MIXING TWO SAMPLES WITH A FRITSCH PLANETARY MILL
Learn more about mixing white aluminum oxide and red pigments in an 80 ml agate grinding bowl with approx. 250 agate grinding balls 5 mm dia. in less than 90 seconds.
Planetary Micro Mill
PULVERISETTE 7
classic line
AT A GLANCE
- Fast fine grinding with rotational speeds up to 800 rpm
- Loss-free comminution also below 1 μm
- Uniform extremely fine comminution of smallest sample amounts
- Useful capacity up to 2 x 20 ml
IDEAL FOR
GEOLOGY AND MINERALOGY
CERAMICS
CHEMISTRY
BIOLOGY
PHARMACEUTICALS
METALLURGY
MATERIAL TECHNOLOGY
SAMPLE PREPARATION FOR ANALYSIS
OVERVIEW
Ideal for smallest quantities
The PULVERISETTE 7 classic line with 2 working stations is ideally suited for fast, uniform, and extremely fine comminution of very small samples down to colloidal fineness of hard, medium-hard, brittle and moist samples. Depending on the desired final fineness can the grinding be performed dry or in suspension.
Besides for comminution, the Planetary Ball Mill can be utilized for mixing and homogenizing of emulsions and pastes.
TECHNICAL DATA
| Working principle | impact force |
| Optimal for material type | hard, medium-hard, brittle, moist |
| Number of working stations | 2 |
| Grinding tools | grinding bowls and grinding balls |
| Materials of the grinding tools | agate, sintered corundum, silicon nitride, zirconium oxide, hardened stainless steel, hardmetal tungsten carbide, polypropylene |
| Grinding bowl sizes | 12, 45 ml |
| Grinding ball diameter | 0.1 – 15 mm |
| Max. feed size (depends on material) | 5 mm |
| Min. sample quantity | 0.5 ml |
| Max. sample quantity | 40 ml |
| Final fineness (depends on material) | < 1 µm |
| Typical grinding time down to analytical fineness | 3 min |
| Grinding process | dry/wet |
| Grinding in inert gas | only possible in glove box |
| Gas pressure and temperature measurement | no |
| Rotational speed of main disk | 100 – 800 rpm |
| Transmission ratio planetary disk / grinding bowl | i relative = 1 : -2 |
| Effective diameter of main disk | 140 mm |
| Centrifugal acceleration (g = 9.81 m/s²) | 50 g |
| Interfaces | yes |
| Electrical details | 100-120/200-240 V/1~, 50-60 Hz, 740 Watt voltage, indicated by customer is set |
| Emission sound pressure level at the workplace according to DIN EN ISO 3746 (depending on the material to be ground, grinding bowls/balls, selected rotational speed) | up to approx. LpAd = 82 dB |
| Weight | 35 kg |
| Dimensions (W x D x H) | bench top instrument 37 x 53 x 50 cm |
WORKING PRINCIPLE
Comminution according to the Planetary Principle
The comminution of the material to be ground takes place primarily through the high-energy impact of grinding balls. To achieve this, the grinding bowl, containing the material to be ground and grinding balls, rotates around its own axis on a main disk whilst rotating rapidly in the opposite direction.
At a certain speed, with this configuration, the centrifugal force causes the ground sample material and grinding balls to separate from the inner wall of the grinding bowl. The grinding balls then cross the bowl at high speed and further grind the sample material by impact against the opposite bowl wall. In addition, impact between the balls themselves on the sample material adds to the size reduction process.
Due to the enormous rotational speed of the main disk – up to 800 rpm – the PULVERISETTE 7 classic line reaches a centrifugal acceleration of up to 50 g.
