IKA A 11 basic Analytical Mill, Impact and Cutting Grinding, Coolable, 0002900000

Kinetics of cutting and shear comminution In materials science and biological sample preparation, tough, extremely elastic and fibrous matrices (such as thermoplastics, textiles, paper, cellulose or plant-based biomass) present a major physical challenge. Conventional impact mills fail in this context from a process engineering perspective, as elastic materials simply absorb the kinetic impact energy (damping effect) rather than fracturing brittle. The IKA A 11.2 cutting blade is geometrically engineered for high-precision shear comminution. Driven by the A 11 basic base unit at speeds of up to 28,000 revolutions per minute, the sharpened blades sever the macromolecular fibre structures by applying massive, localised shear stresses. This rotating, pulling cut continuously disaggregates the sample material and transforms it into a homogeneous, free-flowing analytical matrix. Rheology and prevention of rotational blockages A fundamental mechanical problem in the high-speed grinding of long, tear-resistant fibres is the so-called wrapping effect. Under conditions of severe flow turbulence, fibrous materials tend to wrap themselves around the mill’s rotating tool shaft. This leads to an exponential increase in torsional resistance, which can thermally overload or mechanically jam the drive motor in a fraction of a second. The A 11.2 cutting blade counteracts this rheological phenomenon thanks to its sharp cutting geometry. The blades systematically cut the fibres into short fragments long before static wrapping structures can form around the shaft, thereby maintaining the thermodynamic efficiency of the entire grinding process. Material integrity and thermomechanical stability To withstand the continuous mechanical abrasion caused by tough polymers or lignified plant fibres, the cutting blade is made from solid, highly wear-resistant stainless steel. The blades retain their microscopic sharpness even during extended grinding intervals under thermal stress. The corrosion-resistant, single-material design enables laboratories operating in accordance with strict GLP (Good Laboratory Practice) guidelines to carry out thorough chemical decontamination and residue-free thermal sterilisation in an autoclave, thereby preventing any analytical carry-over between batches. Technical details Product type: Cutting blade / cutting tool (spare part) Processing principle: Cutting and shear comminution Physical scope of application: Tough, elastic and fibrous sample matrices Kinetic design: Designed for rotational speeds of up to 28,000 rpm Compatibility: Exclusively compatible with the IKA A 11 basic analytical mill Material: Solid, corrosion-resistant stainless steel with sharpened blades Assembly: Positive-lock, tool-free mounting on the drive shaft Hygiene: Fully thermally autoclavable and chemically sterilisable Contents 1 x IKA A 11.2 cutting blade (stainless steel) (Important note: The IKA A 11 basic analytical mill and the grinding chamber are not included in the scope of delivery!) Custom requirements & accessories The A 11.2 cutting blade is the most important wear part in terms of process technology for the fibrous cutting and comminution of materials. Processing extremely tough, sometimes abrasive plastics (such as fibre-reinforced polymers) inevitably leads to the gradual blunting of the cutting edges due to micro-collisions. A blunt blade tears the material rather than cutting it, which drastically increases the thermodynamic stress on the sample (frictional heat). To ensure gentle, thermally stable sample preparation, we recommend having replacement tools ready at an early stage should cutting performance begin to decline. Please contact our procurement service at any time for the strategic procurement of laboratory consumables.

