The Planetary Ball Mill PM 100 is a powerful benchtop model with a single grinding station and an easy-to-use counterweight which compensates masses up to 8 kg. It allows for grinding up to 220 ml sample material per batch.
The extremely high centrifugal forces of Planetary Ball Mills result in very high pulverization energy and therefore short grinding times.
The PM 100 can be found in virtually all industries where the quality control process places the highest demands on purity, speed, fineness and reproducibility.
The mill is ideally suited for tasks in research like mechanochemistry (co-crystal screening, mechano-synthesis, mechanical alloying and mechanocatalysis), or ultrafine colloidal grinding on a nanometer scale, as well as for routine tasks such as mixing and homogenizing soft, hard, brittle or fibrous materials.
"This is a very high-performing instrument used for the preparation of nanomaterials including new crystalline phases of perovskite materials. We have used it extensively for making semiconductor and perovskite nanoparticles, quantum dots, etc. It is a very rugged and user-friendly instrument and we have been using it over a decade without much trouble. Its a highly recommended instrument for material research. "
Pravat Giri
Indian Institute of Technology Guwahati
"I use Retsch ball mill PM100 for preparing sample for hydrogen storage applications. This setup is very useful for the required materials."
Chhagan Lal
University of Rajasthan
"It was really simple and safe to use, easy to clean and it helped me with my thesis investigation. I would really recommend this product. "
Jenifer Sauzameda
Dermabon
"This is such an effective planetary ball mill. As an academic and active laboratory researcher, I would choose the best product to conduct my experiments and the PM 100 is a good example. "
Erkul Karacaoglu
Karamanoglu Mehmetbey University
"Absolutely good to use and easy to handle, long lasting compared to other brands. Highly recommended for regular users."
Md Shalauddin
University of Malaya
"It is a versatile instrument that cuts the grinding time by orders of magnitude."
Dragos Zaharescu
University of California, Davis
Benefit from particularly ergonomic handling while achieving the same finenesses down to the nanometer range.
Planetary mills with a single grinding station require a counterweight for balancing purposes. In the planetary ball mill PM 100 this counterweight can be adjusted on an inclined guide rail to compensate for the different heights of the centers of gravity of differently-sized grinding jars and thus avoid undesired oscillations of the machine.
Operation of the RETSCH planetary ball mills is particularly safe. They feature a robust Safety Slider which ensures that the mill can only be started after the grinding jar has been securely fixed with a clamping device. The self-acting lock ensures that the jar is seated correctly and securely. This proven solid mechanical system is less failure-prone than electronic solutions - the user has full access to the sample at any time. When the electronic system fails, it is not possible to unlock the jars, for example.
Wet grinding is used to obtain particle sizes below 5 µm, as small particles tend to get charged on their surfaces and agglomerate, which makes further grinding in dry mode difficult. By adding a liquid or dispersant the particles can be kept separated.
To produce very fine particles of 100 nm or less (nano-scale grinding) by wet grinding, friction rather than impact is required. This is achieved by using a large number of small grinding balls which have a large surface and many friction points. The ideal filling level of the jar should consist of 60 % small grinding balls.
For more details on jar filling, wet grinding and sample recovery watch the video.
The graphic shows the result of grinding alumina (Al2O3) at 650 rpm in the PM 100. After 1 h of size reduction in water with 1 mm grinding balls, the mean value of the particle size distribution is 200 nm; after 4 h it is 100 nm.
Grinding of alumina in water with 1 mm grinding balls (left) after 1 hour (blue) and after 4 hours (green)
In another trial, the material was first pulverized for 1 hour with 1 mm grinding balls and then for 3 hours with 0.1 mm grinding balls. In this case, an average size of 76 nm was achieved.
Grinding of alumina with 1 mm grinding balls (1 hour) and then with 0.1 mm balls (3 hours) in water
The results show that planetary ball mills can produce particle sizes in the nanometer range. The choice of the right ball size, the type of liquid and the liquid/solid ratio (viscosity level) play a crucial role in this process.
The performance and the result of sample preparation are also determined by the choice of the grinding jar and its ball charge. The EasyFit range of jars has been specially designed for extreme working conditions such as long-term trials, even at maximum speed of 800 rpm, wet grinding, high mechanical loads and maximum speeds as well as for mechanical alloying. This line of jars is suitable for all RETSCH planetary ball mills.
