Криогенна мелница

Screw-top grinding jars are dust and air-tight which makes them suitable for dry, wet, and cryogenic grinding. Moreover, they safely enclose the inert atmosphere after being filled in a glove box. Choose a grinding jar size between 5 ml and 50 ml which is suitable for the sample volume to be processed (approx. 30% of the jar should be filled with sample material).

The document „Grinding jar ball charge“ provides details about the usable volume of the grinding jars, maximum feed size and correct filling with grinding balls for dry and wet grinding, as well as for cell disruption.

To ensure efficient grinding, the grinding jars are available in 4 different materials for contamination-free grinding processes (no undesired abrasion).

Available materials:

• Hardened steel (density 7.6 g/cm³; hardness ≤ 250 HB, medium abrasion resistance)
  typically used for pulverizing medium-hard to hard and brittle samples.
  
  
• Stainless steel (density 7.7 g/cm³; hardness ≤ 265 HB, medium abrasion resistance)
  typically used for pulverizing medium-hard to hard and brittle samples.
  
  
• Zirconium oxide (density 6.05 g/cm³; hardness 1250 HV, high abrasion resistance)
  ceramic material suitable for pulverizing medium-hard to hard and fibrous samples. It is typically used for heavy-metal-free grinding processes or applications which aim at ultrafine particle sizes.
  
  
• PTFE (density 2.1 g/cm³; shore hardness ≥ 54, low abrasion resistance)
  suitable for pulverizing soft to medium-hard sample materials, if the subsequent analysis measures the heavy metal content of the sample, and zirconium oxide abrasion is not acceptable.

Please note:

The grinding tool material should be harder than the sample. For further information check the “Material Analyses of Equipment & Accessories” document in the Downloads section.

Grinding balls are available in different diameters. The following rule of thumb applies: for an efficient grinding process, the grinding ball should be at least 3 times bigger than the largest particle. To reduce abrasion and wear, the grinding balls used in a grinding process should all have the same diameter.

The document „Grinding jar ball charge“ provides details about the usable volume of the grinding jars, maximum feed size and correct filling with grinding balls for dry and wet grinding, as well as for cell disruption.

Grinding jars and grinding balls should always be made of the same material.

Available materials:

• Hardened steel (density 7.8 g/cm2; hardness ≤ 235 HB, medium abrasion resistance)
  typically used for pulverizing medium-hard to hard and brittle samples.
  
  
• Stainless steel (density 7.7 g/cm2; hardness ≤ 245 HB, medium abrasion resistance)
  typically used for pulverizing medium-hard to hard and brittle samples.
  
  
• Zirconium oxide (density 6.05 g/cm2; hardness 1250 HV, high abrasion resistance)
  ceramic material suitable for pulverizing medium-hard to hard and fibrous samples. It is typically used for heavy-metal-free grinding processes or applications which aim at ultrafine particle sizes.
  
  
• PTFE (density 2.1 g/cm2; Shore hardness D56, low abrasion resistance)
  suitable for pulverizing soft to medium-hard sample materials, if the subsequent analysis measures the heavy metal content of the sample, and zirconium oxide abrasion is not acceptable.

Please note:

The grinding tool material should be harder than the sample. For further information check the “Material Analyses of Equipment & Accessories” document in the Downloads section.