POWDER CAKING, PARTICLE AGGLOMERATION, POWDER CLUMPING

Powder caking is manifest in many industries, especially chemicals, foods, and pharmaceuticals. Preventing caking or unwanted particle agglomeration can be difficult if factors contributing to these problems are not understood or well-defined.

Common factors affecting powder caking include:

Several important tests can be performed to determine the cause of powder caking, particle agglomeration or powder clumping. These tests are run under representative environmental conditions.

	Powder caking tests		Factors investigated
	Direct shear strength		Effect of pressure, temperature, moisture, chemistry, particle size or shape, and time at rest
	Moisture sorption/desorption		Effect of water vapor uptake or loss at specific temperature
	Morphology		Qualitative observation of particle shape using microscope magnification
	Surface energy		Characterization of solid’s surface

Solutions for reducing or eliminating costly caking problems include:
	Modifying process conditions, like temperature, humidity, storage, or pressure Changing particle size, shape, or distribution Changing silo configuration, such as converting from a funnel to mass flow Implementing a proper drying or conditioning system Adding anti-caking agents like fumed silica, phosphates, or stearates

Other Bench-Scale Tests Attrition Caking Flow Properties Fluidization Particle Properties Segregation Wear