Demulsifiers: Small but Critical Additives for Industrial Oils

Emulsification vs. Demulsification in Lubricants

 

What is emulsification?

Emulsification is when you mix two liquids that normally don't blend together (like oil and water) so that one liquid breaks into tiny droplets floating in the other. If you put oil and water in a glass, they'll quickly separate - oil on top, water on bottom. But if you add a special mixing agent (surfactant) and shake or stir hard, the oil breaks into microscopic droplets that stay mixed in the water. This mixed state is called an emulsion, and creating it is what we call emulsification.

In simple terms, whether you need emulsification in oils depends on what you're using them for. Regular lubricants (like engine oils) should stay away from water mixing because it makes them work worse and can rust metal parts. But for metalworking fluids (like those used in cutting machines), mixing oil and water is actually helpful - the oil keeps things slippery while the water cools things down fast, which is perfect for high-speed cutting jobs.

 

Metalworking fluids (MWFs) often require emulsification.

 

Emulsified oils are commonly used in metalworking fluids. These metal working fluids typically formulated of a base oil, emulsifiers, rust inhibitors, extreme pressure additives, and other additives. They are diluted with water to form an oil-in-water (O/W) emulsion. These are used like cutting and grinding fluids, which both have the lubricating properties of oil and the cooling properties of water.

These metalworking fluids are sometimes also called "soluble oils." which is not truly soluble in water, but they are dispersed evenly in water and form a stable oil-in-water emulsion.

 

For example, sodium petroleum sulfonate has strong hydrophilicity and excellent rust and emulsification properties. It is suitable as an emulsifier to formulate cutting emulsions and rust inhibitors.

 

Lubricants generally need no emulsification but must demulsify well (separate water effectively).

 

Industrial lubricants like gear, hydraulic and compressor oils often have water get in during operation. As the oil circulates, the water may chemically react with some additives, and it creates very small water droplets that remain suspended in the oil, which is unwanted in industrial lubricants.

While water contamination causes multiple problems: it weakens the lubricant oil film, accelerates oil breakdown, promotes rust formation, and reacts with additives to generate damaging sludge that reduces the oil service life.

 

Lubricant Water-Seperation Ability

 

A lubricant's demulsibility means it either: 1) doesn't mix with water, or 2) quickly separates from water if mixed. This water-rejecting* capability is crucial for quality oil.

Demulsifiers are the best way to boost this performance. They work by breaking oil-water mixtures apart. Choosing the right demulsifier is vital for industrial oils. Studies show:

• Proper amounts of demulsifier dramaticly improve water-oil separation
• Too much can backfire, actually helping water mix in
• Precise dosing is key for best results
• These facts make demulsifiers tiny-but-mighty additives - used in small quantities but hugely important.

 

 

Chorus DL-32 Demulsifier

Chorus DL-32 Demulsifier (alternative to LZ 5957) is a high-performance oil additive that helps lubricants to have quick water separation.

It is an oil-soluble ethylene oxide/propylene oxide copolymer. It can quickly separate oil and water, significantly prolong the emulsion instability time, and maintain the oil-water phase separation, ensuring the long-term stable operation of the lubrication system.