The new EasyFit grinding jar series features a structure on the bottom of the 50-500 ml jars called Advanced Anti-Twist (AAT). This ensures that the jars are tightly fixed without the risk of twisting, even at high speed, and that wear and tear is drastically reduced. Secure clamping of the jars is made much easier: to find the correct clamping position, a maximum twist of 60° is required.
The geometry of the EasyFit jars in the 50 ml and 250 ml sizes has been enlarged in diameter and reduced in height compared to the previous "comfort" models. This offers two advantages: better grinding results and interchangeable lids, as there are only three diameter dimensions for the entire grinding jar range.
Diameter categories
Both the aeration lid and GrindControl can now be equipped with inlays of different materials. Thus, the lid can be used for, e. g. a steel and a zirconium oxide jar by simply exchanging the inlay.
With a special adapter, co-crystal screening can be carried out in a planetary ball mill, using disposable vials such as 1.5 ml GC glass vials. The adapter features 24 positions arranged in an outer ring with 16 positions and an inner ring with 8 positions. The outer ring accepts up to 16 vials, allowing for screening up to 64 samples simultaneously when using the Planetary Ball Mill PM 400. The 8 positions of the inner ring are suitable to perform trials with different energy input, e.g. for mechanosynthesis research.
To produce optimum grinding results, the jar size should be adapted to the sample amount to be processed. The grinding balls are ideally sized 3 times bigger than the largest sample piece. Following this rule of thumb, the number of grinding balls for each ball size and jar volume is indicated in the table below. To pulverize, for example, 200 ml of a sample consisting of 7 mm particles, a 500 ml jar and grinding balls sized at least 20 mm or larger are recommended. According to the table, 25 grinding balls are required.
| Grinding jar nominal volume |
Sample amount | Max. feed size | Recommended ball charge (pieces) | ||||||
| Ø 5 mm | Ø 7 mm | Ø 10 mm | Ø 15 mm | Ø 20 mm | Ø 30 mm | ||||
| 12 ml | up to ≤5 ml | <1 mm | 50 | 15 | 5 | - | - | - | |
| 25 ml | up to ≤10 ml | <1 mm | 95 – 100 | 25 – 30 | 10 | - | - | - | |
| 50 ml | 5 – 20 ml | <3 mm | 200 | 50 – 70 | 20 | 7 | 3 – 4 | - | |
| 80 ml | 10 – 35 ml | <4 mm | 250 – 330 | 70 – 120 | 30 - 40 | 12 | 5 | - | |
| 125 ml | 15 – 50 ml | <4 mm | 500 | 110 – 180 | 50 – 60 | 18 | 7 | - | |
| 250 ml | 25 – 120 ml | <6 mm | 1100 – 1200 | 220 – 350 | 100 – 120 | 35 – 45 | 15 | 5 | |
| 500 ml | 75 – 220 ml | <10 mm | 2000 | 440 – 700 | 200 – 230 | 70 | 25 | 8 | |
The table shows the recommended charges (in pieces) of differently sized grinding balls in relation to the grinding jar volume, sample amount and maximum feed size.
RETSCH planetary ball mills are perfectly suitable for size reduction of, for example, alloys, bentonite, bones, carbon fibres, catalysts, cellulose, cement clinker, ceramics, charcoal, chemical products, clay minerals, coal, coke, compost, concrete, electronic scrap, fibres, glass, gypsum, hair, hydroxyapatite, iron ore, kaolin, limestone, metal oxides, minerals, ores, paints and lacquers, paper, pigments, plant materials, polymers, quartz, seeds, semi-precious stones, sewage sludge, slag, soils, tissue, tobacco, waste samples, wood, etc.
