Printing ink is a general term frequently used in printing. These inks can vary depending on colourant pigments and colour-enhancing tools. Furthermore, the printing inks can differ depending on the type of print plates. These inks can be generally categorized as letterpress ink, lithographic ink, photogravure ink and template ink.
Printing ink is the preferred ink in the press which is semi-solid and dries quickly. The inks are mainly divided into eight types. These types are ink, rubber letterpress ink, tin ink, gravure ink, special gravure ink, other inks and newspaper ink. The basic composition of print inks is similar to paint. However, it varies functionally.
Lithographic ink is the most frequently preferred type of ink, also called offset ink. The ink put on a metal or resin plate is not transferred directly to the paper. But once it is transferred to the rubber surface, it can be transferred back to paper. When the flexibility of rubber is used, even if the paper surface is sparse, a good impression can be obtained with a slight print pressure.
The Features of Printing Ink
The colour expansion agent is made of phenolic resin/alkyd resin modified with resin with a boiling point of 250-300bo, vegetable drying oil and petroleum solvent. Almost all commercial prints, such as posters, calendars, catalogues and brochures, are printed with lithographic inks. Letterpress inks, including the letterpress rotary letterpress inks, are used for letterpress printing on letterpress surfaces.
Among these, the ones used for rough paper and low-grade paper are rich in mineral oil when filtered and dried. The main colour plates that use letterpress printing are clear and robust and used for high-quality art printing. The ink composition used for this process is almost the same as the lithographic print ink (sheet paper). Engraving ink is a type of print ink used for engraving rollers. Due to the low boiling point solvent of the main component of the developer, they are easy to evaporate and dry, enabling high-speed printing.
The pigments used in print inks must be light-coloured, have a high-toning power, have excellent light and chemical resistance, and not be toxic. However, the particles must be easy to knead and have a soft tone. Inorganic pigments were used in the past, but now mainly organic pigments are used. Wax, low-viscosity linen seed oil varnish, metal soap giving flexibility to the gel, dryer, antioxidants and so forth are used as supplementary items.
Titanium dioxide products in Kimteks are RC 833, RC 86, RC 823, RC 84, RC 82.
