Application of Surfactants and Interface Softeners in Industrial Grinding Fluids

Overview

This summary compiles the commonly used surfactants and interface softeners (chelating agents / water softeners) in industrial grinding fluids for various metal materials. The data covers grinding processes including magnetic grinding, polishing, and abrasive finishing, comparing typical pH ranges and functional highlights of each formulation.

Metal Material & Typical Grinding Fluid Formulations

Key Notes

Surfactants

• Adjust wettability of the grinding fluid on metal surfaces.

• Disperse abrasive particles, suppress foam, and provide lubrication.

• Steel-based fluids often use antifoams and dispersants; aluminum and stainless steel polishing fluids prefer nonionic surfactants to balance lubrication and scratch prevention.

Interface Softeners (Chelating Agents / Water Softeners)

• Stabilize hardness ions (Ca²⁺ / Mg²⁺) in solution to prevent precipitation and clogging.

• Copper and tungsten carbide fluids often include specialized complexing agents to inhibit metal ion redeposition or excessive corrosion.

pH Control

• Determines the isoelectric point of abrasive particles and suspension stability.

• Influences metal oxidation or softening rates:

  • Acidic (pH 2–4) for aluminum alloys to dissolve surface oxides

  • Alkaline (pH 9–11) for silicate polishing to maintain particle suspension and surface softening

Specialized Formulation Notes

• Fully synthetic fluids (e.g., MORESCO GD) omit surfactants, relying on high-performance lubricants, antifoam technology, and biocides to ensure high-precision finishing and fluid stability.

• Semi- or fully water-soluble fluids (e.g., LLTC SG series) combine anticorrosion, antifoam, dispersion, and chelation functions for versatile applications on ferrous and non-ferrous metals.

Conclusion
The choice of surfactants and interface softeners in grinding fluids must be tailored to the material, desired surface roughness, and machine characteristics. On-site trials and optimization are recommended to achieve the best combination of finishing efficiency, surface quality, and process stability.

Principles of Vibratory Finishing Machines and High-Speed Centrifugal Finishing Machines

Summary Conclusion

Both vibratory finishing machines and high-speed centrifugal finishing machines are mechanical finishing equipment, but their working principles differ significantly:

• Vibratory finishing machines rely on a vibration system composed of eccentric weights and springs to generate high-frequency, three-dimensional vibrations in the finishing bowl. Burrs are removed and surfaces polished through spiral tumbling friction between the media and workpieces.

• High-speed centrifugal finishing machines use centrifugal force generated by a high-speed rotating spindle to drive multiple hexagonal barrels in synchronous planetary motion. The relative movement between barrels, media, and workpieces forms a flowing layer, enabling precise grinding and polishing.

1. Vibratory Finishing Machine Principle

Vibration Drive System

A vibratory finishing machine is equipped with a vibration motor with two eccentric weights fixed to its drive shaft. When the motor rotates at high speed, the eccentric weights generate alternating centrifugal forces transmitted through the frame and springs to the finishing bowl, causing the bowl to oscillate with regular high-frequency motion.

Three-Dimensional Spiral Tumbling Flow

Under vibration, the media, workpieces, and polishing fluid experience combined vertical and horizontal amplitudes, producing a three-dimensional spiral tumbling motion. This ensures continuous friction and compression between the media and workpieces, removing burrs, oxides, or achieving mirror-like surface finishes.

Amplitude and Frequency Adjustment

Vibration frequency and amplitude can be adjusted by changing the position and weight of the eccentric blocks or using an external variable-frequency drive, allowing adaptation to different workpiece materials and shapes while balancing efficiency and safety.

2. High-Speed Centrifugal Finishing Machine Principle

Planetary Motion Structure

Also called an inclined centrifugal finishing machine, this machine uses a powerful motor to rotate a spinning body at high speed. Multiple hexagonal barrels are installed evenly around the spinning body, each performing:

• Revolution: Rotating around the main spindle along with the spinning body

• Rotation: Rotating in the opposite direction via a synchronous belt or chain

Centrifugal Force and Flowing Layer Formation

The high rotation speed generates strong centrifugal force, pushing the media (abrasive stones, water, and workpieces) toward the outer wall of the barrels, forming a high-speed flowing layer. Within this layer, media and workpieces continuously slide and compress against each other, producing strong cutting and friction forces that remove burrs quickly and enhance surface gloss.

Suitable Characteristics

• Ideal for small, complex cavities and precision polishing of heat-treated workpieces

• Grinding efficiency is 10–20 times higher than traditional barrel finishing

• Number of barrels, load weight, and operating time can be adjusted to prevent imbalance or overheating

3. Comparison Table