Grinding & Dispersing Nanomill ZETA RS Innovation in Wet Grinding Technology our technology YOUR SUCCESS
Nanomill ZETA RS The Future Starts Today The demand for materials with particle sizes in the nanometer range is increasing. Reasons are functionoriented advantages that these materials have in the final product. In the colloidal particle size region it is important to distinguish between real comminution, dispersing and disaggregating. For coarse, primary particles, high pressure and impact stresses are required for real comminution. For agglomerated nano-scale particles that require only dispersing, the direct stresses of real grinding damage the crystal structure of the nanoparticle. Reason for this is the change in the mechanical characteristic of the product particles with decreasing particle size, from brittle-elastic to plastic behavior. Changeovers from crystalline to amorphous material structure or mechanical-chemical activated reactions can negatively influence the product characteristics. Specially designed equipment is necessary for dispersing nano-structured systems or for production of nanoscale particles. 2
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Nanomill ZETA RS Mild Dispersing Nano-structured TiO 2 particles for use in photo catalytic coatings are dispersed using varied agitator speeds (4 and 13 m/s). The desired degree of dispersion was achieved with an agitator speed of 13 m/s however the result was the behavior of coatings with this material was inactive. Examinations with X-ray diffraction structure analysis showed that compared with gentle dispersing the crystalline mesh effect of the TiO 2 has been destroyed due to the highly energetic stresses. Agglomerates of nano-scale primary particles should mainly be stressed by shearing under gentle conditions. For this the use of smallest grinding media at very low agitator speeds in agitator bead mills is necessary. For this complex task, NETZSCH-Feinmahltechnik GmbH was developing the new mill generation ZETA RS. 1 1 Median particle size x 50,3 / μm 0.1 Damages in structure, plastic deformation of the primary particles gentle dispersing Median particle size x 50,3 / μm 0.1 GM: ZrO 2 ) GM = 0.9 d GM = 0.1 mm c m = 0.05 v t = 4 m/s v t = 13 m/s 0.06 0 10 20 30 40 50 60 70 Specific energy input E m / kwh/kg 0.06 0 10 20 30 Dispersion time t D / min X-ray structure analysis XRD Diffraction intensity / cps 400 200 TiO 2 - Dispersion 0 sample 13 m/s 14 m/s 0 20 30 40 50 60 70 Diffraction angle 2 / 4
Handling When developing the ZETA RS machine series ergonomics was an important design criteria. Filling and emptying of the machine, service work and cleaning of the machine were parameters. Swiveling grinding unit via hand wheel or electronic drive as an option (standard from machine size of 10 l) Moveable grinding tank Integrated, removable grinding media collection tray Filling position Working position Emptying and cleaning position 5
Nanomill ZETA RS Mode of Operation Agitator bead mills of the type ZETA RS can process in passage or circulation operation. Products in a wide range from gentle dispersing conditions (4 m/s) to very high energy densities (20 m/s) can be handled. Grinding System The agitator bead mills of the ZETA RS series were developed for use of grinding media in the range of 50 µm - 300 µm. Adaptation of geometric proportions of the NETZSCH ZETA system circulation mill and the use of a new, innovative separation system were the design parameters. Peg-grinding system with equivalent length/diameter proportion and high power density Highly efficient centrifugal separation system consisting of a hollow, slotted peg agitator shaft with centrically arranged rotating large-area separation unit Product inlet on bearing side Product discharge through the driveshaft occurs after grinding media separation 6
Separation Systems High throughput rates in circulation operation and the use of grinding media in a range of 50-300 µm, are necessary for dispersing and real comminution down to the nanometer range. These process requirements require a highly efficient grinding media retention system. Further development of the NETZSCH centrifugal separation system resulted in the rotating screen system or a newly developed, patent pending ODC (Open Dynamic Classifying) version. Advantages of the ODC system: Processing of suspensions with coarse agglomerates No loss of grinding media when starting and stopping the machine No grinding media discharge also at high throughput rates Discharge of contaminations and coarse product particles Rotating screen system ODC-system Technical Data ZETA RS 2 ZETA RS 4 ZETA RS 10 ZETA RS 25 Drive Power [kw] 7.5 15 25 45 Speed [min -1 ] 400-3,300 350-2,500 300-2,000 250-1,500 Grinding chamber volume [l] 2 4 10 25 Grinding media diameter [µm] 50-300 50-300 50-300 50-300 7
