5 Common Causes of Foaming Cutting Fluid

Foaming can be caused by various factors such as equipment structure, water tank design, and water pressure. Especially in recent years, with the powerful motors in new machines, both domestically produced and imported cutting oils are prone to foaming issues. Therefore, special attention needs to be paid to water tank design. Below are five potential causes of foaming:

(1) Limited Space in the Water Tank: When there's not enough room in the water tank, it affects cooling and can lead to poor fluid movement. (★Important)

(2) Accumulation of Iron Chips: If iron chips build up in the water tank and aren't cleaned out, they can block drainage holes and cause foaming.

(3) High Water Pressure: Too much water pressure at the filling point and rapid flow can prevent proper defoaming before entering the tank.

(4)Extended Machining Time: Prolonged machining sessions can shorten the lifespan of the cutting oil, leading to foaming.

(5)High Oil Concentration or Low Water Levels: Excessive oil concentration or insufficient water levels in the tank can also contribute to foaming issues.

How to Reduce Foaming in Cutting Oils

A. Check Coolant Tank

Ensure that the coolant tank level is adequate to prevent excessive agitation. Low coolant levels can lead to "spray foam" caused by the pump thrashing the coolant. Additionally, high pressure, agitation, and flow rates can exacerbate foam formation. Redesigning the system can often address these issues.

B. Clean Coolant Tank Regularly

Regularly clean the coolant tank, especially in smaller sumps where changes occur rapidly. Accumulation of particles and swarf can hinder access to the machine and promote foam formation. Regular machine cleaning is essential to prevent foam buildup.

C. Check Temperature

Monitor coolant temperature, as high temperatures can promote foam formation, particularly in synthetic fluids, due to their effect on viscosity. Temperature also influences foam stability.

D. Soft Water Increases Foaming

Soft water, with low mineral content, can increase foam formation, especially during initial system filling. Consider using treated water for emulsion preparation to minimize foaming.

E. Check Your Coolant

Foaming can occur due to entrained air and agitation in the system. Consider adding defoamers temporarily, but be cautious as some defoamers may emulsify leak oil, promoting bacterial growth.If these adjustments are insufficient, consult your cutting oil supplier for recommended antifoam additives. Add antifoams at the lowest recommended dosage to avoid potential filtration issues.

Case Study: Defoaming Coolant Oil

The foaming issue with cutting oil disrupted the workflow of a motorcycle customization client, causing inconvenience and frustration during CNC milling processes. The two-year foaming problem, especially prevalent when machining aluminum and iron parts, led to coolant overflow, necessitating frequent cleaning and maintenance. This not only wasted time but also increased costs.