Printing Pigment - Use of Pigment for Printing Inks

Categories of printing pigments

1. Water-based pigments: they are usually applied in paper printing andpackage printing. They are used more and more widely as they are non-toxic and environmentally friendly.
2. Solvent-based pigments: they are usually applied in plastic film printing and metal printing. They have high light fastness and are not prone to fading.
3. UV curing pigments: they are solvent-free pigments, featuring fast drying, high abrasion fastness, high resistance to bond, etc. They are usually applied in coating, printing, etc.
4. Metallic pigments: they are made by mixing metal powder and resin binder or wetting agent.They are usually applied in package printing.
5. Pigment pulp: it is a kind of high-concentration colorless,transparent and viscous liquid. It can be applied into other pigments for darker colors or higher gloss.

Printing pigments are applied in various printing sectors, usually in commercial printing, package printing, paper printing, plastic film printing, membrane printing, stamping, etc.

Appropriate printing pigments should be used based on pigment categories, printing materials and printing methods. Oil-based printing pigments are suitable for pressure and intaglio printing, water-based printing pigments for paper and package printing, and plastic printing pigments for plastic paper, composite and metal printing, etc.

Printing ink is a kind of uniform mixture that is composed of colorant (e.g. pigment and dye), binder, filler, additive, etc. It can be printed and dried on printing media. Printing ink is also a kind of color pulpy adhesive with fluidity. Therefore, three important indicators of printing ink are the color (hue), physical properties (consistency, fluidity and other rheological properties) and drying performance. Various printing inks are different from each other in physical properties. Some of them are thick while some are not. The binder is vegetable oil in some printing inks, or resin and solvent or water in other printing inks. These factors depend on the printing stock, printing method, printing plate, drying method, etc.

• Water-basedprinting pigments

Water-based printing pigments are environmentally friendly, non-toxic, tasteless and easy to dry, so they are widely applied in printing of lightweight packages of food, medicine, etc. In addition, water-based printing pigments are suitable for printing of various materials due to bright colors, easy fitting, etc. However, water-based printing pigments have lower durability than oil-based printing pigments. As they are easily affected if soaked in water, UV printing protection measures should be taken.

• Oil-based printing pigments

Oil-based printing pigments are suitable for outer package printing as they are durable and not easy to peel. However, oil-based printing pigments have the disadvantages of slow solvent volatilization and serious environmental contamination, so environmental protection should be taken into account during printing.

• UV printing pigments

Due to fast drying, high printing speed and other advantages, UV printing pigments are suitable for prints with speed and quality requirements. With high precision, high speed and high efficiency, they are especially suitable for large-scale printing of high-quality color patterns, and special safety measures should be taken to prevent UV radiation.

In short, printing pigments should be used considering printing materials, patterns, etc. Using appropriate printing pigments will have better printing effects.