40 g sample
500 ml stainless steel grinding jar
8 x 30 mm stainless steel grinding balls
5 min at 380 rpm
315 g sample
250 ml tungsten carbide grinding jar
15 x 20 mm tungsten carbide grinding balls
5 min at 500 rpm
45 ml sample
125 ml stainless steel grinding jar
7 x 20 mm stainless steel grinding balls
2 min at 400 rpm
200 ml sample
250 ml zirconium oxide grinding jar
15 x 20 mm zirconium oxide grinding balls
30 min at 480 rpm
20 g sample
125 ml zirconium oxide grinding jar
50 x 10 mm zirconium oxide grinding balls
30 min at 380 rpm with direction reversal
170 ml sample
500 ml zirconium oxide grinding jar
8 x 30 mm zirconium oxide grinding balls
3 min at 450 rpm
4 sample pieces
50 ml zirconium oxide grinding jar
3 x 20 mm zirconium oxide grinding balls
2 min at 420 rpm
50 g sample + 70 g oil
50 ml zirconium oxide grinding jar
1100 g 3 mm zirconium oxide grinding balls
2 h at 480 rpm (interval operation with 10 min grinding / 10 min break = net grinding time 1 h)
To find the best solution for your sample preparation task, visit our application database.
Our instruments are recognized as the benchmark tools for a wide range of application fields in science and research. This is reflected by the extensive citations in scientific publications. Feel free to download and share the articles provided below.
| Applications | pulverizing, mixing, homogenizing, colloidal milling, mechanical alloying, mechanosynthesis, nano grinding, co-crystal screening |
| Field of application | agriculture, biology, chemistry, construction materials, engineering / electronics, environment / recycling, geology / metallurgy, glass / ceramics, medicine / pharmaceuticals |
| Feed material | soft, hard, brittle, fibrous - dry or wet |
| Size reduction principle | impact, friction |
| Material feed size* | < 10 mm |
| Final fineness* | < 1 µm, for colloidal grinding < 0.1 µm |
| Batch size / feed quantity* | max. 1 x 220 ml, max. 2 x 20 ml with stacked grinding jars |
| No. of grinding stations | 1 |
| Speed ratio | 1 : -2 |
| Sun wheel speed | 100 - 650 min-1 |
| Effective sun wheel diameter | 141 mm |
| G-force | 33.3 g |
| Type of grinding jars | EasyFit, optional areation covers, safety closure devices |
| Material of grinding tools | hardened steel, stainless steel, tungsten carbide, agate, sintered aluminum oxide, silicon nitride, zirconium oxide |
| Grinding jar sizes | 12 ml / 25 ml / 50 ml / 80 ml / 125 ml / 250 ml / 500 ml |
| Stackable grinding jars | 12 ml / 25 ml / 50 ml / 80 ml |
| Adapter for single-use glas vials | 24 x 1.5 ml / 7 x 20 ml |
| Setting of grinding time | digital, 00:00:01 to 99:59:59 |
| Interval operation | yes, with direction reversal |
| Interval time | 00:00:01 to 99:59:59 |
| Pause time | 00:00:01 to 99:59:59 |
| Storable SOPs | 10 |
| Interface | RS 232 / RS 485 |
| Drive | 3-phase asynchronous motor with frequency converter |
| Drive power | 750 W |
| Electrical supply data | different voltages |
| Power connection | 1-phase |
| Protection code | IP 30 |
| Power consumption | ~ 1250W (VA) |
| W x H x D closed | 640 x 480 (780) x 420 mm |
| Net weight | ~ 86 kg |
| Standards | CE |
| Patent / Utility patent | Counter weight (DE 20307741), FFCS (DE 20310654), SafetySlider (DE 202008008473) |
The grinding jar is arranged eccentrically on the sun wheel of the planetary ball mill. The direction of movement of the sun wheel is opposite to that of the grinding jars in the ratio 1:-2. The grinding balls in the jars are subjected to superimposed rotational movements, the so-called Coriolis forces. The difference in speeds between balls and jars produces an interaction between frictional and impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill, both, in ball to ball and ball to wall interactions.
Planetary mills with a single grinding station require a counterweight for balancing purposes. In the Ball Mill PM 100 this counterweight can be adjusted on an inclined guide rail. In this way the different heights of the centers of gravity of differently-sized jars can be compensated in order to avoid disturbing oscillations of the machine.
Any remaining vibrations are compensated by feet with some free movement (Free-Force Compensation Sockets). This innovative technology is based on the d’Alembert principle and allows very small circular movements of the machine housing that result in an automatic mass compensation. The laboratory bench is only subjected to minimal frictional forces generated in the feet.
In this way the planetary ball mill PM 100 ensures a quiet and safe operation with maximum compensation of vibrations even with the largest pulverization forces inside the grinding jars and therefore can be left on the bench unsupervised.
Content may be subject to modifications or corrections
Powered by Bioz
