With its special cutting knife system and variable-volume grinding chamber, the laboratory knife mill GRINDOMIX GM 300 processes a great variety of sample materials quickly and reproducibly to completely homogeneous analytical samples – within seconds!
Thanks to the 5000 ml grinding chamber volume, this mill easily homogenizes an entire loaf of bread or a complete pizza in one working run.
Thanks to reproducible setting of parameters and programs, the knife mill GM 300 ensures analytical results with minimum standard deviation. These features plus the wide selection of lids and containers, allowing for adaptation of the mill to individual application requirements, make the GRINDOMIX GM 300 a professional device superior to any commercial household mixer.
Tough or elastic materials which cannot be homogenized at room temperature, are safely and effectively homogenized in the knife mill GM 300 with the help of dry ice. For this application, a special cryo lid with a small opening to allow for possible overpressure to escape is available. Used in combination with a stainless-steel container and full metal knife, it ensures safe and efficient cold grinding.
Operation of the laboratory knife mill GRINDOMIX GM 300 is exceptionally comfortable and safe. The grinding container and knife are easily attached without tools. When the set time has expired, the motor is automatically switched off and the container can be removed. Thus, the GRINDOMIX, unlike many commercial household mixers, allows filling and emptying the container outside the mill. The knife remains on the knife holder during the process and can be easily removed for cleaning afterwards. Thanks to this quick and easy procedure, cross contaminations caused by sample residues are successfully prevented. Another advantage of the GRINDOMIX knife mills: the grinding tools are autoclavable. The GM 300 features a convenient 1-button operation with graphic display. All parameters are digitally set and 10 Standard Operating Procedures (SOPs) can be stored.
RETSCH has developed a gravity lid for the GRINDOMIX knife mills which reduces the volume of the grinding container, preventing the sample from escaping the homogenization process by clinging to the container walls. The lid drops under its own weight during grinding and always rests directly on the sample. The result is thorough homogenization of the complete sample material. The gravity lid is also available with overflow channels. It ensures that the cell liquid released by the sample during grinding is returned through these channels to the center of the container, allowing for perfect homogenization.
| Applications | size reduction, homogenization and mixing |
| Field of application | agriculture, biology, food, medicine / pharmaceuticals |
| Feed material | soft, medium-hard, elastic, containing water / fat / oil, dry, fibrous |
| Size reduction principle | cutting |
| Material feed size* | ~ 130 mm |
| Final fineness* | < 300 µm |
| Batch size / feed quantity* | with standard lid 4500 ml with gravity lid 4000 ml |
| Grinding chamber volume | 5000 ml, reduction with gravity lid |
| Speed setting | digital, 500 - 4000 min-1 |
| Dry grinding | yes |
| Wet grinding | yes |
| Material of grinding tools | grinding container: autoclavable plastic PC, stainless steel 1.4435 blade: stainless steel 1.4034 holder for blade: PVDF sealings: EPDM, FKM |
| Setting of grinding time | digital, 5 s - 3 min |
| Interval operation | yes |
| Interval time | adjustable |
| Storable SOPs | 10 |
| Drive | 3-phase asynchronous motor with frequency converter |
| Drive power | continuously 1.1 kW, short term 3 kW |
| Electrical supply data | different voltages |
| Power connection | 1-phase |
| Protection code | IP 20 |
| W x H x D closed | 440 mm x 340 mm x 440 mm |
| Net weight | ~ 30 kg |
| Standards | CE |
*depending on feed material and instrument configuration/settings
The laboratory knife mill GM 300 features four sharp, robust blades, which rotate in the center of the grinding container. Depending on the rotational direction, size reduction is effected with the blunt side (preliminary size reduction) or the sharp side (fine grinding). The knifes are protected with a counterblade from damages by hard sample materials.
The knife is indirectly driven by a powerful motor of 1.1 kW which can reach temporary peaks of 3 kW. A pre-selectable speed which is maintained electronically ensures reproducible results.