Solid-state physics and tribological resistance In geochemical analysis, materials testing and building materials inspection, the comminution of extremely hard, mineral or ceramic sample matrices reaches fundamental physical limits. Standard stainless steel grinding tools suffer severe tribological deformation and extreme material wear when used on matrices with a Mohs hardness of over 6. The IKA A 11.3 beater is designed as a highly specialised tungsten carbide tool (tungsten carbide alloy). This intermetallic carbide compound is characterised by extreme structural density and hardness. This material-scientific superiority makes the tool completely immune to plastic deformation caused by abrasive micro-collisions with hard ores, quartzites, glasses or slags within the grinding chamber of the A 11 basic. Kinetics of extreme impact comminution The process principle is based on high-speed impact and shock comminution. Driven at rotational speeds of up to 28,000 revolutions per minute, the A 11.3 beater transforms the motor’s electrical energy into massive kinetic impact energy. Due to the extreme hardness and very high specific gravity of the cemented carbide alloy, the mechanical impulse transferred to the sample material upon direct impact is significantly stiffer and involves less energy loss than with more ductile steel alloys. The lattice structures of even extremely brittle, crystalline solids are shattered by these incoming shock waves in fractions of a millisecond and converted into a highly fine, analytically usable powder matrix. Analytical purity and minimisation of abrasion A key problem in the analytical sample preparation of hard rocks is contamination caused by mechanical abrasion of the grinding tool (carry-over). Grinding with conventional stainless steel tools inevitably leads to a massive introduction of foreign ions into the sample. The use of the A 11.3 carbide beater physically reduces this tribological wear to an absolute minimum. The structural integrity of the striking edges is maintained even after intensive grinding cycles, ensuring that the mill’s thermodynamic efficiency remains constant and drastically minimising analytical contamination of the sample caused by metallic abrasion. Technical details Product type: Beater for extreme impact comminution (replaceable tool) Material: Highly wear-resistant carbide (tungsten carbide alloy) Processing principle: Impact and percussion comminution (impact milling) Physical scope of application: Extremely hard and brittle matrices (Mohs hardness > 6) Kinetic design: Designed for rotational speeds of up to 28,000 rpm Analytical advantage: Minimisation of tribological wear and cross-contamination Compatibility: Exclusively compatible with the IKA A 11 basic analytical mill Assembly: Positive-lock, tool-free mounting on the drive shaft Contents 1 x IKA A 11.3 beater (carbide) (Important note: The IKA A 11 basic drive unit and the grinding chamber are not included in the scope of delivery!) Customised requirements & accessories The A 11.3 beater is the ultimate high-end solution for the hardest materials in the IKA A 11 basic. Whilst carbide is extremely hard and abrasion-resistant, its crystalline structure makes it more susceptible to bending or lever forces than ductile stainless steel. When inserting or removing the tool from the grinding chamber, it must never be forced at an angle to prevent brittle fracture of the shank. Please contact our specialist procurement service at any time for the metrologically correct configuration of your grinding systems.

Kinetics of impact comminution on a scaled volume scale The comminution of larger sample batches in instrumental analysis requires a tailored fluid-dynamic design. The IKA A 11.4 grinding beaker significantly expands the primary working zone of the A 11 basic analytical mill to a volume of 250 ml. This specific cylinder geometry creates an extended rheological flow space. The high-speed rotation of the grinding tool generates strong hydrodynamic turbulence (vortex) within this chamber. These flow vectors continuously circulate soft to medium-hard solids (such as agricultural products, soft polymers or plant tissue) through the kinetic impact zone of the beater, thereby achieving a homogeneous particle size distribution across the entire batch without any fluid-dynamic dead zones. Polymer physics and optical process control To ensure the structural integrity of the system during massive impacts, the A 11.4 grinding bowl is made from amorphous high-performance polycarbonate (PC). This thermoplastic polymer is characterised by extremely high ballistic impact resistance and absorbs kinetic fracture energy more effectively than conventional plastics. However, the key metrological advantage of this material is its absolute optical transparency. The user can visually monitor the macrokinetics of the mixing process and the gradual reduction in particle size in real time. This enables a prompt, physical determination of the ideal grinding interval and prevents excessive thermodynamic stress (exothermic reactions due to friction) on the sample caused by unnecessarily long process times. Thermomechanical limitations and containment As a closed system, the A 11.4 beaker acts as hermetic mechanical containment, reliably preventing the aerodynamic dispersion of respirable fine dust or toxic aerosols into the laboratory environment. From a process engineering perspective, however, the thermodynamic threshold of the polycarbonate must be strictly observed: Due to its macromolecular structure, this beaker is strictly excluded