Talc

What is Talc
Talc is well-known as talcum powder. It is a natural hydrated magnesium silicate – H2Mg3(SiO3)4. Talc is a soft, low abrasive, flat-like particle, chemically inert and organophilic material. These are reason why many paper mill use this filler. commercially talcum powder is a wide range of mineral mixtures. Hence pure talc is difficult to find. Following parameters are important for choice of talcum powder brightness, loss on ignation, fineness, moisture, pH value etc.

Advantages of Talc

• The uses of talc as a paper filler is suitable for rotogravure printing process. Two things are very important for rotogravure paper; paper smoothness and good spool formation. As talc is a flat-like particle, it helps improve the paper smoothness. The low coefficient of friction of talc helps to produce a large spool with constant tension.
• Talc is an organophilic, so absorbs impurities from the process, such as pitch, resin particles. Hence talc is used as a cleaner of the wet-end system of the paper machine. Talc also prevents agglomeration. Therefore improve paper machine runnability.
• Low cost hence it is economical.
• Good retention
• Less wire abrasion hence extends life time of the wire cloth in paper machine compare with the GCC and PCC.
• Improve dewatering.
• Lower effect on the paper strength compare with other fillers.
• As talc is organophilic it is helps to reduce dye consumption and two-sidedness in colored paper.

Disadvantages of Talc

• Higher dusting tendency during printing and in dryer section during paper production.
• Talc is a hydrophobic, hence it is difficult to preparation water-based dispersion.
• As talc is an organophilic, hence it is not suitable for offset printing. Because in offset printing process image transfer by using a hydrophilic/hydrophobic action.