00 0.22 77.37 1.00 > Fig. 15 UCC 014885 A07741 SOLIDS, PER CENT BY WEIGHT EFFECT ON VISCOSITY OF VARIOUS THICKENERS IN BAKELITE EPOXY RESIN ERL-2774 Ftg. 16 UCC 014886 AQ7742 BR O O KFIELD VISCOSITY, CPS., at 2 RPM. and 25C. 9 6 EFFECT ON VISCOSITY OF VARIOUS THICKENERS IN EAKELITE RESIN HARDENER ZZL-0314 AO7743 Fig. 17 UCC 014887 SOLIDS, PER CENT BY WEIGHT EFFECT ON THIXOTROPY OF VARIOUS THICKENERS IN BAKELTTE EPOXY RESIN ERL-2774 Fig. 18 UCC 014888 *07744 s CL <r o CN CN X UJ Q O El O QC H O X H E7FECT ON THIXOTROPY OP VARIOUS THICKENERS IN BAKELITE RESIN HARDENER ZZL-0814 Fig. 19 UCC 014889 AO774b 4 THICKENING OF BI5PHENOL-BASED RESINS 1 SliJO I WITH CAUDRIA RESIN-GRADE 144 ASBESTOS ingredient BAKBUTI UU2774 CAUDRIA Redo* Orad# 14A Asbostsa flraakflaid RVF Vinoarty. epa. X 10~* 24 hours 7 day* 30 days Room Tam par*turn 45 day* 1(90 1 'RPM. 2 20 Thixotropic Indoi CT. 1.) (a) 34 22 1.5 32 20 <b) Cb) 1.6 (b) Parti by Weight 100 100 23 RPM. 2 j 20 137 j 39 Thixotropic Indoi CT. t.) RPM. 2 20 3.5 250 53 Thi iptropic Index (T. 1.) 4.7 132 36 (b) (b) 3.6 244 54 (b) Cb) Cb) 4.5 CW 100 4 RPM. 2 20 Thixotropic Index (T, 1.) 464 87 5.3 430 76 5.7 480 94 5.1 Vortical Dratdown. mil (c) Cb) Cb) Cb) 125 (b) (b) Cb) 125 Ingredient BAKtUTK ERL.27M CAUDRIA RectoOrada 14C Aihaatee Brookfield RVF Viscosity, cpa. X 10~* 24 hours 7 day* 30 days Room Tempanitur* 45 days 100 RP*, t Thixotropic 2 20 18 3.8 om.) 4.7 16 3.7 (b) O) 4.3 (b) Cb) (b) Parts by Waijht 100 100 RPM, 2 20 1 Thixotropic IndM (T. L> 38 6.3 6.0 3 Apt*. Thixotropic 2 20 70 11 CT. 1.) 6.4 35 6.8 5.1 68 12 5.5 Cb) Cb? (b) Cb) Cb) Cb) Vortical Drawdown, mil (c) Cb) (b) Cb) <b> 2 91 122 125 100 4 Thixotropic Index 20 CT. 1.) 13 6.9 22 5.5 25 5.0 80 70 (a) Thlxotrop* Index (T. I.) vtacoalty at 2 rpm. viaeoaity at 20 rpm. (b) Net run. (e) Varttemi Drawdown; A 2-bisit wide drawdown was mad* on a hortxontel aandbtected steal panel. The panel wax im mediately reload to a vortical petition and any a*( noted. tl ntui occurred in 10 minutes, the orocoduro waa rapaatao and the thidinaaa incraaaad untU caning occurred. Tahlfi O THICKENING of amine haroeners I SUllf WITH CAUDRIA RESIN-GRADE 144 ASBESTOS Formulation . Brookfield RVF Vlacaaity, cpa. X 10-* 24 hours 7 days 30 days Vortical Drawdown Room Temperature (R. T.) 50*C. 80*C. 30 days at R. T. 30 days at 80*C, Psrta BAKBUTt Z2U0S14 . "lOO CAUDRIA Raato-Orada 144 Asbastot..................... 4 ARM. 2 20 Thixotropic Index CT. 1.) Psrta bywt BAKHJTC zrU0B20...... 100 CAUDRIA R*sIn-Orida 144 Aabastsis......................4 RPM. 2 20 Thliutispl* Index or.i.) Parti by m. BAXEUTX PU-0B54...... 100 CAUDRIA RaaiSrOmdn 144 Asbestos..................... 4 RPM. 2 20 TMxottopic Index (T.l.) 187 36 5.3 67 32 2.1 102 23 4.5 172 34 5.1 66 32 2.1 104 23 4.6 177 34 5.2 67 35 1.9 104 24 4.4 HHI wIII Mn 70 40 40 20 -- -- -- ) 40 70 j 40 40 40 - Fig. 20 40 - 40 a n 77 f UCC 014890 REINFORCED VYNS-COMPRESSION MOLDED None R-G 144 7RF9 7R05 Tensile Strength,pal. Tensile Modulus, 103 psl. Elongation, % Izod, ft-lb/in. HDT, C. Color Clarity 7600 396 2 . 0.6 63.0 Lt. Gray Clear 9000 531 3 0.5 69.9 Lt. Tan Clear 7700 470 16 0.5 64.6 Dk. Gray Opaque 7800 490 % 0.5 63.3 Dk. Gray Opaque Formulation: VYNS Teoex 5 Advastab CH-90 Advastab ABC-18 Stearic Acid Asbestos 100.00 1.20 0.50 0.75 1.00 10,00 Fig. 21 UCC 014891 A07747 MECHANICAL PROPERTIES OF IN JE C TIO N MOLDED SAMPLES 3 QO OO OO ^* ^ 9 O I 3 m ^oH o O -rt cm m I oe H >\ SB OOo I OO f\O0t . -<H"l 0u-0i Oh i-rt <T oO uo*ol T Oh <N Q * co t HH rtrt --rt oo u at I O' g Oo of. Oo rt -a- ox . S |C4 V JS Oh rtf Oi at to-f oo r-. O 00 -rt oo Lf| PH. <S rtf OH l~- <N O I U1* rt PH. m 4 OB m* o M* tm on co H2k * Q. O. rtrt HQ a.o d 0.0 jut n -40CJ0 t3a- tJ to C rtrt 00 3 S -rt e wtrt 01 ^ 3 *oD X ft en O .rtort 4) W c <u V c ot 4Irt 3 X 41 --rt ql-i 3 X 4t- irt a -brtl i UtJrt a 3> .o ? -- N H h Cb Cb M HI UCC 014892 ft ft * --BtO Db A07748 t VISCOSITY, CPS. X 10 3 (6 RPM.) SOLIDS, PER CENT BY WT. Comparison of Thickening Efficiency of ResinGrade 244 Aabestos with that of Colloidal Silica in Polyester Resin Fig. 23 A 07 74 9 UCC 014893 % TYPICAL HEAT-CURABLE VINYL SEALANT FORMULATION Ingredient BAKELITE Vinyl Dispersion Resin QYLF-2 BAKELITE Vinyl Re3in Solution VMCC "Elvacite" 2044(a) "Hycar" 1411(b) "Camel White"(c) FLEXOL Plasticizer 10-10 FLEXOL Plasticizer TC? "Monomer X-970"(d) ''Mark" LL(e) Resin-Grade 244 Asbestos "Dicup" R(f ) Per Cent by Weight 24.54 3.92 0.98 0.37 29.20 29.20 2.70 4.91 0.49 3.68 0.01 106.00 > .Dissolve BAKELITE Vinyl Resin Solution VMCC in FLEXOL Plasticizer 10-10 at about 100C. Dissolve "Elvaelte" 2044 in FLEXOL Plasticizer TCP at 100C. Mix the two solutions and all the other ingredients together in a pony, "Hobart" or similar mixer. (a) Acrylic resin; Du Pont, Wilmington, Delaware (b) Powdered rubber; B. F. Goodrich, Akron, Ohio (e) Calcium carbonate; H. T. Campbell and Son's Corporation, Baltimore, Maryland (d) Polymerizable monomer; Rohm and Haas, Philadelphia, Pennsylvania (e) Stabilizer; Argus Chemical Corporation, Brooklyn, New York () Catalyst; Hercules, Wilmington, Delaware Fig. 24 UCC 014894 VISCOSITY, CPS. X 10" k m SHEAR RATE, SEC.~l 407751 Comparative Thixotropic Characteristics CALIDRIA R-G 244 Vs Pyrogenic Silica Fig. 25 UCC 014895 TRADE JOURNAL FEBRUARY 14, 1966 A077.52 .~ UCC 014896 New type of asbestos shows advantages in papermaking Blair L. Ingalls, Tech. Service Rep., Mining and Metals Division, Union Carbide Corp. and Charles P. Klass, Associate Editor, Paper Trade Journal Unique product, when used as ingredient in furnish, has increased filler retention and save-all recovery, improved opacity, enhanced softness and helped to disperse pitch. In 1958, Union Carbide began work on an unusual deposit of chrysotile asbestos 160 miles south of San Francisco, Cal. Unlike conventional deposits that extend through the host rock, this deposit was not associated with hard, consolidated rock masses. Wet processing techniques were then developed to produce a high-purity asbestos product--grit-free and of such high brightness that it could be used in paper. In fact, radiometric deter minations have shown that this as bestos is considerably less abrasive than ordinary fillers or bleached sul phite pulp. When added to the pulper or beater, this high-purity asbestos behaves in an unusual manner. The pellets of asbestos (pellets are used for com pactness in shipping) open up and dis perse into short fibers that mix thor oughly with the furnish components. Being positively charged, the fibers then attract negatively charged furnish components, including cellulose and fines, titanium dioxide, clay, and dye stuffs. Asbestos thus improves the re tention of these components on the wire, substantially reducing the loss of solids to the white water. The presence of asbestos in the papermaking system also allows im proved recoveries of solids in the saveall. Asbestos attracts fines in the same manner as on the machine, thereby reducing the loss of solids in the mill effluent. Mills adding asbestos for retention generally use about 2Vi per cent, re placing a similar amount of clay. The improved retention provided by the asbestos also allows reductions in pig ment additions such as titanium di oxide and clay. Since the mining and metals division of Union Carbide sells this asbestos in the price range of many cellulose pulps, savings in pig- UCC 014897 A07753 3 FIGURE I--Electron micrographs (x24,000) of commercial 50 lb. offset containing 1.68 per cent TiOt and 22.5 per cent clay. Sheet at left does not contain asbestos and has densely packed agglomerates of TiOi (black) and clay (gray, angular) with large surrounding voids. Sheet at right contains 1.5 per cent asbestos and has a more uniform distribution of TiOi and clay. Thus, latter structure provides belter light-scattering efficiency. ment costs are significant. To these savings can be added the reduction in solids losses at the save-all. Effective TiO> extender An additional benefit obtained from having asbestos in the furnish is its ability to improve opacity by optimiz ing the light-scattering efficiency of titanium dioxide. Thus, less titanium dioxide is needed in the sheet to ob tain a given opacity, lowering costs. This effect is illustrated by the elec tron micrographs of commercial sheets shown in Figure 1. Ideally, the particles of titanium dioxide should be scattered uniformly throughout the sheet so that the optimum surface area and size for light scattering can be retained. Without asbestos, however, the particles tend to agglomerate, re ducing the light-scattering efficiency. By having an opposite charge, as bestos fibers attract titanium dioxide and help keep the particles distributed more uniformly than previously. Other benefits Some mills are using asbestos to prevent pitch buildup. In this way, asbestos helps keep cleaner felts and fourdrinier wires, reducing machine breaks and down time, and reduces rejections for paper blemishes. From 0.6 to 2 per cent asbestos, depending on mill conditions, has been found to prevent pitch agglomeration and keep it dispersed in a finely divided form throughout the pulp. Mills using as bestos for pitch control also have ob- AVERAGE ANALYSIS IN PAPERMAKiNG SYSTEM 50 LB OFFSET % Ti02 5.74 2.85 FIGURE 2--Average analyses in paper making system pro ducing 50 lb. offset. During the 7 hours that 1.7 per cent as bestos was added to the system, TiO-, re tention increased from 48 to 62 per cent while clay reten tion increased from 45 to 57 per cent across the wire. HEAD BOX % CLAY SHEET m^LRE DURING RUN WITH ASBESTOS TRAY 75.00 35.92 A 0 7 75 4 .16.02 15.8? HEAD BOX SHEET TRAY 4 UCC 014898 PERCENT RECOVERY IN SAVEALL AT CUDUDY EFFLUENT TiOg CLAY ASBESTOS TOTAL SOLIDS FIGURE 3--The pres ence of asbestos in this drum-filter saveall in creased solids recover ies from 44.4 to 74.1 per cent at the cloudy effluent and from 82.3 to 92.3 per cent at the clear effluent. the head box and in the tray water. At the head box, titanium dioxide and clay levels were reduced by about onethird and one-fifth respectively. In the tray water, solids were reduced by 36 per cent during the trial with asbestos. Tray-water reductions for titanium dioxide and clay were 49 and 43 per cent respectively. The presence of asbestos in the papermaking system also substantially improved the recovery of solids in the save-all. The solids content, per cent ash, and per cent titanium dioxide of the influent and effluent are shown be low: No With Asbestos Asbestos Save-ail Influent Solids, lb./1000 gal. 19-1 15.0 % Ash 45.6 38.7 % TiO, 2.42 1.41 Save-all Effluent Solids, Ib./lOOO gal. % Ash % TiO, 4.16 75.2 4.45 2.24 76.1 3.57 W BEFORE \ \\\ TRIAL DURING TRIAL WITH ASBESTOS Based on these figures, save-all re coveries improved from 78 to 85 per cent with the use of asbestos. Solids losses at the effluent were reduced 46 per cent. Of even greater economic significance, losses of titanium dioxide in the effluent were reduced by 58 per cent. Retention save-all recoveries gain tained improved retention of fillers. In addition, mills making tissues and towels have added asbestos to im prove softness. A two to four per cent asbestos content in the sheet gives improved hand feel, and its effect on sheet softness is readily measurable on Handle-o-meter and other softness measuring devices. Where economi cally attractive, asbestos allows mills to replace