How to Dilute Silicone Defoamer: Step-by-Step Guide
Prerequisites & Equipment Required Before starting the dilution process, ensure your setup meets the following industrial standards:
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Low-shear mechanical agitator: Must be capable of operating at or below 60 RPM. High-speed dispersion will permanently break the emulsion.
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pH meter: Calibrated for accurate readings between pH 6.0 and 8.0.
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Clean mixing vessel: Sanitized to prevent bacterial contamination of the thickener.
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Temperature control: All processes must be conducted using water at ambient temperature (15-25°C).
Standard Dilution Formulation (Reference: 1:9 Ratio to yield 1000g)
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Thickening Agent: 26g (Approx. 2.6% – 3.0% of total weight. ).
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Preservative (Biocide): 0.5g – 0.8g (0.05% – 0.08% of total weight, compatible with the system pH).
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Deionized (DI) Water: 874g (Add to 100% of total weight. Do not use municipal tap water).
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pH Adjuster: 20% NaOH solution (Chemically pure grade).
Take dilution 10 times, 1000g as an example. If you need to get any concentration, adjust according to this ratio
Direct addition of unthickened water at ambient temperature (15-25°C) instantly disrupts the delicate surfactant balance. This thermal and chemical shock causes the microscopic silicone droplets to coalesce, inevitably leading to permanent demulsification and severe oil slicking (creaming). You must prepare the thickened water phase first.
Ingredients Required for Dilution
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Silicone Defoamer Concentrate (20%): The active antifoaming agent.
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Thickener (3%): Ensures stability and prevents stratification (e.g., Xanthan gum or Acrylic).
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Deionized Water (q.s.): The carrier medium.
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Preservative (0.2%): Prevents mildew and bacterial growth over time.
⚠️ Critical Warning: Can I just add water? NO. Directly diluting silicone defoamers with water disrupts the emulsification balance, leading to stratification, oil bleaching (floating oil), and demulsification. You MUST use a thickening system to maintain stability.
3 Steps to Dilute Silicone Defoamer Properly
Step 1: Thickening
Add 26g Thickener into 874g Water (approx 3% ratio).
Adjust pH to 6.0-8.0 using 20% NaOH solution while stirring. Continue until the solution becomes transparent and thickened.
Step 2: Dilution
Slowly add 100g Silicone Defoamer into the prepared thickener water.
Stir gently at low speed for 10-20 minutes. Ensure the defoamer is evenly dispersed without breaking the emulsion.
Step 3: Preservation
Add 0.5~0.8g Preservative under constant stirring to prevent mildew.
If the preservative is acidic, do a final pH adjustment to 6.0-8.0 to ensure long-term stability.
*Note: Always use deionized water and chemically pure NaOH for best results.
Note:
- In this case, the concentration of the thickener is 3.0%. If you think the final product viscosity is low, you can increase the thickener concentration (such as increased to 3.5%, 4% or higher) and vice versa. However, it should not be less than 1.5%, and it should not be diluted directly with water. Otherwise, the diluted defoamer is unstable and cause seperated, demulsifie and oil floating.
- The speed should not be too fast when mixing and stirring , the recommended rotation speed should not exceed 60 rpm. Generally, the mixture can be sampled for 5 minutes to observe whether there are obvious doughs and avoid stirring for a long time.
- It is recommended to carry out pre-sterilization treatment on the clean water source (such as tap water and deionized water). Such as adding 5~10ppm of strong chlorin.
- This method is only applicable to INVINO silicone defoamer. we don’t guarantee whether it is also applicable to other company products, so customers should do experiment according to this method.
INVINO is not responsible for the adverse consequences of qualified products due to improper dilution (such as: decreased stability, decreased foaming performance, bleaching, demulsification, delamination, mildew, etc.). - The NaOH should be chemically pure. If industrial grade caustic soda is used, the viscosity of the system may be low. It is recommended to conduct a small test before use.
Quality Control & Handling Notes
- Visual Inspection: After introducing the thickener into the DI water, allow the solution to agitate gently. Inspect the batch visually for any undispersed agglomerates (polymer lumps). The water phase must be completely transparent and uniform before adding the silicone concentrate.
- Preventing Contamination: Organic thickeners are highly susceptible to bacterial degradation. Preemptive addition of a standard industrial biocide is mandatory for any formulation that will be stored. Failure to do so will result in a drastic drop in viscosity and emulsion collapse.
- Identifying Demulsification: If you observe oil slicking (a thin layer of floating free silicone oil) or creaming on the surface of your diluted mixture, the emulsion has been broken. This is typically caused by exceeding the 60 RPM shear limit or using water with high mineral content.
