Particle size, morphology, and size distribution are critical factors in a material’s functional performance — the way the material behaves in its intended use. For example, very finely milled particles produced through micronization can tend to agglomerate, making them tough to handle, disperse, and blend.
And it’s not just physical properties that can complicate particle behavior. Surface chemistry also plays a role in how materials perform on the job. Certain chemical characteristics can make an important constituent difficult to handle, blend, or compound. A material may be hydrophilic, reactive, conductive, or have another property that needs to be addressed.
That’s where a toll manufacturing partner with advanced particle surface treatment capabilities can be a critical factor in achieving the functional results you need from your materials. From air jet mill services that alter particle morphology or size, to encapsulation that modifies surface chemistry, surface treatments can be a game-changer in your product formulation — overcoming limitations and expanding R&D options.
Toll processors have a range of equipment options for surface treatments, including blending and milling equipment, air jet mills, fluidized beds, and spray systems. A less complex surface treatment might use a fine spray application of oil to prevent dusting in micronized materials.
Jet milling uses physical forces to alter particle surfaces. Particles can be smoothed or spheronized to achieve characteristics like gloss in a polymer or color tone in a mineral pigment.
Jet mill blending disperses particles in air, and when coating a particle surface, it’s critical to completely encapsulate the particle — essentially replacing the original surface with one that has the properties needed for the formulation. In an air jet mill, micronized or nanonized particles can be introduced into the chamber on a jet of air or other gas, coating the larger particles as they circulate.
A similar coating process can be applied in a fluidized bed, allowing even finer particles to be surface treated. These methods make innovation possible in an incredibly broad range of industries, including:
A common example is titanium dioxide, used across industries from pigments and paints to cosmetics and food. To improve wettability and create a hydrophilic particle, a surface treatment might involve coating titanium dioxide particles with nanoparticles of silica. As more industries move from solvent-based to water-soluble formulations, characteristics like wettability and dispersion become increasingly important.
In paints, pigments, and coatings, surface treatments can influence both how a product performs during application and how it holds up over time. These properties can include coverage, opacity, lightfastness, brightness, weather resistance, smudge resistance, durability, and sheen.
In polymers and pharmaceuticals, treatments can be applied to compounded constituents like fillers. For example, a silane coupling agent may be used to ensure even distribution of fillers, such as glass fibers or other reinforcing materials. This can add strength and thermal stability, improve moisture or flame resistance, and provide conductivity or insulation.
Some applications require multiple surface treatments applied in a specific order to achieve the desired results. This can help address pH sensitivity, unwanted reagent interactions, or other formulation challenges.
Different surface treatments can deliver entirely different outcomes — even when starting with the same particle. With ongoing advancements in particle technology, micronization, and equipment capabilities, as well as the expertise of material scientists and engineers, your toll manufacturing partner can help you achieve results you might not have thought possible.
Learn more with our Particle Technology Glossary, or contact us directly for answers to your questions about Custom Processing Services’ capabilities.