Ink

Ink, a substance used to paint a surface or write, was discovered by Tien-Lcheu under the rule of Chinese dynasties dating back to pre-Christian times. The first ink factory was founded in 1818 by French printer Pierre Lorilleux. Early printers made their own inks by mixing carbon black into boiling linseed oil until the desired consistency was reached.

Ink formulation basically consists of the following substances:

• Pigments • Additives • Binders • Solvents

Ink is generally divided into four categories:

• Aqueous • Liquid • Paste • Powder

Pigments

Pigments used in printing inks provide color, consistency and fluidity to the ink. When examined under a microscope, some pigments are seen to have the form of long rods, while others have small and large leaf-like shapes. A pigment particle size ranges from 0.01 to 0.1 microns. Pigment size is directly related to color development. Types include inorganic pigments, mineral pigments, metal pigments and organic pigments.

-Organic Pigments:

Their raw material is petroleum. The majority of paint pigments used in printing are organic paint pigments. For the production of organic pigments, petroleum is separated in chemical factories. This yields aliphatic and aromatic substances. They are then passed through a series of intermediate processes to obtain the raw materials for organic paint pigments. Most of these raw materials are referred to as "Azo pigments."

Binder Materials

These are resins. The purpose of using binders in ink production is to combine pigment particles, which in powder form are not suitable for printing, with the surface of printing materials, thereby creating a durable ink layer on the printing material. The types of resins used in inks vary depending on the type of printing material. First, the powder-form pigments must be converted to liquid form for printing machines. Binder materials are used to convert ink pigments to liquid form.

Primary Functions of Resins:

To enable the pigment to be transferred to paper by the printing machine and to allow it to adhere on the paper. Resins determine properties such as gloss and drying.

Solvents (Thinners)

These substances are used to increase the durability and printing degree of the ink.

Commonly Used Substances:

• Isopropyl Alcohol • Ethyl acetate • Acetone, Methyl-Ethyl Ketone • Ethyl glycol The most important functions of solvents are to dissolve resins and to reduce the viscosity of the printing ink and provide fluidity. Solvents, as in the same paint formulation, evaporate after printing and leave the environment. Solvents are also used to control ink drying.

Additives

These include drying agents, viscosity adjusting agents, adhesives and similar substances. Extenders and fillers are sometimes added to printing inks to reduce cost, extend shelf life and increase ink consistency. Some commonly used thickening agents include barium compounds, clay, barium sulfate, whiteners and silica.

Plasticizers:

Added to ink to enhance properties such as flexibility and good adhesion to surfaces. Bilge Çalışkan Kaya / Product and Service Development Manager / Aleph Trade Basic Production Scheme

Sources •THE DICTIONARY OF PAPER, 1980: Fourth Edition. American Paper Institute Inc. New York. •Forest Faculty Journal •https://chem.ku.edu/sites/chem.ku.edu/files/docs/CHEM190/printing_ink.pdf •ZX China Printing