ESDU Challenge: Toothpaste Flow

In this new series from IHS ESDU, challenge questions will be posted for the community. Some questions may require calculations and others are general knowledge questions.

Here's this week's question:

How would you characterize the flow of toothpaste at room temperature?

a) Newtonian flow

b) Non-Newtonian, viscoplastic

c) Non-Newtonian, shear-thickening

And the answer is:

b) Non-Newtonian, viscoplastic. An initial shear stress (tube squeeze!) is required to initiate flow, and the more you squeeze, the faster it comes as the substance thins. ESDU 97034 gives guidance on this and other Newtonian and non-Newtonian flows

Visit the IHS ESDU website for more information about the validated design methods, or to request a trial subscription.