hardwood with stronger softwood without sacrificing softness. To date, over 100 mills have evalu ated asbestos and many are using it on a regular basis. Some of the results of this mill experience are given below. that titanium dioxide and clay reten tion across the wire improved about 28 per cent during the asbestos trial. Average titanium dioxide retention in creased from 48 to 62 per cent. Clay retention improved from 45 to 57 per cent. The average retention for as bestos during the trial was 69 per cent on the wire and 86 per cent for the overall system. This improved retention substanti ally reduced the buildup of solids in Similar results were obtained by a mill making 50-pound offset printing paper. In a four-hour trial, 2.4 per cent asbestos was added to the pulper. Clay was reduced in two steps from 27.4 to 18.0 per cent while titanium dioxide was reduced from 8.40 to 7.12 per cent. Despite these reductions, the titanium dioxide content of the reel averaged the same as before (at 5,2 per cent), indicating an increase in titanium dioxide retention from 63 to 73 per cent. The clay content of the reel decreased slightly; however, over- TABLE I--Production Run on 30-pound Towel Retention Improved 28% In one production run on 50-pound offset paper, asbestos was used to im prove the retention of the furnish components. The trial run lasted for seven hours, during which 1.7 per cent asbestos was added to the pulper, replacing 3.4 per cent clay. Figure 2 shows the titanium dioxide and clay analyses at various points in the papermaking system before and during asbestos usage. Retention cal culations from these figures indicate Basis Weight (lb./24 in. x 36 in.-- 480) Softness (Crush Test) % Stretch Wet Tensile Aged Machine Direction Cross Direction Dry Tensile (1-in. strip) Machine Direction Cross Direction Wet Tear Machine Direction Cross Direction Per Cent Asbestos in Paper 0234 30.0 2200 6.5 2.7 1.7 9.6 5-7 30 34 30.1 1700 7.4 -- -- _ -- -- -- 29.8 1680 7.2 2.8 1.5 9.3 5.5 36 42 30.4 1680 7.1 2.7 1.6 8.6 5.5 42 52 UCC 014899 AO 7 75b 5 all clay retention increased from 49 to 56 per cent, Opacity averaged 94 per cent while brightness averaged 85 per cent, the same as before the trial. AVERAGE ANALYSIS IN PAPERMAKING SYSTEM SUB 10 OPAQUE BOND A detailed analysis at the drumfilter save-all showed that asbestos also substantially improved recoveries at %Ti02 53.85 both the cloudy and clear effluents. As shown in Figure 3, asbestos improved recoveries at the cloudy effluent from 44.4 to 74.1 per cent. At the same time, recoveries at the clear effluent were improved from 82.3 to 92.3 per cent. In terms of losses, asbestos re duced solids in the cloudy effluent from 0.85 to 0.38 lb./1000 gal. At the clear effluent, asbestos reduced solids from 0.27 to only 0.11 lb./1000 gal. Opacity improved Another mill tried asbestos in hopes of improving titanium dioxide reten tion and meeting opacity specifications at lower titanium dioxide levels. The grade of paper used in the trial was substance 10 opaque register bond. During this eight-hour production run, FIGURE 4--Average analyses in papermak ing system producing sub, 20 opaque regis ter bond. During this 8 - hour production ' run, a 1.2 per cent asbestos addition in creased TiO, retention by IS per cent. HEAD BOX % CLAY REEL TRAY 1.2 per cent asbestos was added to the pulper, replacing three per cent 27.21 clay. This addition was less than the 20.72 2.5 per cent asbestos addition that the mill had planned on making. Never theless, impressive results were ob tained. The titanium dioxide and clay analyses before and during the trial are shown in Figure 4. Single-pass re tention calculations showed that titan HEAD BOX REEL TRAY ium dioxide retention increased by 15 per cent during the use of asbestos. The