# How do foamers create foam from a liquid product? **URL:** \ **Category:** Factual Questions\ **Created:** [September 1, 2021, 8:43pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935 "2021-09-01T20:43:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![All\_About\_M3](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@All\_About\_M3](https://boards.straightdope.com/u/All_About_M3)\ **Post date:** [September 1, 2021, 8:43pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/1 "2021-09-01T20:43:04Z")
There are tools that take a liquid product (e.g. soap) & spray it as a foam (some of these tools use a hand-pumping action, while others use a pressure washer, or even a stream of water.) How do these products do this (turn the liquid into a foam)? I imagine it has something to do w/ pressure & maybe viscosity, since I don’t think water can be foamed? If there’s a difference b/w the different versions (hand vs electric. etc), I’m okay with only explaining the hand version. Also, possibly worth noting is that I don’t really know what the difference between foam and a liquid is, so perhaps this question is equivalent to “what is foam”. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [September 1, 2021, 8:47pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/2 "2021-09-01T20:47:21Z")
My best guess, it must be some way that it takes air from the outside (when you press down on the handle) and forces the air as many little bubbles into the liquid. The handles probably consist of a double tube for this purpose. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 1, 2021, 11:46pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/3 "2021-09-01T23:46:18Z")
Foam is liquid with a whole bunch of tiny air bubbles in it. ---
**Author:** ![All\_About\_M3](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@All\_About\_M3](https://boards.straightdope.com/u/All_About_M3)\ **Post date:** [September 1, 2021, 11:50pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/4 "2021-09-01T23:50:06Z")
Ah, so then they are forcing air into the liquid. How does this happen though? Putting air & a liquid in a bottle together doesn’t make them mix. Is it through increasing the pressure in the container (by adding more air?), or maybe they have a sieve or special valve or something. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [September 2, 2021, 1:43am UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/5 "2021-09-02T01:43:46Z")
A thorough autopsy, [![](https://img.youtube.com/vi/Y8RCrJ5w5Qk/maxresdefault.jpg "Inside an automatic foam soap dispenser with clever pump.") ](https://www.youtube.com/watch?v=Y8RCrJ5w5Qk) ---
**Author:** ![All\_About\_M3](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@All\_About\_M3](https://boards.straightdope.com/u/All_About_M3)\ **Post date:** [September 2, 2021, 2:42am UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/6 "2021-09-02T02:42:26Z")
I guess it is essentially comes down to a sieve (or sieve-ish thing) then. Thanks. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [September 3, 2021, 12:49pm UTC](https://boards.straightdope.com/t/how-do-foamers-create-foam-from-a-liquid-product/949935/7 "2021-09-03T12:49:35Z")
I know it was going to be Big Clive. He’s got great videos on his channel.