from cryogenic grinding. The direct application of liquid nitrogen (LN₂) or dry ice would immediately cool the polymer below its glass transition temperature, causing the thermoplastic matrix to become extremely brittle and, under the radial centrifugal forces, lead to a catastrophic mechanical cold fracture (splintering). Technical details Product type: Large-volume grinding chamber Material: Highly transparent polycarbonate (PC) Maximum usable volume: 250 ml Processing principle: Impact and shock comminution Physical scope of application: Soft to medium-hard sample matrices Visual benefits: Unobstructed in-situ visualisation of the comminution process Health and safety: Acts as a mechanical aerosol containment system Thermodynamic limitation: Not approved for cryogenic cooling media Compatibility: Suitable exclusively for the IKA A 11 basic analytical mill Contents of delivery 1 x IKA A 11.4 grinding beaker (polycarbonate, 250 ml) (Important note: The A 11 basic drive unit, grinding tools and housing lid are not included in the scope of delivery!) Individual requirements & accessories The A 11.4 polycarbonate beaker is the ideal solution from a process engineering perspective for bulky, soft samples where visual monitoring of the degree of grinding is critical. However, if your laboratory needs to grind hard mineral rocks or if cryogenic cooling media must be used to prevent thermal denaturation, switching to the solid IKA A 11.5 stainless steel grinding beaker (item no. 0002983100) is physically essential. Please contact our procurement service at any time for assistance in selecting the correct grinding vessels based on thermodynamic and materials science criteria.

Kinetic containment and radial impact comminution In instrumental analysis, the high-speed digestion of hard and brittle matrices requires a sealed chamber capable of withstanding high mechanical loads. With its geometric working volume of 80 ml, the IKA A 11.5 replacement grinding bowl defines the primary fluid-dynamic working chamber of the A 11 basic analytical mill. The inner cylinder wall is made of solid, highly wear-resistant stainless steel. At rotational speeds of up to 28,000 revolutions per minute, the grinding tool hurls the solid particles radially outwards with extreme centrifugal force. The stainless steel wall acts physically as a static anvil, reflecting the kinetic energy of the incoming particles back into the matrix in the form of mechanical shock waves, thereby forcing homogeneous particle size reduction through secondary wall collisions. Thermodynamic resilience and cryogenics The conversion of kinetic friction energy into heat that is detrimental to the process (exothermic reaction) is the main process-engineering challenge when grinding temperature-sensitive, elastic or biologically active samples. To prevent molecular degradation or melting of the matrix, the A 11 basic is certified for cryogenic grinding. The molecular lattice structure of the A 11.5 stainless steel interior allows liquid nitrogen (LN₂ at –196 °C) or dry ice (solid CO₂ at –78.5 °C) to be applied directly to the sample. Unlike thermoplastic polycarbonate vessels, this metallic matrix fully withstands extreme thermal shock (temperature gradients) without suffering mechanical cold fracture (embrittlement and splintering). Macromolecular insulation matrix and occupational safety The use of extreme cryogenic cooling media or, alternatively, the generation of extreme frictional heat over long grinding intervals requires absolute thermodynamic protection for the user. The A 11.5 grinding beaker features a dual-architecture design based on materials science: the stainless steel interior is completely enclosed by a solid outer jacket made of Tefcel (a modified ETFE fluoropolymer). This high-performance polymer has an extremely low thermal conductivity coefficient. It acts as a physical insulator, blocking the flow of heat to the outside and thus enabling the vessel, which is cryogenically cooled to –196 °C, to be handled without immediate risk of frostbite. Furthermore, as a hermetic containment system, the sealed beaker system prevents the spread of toxic dusts and aerosols into the laboratory environment. Technical details Product type: Standard grinding beaker / replacement grinding chamber Useful volume: 80 ml Material (interior): Solid, corrosion-resistant stainless steel Material (outer jacket): Tefcel (ETFE fluoropolymer) Process function: Radial impact surface and hermetic containment Thermodynamic approval: 100% suitable for cryogenic media (LN2, dry ice) Thermal insulation: Protection against cold burns and frictional heat Hygiene: Solvent-resistant and suitable for chemical decontamination Compatibility: Designed exclusively for the IKA A 11 basic analytical mill Contents 1 x IKA A 11.5 replacement grinding beaker (80 ml, stainless steel/Tefcel) (Important note: The A 11 basic drive unit, grinding tools and housing cover are not included in the scope of delivery!) Individual requirements & accessories The A 11.5 beaker forms the physical container for the grinding process and requires the corresponding grinding tool to generate kinetic energy. The metal inner wall allows unrestricted use of the A 11.1 stainless steel beater (for standard impact grinding) as well as the A 11.2 cutting blade (for tough and fibrous samples). To ensure the chamber is hermetically sealed, the beaker must always be closed with the original A 11 basic lid during operation. Please contact our procurement service at any time for the strategic procurement of laboratory consumables and spare parts.

