Particles in Band Saw Coolant: Size Distributions and Implications for Guide Clearances and Friction

Area of Science:

• Materials Science
• Mechanical Engineering
• Tribology

Background:

• Higher cutting speeds in metal band sawing increase frictional heat at sliding guide blocks.
• Metalworking fluids (MWFs) often lack fine filtration, leading to debris accumulation and potential damage at the guide-band interface.

Purpose of the Study:

• To quantify particle load and size distribution in MWFs during high-speed band sawing.
• To investigate the impact of particle contamination on coolant properties and guide block friction.
• To provide data for designing improved guide clearances and filtration systems.

Main Methods:

• Collected and analyzed 1 L coolant samples after 22.5 m² of cutting.
• Utilized optical sizing to determine particle size distribution (number-median maximum Feret diameter).
• Measured coolant viscosity and friction using HFRR tribometry.

Main Results:

• Particle load reached 0.438 g/L with particles up to 1.5 mm, significantly larger than typical guide clearances (~0.1 mm).
• Coolant viscosity decreased by ~2% K⁻¹ around 40 °C, following an Andrade relation.
• Steady-state friction coefficient (µ) was measured at approximately 0.12, comparable to cutting oil.

Conclusions:

• Particle ingress and three-body interactions are frequent in high-speed band sawing due to large debris sizes relative to guide clearances.
• Quantitative data on particle load, size, and coolant properties offer critical design inputs for next-generation band sawing systems.
• Targeted filtration and coolant delivery concepts are essential for enhancing efficiency and longevity in high-speed band sawing operations.