Frequently Asked Questions – Construction Chemicals

Why is polycarboxylate superplasticizer required in non-shrink grouting?

The key technical features of non-shrinkage grouting materials include strength, no shrinkage, slight expansion, high fluidity, and no segregation. Polycarboxylate superplasticizers are indispensable for achieving high fluidity, high strength, and low shrinkage.

How to judge if the defoamer is suitable for the target mortar material application?

The defoamer should be tested directly in the application system. Pay attention to a comprehensive evaluation across defoaming time, wet density, storage stability, temperature adaptability, and appearance state.

What are the main types of defoamers?

The main types of defoamers are: mineral oil-based defoamers, polyether defoamers, silicone defoamers, and polyether-modified silicone defoamers. Different types of defoamers have different characteristics.

What are the characteristics of Sunbo’s powder defoamer?

Sunbo powder defoamer products have different models, which comprehensively balance the performance of anti-foaming effect, defoaming rate, continuous defoaming time, surface uniformity, and adaptability to temperature changes.

Can Sunbo powder defoamer be used in both cement based mortar and gypsum based mortar?

Yes, Sunbo powder defoamer can be used for both cement based mortar and gypsum based mortar.

What are the possible reasons for the significant difference in the performance test results of defoamers in cement self-leveling between laboratory and construction site conditions?

If defoamer performance indeed differs significantly between laboratory and construction site, it is recommended to analyze the reasons from the following aspects:

1） Materials: Compare whether raw materials in the laboratory formulation and actual production process are accurately weighed and uniformly mixed. Check whether there are significant differences in water addition, flowability, or flow retention.

2） Application environment: Compare the temperature and humidity between the laboratory and the construction site to see if there are significant differences; Compare whether there are significant differences in temperature and humidity between the laboratory and construction site environments, as well as whether there are significant differences in the substrate, substrate preparation measures, and substrate preparation effectiveness for the application of cement self-leveling compounds.

3） Usage process: Check if there are significant differences in the operational methods for self-leveling pouring or application.

I once used a defoamer that performed very differently in winter and summer, is this normal?

The same mortar will show noticeable changes in material state with temperature changes, and defoamer performance will also vary to some extent. However, if a defoamer works normally at room temperature but fails to defoam at high or low temperatures, that indicates the selected defoamer has performance shortcomings. Sunbo's defoamers have good adaptability to environmental temperature variations.

Some defoamers have an odor. Are such defoamers environmentally friendly?

Many chemical additives have have some odor. Whether a defoamer is environmentally friendly should be determined by reference to the relevant standards and regulations in your area. This may refer to the chemical product standard for the admixture itself, the standard for the building material that uses the admixture, or regulations related to construction, interior decoration, air quality, or other environmental requirements.

What are the main types of gypsum retarders?

The main types of gypsum retarders used in the market are:

1) organic acids and their salts, such as tartaric acid, citric acid, etc.;

2) modified protein retarders;

3) modified polypeptide or amino acid retarders.

These three types differ in retarding effectiveness and in their effects on gypsum’s own properties.

Is a higher retarding efficiency for gypsum retarders always better?

Theoretically, a higher retarding efficiency indicates a higher technical level for the product. But from the user’s perspective, higher retarding efficiency means lower dosage, which places higher demands on the dosing accuracy and mixing uniformity of gypsum mortar production equipment.

What is the “linear relationship” of gypsum retarder? Is the linear relationship important?

The “linearity” refers to the relationship between retarder dosage and the change in setting time. Good linearity means the setting time changes in a regular and stable manner as retarder dosage changes. This characteristic facilitates adjustment of the gypsum retarder dosage during use, making it easier to use.