Q1: What are flow properties of powders, and why are they important?
A1: Flow properties refer to the ability of powders to flow smoothly and consistently. They’re crucial in industries like pharmaceuticals, food, and cosmetics, as they affect product quality, processing efficiency, and equipment design.
Q2: What factors affect powder flow properties?
A2: Factors include particle size, shape, distribution, moisture content, surface roughness, and electrostatic charges. These factors can influence powder behavior, such as flowability, segregation, and agglomeration.
Q3: How do you measure powder flow properties?
A3: Common methods include:
* Angle of repose
* Carr’s index (compressibility index)
* Hausner ratio
* Flow function coefficient (ffc)
* Shear cell testing
Q4: What is the difference between cohesive and free-flowing powders?
A4: Cohesive powders have strong interparticle forces, leading to poor flowability, while free-flowing powders have weaker forces, resulting in better flowability.
Q5: How can you improve powder flow properties?
A5: Strategies include:
* Optimizing particle size and distribution
* Controlling moisture content
* Using flow aids or glidants
* Modifying equipment design
Q6: What is the significance of powder flow properties in pharmaceutical applications?
A6: Powder flow properties affect tablet or capsule uniformity, content uniformity, and manufacturing efficiency. Poor flowability can lead to issues like weight variation, segregation, or clogging.
Q7: Can you describe a situation where powder flow properties would be critical?
A7: In a tablet manufacturing process, poor powder flowability could lead to inconsistent filling of tablet dies, resulting in weight variation and potentially affecting product efficacy and safety.
These questions assess the candidate’s understanding of powder flow properties, measurement methods, and applications.
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ABAC
