The Planetary Ball Mill PM 300 is a powerful and ergonomic benchtop model with two grinding stations for grinding jar volumes up to 500 ml. This setup allows for processing up to 2 x 220 ml sample material per batch. Thanks to the high maximum speed of 800 rpm, extremely high centrifugal forces result in very high pulverization energy and consequently in short processing times.
The PM 300 is ideally suited for virtually all industries where the quality control process places the highest demands on purity, speed, fineness and reproducibility. Thanks to its enormous energy input of up to 64.4 times the acceleration of gravity, this mill is the perfect choice for tasks in research like mechanochemistry (co-crystal screening, mechanosynthesis, mechanical alloying and mechano-catalysis), or for ultrafine colloidal grinding on a nanometer scale.
Benefit from particularly ergonomic handling while achieving the same finenesses down to the nanometer range.
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. A unique safety feature of the PM 300 is an acoustic signal and notification in the display when the clamping unit has been fixed with the required force of 25 Nm. RETSCH offers a convenient clamping aid to facilitate the process. This is particularly helpful when the machine is operated in the upper speed range between 600 and 800 rpm.
Măcinarea umedă este utilizată pentru a obține dimensiuni de particule sub 5 µm, deoarece particulele mici tind să se încarce pe suprafețele lor și să se aglomereze, ceea ce face dificilă măcinarea ulterioară în regim uscat. Prin adăugarea unui lichid sau a unui dispersant, particulele pot fi dispersate.
Pentru a produce particule foarte fine de 100 nm sau mai puțin (măcinare la scară nanometrică) prin măcinare umedă, sunt necesare mai degrabă forțe de frecare decât de impact. Acest lucru se realizează prin utilizarea unui număr mare de bile de măcinare mici, care au o suprafață mare și multe puncte de frecare. Nivelul ideal de umplere al incintei ar trebui să fie format din 60% bile mici de măcinare.
Pentru mai multe detalii despre umplerea incintei, măcinarea umedă și recuperarea probei măcinate, urmăriți videoclipul.
În acest material video este prezentată măcinarea umedă în Moara Planetară cu Bile PM 100.
The graphic shows the result of pulverizing titanium dioxide (TiO2) at 650 rpm and 800 rpm in the PM 300 and the net processing time. With the higher energy input at 800 rpm, the particle size decreases faster. However, the increased warming effects at 800 rpm should also be considered, as they might make longer breaks necessary.
Net processing time of titanium dioxide with 0.1 mm grinding balls in sodium phosphate solution
RETSCH Planetary Ball Mills are perfectly suited for processes like mechanical alloying or mechanosynthesis. For most reactions, the 1:-2 speed ratio of jar to sun wheel of the models PM 100 and PM 200 is fully adequate, as the ball charge produces enough impact energy. However, greater energy is required for some reactions. Here the PM 400 MA can be used with the increased speed ratio of 1:-2.5 or 1:-3.0.
The PM 300 works with a speed ratio of 1:-2, but in contrast to other models, it reaches up to 64.4 x acceleration of gravity thanks to the maximum speed of 800 rpm and the large sun wheel. Together with the option to use four small, stackable grinding jars sized 12 to 80 ml for small scale operations, or two jars sized up to 500 ml for upscaling purposes, this planetary ball mill is highly suitable for research applications in mechanochemistry.
Achievable acceleration in different planetary ball mills dependent on speed setting
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
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.
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.
Pentru a obține rezultate optime de măcinare, dimensiunea incintei trebuie adaptată la cantitatea de probă care urmează să fie prelucrată. Dimensiunea ideală a bilelor de măcinare trebuie sa fie de 3 ori mai mare decât cea mai mare particulă din probă. Respectând această regulă empirică, numărul bilelor de măcinare pentru fiecare dimensiune a bilelor și volum al incintei este indicat în tabelul de mai jos. De exemplu, pentru a măcina 200 ml probă formată din particule de 7 mm, se recomandă o incintă de 500 ml și bile de 20 mm diametru sau mai mari. Conform tabelului sunt necesare 25 de bile de măcinare.
| Volum nominal incintă de măcinare |
Volum probă | Dimensiune max. probă | Încărcătura de bile recomandată (bucăți) | ||||||
| Ø 5 mm | Ø 7 mm | Ø 10 mm | Ø 15 mm | Ø 20 mm | Ø 30 mm | ||||
| 12 ml | până la ≤5 ml | <1 mm | 50 | 15 | 5 | - | - | - | |
| 25 ml | până la ≤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 | |
If a pulverization process in a planetary ball mill is successful depends on the machine settings but also on the filling level of the grinding jar. The usable volume of the jars depends on the type of sample material. The number of grinding balls given in the table reflect the minimum amount per jar. A better result is obtained with a larger number of suitable balls, if indicated. In exceptional cases, the number of balls can be reduced by not more than 15%; however, that will result in increased wear of the grinding tools.
