Global expertise in defoamers and foam control

English | French | Spanish

Our Research and Development department at PMC Ouvrie possesses a wide range of innovative equipment and systems, and is in a position to undertake studies concerning the most recent and emerging applications in the field of defoamers.

Thanks to its expertise, our development team endeavors to keep ahead of the most demanding legal requirements, thus proposing highly efficient solutions that respect the requirements of the different legislation so that our defoamers follow the best regulatory changes.

1. Why should you use defoamers and antifoams?

PMC Ouvrie's antifoams are very effective in controlling foam, increasing productivity and reducing production costs.
An antifoam enables you to:

• Fulfill containers and vessels to maximum capacity
• Prevent product losses from overflows
• Increase production efficiency
• Improve safety and housekeeping

2. What's the difference between an antifoam and a defoamer?

"Defoamer" and "Antifoam" are terms often used interchangeably to describe products designed to control or to prevent foaming. But as well as their chemistries, their effects are different:

• Defoamer will be used in urgent situation, when foam already appears, and need to be eliminated quite urgently, before to reach harmful consequences. (Post-Defoaming)
• Antifoam will be used in order to control a situation, to avoid foam. (Pre-Defoaming)

Indeed, Antifoam are developed to prevent foam, whereas Defoamers eliminate existing foam.

In concluson, the distinction between the different terms is somewhat blurried since in several industries combination of both effects is used.

3. How do we test the performance of an antifoam?

What do we do, here in PMC Ouvrie, is to mimic all parameters that our clients can encounter in them application. In different industries, entrapped air can be induce chemically, biologically, or more often physically. This way of incorporated gas inside liquid, plus the nature of foaming media, are the two main criteria that we are using to test our antifoams.

Shake Test - Easy to implement and useful for quantitative comparisons on effectiveness. But it usually need further investigation.

Stirrer Test - Antifoam Test that more accurately reflects many foaming problems observed during dilution and formulation.

Air Sparge & Recycling Pump Test – Those tests are performed by an automatic system. They allow our Lab Team to setup many parameters (Temperature, Pressure, pH, …) to reach exact industrial conditions. Furthermore, this test is calibrated according to ROSS-MILES method, which condition are set in ASTM D1173 standard. Foam level is measuring by light sensors, and time is set by operator. Finally, measurement can by achieve in Static or Dynamic manner. With this test our lab Team is able to find any solution, to any foam problem.

4. How can I select the best antifoam for my application?

Many factors impact selection of the right antifoam:

• What's the application
• What's foaming media
• What's the process stream
• Temperature
• pH
• Operating and regulatory limitations
• How will the antifoam be applied

For help making the best choice, turn to us for support. With our years of experience, we truly believe that it foams, we can handle it!

5. How do antifoams work?

While 95% of all foam problems occur in aqueous media, pure water does water thermodynamically does not foam. The addition of surfactants and other surface-active retard the coalescence of gas bubbles and thus stabilize foam.

Designing an antifoam is usually finding the right balance between Hidrophobicity and Hydrophilicity. Indeed, a defoamer or antifoam must be insoluble in the foaming media, and have a low surface tension so it spreads across the foam surface. Nevertheless, a higher dispersibility results in quicker knockdown, but may reduce persistency.

6. What's in an antifoam?

Carrier - usually an oil that is insoluble in foaming medium. Oils have low surface tensions and migrate to the air/liquid interface. It may be vegetable oil, mineral oil, or silicone based.

Hydrophobe - finely divided solids that move with the carier across the surface and physically disrupt bubble walls.

Diluent - usually water. Antifoams and defoamers are effective at low doses (often less than 0.01%) so stable dilutions ammow better dosing control resulting in cost savings for the user.

7. What is the best choice - an Emulsion or 100% Active?

Actually, it depends! Emulsions per definition content a certain amount of water. They tend to have lower viscosity, as well as lower price point, and extremely fast knockdown, even in cases where agitation is poor.
Wherease, 100% Active Antifoams are concentrated to have a higher viscosity and also higher unit cost.

The decision as to which is best for you dépends on your specific application and on how well you can control antifoam usage.
With better control, the 100% active formulations are often more cost effective. For a "bucket-brigade" environment where antifoam dosing is hard to control, the lower unit of emulsions may be better choice.