What Is an Industrial Ink?
Industrial Ink is a type of ink used in industrial inkjet printers and printing machines.
Since printing on a wide range of materials is required for industrial use, a variety of pigments and dyes are included.
Applications of Industrial Inks
Industrial products may require various types of printing, such as lot numbers, quality markings, and inspection stamps. Stamp marking inks are used for printing on various materials, including metal, plastic, paper, cardboard, ceramics, glass, wood, cloth, and leather.
Industrial inkjet printers are also used in diverse applications such as commercial printing, textiles, and building materials. Major applications include sign graphics; textile products such as digital textile printing, DTG, and banner flags; 3D modeling such as models, parts, and molds using UV curable resins and plaster; and name tag, label, and metal can printing. Diverse types of ink for inkjet printers are available to suit these product materials.
Principles of Industrial Inks
1. Inkjet Printing
In industrial production, industrial inkjet printers are used to print many products. Inkjet printing with inkjet printers is a printing method in which images are drawn by applying liquid ink drop by drop.
Ink for inkjet printers is composed of colorants such as dyes and pigments dissolved in a solvent. Pigments are large particles that remain on the surface of the object without penetrating it, while dyes are colorants that soak into and penetrate materials like paper. Pigments print clearly and vividly, while dyes can be mixed to produce delicate colors and gradations. Solvents include volatile organic solvents such as MEK (methyl ethyl ketone), ethanol, acetone, water, and other organic solvents.
Other agents found in ink include penetrating agents (which lower the surface tension between paper and ink to facilitate ink fixation on paper), anti-drying agents (which prevent ink from drying out and clogging the print head), pH adjusters, preservatives, and fungicides. These auxiliaries are necessary to maintain ink quality and print quality.
2. Ink for Stamp Marking
Ink used for printing lot numbers and other information is called a stamp marking ink. It is used for stamp marking and is used in the same way as general stamp inks. There are oil-based pigment-based, oil-based dye-based, water-based pigment-based, and water-based dye-based inks, and they are used according to the material to be stamped. Inks used on non-absorbent material surfaces are solvent-based dyes. There are also special inks. In addition to the ink itself, some inks are sold as ink pads impregnated with ink.
Types of Industrial Inks
Industrial Inks are available in a variety of basic colors, such as black, white, red, blue, yellow, and green. In addition to classification by colorants such as dyes and pigments, there are also different types of inks depending on the solvent used, such as water-based inkjet inks, solvent-based inkjet inks, and UV-curable inkjet inks. Since the materials suitable for printing differ depending on these different solvents, care must be taken when making a choice. In addition, some solvent-based inkjet inks are quick-drying and others are not, depending on how easily the solvent volatilizes.
1. Water-based Ink
Water-based ink uses purified water as the solvent. Unlike organic solvents, there is no adverse effect on the human body and no concern about environmental pollution, but compared to methyl ethyl ketone and ethanol, it has a longer drying time and is more difficult to dry. Therefore, printing is limited to permeable materials such as paper. This ink is suitable for continuous forms, commercial printing, cardboard, flexible packaging, labels, etc.
While water-based ink is the most commonly used ink in inkjet printers for office automation, water-based ink is less commonly used in industrial inkjet printers. In addition to water and colorants, additives such as moisturizers, penetrating agents, pH adjusters, and preservatives are included.
2. Solvent-based Inks
MEK (methyl ethyl ketone) is mainly used for fast-drying solvent-based inks. Inks using methyl ethyl ketone dry and solidify quickly, so they can only be used in continuous inkjet printers that constantly circulate ink. Because it dries and solidifies quickly after printing, it can be used to print on non-permeable materials. In addition, inks containing methyl ethyl ketone are designated as Class 4 Hazardous Substance, Petroleums No. 1 (non-water soluble liquid).
Ethanol and acetone are used for solvent-based inks that do not contain methyl ethyl ketone. Ethanol is a solvent that takes longer to dry than methyl ethyl ketone, but is used in food packaging and other applications because of its volatility and lack of risk of chemical contamination. Acetone, although flammable, dries more quickly than methyl ethyl ketone and is used for printing on soft packaging materials such as plastic wrap. Demand for such solvent-based inks that do not use methyl ethyl ketone is increasing due to safety measures and cost reductions in complying with regulations.