Morile planetare cu bile RETSCH sunt perfect adecvate pentru reducerea dimensiunii, de exemplu, a aliajelor, bentonitei, oaselor, fibrelor de carbon, catalizatorilor, celulozei, clincherului de ciment, ceramicii, cărbunelui, produselor chimice, mineralelor, cărbunelui, cocsului, compostului, betonului, deșeurilor electronice, fibrelor, sticlelor, hidroxiapatită, minereu de fier, caolin, calcar, oxizi metalici, minerale, minereuri, vopsele și lacuri, hârtie, pigmenți, materiale vegetale, polimeri, cuarț, semințe, pietre semiprețioase, nămol de epurare, zgură, soluri, țesuturi, tutun, mostre de deșeuri, lemn etc.
11 g sample
50 ml tungsten carbide grinding jars
4 x 20 mm tungsten carbide grinding balls
4 min at 400 rpm
85 g sample
125 ml zirconium oxide grinding jars
7 x 20 mm zirconium oxide grinding balls
12 min at 500 rpm
100 g sample + 190 ml sodium-phosphate solution
500 ml zirconium oxide grinding jars
1 kg 2 mm zirconium oxide grinding balls
3:30 min net-grinding at 650 rpm
Grinding breaks help to keep temperature lower
125 g sample
500 ml zirconium oxide grinding jars
8 x 30 mm zirconium oxide grinding balls
3 min at 350 rpm
| Aplicabilitate | pulverizing, mixing, homogenizing, colloidal milling, mechanical alloying, mechanochemistry, co-crystal screening |
| Domenii in care se utilizeaza | agricultura, biologie, geologie / metalurgie, industria chimica, materiale de constructii / electronice, medicina / farmaceutice, mediu / reciclare, sticla / ceramica |
| Material probă | moale, dur, fragil, fibros - ud sau uscat |
| Principiul de reducere a dimensiunii | impact, frecare |
| Dimens. max. probă* | < 10 mm |
| Finețe finală* | < 1 µm, pentru macinare coloidală < 0.1 µm |
| Volum/masă probă admisă* | max. 2 x 220 ml |
| Posturi de macinare | 2 |
| Rata de viteză | 1 : -2 |
| Viteza roții solare | 50 - 800 min-1 |
| Diametrul efectiv al roții solare | 180 mm |
| Acceleratie | 64 g |
| Tipul incintelor de măcinare | optional areation covers, safety closure devices |
| Material de constructie a elementelor de macinare | hardened stainless steel, carbura de wolfram, agat, alumina sinterizata, oxid de zirconiu |
| Dimensiuni recipiente de macinare | 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 |
| Setarea timpului de macinare | digital, de la 00:00:01 la 99:59:59 |
| Operare interval | da, cu inversarea sensului de rotatie |
| Durată interval | 00:00:01 la 99:59:59 |
| Durata pauzei | 00:00:01 la 99:59:59 |
| POS-uri stocabile | 12 |
| Programe de cicluri stocabile | 4 |
| Măsurarea energiei posibile de intrare | da |
| Interfață | USB, RASPI |
| Antrenare | motor asincron cu convertizor de frecvență |
| Putere motor | 2,5 kW |
| Alimentare electrica | 200-240 V, 50/60 Hz |
| Conectare sursă de alimentare | monofazic |
| Grad de protecție | IP 20 |
| Putere instalata | ~ 3335 VA |
| W x H x D (închis) | 745 x 525 x 580 mm |
| Masa netă: | ~ 118 kg |
| Standard | CE |
| Brevet / brevet instalație | da |
În moara planetară cu bile incintele de măcinare sunt dispuse excentric pe un "disc solar". Discul se rotește în sens opus mișcării incintelor de măcinare, în raport de 1:-2. Bilele din incinte sunt supuse unor mișcări de rotație suprapuse, așa-numitele forțe Coriolis.
Diferența de viteză dintre bile și incintele de măcinare produce o interacțiune între forțele de frecare și de impact care eliberează energii dinamice ridicate. Interacțiunea dintre aceste forțe are ca rezultat un grad ridicat și foarte eficient de reducere a dimensiunilor în moara planetară cu bile.