FEATURES
- Rotational speed up to 800 rpm – precise rotational speed regulation with display of set/actual values
- Fast fine grinding of small quantities
- Small footprint
- Simultaneous processing of 2 samples
- Useful capacity up to 2 x 20 ml
- Programmable microprocessor control
- Up to 99 repetitions of the grinding cycle
- Programme-timer for grinding operation and cooling phases
- Reversing function
- Energy-save function (electricity-saving mode)
- RS232 interface for output of process data and programming cycles
- Grinding chamber completely encapsulated, but easy to open
- Cooling of the grinding chamber with a built-in fan for long grinding times
- Ergonomic IP64 membrane keyboard
- Maintenance-free drive with asynchronous motor and frequency converter
- Extensive accessories for simplifying your daily work
VIEW EXTENSIVE ACCESSORIES
REPRODUCIBLE GRINDING RESULTS
Particularly high grinding performance – low bench space requirements
The special microprocessor control with up to 99 programmable repetitions of the grinding cycle ensures exceptionally fast, precise, reproducible results. A mill that combines particularly high grinding performance with low bench space requirements!
EQUIPMENT / ACCESSORIES
Configure your Planetary Micro Mill PULVERISETTE 7 classic line exactly to your specific application
The Planetary Micro Mill PULVERISETTE 7 classic line operates with two grinding bowls of sizes 12 ml or 45 ml, which turn with a transmission ratio 1 : -2 relative to the main disk. To achieve best grinding results and for direct prevention of contamination of the samples due to undesired abrasion, grinding bowls and grinding balls are available in 7 different materials.
APPLICATIONS / SOLUTIONS
ROCK, PAPER, SCISSORS: WAYS THAT MILLING AND SAMPLE PREP AFFECT OUR EVERYDAY LIVES
Find out what the children’s game “Rock, Paper, Scissors” has to do with the science of milling and sample preparation.
INFLUENCE OF PROPERTIES OF GRINDING BOWLS IN THE PLANETARY SYSTEM
A clean and constant wear on the inner grinding bowl surface is a question of the amount of grinding balls and size, material amount and size (coarse or fine), the grinding condition like wet or dry grinding, the grinding duration and the adjusted rotations of the planetary system.
FROM “BOULDER” TO NANO-PARTICLES
Medium-hard to hard materials with edge lengths up to 95 mm can be pre-crushed with the FRITSCH Jaw Crusher PULVERISETTE 1 so an additional fine comminution with many FRITSCH mills is possible.
ADDITIVES FOR DRY MILLING
During a dry grinding, often only after a short grinding period hygroscopic material tends to stick. A second factor causing this is the static charge respectively adhesive powers of fine particles.
PURPLE MOOR-GRASS – COMMINUTION OF MOLINIA CAERULEA
Interesting for research are the absolute contents and the ratios of carbon and nitrogen in the plant material. For the determination of these values mostly carbon and nitrogen analyzers are utilized. First, the sample must be ground though.
PLANETARY BALL MILLS AS AN INSTRUMENT IN MECHANOCHEMISTRY
One of the most significant fields of application for FRITSCH Planetary Mills is mechanochemistry. This subject is in theory, as well as in practice very wide-ranging and versatile. In the article you will find summarized information about history, functionality and the fields of application of mechanochemistry.
MECHANOCHEMISTRY – CHEMISTRY WITH THE HAMMER
The article „Mechanochemistry – Chemistry with the Hammer“ published in the magazine Chemie unserer Zeit (Chemistry of our time) was written compact and comprehendible by three experts. The article sums up the multifaceted area of mechanochemistry: from the historical developments to physical mechanisms to application possibilities. Article only available in German.
ORGANIC CHEMICAL SYNTHESIS VIA PLANETARY BALL MILLS
The Institute for Technical Chemistry and Environmental Chemistry of the University of Jena is intensively researching in the area of organic chemical syntheses with Planetary Ball Mills: especially the Suzuki-Miyaura reactions, the oxidation with potassium manganite, the synthesis of cyclic boronic acid ester and the Knoevenagel condensation.
DRUG TESTING VIA HAIR ANALYSIS
In order to proof the consumption of drugs (cocaine, cannabis products, amphetamines) even after long periods of time, hair is frequently analyzed.
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