S1066
V.S. Chauhan, N.K. Bhardwaj
particle size of talc. However, the retention of talc of a lower particle size was critical and had an inversely proportional relationship with particle size. The decrease in the filler reten- tion in paper was due to higher specific surface area of a lesser particle size talc filler. The retention aid polymer helped in maintaining the charge chemistry of papermaking slurry and increased the filler retention.
Paper
Filler
100 120 140
123.8
123.6
122.9
122.9
0 20 40 60 80
49.3
50.0
49.2
49.7
Acknowledgements
The authors are thankful to the Director, Thapar Centre for Industrial Research & Development, Yamuna Nagar, Haryana, India for providing the facilities to complete this work. The supply of pulp, mineral fillers and other chemicals from various suppliers is also gratefully acknowledged. The first author also acknowledges the guidance received from Dr. S.K. Chakrabarti while conducting this experimental work.
Water only Wetting agent (7 kg/t)
Dispersant (3 kg/t)
Wetting agent (7 kg/t) & dispersant (3 kg/t)
Figure 8 Effect of wetting and dispersing chemicals on scattering coefficient of paper and Talc-3 filler with addition of CPAM.
dispersion technique was not having any effect on scattering coefficient of filler which was comparable for all Talc-3 fillers ( 50m 2 /kg). As the scattering coefficient of filler was compa- rable and the ash content in paper was also same, the scatter- ing coefficient of paper ( 123m 2 /kg) was comparable with the loading of differently dispersed Talc-3 fillers in paper. The dis- persion technique was not having any effect on filler retention and light scattering coefficient of paper and talc filler (Fig. 8).
References
Al-Mehbad, N.Y., 2004. Polym. Plast. Technol. Eng. 43, 963. Charnay, C., Lagerge, S., 2003. J. Disper. Sci. Technol. 24 (2), 273. Chauhan, V.S., Bhardwaj, N.K., Chakrabarti, S.K., 2012a. Can. J. Chem. Eng. (in press), http://dx.doi.org/10.1002/cjce.21708. Chauhan, V.S., Chakrabarti, S.K., Bhardwaj, N.K., 2012b. IPPTA J. 24 (1), 171. Chauhan, V.S., Sharma, A., Chakrabarti, S.K., 2011. IPPTA J. 23 (2), 171. Ciullo, P.A., Robinson, S., 2003. Paint & Coating Industry Magazine, Available online at http://www.pcimag.com/articles/print/talc- shape-and-form-meet-function [16/10/2012]. Dong, C., Song, D., Patterson, T., Ragauskas, A., Deng, Y., 2008. Ind. Eng. Chem. Res. 47 (21), 8430. Fuerstenau, M.C., Lopez-Valdivieso, A., Fuerstenau, D.W., 1988. Int. J. Miner. Process. 23 (3–4), 161. Goalard, C., Samimi, A., Galet, L., Dodds, J.A., Ghadiri, M., 2006. Part. Part. Syst. Char. 23, 154. Lee, C.H., Park, H.B., Park, C.H., Lee, S.Y., Kim, J.Y., McGrath, J.E., Lee, Y.M., 2010. J. Power Sources 195 (5), 1325. Ma¨ lhammar, G., 1990. Colloid Surface 44, 61. Rojas, O.J., Hubbe, M.A., 2005. J. Disper. Sci. Technol. 25 (6), 713. Trivedi, N.C., 1997. In: O’Shea, J.E., Hagenmeyer, Robert W. (Eds.), Pigments for Paper. Tappi Press, Atlanta, GA, p. 199. Wallqvist, V., Claesson, P.M., Swerin, A., Schoelkopf, J., Gane, P.A.C., 2009. Langmuir 25, 6909. Wilson, I., 2006. In: N. Jessica Elzea Kogel (Ed.), Industrial Minerals & Rocks, Littleton, Colorado, USA, Society for Mining, Metal- lurgy, and Exploration, Englewood, USA, pp. 1287.
4. Conclusions
The amphiphilic structure of the sodium polyacrylate en- hanced the dispersion of hydrophobic talc. The wetting and dispersing chemicals added in talc changed the rheology of talc slurry through reducing the viscosity. They also reduced the fil- ler retention due to an increase in anionicity and cationic col- loidal charge demand. The particle size distribution of talc was not affected with the addition of wetting and dispersing agents. The decreased filler retention could be compensated using poly(acrylamide) based retention aid polymer in the pulp stock. There was no effect of wetting and dispersing chemicals on the light scattering power of either paper or filler. Due to this behavior it may be concluded that the wetting and dispers- ing chemicals are not essential for the dispersion of talc for use in papermaking. The talc dispersed in water and agitation for around 30 min in the high speed agitator could be used effi- ciently for papermaking applications. The light scattering coef- ficient of both talc and paper was increased on reducing the
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