Paste (rheology)

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For other meanings of paste see Paste (disambiguation)

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In physics, a paste is a substance that behaves as a solid until a sufficiently large load or stress is applied, at which point it flows like a fluid. In rheoological terms a paste is an example of a Bingham plastic fluid.

Pastes typically consist of a suspension of granular material in a background fluid. The individual grains are jammed together like sand on a beach, forming a disordered, glassy or amorphous structure, and giving pastes their solid-like character. It is this "jamming together" that gives pastes some of their most unusual properties.

In pharmacology, paste is basic pharmaceutical form. It consists of fatty base (e.g. petroleum jelly) and at least 25% solid substance (e.g. zinc oxide).

A thick glue is often referred to as "paste".

Examples include starch pastes, toothpaste, mustard, and putty.