Factors that affect the gloss of water-based varnishes!

The coating process of varnish is essentially the process of leveling and drying the varnish on the print

The factors affecting the gloss of water-based varnishes include the selection of polymer monomers for resin, the mixing ratio of water-soluble resin and emulsion, the leveling, viscosity, pH value and surface tension of varnishes

1 The effect of polymer monomers on the gloss of water-based varnishes

The different properties of polymer monomers have a very important influence on the gloss and other properties of the prepared water-based varnish.

The monomers that may be used in the acrylic resin of water-based varnish are: methyl methacrylate, styrene, methyl acrylate, acrylic acid-β-hydroxypropyl ester, acrylic acid,

2 Mixing ratio of water-soluble resin and emulsion

As mentioned above, the mixing ratio of water-soluble resin and emulsion has a great influence on the gloss of water-based varnish

3 The effect of leveling on the gloss of water-based varnishes

The leveling of water-based varnish is another important factor affecting its gloss, which is affected by the viscosity, pH value and surface tension of the varnish

If the varnish has good leveling, it can be quickly leveled before the coating is dried to form a smooth surface, and the coating will have high gloss; if the varnish cannot be dried before leveling, It will leave some streaks, sand holes, etc.

The key factors affecting the leveling are the leveling viscosity and drying speed of the varnish during the leveling process

4 Influence of viscosity on gloss of water-based varnishes

The viscosity of the water-based varnish has a very important influence on the coating suitability such as leveling and wetting during the coating process

5 The effect of pH value on the gloss of water-based varnish

The pH value of water-based varnish is mainly adjusted by ammonia water.

6 The effect of surface tension on water-based varnishes

The surface tension of the varnish is an important factor that affects not only the gloss but also the overall quality of the varnish
.
Because the coating of varnish is usually realized on the solid or the ink film, and their surface free energy is usually small, the surface tension value of the varnish is very different for the wetting, adhesion and penetration of the same print.
The effect of film formation after coating and calendering is also very different
.
If the surface tension value of the varnish is small, the varnish is easy to wet the surface of the printed matter, and under the action of the surface tension, it is easy to level into a smooth and uniform film surface; if the surface tension value of the varnish is large, Then it is difficult to wet the ink film on the surface of the printed matter, and it is not easy to form a uniform coating layer; when the value is greater than the surface tension value of the ink film of the printed matter, the coated varnish coating will shrink to a certain extent, even Phenomena such as trachoma appear in some parts
.

The above are the main factors that affect water-based varnish.
In addition, the solid content of water-based varnish also affects its gloss, and the effect of solid content on gloss is similar to that of viscosity
.
Generally, the solid content of water-based varnish should be controlled at 30% - 40%
.

In short, in the preparation of water-based varnishes, various factors must be considered comprehensively, and various conditions must be strictly controlled in order to obtain high-quality water-based varnishes with high gloss
.