Frequently asked questions for
Here are some of the most frequently asked questions with their answers from Construction Chemicals.
As you know, apart from others, organic modifications such as starch ether or cellulosic ether derivatives can negatively contribute to cement hydration, open time and water sensitivity of your cementitious products. You may need to lower the overall amount of your organic additive by partial substitution with OPTIBENT. In this case we would recommend OPTIBENT-1008, a rheology modifier, based on a natural occurring phyllosilicate which improves both, workability and anti-sag properties.
You can improve the penetration of the emulsion to the substrate by adding our BYK-3455, a fluorine-free, silicone-containing additive for improving substrate wetting and leveling properties in aqueous systems.
Highly efficient defoamer very often cause phase separation in the PU binder system. Unfortunately a more compatible defoamer does not reduce the amount of air content sufficiently which contributes to a reduction of flow. We recommend following our novel defoaming concept by using our liquid defoamer BYK-1794 in the polyol and our solid defoamer BYK-1690 SD in the component C (powder mix). For further information please refer to our guide line formulation available on request.
Apart from the binder being used, the flow properties could depend on the wettability of the aggregates/fillers but also on the air content. To increase the density and decrease air content, we would recommend BYK-S 732 as defoamer. BYK-9076 or BYK-W 996 would be recommended as wetting additive which furthermore will improve the flow properties of the system. Applied on the powder components, the latter can also help to de-dust the product. For further information please refer to our starting point formulations (SPF), available on request.
For this purpose, we would recommend OPTIBENT-NT 10 or OPTIBENT-616, both rheology modifiers based on natural occurring layered silicates. While OPTIBENT-NT 10 can slightly reduce water sensitivity of the final product, OPTIBENT-616 can help to lower raw density to a certain extend improving overall workability and anti-sag properties.
If the lump formation is related to any wetting issues of the fine binder and other fillers, OPTIBENT-616 or OPTIBENT-NT10 is recommended
Our recommendation for this application is BYK-DYNWET 800 N. This additive is silicone-free and based on alcohol ethoxylates. It improves the substrate wetting by reducing the surface tension.
DISPERBYK-199 is a VOC-free wetting & dispersing additive for aqueous coatings and adhesives as well as pigment concentrates for organic and inorganic pigments and fillers.
We recommend our OPTIBENT product range for dry mix mortar applications (i.e. plasters, renders, tile adhesives) and our OPTIGEL product range for liquid, polymer latex based construction products. Both product lines are supplied in powder form and are well known as rheology modifiers with shear-thinning application properties based on phyllosilicates for aqueous building material systems. For detailed product recommendation, please search for the individual brands.
We recommend OPTIBENT-NT 10, a rheology modifier with hydrophobic properties. Additionally, the product can help to partially substitute cellulosic ether derivatives helping to improve washability of the tiles after application of the tile grout.
Numerous defoamers are too incompatible and therefore cause phase separation in concrete admixtures. In contrast to this, BYK-1680 is a VOC-free liquid polymer defoamer, characterized by its excellent and long-lasting defoaming effect though showing a very good compatibility in aqueous polymer solutions and building material formulations.
For your purpose we would recommend OPTIBENT-6042. This product will lead to a buttery like feeling of the adhesive even at higher water amount allowing improved anti-sag properties and open time either, without harming the anti-sag properties.
BYK-1690 SD and BYK-1691 SD are solid, versatile, efficient, VOC- and silicone-free defoamers for cementitious construction material systems and are very compatible in various mineral binder systems. Even at low dosages, the additives show a consistent, good defoaming effect over a long period of time with optimum surface characteristics of the end product. Both product match the requirements for EMICODE® EC1 PLUS formulations.
OPTIGEL-WX is an excellent alkaline stable rheology modifiers which enhances low shear viscosity in order to improve storage stability and anti-settling properties of aqueous building material formulations.