average asbestos retention across ^TRFIA0LRE DURING TRIAL WITH ASBESTOS the wire was 54 per cent. At the same time, tray-water and save-all effluent solids decreased markedly. Solids in the tray water declined from 35.7 to 15.5 lbs./1000 gal. while the solids in the save-all effluent dropped from 0.84 to 0.17 lbs./1000 gal. Of major significance to this mill was its ability to meet its minimum opacity specification of 74 per cent at lower titanium dioxide levels. The ti tanium dioxide content of the sheet was reduced from 10.56 per cent before the trial to 6.30 per cent with asbestos. Despite this severe drop, opacity speci fications were met with 1.13 per cent asbestos in the sheet, as shown in Figure 5. Although data on opacity before the trial are limited, the curves indicate that the asbestos-bearing sheet needed 20 per cent less titanium di oxide to obtain the same opacity as the sheet without asbestos. Thus, as bestos improved the light-scattering efficiency of the titanium dioxide. Similar results were obtained in a six-hour trial by a mill making thirty- pound pouch paper (82 G.E. bright TIME TABLE II--Production Run on 13.5-pound Toilet Tissue FURNISH PROPERTIES Softness Tensile Pine and Brake Machine Cross Machine Cross Hard Asbes Direc Direc % Direc Direc wood tos tion tion Stretch tion tion ness). A two per cent asbestos addi tion was made to the beater, replacing a similar amount of clay. The titanium dioxide addition was cut by 16.7 per cent in hopes of obtaining equivalent opacity values at reduced titanium di 1:25 20% Pine 1:45 80% Pine 15% 2:50 60% Pine Broke 20% 3:30 60% Pine Broke 20% 4:45 40% Pine Broke 20% 5:55 40% Pine Broke 80% 20% 0 4.0 3% -- 13.0 -- 37.5 2.7 1.8 -- _ ----- -- 15% 3% 6.3 14,5 32.5 5.0 1.5 20% 3% 6.3 9.0 19.3 4.7 1.6 40% 3% 6.5 11.5 22.5 4.0 1.5 40% 3% 6.0 10.0 24.4 3.3 1,5 oxide levels. Retention of titanium dioxide increased from 60 to 84 per cent with the asbestos addition. Aver age opacity during the run with as bestos was 62.6 per cent, a slight im provement over the 61.9 per cent average before the trial. Average brightness was 85.1 per cent, up q y -jslightly from 84.6 per cent before the use of asbestos.^ j-- ^ 6 UCC 014900 EFFECT OF ASBESTOS ON Ti02 AS AN EXTENDER FIGURE 5--Sub. 10 opaque register bond containing 1.13 per cent asbestos met opacity specifications at lower Ti03 levels than paper containing no asbestos. Thus, asbestos improved the light-scattering efficiency of TiOi. Softness improved 20% In this trial run at another mill, enough asbestos was added to the pulper to obtain two, three and four per cent asbestos in 30-pound towel ing. The object of the trial was to determine if asbestos would improve softness of the stock. The results are shown in Table I. Using the crush test as the measure of softness, the mill found that softness improved from 2200 without asbestos to 1680 with four per cent asbestos. (Lower values indicate improved softness.) Thus, an improvement of over 20 per cent was achieved. At the same time, per cent stretch increased from 6.5 to 7.1, and wet tear strength was improved 40 per cent in the machine direction and over 50 per cent in the cross direction. There was no significant change in either the wet tensile aged or dry tensile strength with the addition of asbestos. Another mill took advantage of the improved softness provided by asbestos by increasing its use of pine in the furnish. This mill normally used an 80 per cent hardwood, 20 per cent pine furnish, because it needed at least 80 per cent of the short-fibered hardwood to meet softness specifications of its 13.