Why Foam could be so inconvenient ?
A light foam is generally not problematic in most applications however heavy foaming can often lead to various processing problems. These problems range from inaccurate readings from control and measuring equipment such as temperature, level and density controllers to poor mixing of reactants in chemical reaction vessels and products hanging in the foam, all too often leading to losses in production. Finally the presence of foaming can give a bad image of the way a process is operated in the eyes of a customer. The presence of foam in discharged effluent can cause complaints from local people and authorities even if the foam is harmless to people and the environment.
How do silicone defoamers work ?
Foam is a gas dispersion in a liquid or solid continuous phase. Foam iscreated by the surfactants which are at the air/liquid interface. Therefore air bubbles occur and are stabilised by the surfactants. Today, silicone antifoams are thebest solution to a foaming problemthanks to a very competitive ratio of cost/efficiency.Based on a silicone oil and silica particles, INVELYDEFOAMERS products work following the outlined principles :
Foam destabilisation mecanism:
- In spreading over the foam, the silicone active ingredient displaces surfactant molecules and thins out
the lamellae, leading to destabilisation and collapse.
- Silica particles transported by the siloxanes onto the foam lamelle have an additional destabilizing effect on the foam.
- The foam bubble bursts and the entrapped air escapes.
Silicone antifoams/defoamers
Today silicone antifoams remain the best solution to foaming problems because they give better
efficiency/cost compared to organic antifoams. Silicone based products meet perfectly the three crucial requirements to make an effective antifoam :
• Low surface tension(approximately 21 mN/m)
• Insoluble in the foaming medium
• Good spreading coefficient
Silicone antifoams have other interesting properties :
• They are highly efficient and are therefore often more economical to use than organic defoamers.
• They control almost all types of foam encountered in any effluent.
• They are chemically inert and therefore resistant to chemical attack.
• They are thermostable.
• They make for safe operating conditions.
• As they do not produce any undesirable degradation products, they are environmentally compatible.
A silicone oil named 
polydimethylsiloxane (PDMS) and silica particles are the two major ingredients of a silicone antifoam agent.
Silicone antifoam can be compound (100% active content), emulsion(variable active content) or powder.
The Invely range of antifoam agents are in emulsion form.
INVELYDEFOAMER products are of the oilin-water type, and therefore suitable for easy dispersion in aqueous media. Thanks to their relatively low viscosity they are easy to pump
for more details:
https://www.linkedin.com/company/china-defoamer
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