IKA MultiDrive MI 400.1 standard hammer, stainless steel, for MI 400, 0020023170

Kinetics of high-speed impact crushing on a scaled-down scale

In geochemical analysis, agricultural science and the quality control of building materials, the physical comminution of hard and brittle sample matrices (such as minerals, cereal pellets or ceramic precursors) requires a significant amount of mechanical energy. The IKA MultiDrive MI 400.1 standard grinding tool operates on the process engineering principle of impact and percussion grinding and is specifically dimensioned for the enlarged 400-ml grinding chamber. Driven by the MultiDrive base station (at up to 30,000 revolutions per minute), the rotating stainless-steel beater generates immense circumferential speeds at its extended outer edges. The resulting kinetic energy is transferred to the sample material in fractions of a millisecond upon direct impact. This extreme mechanical impulse overcomes the internal tensile and compressive strength of the solids, leading to the sudden shattering of the crystal lattices.

Particle kinematics and volume scaling

Processing larger sample volumes (up to 400 ml) significantly alters the macro-kinematics within the enclosed grinding chamber. The specific length geometry of the MI 400.1 beater is precisely calculated, in accordance with the laws of physics, to match the extended radius of the MI 400 chamber. The high-speed rotation hurls the particles against the stainless steel wall with enormous radial acceleration. The increased distance between the axis of rotation and the chamber wall creates a highly efficient kinetic cycle comprising a primary impact and a secondary impact against the wall. This optimised geometry ensures that, despite the increased batch volume, no fluid dynamic dead zones arise and a reproducible particle size distribution is achieved in the analytically relevant micrometre range.

Material integrity and tribological resistance

When comminuting samples with a high Mohs hardness, the tool is subjected to severe tribological stresses (mechanical wear caused by friction and micro-collisions). To minimise analytical contamination of the sample due to metallic abrasion (carry-over), the MI 400.1 beater is manufactured from a highly wear-resistant, solid stainless steel. The structural integrity of this monomaterial design prevents plastic deformation of the striking edges. To ensure strict compliance with GLP (Good Laboratory Practice) guidelines, the electropolished metal surface allows for complete chemical decontamination as well as residue-free thermal sterilisation in an autoclave.

Technical details

• Product type: Standard beater for increased chamber volume (interchangeable tool)
• Process principle: Impact and percussion comminution (impact milling)
• Physical scope of application: Dry milling of hard and brittle matrices
• Compatibility (vessel): Exclusively suitable for the IKA MultiDrive MI 400 (400 ml chamber)
• Compatibility (drive): IKA MultiDrive basic and MultiDrive control
• Material: Solid, highly wear-resistant stainless steel
• Assembly: Tool-free, form-fit attachment to the drive shaft inside the vessel
• Cleaning and hygiene: Fully autoclavable and solvent-resistant

Contents

• 1 x IKA MultiDrive MI 400.1 standard beater (stainless steel)

(Important note: The MultiDrive drive unit and the large-volume MI 400 grinding chamber are not included in the scope of delivery!)

Customised requirements & accessories

The MI 400.1 beater is the primary mechanical wear part in impact grinding. The continuous grinding of highly abrasive materials inevitably leads to a gradual blunting of the striking edges. This prolongs the required grinding time and increases the undesirable thermodynamic energy input (friction heat) into the sample. To ensure that the kinetics of the grinding process and the reproducibility of particle sizes remain in compliance with standards in the long term, regular replacement of the tool is essential. Please contact our procurement service at any time for the strategic procurement of laboratory consumables.