Omya Fillers for the Building Industry
There are many different mineral fillers used in the building industry. The main ones are natural ground calcium carbonate, barium sulphate (barytes), talc, mica, and china clay (kaolin).

Calcium carbonate (CaCO₃) is the predominant filler used in adhesives and jointing compounds. Selection of fillers, as is the case with other ingredients, involves consideration of the available types and their effect on processing, product properties, and economics. CaCO₃ fillers, in one form or another, generally impart the most favourable balance of these factors.

When selecting the correct filler you need to consider the following requirements:

• Brightness
• Oil absorption
• Particle Size Distribution

The brightness or colour of fillers is of particular importance when considering the end application. In the case of grouts, OMYACARB 40 is selected due to its high brightness when compared to other fillers and as such can be used in white grouts or used in tile adhesives which may used to fix translucent tiles.

Particle size distribution is of importance when selecting a filler for use in a jointing compound. For example, CIRCAL 60/16, the main filler recommended for use in jointing compounds has a low level of fines and a minimum of larger particles. This allows maximum loading with no mudcracking or scoring.

Oil Absorption is particularly relevant for end products that require maximum loading for reduced costs but still require a high degree of flow and workability. Fillers such as OMYACARB 20, 40, 50 meet this criteria.