Paste (rheology)

This page is about substances rheologically similar to toothpaste. See cut and pasteor copy and pastefor computer text editing. See Gluefor the adhesive. See Paste (magazine)for the magazine.

In physics, a paste is a substance that behaves as a soliduntil a sufficiently large load or stressis applied, at which point it flows like a fluid. In rheoologicalterms a paste is an example of a Bingham plasticfluid.

Pastes typically consist of a suspensionof small particles in a background fluid. The small particles are jammed together like grains of sandon a beach, forming a disordered, glassyor amorphousstructure, 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 Glueis often referred to as "paste".

Examples include starchpastes, toothpaste, mustard, and putty.

See also fragile matter, granular material.

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It uses material from the http://en.wikipedia.org/wiki/Paste+%28rheology%29 Wikipedia article Paste (rheology).