The solvent used for the connecting material is water first, but pure water (sterile water) is needed. Alcohols are mainly isopropanol, ethanol and so on. Water accounts for the main component, while alcohols only account for 5% to 6% or 20% to 30% of water, depending on the types and properties of resins and pigments. The use of alcohols is mainly to assist water to enhance the ability to dissolve resins and improve the dispersibility of pigments and dyes, and can accelerate penetration and inhibit foaming. Cellosolve and glycol can adjust its dryness.
Commonly used auxiliary solvents are alcohols, glycol ethers (such as cellosolve) and glycols. Two issues must be paid attention to when using these auxiliary solvents, namely the influence of solvent volatilization on solubility and flammability.
1. Alcohol solvent
(Alcohols evaporate much faster than water, so the solubility of inks that use alcohols as auxiliary solvents depends on the content of alcohols, and there will be problems with viscosity and solvent balance during printing.
After adding an alcohol auxiliary solvent to the water-based ink, its burning point will decrease, and a small alcohol concentration will reduce the burning point of the water-based ink a lot, which must be paid attention to when adding the auxiliary solvent.
2. Glycol ethers
The different ratio of water and cellosolve (ethylene glycol monoethyl ether) mixture will change its ignition point, so be careful when using it.
3. Dihydric alcohols
Such as propylene glycol or ethylene glycol. The mixture with water has little effect on the ignition point, so when this type of solvent is used as an auxiliary solvent, there is no problem of flammability.