Stay strong with our defoamers
Not just hot air
The entrainment of uncontrolled air into cement and gypsum based mortars is unavoidable and leads inevitably to a loss of quality in high performance systems. Undesired air voids weaken the system resulting in lower mechanical strength and reduced abrasion resistance. In addition, surface air voids often compromise the desired quality requirements of a product.
Defoamers are preferably used for the prevention and
removal of large air inclusions at the concrete’s surface and
for rapid foam collapse in aqueous formulations. If, on the
other hand, it is necessary to remove finely distributed air
from a system, deaerators are the preferred alternative.
However, practice has shown that a clear differentiation
between defoamers and deaerators is usually not possible.
Most defoamers also have a deaerating effect to some
extent and vice versa.
How defoamers work can be best explained in the images below. Defoamers and deaerators are active at the air/water
interface; they cause the stabilized structure of air voids to rupture in a liquid medium, thus allowing air to escape.
Defoamers are characterized by:
Low surface tension
Insolubility in the formulation to be defoamed
Positive spreading coefficient
Positive penetration coefficient
Optimized aesthetics with improved durability
External appearance and mechanical strength play a crucial role nowadays,
with architecture being more sophisticated and creative than ever.
With the SITREN AirVoid® brand, we offer highquality defoamers that allow air voids to be selectively removed from the system. This not only results in easier workability and an optimized surface finish but also in higher mechanical strength. Mortar systems defoamed with our products meet the highest demands of aesthetics and durability.
Floor systems (e.g. leveling compounds, screeds and decorative coatings)
Grouts (e.g. masonry mortars and joint fillers)
Grouting and repair mortars
Thermal insulation systems (EIFS/ETICS)