Choosing the Best Powder Defoamer for Construction Projects

April 7, 2025
9:04 AM

Bubbles may seem like a minor issue in construction projects, but they can seriously affect the quality of construction. Air bubbles created during concrete mixing can reduce the final strength. Experimental results have concluded that excessive air bubbles can cause a 10 to 15 percent reduction in the compressive strength of concrete. Air bubbles in coatings or waterproofing materials can lead to pinholes on the surface of the coating, affecting the waterproofing performance. The presence of bubbles in mortar will reduce the compactness and lead to the risk of cracking. As a professional powder defoamer manufacturer, we can help you solve these problems.

I.What is powder defoamer?

Powder defoamer is a modified polyether solid defoamer, especially suitable for dry-mixed materials. The main function is to quickly eliminate existing foam and prevent the formation of new foam, that is, defoaming and foam inhibition function.

1.Working Principle

Powder defoamers are usually made of silicone, polyether or mineral oil based materials, processed into micron-sized particles by special techniques. Its core principle is to make the foam wall thinner and rupture by reducing the surface tension of the liquid.

2. Powder vs. liquid defoamer

Powder defoamer has better storage stability and is easy to transport. Easier to handle in dry mix production, can be directly mixed with dry mix materials (cement, gypsum powder) uniformly, will not affect the fluidity.

Liquid defoamer is easier to be dispersed in aqueous system, it needs to be anti-freezing and anti-settling.

II. Key Factors to Consider When Selecting Powder Defoamers

1. Material compatibility

The powder defoamer you choose must be compatible with your formulation. Choose an antifoamer that does not interfere with the hydration reaction of the cement. For example, in tile adhesives containing HPMC and redispersible polymer powder, incompatible defoamers may reduce workability or cause separation problems.

Tip: Always test application formulations for compatibility, especially if complex formulations are used.

Test method: Add the defoamer to the material at a rate of 0.1%-0.3% and observe the compatibility and defoaming effect.

2. Defoaming and foam inhibition efficiency

As tested by the ASTM D892 standard, a good quality powder defoamer should eliminate more than 90% of air bubbles within 5 minutes. Not only to break bubbles, but also to prevent bubbles from reappearing, a good defoamer should:
Quickly eliminate surface air bubbles during mixing.
Prevent air from being trapped in the final product.
Maintain long-term performance even after prolonged storage.

3. Application Adaptability

Different systems have different needs, and a defoamer that works well in cement-based mortars may not be suitable for gypsum-based applications. We can offer you a wide range of defoamers to ensure that the powder defoamer is suitable for the type of material.

4.Low Dosage

Powder defoamer adding amount is usually 0.1%-0.3%, in this dose range to avoid affecting other properties.

5. Environmental protection and safety

As global regulatory standards become more stringent, choose defoamers that are environmentally friendly. Our powder defoamers:

VOC-free

Free of APEO and heavy metals

Low odor and safe to handle

III.Typical application cases of powder defoamer in construction projects

1. Wall Putty Construction

A customer in Southeast Asia who manufactures polymer-modified putty was experiencing problems with bubbles and pits in their walls after drying. Their previous defoamer had poor dispersion and inconsistent results.

After testing our TENESSY® powder defoamer, the results were obvious:

Reduced trapped air by over 60%.

Improved surface smoothness and finish.

Lower dosage required (0.3% vs. 0.6% previously).

No effect on workability or setting time.

They not only improve product quality, but also reduce production costs.

2. High-rise building concrete pouring

The air content of ready-mixed concrete is too high, after adding 0.1% powder defoamer, the strength is up to standard and there is no honeycomb hole on the surface.

IV. Common types of powder defoamers

Type	Advantages	Limitations	Typical Application
Polyether-based	Good compatibility with polymers	May be slower to act	RDP-modified systems
Silicone-based	Strong, fast defoaming and long-lasting effect	May affect paintability or surface finish	High-performance mortars, plasters
Mineral oil-based	Economical, decent foam control	Less effective at very low dosages	Standard tile adhesives
Bio-based/Green options	Environmentally friendly, low odor	Higher cost, limited availability	Sustainable building materials

TENESSY® powder defoamer is a modified polyether high efficiency powder defoamer. It has excellent defoaming and foam inhibition function, acid and alkali resistance, low dosage and low use cost.

VI.Conclusion

Choosing the right powder defoamer isn’t just about eliminating foam, it’s about improving the performance of your entire product, from production to application. As a trusted manufacturer, we offer solutions tailored to your formulation and objectives.

If you’re not sure which powder defoamer is right for your formulation, our technical team will support you with lab testing, custom formulation recommendations and reliable supply.