As summer temperatures rise, many manufacturers begin noticing phase separation, sedimentation, or even caking in stored Defoamers.

For some users, this immediately raises concerns about product quality. Entire drums may be discarded unnecessarily, while others continue using the product without proper reconditioning—only to experience reduced foam-control performance, unstable production, or even unexpected process interruptions.

So what does separation actually mean? Is the product still usable? And how can it be stored properly during hot weather?

In this article, Sixin Technology answers the most common questions about defoamer separation and provides practical recommendations for recovery and storage.

1. Separation Is Often Normal — Not a Sign of Product Degradation

First, it is important to understand one key fact:

In most cases, phase separation during storage is a normal physical phenomenon rather than a sign of product deterioration.

Whether the defoamer is based on silicone, mineral oil, or polyether technology, the formulation contains components with different densities. During prolonged storage, heavier components gradually settle while lighter fractions rise to the top, resulting in visible layering or sedimentation.

This does not necessarily indicate product failure.

Genuine product degradation is usually indicated by:

• Irreversible flocculation or hard agglomerates that cannot be redispersed through mixing.
• Sour, rancid, or otherwise abnormal odors.
• Severe emulsion breakdown accompanied by free oil separation that cannot be restored after intensive agitation .

If the product can be restored to a uniform and homogeneous state through proper mixing, its performance is generally unaffected.

2. How to Restore a Separated Defoamer: A Three-Step Process

When separation occurs, many operators simply shake the container and hope for the best. While this may help in some cases, it is often insufficient to fully restore uniformity.

The following three-step process is recommended.

Step 1: Invert and Roll the Container

If possible, place the drum upside down for 2–3 hours before opening. This helps loosen settled material.

Afterward, gently roll the container for 5–10 minutes to encourage re-dispersion.

This procedure is suitable for various package sizes, from 20 kg drums to 1000 kg IBC totes.

Step 2: Mechanically Mix Thoroughly

After opening the container, use a mechanical or pneumatic mixer to thoroughly agitate the product from the bottom upward.

Mixing speed requirements vary depending on the product type. Always refer to the product technical data sheet or consult Sixin technical specialists for guidance.

Continue mixing until the material exhibits a consistent appearance, color, and viscosity throughout the container.

Step 3: Verify Uniform Dispersion

After mixing, collect samples from both the upper and lower portions of the container.

When added to water, both samples should disperse quickly and form a uniform milky emulsion.

If the upper sample appears noticeably thinner while the lower sample is significantly thicker or paste-like, additional mixing is required.

Where possible, performance testing should also be conducted. Add equal quantities of each sample to the same foaming system and compare defoaming performance under identical conditions.

If the difference in defoaming efficiency exceeds approximately 30%, homogenization is likely incomplete and further mixing is recommended.

A Common Mistake to Avoid

Avoid using only the top layer or bottom sediment after separation.

Active ingredients are often unevenly distributed following storage. Using only part of the product may result in inaccurate dosing, inconsistent performance, or unnecessary product consumption.

3. Four Storage Practices to Minimize Summer Separation

Although separation can often be corrected, prevention remains the most efficient approach.
The following storage practices can significantly reduce the likelihood of separation during hot weather.

01. Keep Storage Temperatures Below 25°C Whenever Possible

Excessive heat can reduce emulsion stability and increase the likelihood of separation or oil bleeding.

Store defoamers in cool, dry, and well-ventilated areas away from direct sunlight whenever possible.

02.Periodically Rotate Stored Containers

Long-term static storage is one of the primary causes of sedimentation.

For products expected to remain in storage for more than one month, rotate or roll containers every 15–20 days to help maintain uniform dispersion.

03. Use Opened Products Promptly

Once opened, defoamers become increasingly exposed to air, moisture loss, oxidation, and potential microbial contamination.

Containers should always be tightly resealed after use, and opened products should be consumed as soon as practical.

Where consumption rates are relatively low, smaller package sizes may be a more suitable option.

04. Avoid Mixing Different Batches or Product Types

Combining partially used containers from different batches or formulations is generally not recommended.

Even minor differences in emulsifier systems or stabilizer packages may disrupt formulation balance, increasing the risk of separation or emulsion instability.

If consolidation is unavoidable, conduct a small-scale compatibility test before mixing larger quantities.

4. Stability Starts with Formulation Design

While proper storage and handling can significantly reduce separation, the intrinsic stability of the formulation remains equally important.

At Sixin Technology, storage stability is considered a critical performance parameter during product development.

Each production batch undergoes stability testing prior to release to help ensure consistent performance under a wide range of storage and operating conditions.

If you are experiencing recurring issues with defoamer separation, sedimentation, caking, or inconsistent foam-control performance, our technical team can assist with:

• Product performance evaluation
• Application-specific defoamer selection
• Storage and handling recommendations
• Process optimization and troubleshooting support

Contact Sixin Technology today to discuss your application requirements or request product samples.