Batteries and Electronics
ROSS supplies a full range of mixing, blending, drying and dispersion equipment to the battery industry. Our mixers are installed in manufacturing facilities around the world for efficient and accurate batching of pastes, gels, slurries, solutions and powders used in various battery types and chemistries.
We understand that each formulation is unique and we work closely with every customer to match their processing objectives with the best mixing strategy.
- Aluminum Oxide-Filled Silicone Gels - conductive thermal interface material for use in high-speed computer processor applications.
- Battery Pastes and Slurries - Homogenous dispersion of the active material into the binder solution is critical for consistent battery performance. Presence of agglomerates also gives rise to problems encountered in downstream equipment such as coating machines. Typical applications include sodium hydroxide and potassium hydroxide battery pastes, nickel metal hydride battery paste, lithium cobalt oxide battery cathode paste,carbon black battery paste and lithium ion cells.
- Conductive Inks - can be a blend of finely ground carbon black into high molecular weight resin. The more viscous solutions are not easily turned over by single shaft high-speed dispersers. For these cases, the ROSS PowerMix (Planetary Disperser) yields better color development, greater particle size reduction and shorter addition and mixing times.
- Copper Pastes - used in screen-printing processes as part of multi-layered microchip production. Vacuum mixing is of benefit for this application as air in the product can cause defects in screened wires.
- Encapsulation Materials - Protective materials used to isolate circuits from moisture and other harmful contaminants, provide electrical insulation for high voltages and also protect the circuit from thermal and mechanical stresses.Encapsulants are typically applied in thick layers--exceeding 125 mils. When the two-part liquid components are thoroughly mixed, the mixture cures to a flexible elastomer either at room temperature or with the application of heat.
- Epoxy Insulators - when prepared in single shaft mixers, heating of powder ingredients is necessary and solids are slowly added to the top of liquid epoxy resin and hardeners. The ROSS PowerMix and Double Planetary Mixer are recommended for this application. Heating of raw materials can then be eliminated since these mixers can tolerate the viscosity. Vacuum mixing will reduce air entrapment in the end product. This is important because air voids can cause the insulator assembly to rupture.
- Ferrite Compounds - Our Double Planetary Mixers with HV Blades are excellent equipment for manufacturers of battery, capacitors and power storage products utilizing Carbon Black Slurry and Ferrite in Binder technologies.
- Ferrite in Propylene - in the manufacture of components for capacitors, ferrite powders are mixed into wax, copolymer and polypropylene binder. Downstream, the cooled mixture is broken up to smaller pieces for injection molding. Former users of Sigma Blade Mixers and Two-Roll Mills have successfully transitioned to ROSS Double Planetary Mixers and Discharge Systems and improved their over-all production.
- Fuel Cell Powders - an example is a lithium cake mixture, which functions as a porous, insulating, and chemically inert ceramic matrix inside the fuel cell. The cake is thoroughly blended using a ROSS Ribbon Blender with little heat introduction.
- Solder Pastes - fusible metal alloys, melted at relatively low temperatures (120-450°C) to join metallic surfaces. The solder particles are frequently a mix of tin and lead, though newer legislation is forcing a move to lead-free solder. Proper dispersion of solder particles throughout the liquid vehicle is key to achieving the required physicochemical characteristics. Basic single planetary mixers, sigma-blade tilt-type units and pony mixers have been used to make solder pastes. However, the level of success achieved by such types of equipment is often compromised by the lack of vacuum capability, temperature control and/or shear power.
- Thick Film Inks - dispersion of very small particles of inorganic powders in a viscous liquid vehicle. The type of powder used determines the nature of the thick film ink; metals for conductors, metal oxides for resistors and dielectric glasses for insulating coatings. Effective mixing and dispersion of these electronic links is the key to successful production of advanced multilayer hybrid microelectronics.
- Tungsten Carbide Powders - The ROSS Double Planetary Mixer is extremely successful in blending a slurry of these extremely dense materials, then vacuum drying the batch to form a light, fluffy powder.
- Recommended Mixing Equipment for Encapsulation Materials
The majority of encapsulation materials utilized in electronic packages are highly-filled epoxy and hardener resin systems.
- Recommended Mixing Equipment for
Thermal Interface Materials.
Thermal greases are viscous gels or pastes applied to electronic components to increase heat conductivity. They improve the efficiency of a heat sink by filling gaps that would otherwise hold air. Common formulations consist of ceramic or metal powders suspended in synthetic oil or grease, typically silicone.
- Simplified production of fine solid dispersions.
This bulletin discusses a new technology for producing stable dispersions of solids in liquid. Ultra-high shear mixers such as the ROSS PreMax utilize specially engineered rotor/stators that can deliver extremely fine particle size distributions faster and more cost-effectively than conventional milling devices.
- Prevent localized overheating
in your batch mixer.
Localized overheating is a mixing issue that happens more commonly in viscous applications. Utilizing the appropriate mixer for a given viscosity range is the best way to avoid localized overheating and product degradation.
- Ultra-high shear mixing of
Batch and inline ultra-high shear rotor/stator mixers can effectively disperse nanoparticles into liquid. Advantages include short processing times and volume flexibility, as well as easier maintenance and lower capital cost compared to traditional milling equipment and high pressure homogenizers.
- Conserve raw materials in a scalable R&D mixer.
Scalable mixing equipment allow R&D scientists to conserve expensive ingredients while following a repeatable, consistent agitation method that can be easily replicated in pilot or production scale. This bulletin presents some R&D mixers and their smallest recommended batch volumes.
- Best practices for safe and efficient three roll milling
The three roll mill remains to be one of the best methods for preparing very fine particle dispersions. This bulletin discusses some best practices to help users operate the three roll mill safely and efficiently.
- Hybrid planetary mixers
produce high viscosity mixtures with ultra-fine dispersion quality.
Hybrid planetary mixers are utilized for creating fine dispersions in viscous mixtures, typically within the viscosity range of 100,000 to 2 million cP. Intense mixing is applied to the product by constantly advancing a high speed disperser and a low speed stirrer into the batch. Solids are quickly incorporated into the viscous bulk material and agglomerates are dispersed regardless of product flow characteristics. Designs for multiple planetary stirrers and disperser blades are available for more demanding applications.