The theory of ink is suitable for all printing processes, but different printing processes have specific requirements. Screen printing inks, like other inks, are made by mixing and grinding pigments, resins, solvents, and additives.
1. Drying can be divided into:
1) Evaporative drying type; ink film forming and adhesion method by solvent evaporation
2) Oxidative polymerization type; method for forming ink adhesion by oxidation reaction
3) Two-fluid reaction type; ink forming film adhesion method by two-component chemical reaction
4) Ultraviolet ray curing type; Method of forming ink adhesion by chemical reaction caused by ultraviolet irradiation
Different drying inks can bring different gloss, different resistance (mechanical, chemical and weathering resistance) of the ink film after printing, as well as different drying equipments, which constitute different costs and therefore need to be carefully selected.
2. According to the type of linking material, the ink can be divided into many types. Different inks are selected for the production of different resins, which are roughly divided into epoxy resin, polyurethane, polyester, vinyl, acrylic, and rubber. Only the different materials of the substrate can be used to select inks of different resin types to avoid the adverse consequences of ink selection errors.
3. Different types of inks use the thinners provided by their manufacturers, mainly because various diluents have different solvency for different types of inks, so as to avoid producing bad printing effects.
Substrates can be printed at the same time by several types of inks. The user must choose according to the cost of the ink, the conditions after the printing, and the printing method.
In order to prevent ink delamination and pigment precipitation, thixotropy is generally provided, and the user must stir well before printing.
The curing agent, driers, and thinners must be used accurately. Generally speaking, the proportion provided in the product instruction manual is the best use ratio. The user can also make appropriate adjustments according to the printing environment and conditions. The ink with the curing agent and driers should pay special attention to its service life.
