Chemicals & ceramic glaze application (Part two)

Name: Goodpods
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04/03/23 • 12 min

Apparently invisible. Chemistry in ceramics.

In the previous episode, we offered a general overview on the most important chemicals normally used for ceramic glaze applications.
We went deeper by addressing all those categories that are used during the preparatory step, that is the grinding stage, moving later towards the glazing line where we focused on the so-called binders for glazes.
This episode closes the subject with a panorama about actions and benefits provided by surfactants, wetting and suspending agents, defoamers and binders usually added along the glazing line, when the production is already ongoing.

Previous Episode

Chemicals and ceramic glaze application (Part one)

The ceramic glaze application that takes place along the glazing line is one of the most delicate steps of the ceramic production process.
If you want to get high performances in terms of process and product, the glaze must be marked by proper rheological features that always change according to the application conditions of the production line.
The right formulation of glaze suspensions, therefore is a precondition for a proper application and a result without technical and aesthetic defects.
What are the most important categories of chemicals used for glaze suspensions?
How do they act, and what kind of problems do they solve?

Next Episode

Superficial halos formation during the drying process

In ceramic, the drying process takes place inside dryers where raw tiles are placed on metal supports (roller stands) for a preset time, until the residual humidity's percentage is close to 0%.
The heating to which the ceramic body is subjected leads to a migration of the water molecules and so to their evaporation.
Sometimes this process can be not completely homogeneous over the entire surface of the tile.
More precisely: the parts of the ceramic body that rest on the basket rollers may have different evaporation times compared to those areas of the tile that are not in contact with the metal parts of the dryer.
This different evaporation process can sometimes produce striped halos on the surface that may remain visible even after the drying cycle. What are the reasons and the mechanisms of the problem and what kind of actions must be previously take to avoid it?