-5 pound toilet tissue. As shown in Table II, a three per cent asbestos addition was used dur ing the four-hour production run while the mill made various adjustments in its furnish. For the first three hours, pine and broke were increased to 80 per cent of the furnish. Then, for the last hour, a 60 per cent pine-broke furnish was used. The properties of the tissue are also shown in Table II. With the 80 per cent pine-broke furnish, softness de clined somewhat according to Handleo-meter readings. (Higher values indi cate reduced softness.) When the pine and broke in the furnish were reduced to 60 per cent, softness values began to return to pre-trial conditions in the machine direction and were better than before the trial in the cross direction. Per cent stretch and tensile values went through similar cycles. Based on this trial and subsequent tests, mill management concluded that the in creased softness provided by asbestos would allow them more flexibility in their choice of furnish components and still produce equal or better qual ity tissue. These typical examples from mill experience show that asbestos can be an effective retention agent, extender, and softening material. Proper use can lead to extensive savings and improve ments in the papermaking process. This paper contains asbestos too... The paper on which this reprint was printed contains Union Carbide's highpurity asbestos "T." The rigid opacity and brightness specifications for this high-quality paper were maintained when asbestos "T" was substituted for part of the TiO* in the furnish. This substitution allowed substantial savings in furnish costs. 407757 UCC 014901 Have you used these PELLETS These pellets of Union Carbide high-purity asbestos burst into short, non-abrasive fibers when added to a pulper or beater. The fibers disperse uniformly throughout the pulp and give these improvements and cost savings: over lOO Mills have... . IMPROVED ' * * PITCH . . CONTROL Union Carbide asbestos effectively prevents pitch buildup. In this way, it helps keep cleaner felts and fourdrinier wires, reduces machine breaks and down time, and reduces rejec tions for paper blemishes. Several mills with severe pitch problems have found that 1% asbestos keeps pitch harmlessly dispersed throughout the sheet. EFFECTIVE Ti02 EXTENDER Asbestos improves opacity by opti mizing the light-scattering efficiency of Ti02. Thus, higher opacity can be obtained at lower Ti02 levels, reduc ing Ti02 costs. A typical mill reduced Ti02 content of its sheet from 10.6 to 6.3% without any loss of opacity. F-66-042 IMPROVED RETENTION OF FURNISH Positively charged asbestos strongly attracts negatively charged pigments and fillers. A typical mill improved Ti02 retention from 65.5 to 88% with 2% asbestos and saved $3.60 per ton. Another improved single-pass re tention of all fillers by 21% with 3% asbestos. Also, the large surface area of asbestos readily absorbs dyes, im proving retention and reducing twosidedness. INCREASED SOFTNESS Tissues and towels containing Union Carbide asbestos have improved soft ness. One mill increased softness of towels by 20% with 3% asbestos. It also improved wet tear and per cent stretch. Another mill used asbestos to replace hardwood with stronger soft wood without sacrificing quality. The change also netted significant savings in furnish costs. TUTCrCr m01/14Q90029 BETTER SAVEALL EFFICIENCY With asbestos in the saveall, mills have improved their recoveries of solids, Improvements have been made in flo tation, filtration, and sedimentation types of savealls. One mill increased saveall recoveries from 74 to 93%, saving $27,000 per year. By discharg ing a clearer effluent, it also reduced river pollution. UNION CARBIDE CORPORATION MINING AND METALS DIVISION 270 Park Avenue, New York, N. Y. 212-LL1-4420 1371 Peachtree St. N.E., Atlanta, Ga. 404-876-3331 6855W.65thSt.,Chicago, III. 312-581-5000 22 Battery St,, San Francisco, Cal. 415-982-1360 UNION CARBIDE ASBESTOS AG7758 Lithographed in U.S.A.