Ribbon blenders (U-trough with helical ribbons) are most suitable for homogeneous mixing of which type of materials?

Introduction / Context:
Ribbon blenders are common in foods, chemicals, and pharmaceuticals. The counterflow motion of inner and outer ribbons promotes convective mixing in free-flowing bulk solids.

Given Data / Assumptions:

• Blender has a U-trough and a double-helix ribbon agitator.
• Target materials vary in flow properties.

Concept / Approach:
Ribbon blenders excel with free-flowing dry powders and granules (e.g., flour, polymer pellets, additives). They provide reasonable mixing times and gentle handling with low power compared to high-shear mixers.

Step-by-Step Solution:
Match mechanism (bulk conveyance) to material flowability.Select “Dry powders.”Exclude viscous/pasty feeds that require high-torque kneaders or planetary mixers.

Verification / Alternative check:
OEM datasheets specify recommended bulk density and angle of repose ranges for effective ribbon mixing.

Why Other Options Are Wrong:
High-viscosity/pastes/gums: need sigma-blade or double planetary mixers.Lumps with liquids: not ideal without pre-breaking and may smear.

Common Pitfalls:
Overfilling the trough, which reduces mixing efficiency.

Final Answer:
Dry powders