Kinetics of impact comminution on a scaled-up macro-scale In instrumental analysis, scaling the sample volume leads to a significant change in the physics of comminution. When the IKA A 11 basic analytical mill is operated with the large 250 ml grinding chamber (A 11.4), the axial reach of a standardised single beater is no longer sufficient to penetrate the increased volume kinetically. The IKA A 11.6 dual-beater has been geometrically engineered precisely for this macro-scale. Driven at up to 28,000 revolutions per minute, this tool simultaneously applies immense mechanical impulses across two superimposed planes of rotation. This dual impact energy shatters soft to medium-hard solids (up to approx. Mohs hardness 3) with enormous efficiency, as the probability of a direct particle impact on the striking edges is drastically increased by the doubled effective surface area. Macro-fluid dynamics and vortex generation A fundamental mechanical problem in comminution within large-volume chambers is the formation of fluid dynamic dead zones – areas in which the sample material accumulates without being caught up in the rotor’s kinetics. The asymmetrical blade geometry of the A 11.6 double-beater functions not only as an impact tool but also as a hydrodynamic impeller. The high-speed rotation generates massive three-dimensional flow turbulence (vortices). These vectorial flows force the entire particle matrix into continuous vertical and radial circulation, thereby constantly drawing the material back into the active impact zones and achieving a strictly homogeneous particle size distribution across the entire 250 ml batch. Material integrity and thermomechanical stability The acceleration of large sample volumes induces significant torsional forces on the drive shaft and the tool itself. To prevent plastic deformation under this continuous load, the double beater is made from solid, tough stainless steel. This monomaterial design guarantees the highest tribological resistance to mechanical abrasion and prevents analytical contamination of the sample (carry-over). The electropolished, seamless metal surface enables full compliance with GLP (Good Laboratory Practice) guidelines through complete chemical decontamination and residue-free thermal sterilisation in an autoclave. Technical details Product type: Double-beater / Extended grinding tool Processing principle: Impact and percussion comminution on two levels Fluid mechanics: Three-dimensional vortex generation on a macroscopic scale Physical scope of application: Soft to medium-hard sample matrices (up to Mohs hardness 3) Compatibility (vessel): Essential for the IKA A 11.4 grinding beaker (250 ml) Compatibility (drive): Exclusively compatible with the IKA A 11 basic analytical mill Material: Solid, highly wear-resistant stainless steel Assembly: Form-fit, tool-free locking onto the drive shaft Hygiene: Fully thermally autoclavable Contents 1 x IKA A 11.6 double beater (stainless steel) (Important note: The A 11 basic drive unit and the essential A 11.4 grinding beaker are not included in the scope of delivery!) Individual requirements & accessories The A 11.6 double beater is not a self-contained standard tool, but forms an essential fluid-dynamic unit together with the IKA A 11.4 grinding beaker (item no. 0002904100). The use of this double beater in the small 80 ml standard beaker is geometrically impossible. Please also note that when grinding large volumes, the thermodynamic load (exothermic reaction due to frictional heat) on the drive motor increases; the maximum duty cycles (ED) defined by IKA must be strictly adhered to in order to protect the motor windings from overheating. Please contact our procurement service at any time for metrologically correct scaling of your grinding processes.