Highly Efficient, Compact Device Semi-circular Nano-scale Laboratory Planetary Grinding Machine

The terms "Semi-circular planetary ball mill," "nano-scale laboratory planetary grinding machine," and "small and fast ball mill" all describe a highly efficient, compact device designed for ultra-fine grinding and mixing of materials down to the nanometer scale. It is an essential piece of equipment in advanced research and development laboratories.

Think of it as a high-tech, precision kitchen blender, but instead of a spinning blade, it uses the immense energy of grinding balls smashing into the sample inside violently rotating jars. The "planetary" motion is the key to its high performance and ability to achieve nanoscale particles.

• Grinding Jars (Mill Pots):

  Typically come in pairs (for balance). Made from materials that must not contaminate the sample, such as:

  • Agar (Polystyrene): For non-contaminating, low-energy grinding.
  • Stainless Steel: Durable, for hard materials.
  • Tungsten Carbide: Extremely hard, for very abrasive materials.
  • Zirconia (ZrO₂): Excellent combination of hardness, wear resistance, and low contamination; very common for nano-grinding.
  • PTFE (Teflon) or Nylon: For chemical resistance.
• Grinding Balls (Media):

  Small spheres that occupy the jar along with the sample. Their size and material are critical for achieving nano-scale results.

  • Sizes: Range from 0.1mm to 20mm. Smaller balls (e.g., 1-3mm) are used for nano-grinding as they provide more impact points and a larger total surface area for grinding.
  • Materials: Must match or be harder than the jar material (e.g., Zirconia, Agate, Stainless Steel).
• Main Drive & Planetary Disk:

  The heart of the machine. A powerful motor spins the central disk (sun wheel), which in turn rotates the jar-holding platforms (planet wheels).

• Control System:

  A digital interface (often with an LCD screen) for precise setting of:

  • Rotational Speed (RPM): Controls the energy input. Higher RPM = higher forces = finer particles/faster grinding.
  • Grinding Time: From minutes to several hours, with auto-reverse functionality to prevent material caking.
  • Pause/Cycle Settings: For complex grinding protocols.
• Safety Features:
  • Mechanical Lock: Prevents the lid from opening while the machine is in motion.
  • Safety Interlock: Automatically cuts power when the cover is opened.
  • Over-speed and Over-temperature Protection: Safeguards the motor and sample.

The magic lies in the interplay of two types of rotation:

• Revolution: The entire platform holding the jars rotates around the central axis of the mill (like the Earth around the Sun).
• Rotation: Each individual jar spins around its own axis, in the opposite direction to the revolution (this is the standard and most effective configuration).

This dual motion creates powerful Coriolis forces. The grinding balls are first flung away from the jar wall due to rotation, but then are yanked into a different trajectory by the revolution. The result is that the balls follow a complex path, impacting the sample with tremendous energy at the jar walls.

The "Semi-Circular" Path is an engineering design that efficiently generates these high-impact forces in a more compact mechanism, making the machine "small and fast."

This machine is indispensable in fields where material properties at the nanoscale are critical:

• Materials Science:
  • Synthesis of nano-powders (metals, ceramics, oxides).
  • Mechanical alloying of metals.
  • Preparing composite materials.
• Pharmaceuticals:
  • Nano-sizing of poorly soluble drugs to enhance their bioavailability (Nano-Milling).
• Geology & Mining:
  • Preparing rock and soil samples for XRF (X-ray Fluorescence) or other chemical analyses.
• Chemistry:
  • Solid-state chemical reactions (Mechanochemistry).
  • Creating catalysts with high surface areas.
• Electronics:
  • Preparing precursor powders for functional ceramics and electronic components.
• Biology:
  • Cell disruption and DNA/RNA extraction (using specialized jars and media).

• High Grinding Efficiency: Achieves nano-scale fineness much faster than traditional ball mills.
• Precise Control: Digital settings ensure reproducible results.
• Versatility: Can handle a wide range of materials (brittle, fibrous, soft, hard) by adjusting parameters.
• Multiple Grinding Modes: Can be used for dry grinding, wet grinding (with a solvent), or inert-atmosphere grinding (using vacuum jars).
• Compact Size: Saves valuable lab space.
• Safety: Built-in interlocks and robust design protect the user.

Front View

Side View

Operation View

Grinding Mechanism