Nanomill ZETA RS Grinding Chamber Materials The machines of the ZETA RS series are available in different wear resistant and corrosion resistant materials. All grinding chamber parts of stainless steel Zirconium or SiC/Si N design for 3 4 metal-free fine grinding of solventbased products Polyurethane or on request polyethylene design for metal-free fine grinding of water-basedproducts We offer the optimal solution for your demand. Polyurethane design ZrO 2 design 8
Changeover A special conversion kit was developed for the production of small product quantities. It enables a changeover from ZETA RS 4 with 4 l grinding chamber volume to the grinding chamber design of the smaller ZETA RS 2 with 2 l grinding chamber volume. Two adapter rings that are easily assembled (displayed in orange) provide a reduced grinding chamber diameter and smaller agitator shaft. ZETA RS 4 ZETA RS 2 Advantages at a Glance Compact design for minimal space requirement Easy handling by swiveling grinding unit and sliding grinding chamber Grinding media collection tray provides retention of expensive small beads and easy cleaning Reliable use of smallest grinding media in a range of 50-300 µm No screen blocking due to the ODC separation system (Open Dynamic Classifying-System) Variety of materials available for grinding systems (can be interchanged) Changeover from 4 l to the smaller 2 l design 9
Nanomill ZETA RS Applications The machines of the ZETA RS series are used for gentle dispersing as well as real comminution of various products such as pigments, inkjet, MLCC, functional coatings, nano ceramics, cosmetics and personal care, and many more. The following table shows a survey of dispersing results of different applications that had been tested under gentle conditions. Product Application Grinding media material Grinding media diameter Peripheral speed Pigment LCD ZrO 2 ) 0.1 mm 6 m/s 40-60 Pigment Inkjet ZrO 2 ) 0.1 mm 6 m/s 13 TiO 2 Photo catalyst ZrO 2 ) 0.1 mm 6 m/s 44 ITO Electronic ZrO 2 ) 0.1 mm 6 m/s 44 ZrO 2 Electronic ZrO 2 ) 0.05 mm 4 m/s 37 Diamond Polishing agent ZrO 2 ) 0.1 mm 10 m/s 19 BaTi MLCC Glass 0.1 mm 3 m/s 200 SiO 2 Paper Glass 0.1 mm 8 m/s 40 Achieved particle size x 50 BaTi before BaTi after 10
Availability A state-of-the-art application laboratory is available for tests at our headquarters in Selb, Germany. With the ZETA RS 4 test station we can disperse, disaggregate or comminute nanoscale products. Analytics Extensive analytical instruments for determination of the grinding and dispersing particle size results and product viscosity are also provided in our laboratory. Ultra sonic spectrometer DT 1200 with integrated measurement of the Zeta potential for suspensions in a concentration range from 1 to 50 Vol. %; measuring area 0.005 to 100 µm Horiba LB-550, dynamic light scattering, integrated measurement of viscosity, measuring area 1-6,000 nm Horiba LA-950, static light scattering combined with laser deflection, measuring area 20 nm - 2 mm ETA RS 11
The World s Leading Grinding Technology The Companies of the Grinding & Dispersing Business Unit NETZSCH-Feinmahltechnik GmbH, Selb, Germany NETZSCH-CONDUX Mahltechnik GmbH, Hanau, Germany NETZSCH Premier Technologies, LLC., Exton PA, USA NETZSCH Indústria e Comércio de Equipamentos de Moagem Ltda., Pomerode, Brazil NETZSCH (Shanghai) Machinery and Instruments Co., Ltd., Shanghai, China NETZSCH Mastermix Ltd., Lichfield, Great Britain NETZSCH-España, S.A., Terrassa/Barcelona, Spain ZAO NETZSCH Tula, Tula, Russia The Grinding & Dispersing Business Unit is part of the NETZSCH Group. The NETZSCH Group is an owner-managed, internationally operating technology company headquartered in Germany. Three Business Units Analyzing & Testing, Grinding & Dispersing, and Pumps & Systems provide tailored solutions for highestlevel needs. Over 2200 employees at 125 sales and production centers in 23 countries across the globe guarantee that expert service is never far from our customers. NETZSCH-Feinmahltechnik GmbH Sedanstraße 70 95100 Selb Germany Tel.: +49 9287 797-0 Fax: +49 9287 797 149 info.nft@netzsch.com www.netzsch.com G&D ZETA RS / 12 EN 500 04/10 MD Technical specifications are subject to change.