Settling happenned because gravity forces that pulling down the heavy pigments toward the bottom part of the container. Physically, settling is depending on viscosity of the paint. The less viscosity of the paint will result in faster settling phenomena. However, the higher viscosity will slow down the process but if given more time, settling can also happen.
Below listed all the factors that can influence settling phenomena :
1. Viscosity of the system
2. Density of the pigments
3. Container size
4. Pigmentation of the system
In general there are 2 types of settling:
Hard settling are the phenomena that all paint formulators, trying to avoid. When hard settling occurs, all the pigments that settled to the bottom, pack very close to each other. Sometimes it can be hard and if it turns out to be, it will be impossible to be separated again.
Soft settling is mainly related to Hydrogen Bonding. The hydrogen bonding formation are mainly form between resin, solvent, anti-settling agent that added and also to the surface of the pigments. This hydrogen bonding will form a network in the system in order to prevent the pigment come close to each other. This kind of settling happens mainly to a system that has use an anti-settling agent. However it is still depending on the efficiency of the anti-settling agent used. An inefficient anti-settling agent will change the settlement from soft to hard settling after longer period.
Types of Anti-Settling Agent
Anti settling agent can be categorized as Organic Clay, Conventional Polyamide, Polyethylene Vinyl Acetate, Fume Silica, and Calcium Sulfonate Derivatives. Each type of anti-settling agent have their own limitation. Some are very effective, like the Organic Clay and Fume Silica, but give more disadvantages comparing to other. Some are less effective or need higher dosage, give less disadvantages, but cannot satisfied the users needs and requirements.
We recomend Touch ANSET 3000 series, as Anti-Settling agent, because compare to all the types above, Touch ANSET 3000 series have more advantages.