Know Ink

- Dec 09, 2019-

It has been almost two decades since entering the carton machinery design and manufacturing industry. Because I often go deep into the carton production line, I see a lot of problems, and I often come across some very speechless problems.


Whenever the carton is abnormal in printing, 80% of the situation is this: whether it is a printing master, a supervisor, or even the first response of an executive boss is to call a machine manufacturer. Of course, I am not saying that I should not look for a machine manufacturer (I also do the machine myself, but I have no intention of excusing myself).


But before calling someone from the machine factory, have you analyzed what caused the problem? There are so many factors that can cause printing problems. Please analyze it yourself. After an effective analysis, you decide to find the corresponding supplier. Didn't you save a lot of time?


The waiting time must be money and cost, right?


How much do I say in this case? You may wish to compare.


Not much nonsense, let's talk about the embodiment of printing-ink.


What we see on the carton is not the printing plate, anilox roller, and machine, but the dried water-based ink. How to make the water-based ink better adhere to the carton when printing, we must first understand the main ingredients of water-based ink.


1. What is water-based ink:

Water-based inks are made of pigments, binders, and water as a solvent at a certain ratio. They are produced through a special processing process and have a certain fluidity. Mainly suitable for printing on flexographic printing machines and corrugated boxes.


2. Composition of ink and wash:

Colorants (6%-30%): Divided into pigments and dyes. Pigments are divided into organic pigments and inorganic pigments. It is insoluble in water and other solvents. It always exists in solid form in ink. Its role is to provide color and color density (brightness). It cannot be directly attached to paper. .


Link material (proportion 15%-35%): commonly known as the heart of ink. It determines the type, quality level and printing characteristics of ink. The pigment is evenly dispersed in the binder and transferred to the corrugated cardboard surface by an appropriate method.


Resin-coated pigment particles are printed on the printed product to make the pigment solidify and adhere to the corrugated cardboard. It provides the hardness and viscosity of ink. The resin usually exists in a solid form, but can be dissolved into a liquid when the pH value is higher than 8 and is alkaline.

3. Solvent (proportion 10%-40%): dissolve the resin in ink, dissolve the solid resin into liquid, help control the viscosity and drying speed, and make it have a certain fluidity.


Solvents are divided into true solvents, co-solvents, and pseudo solvents.


True solvents refer to organic amines, such as ammonia, monoethanolamine, diethanolamine, triethanolamine, and the like. The main role is to neutralize the acidity of the resin, making it soluble in water.


Co-solvents generally refer to alcohol solvents that help the resin to be miscible with water, such as ethanol, isopropanol, ethylene glycol, etc., which can promote the resin to better dissolve in water and can adjust the drying speed of ink.


The pseudo-solvent mainly refers to the dilution effect of water.


4. Auxiliaries (proportion 0.5% -10%): important auxiliary ingredients to adjust the quality of ink and wash. Such as antifoaming agents, antiwear agents, preservatives, etc.


All water-based inks contain the above components. For each printing requirement, some of the component ratios can be changed to readjust the adaptability of printing on corrugated cardboard.