New research on the application of Haicheng talc in the paper industry (1)
I. Application Status
Talc is widely distributed in the crustal lithosphere has a large output, which can be widely used in the paper industry. Talc has chemical stability, low hardness, lubricity, lamellar structure, lipophilicity, hydrophobicity. The reasonable use of talc in the paper industry can effectively improve the performance of paper. In China, more than 50% of the talc output is used in the paper industry, its uses mainly include paper fillers, coatings resin control agents.
Talc has the following advantages when used as a filler in the papermaking process: ① It is beneficial to improve the smoothness, opacity printability of the paper; ② The wear value is small, which can extend the service life of the papermaking web; ③ The chemical properties are stable, only suitable for Acid papermaking, can also be used with calcium carbonate for neutral papermaking; ④ has a good combination with the sizing agent to keep the rubber prevent the printing ink penetrating; ⑤ has lipophilicity, can absorb organic substances, make white water pulp The material system is kept clean, as a filler, it also has the effect of avoiding resin barriers, it helps to remove the ink in the deinking of waste paper; ⑥ It has certain hydrophobicity lubricity, which can reduce the water absorption of the paper sheet. Improve the smoothness softness of the paper sheet, reduce the operational obstacles such as calendering finishing; 饰 It is conducive to stay in the paper sheet reduce the fiber consumption of tons of paper products.
Talc is used as a coating pigment. It has good fiber coverage printing effect. It can increase the whiteness, opacity, smoothness, printing gloss of coated paper, give the paper higher ink absorption, improve the quality of gravure printing. talc has lubricity, the coated paper made it can obtain high finishing on the calender reduce the amount of lubricant in the coating. However, talc also has corresponding disadvantages due to its hydrophobicity: it is difficult to wet disperse during the preparation of coatings, the resulting coatings have shear expansion properties, low retention rates, easy to cause paper powder. Therefore, some talc Surface treatment is required before use.
Due to the lipophilic nature of the talc structure, the application of talc in pulp paper can effectively control the resin anionic viscosity. On the one hand, it can adsorb the hydrophobic adhesive substances in the papermaking system, reduce the surface energy of the anionic adhesive, make it lose its unique viscosity, thereby inhibiting the adhesion, agglomeration deposition of the adhesive; on the other hand, agglomeration has occurred. Adhesives can also adsorb talc, thereby reducing the viscosity of the surface of the adhesive avoiding further agglomeration deposition.
In general, talc plays an important role in the paper industry due to its unique hydrophobic properties. How to make good use of the talc's characteristics to avoid weaknesses needs to be continuously explored.