Powder

Powder refers to a substance that consists of fine particles, typically dry and free-flowing when not agglomerated. Powders cover a broad range of materials, including minerals, metals, organics, and manufactured formulations. They are often described by particle size distribution, surface area, moisture content, and flow properties, all of which influence handling, processing, and performance.

Powders are produced by methods such as milling, grinding, atomization, spray drying, precipitation, or crystallization. The resulting powders can vary in particle size, shape, and tendency to aggregate. Flowability depends on size, shape, roughness, and cohesiveness; the angle of repose and bulk density are common measures. Some powders are highly reactive or hygroscopic due to large surface areas.

Common categories include food powders (milk, flour, coffee), pharmaceutical powders (active ingredients and excipients), cosmetic powders (talc, mica, titanium dioxide), metal powders (used in powder metallurgy and additive manufacturing), polymer and ceramic powders, and energetic powders used in pyrotechnics or propulsion.

Powders are used for dosing and formulation, instant beverages, drug delivery, coatings, catalysis, 3D printing, metal forming, cleaning, and agricultural products. Processing to produce powders may involve drying, controlled milling, or atomizing liquids into fine solid particles that solidify into powder.

Safety and handling considerations include dust control, health hazards from inhalation, and fire or explosion risks in certain dust-air mixtures. Industrial use typically requires ventilation, containment, proper storage, and personal protective equipment.