What makes a good pouring spout

TJR Posted September 5, Judith B Posted September 5, Pres Posted September 5, Min Posted September 6, Posted September 6, Ginkgo Posted September 7, Posted September 7, I can't imagine what is meant by "splitting the rim into two edges". Thanks for any clarification. Guest Posted September 9, Posted September 9, Pres has posted this image before, hope it helps.

Archived This topic is now archived and is closed to further replies. Go to topic listing. The spout's diameter, curvature of the lip, and the "wettability" the preference of a liquid to be in contact with a solid surrounded by another fluid of whatever material the teapot is made of, are also factors that can affect whether or not the kettle drips. But they aren't the primary culprit. In a paper , a team of French physicists from the University of Lyon demonstrated that the actual cause of the dribbling is a kind of "hydro-capillary effect" that prevents at slower pour speeds the liquid from detaching from the spout for a smooth, clean flow.

All the other factors play a role in determining how strong that hydro-capillary effect will be. As is so often the case, this latest study grew out of a curious scientist noting something odd and trying to ferret out an explanation. Etienne Jambon-Puillet, a postdoc at the University of Amsterdam, was cleaning syringes with a squirt bottle in the lab one day and was fascinated by how the liquid wrapped around the cylindrical needle to form a kind of helix structure.

A quick perusal of the existing physics literature didn't yield any truly viable models to explain the phenomenon, so he decided to do "a proper experiment. They set up a series of vertical cylinders one set made of glass, the other of Teflon and shot jets of dyed water at them, videotaping how the liquid behaved at varying flow rates. Subscribe to my email list. The channel of the spout and its ultimate opening must work in concert. Share this:. Previous post: Thinking Inside the Box.

Next post: Hacking an Ikea Cart. Best way to make good spouts is to make a lot of them and test and be critical. Liz Crain. Kate Pierce. Very useful information — thank you for researching and sharing. Yes, Kate, glad to be helpful. I wish I knew this years ago! Carter Gillies. Good stuff Liz! The Lyon team's verdict: marry a superhydrophobic surface with the more traditional method of using a sharp edge at the end of the spout, creating a drip- and hassle-free pot.

What about other brew-time dilemmas? In the Royal Society of Chemistry released guidance on how to make the perfect cup of tea [pdf] , and in researchers from the University of Bristol published a scientific formula for dunking a biscuit. Dripless teapots: here's my handle, here's my superhydrophobic spout. Why do teapots dribble?