What is the Difference Between Plastic and Pseudoplastic Flow?

The main difference between plastic and pseudoplastic flow lies in their behavior when subjected to stress. Here is a summary of their differences:

• Plastic Flow:
• Occurs in materials that exhibit a hard, solid-like behavior until a critical stress is reached.
• Once the critical stress is applied, the material starts to flow like a liquid.
• Examples of plastic flow include bending a piece of metal or pounding it into a new shape.
• Pseudoplastic Flow:
• Also known as shear-thinning flow, pseudoplastic flow exhibits the behavior of both Newtonian flow and plastic flow.
• The viscosity of pseudoplastic fluids decreases with increasing shear rate.
• Examples of pseudoplastic fluids include blood, sand in water, honey, nail polish, lava, ketchup, and whipped cream.

In summary, plastic flow describes the flowing behavior of a material after applying a critical stress, while pseudoplastic flow exhibits the behavior of both Newtonian flow and plastic flow, with a decreasing viscosity as the shear rate increases.

Comparative Table: Plastic vs Pseudoplastic Flow

The difference between plastic and pseudoplastic flow can be summarized in the following table:

In summary, plastic flow describes the behavior of materials that deform permanently under stress, while pseudoplastic flow exhibits both Newtonian and plastic flow behavior, and may have a yield stress. The relationship between viscosity and shear rate can be different for these two types of flow, and the materials may or may not return to their original shape after the applied stress is removed.