When evaluating a Double Cone Mixer, prioritize the working volume vs. total volume, as these machines typically operate most efficiently at 40% to 60% of their total capacity. Ensure the material of construction is SUS304 or SUS316L stainless steel for all contact parts to prevent contamination. Additionally, check for internal polishing (Ra < 0.4μm) to ensure smooth discharge and easy cleaning, and verify the motor power and rotation speed (typically 6-25 RPM) are adjustable via a Frequency Drive (VFD) to handle different material densities.