Formula for making inkjet ink
Inkjet ink and cartridges are a staple in any office, and in many homes. While all inks serve the same purpose, the quality of the ink can differ greatly from one manufacturer to another. Find out more about what's inside inkjet ink.
The Ink Recipe
Although there are many variations to the inkjet ink formula, the basic components of this ink are: water, colourant, humectants and co-solvents, fixative, surfactants, resin, biocides/fungicides, and buffering agents.
The Key Ingredients
Water, colourant, co-solvents and humectants are the basis of all inkjet ink, regardless of quality. It is the quality and amount of each component that determine the level of performance. Water, which makes up 50 to 90 per cent of the mix, is what dilutes the colourant and other chemicals to make the ink spread thinly and evenly as it is distributed from the cartridge. Purity of the water used is crucial in developing a formula that won't be contaminated, causing quality and performance issues.
Colourants (dyes or pigments) can vary widely in quality and style. Specific dye and pigment combinations determine the levels of all other chemicals to be used in manufacturing inkjet ink. Lower quality colourants make it more difficult to render a good ink. A variety of tests are used to determine a colourant's viscosity, pH, colour matching and other factors that determine its final performance quality.
Co-solvent and humectants are used to prevent or deter evaporation of the water-based formula. As evaporation occurs at the print head, the formula and viscosity of the ink can alter unfavourably. To control or prevent this change, humectants, such as glycol, are added to the formula in varying degrees.
The Finishing Touches
Other agents and chemicals are blended with the three major components of the ink formula to create a final product that spreads and dries evenly and adheres to the paper without flaws, such as feathering. Biocides, fungicides and buffering agents are used to keep the ink free from bacteria and fungi that might alter the formula and control the pH balance that is required for long term storage. Carefully monitored levels of fixative and penetrant materials are added to assist with delivery of ink to paper, and to control just how much ink adheres to the surface. Surfactants control the consistency of the ink, and allow it to flow smoothly through the cartridge. Too little surfactant might cause the ink to gum up inside the cartridge, while too much surfactant would loosen it up and then cause it to drip out. Resins are sometimes added to control the durability of the printed character after it has dried on the paper.
Getting it Down to a Science
Making inkjet ink is an exacting process that has been modified and improved as printers change. The ink must be able to function without causing damage to the print heads. Research and development are ongoing processes in the ink industry. Precise testing methods are developed and implemented to ascertain the quality and functionality of the ink. Everything from the water to the colourant is run through several tests to ensure the highest levels of purity. New formulas are constantly being created that improve upon the finished product.
While many things can be made at home, inkjet ink is probably not one that should be attempted. The development and manufacturing of inkjet ink is a complicated process that requires many elements not available directly to consumers, without considerable cost. While the price of inkjet cartridges has declined over the years, this is due to manufacturers being able to streamline the process and develop faster methods of production.