[xchcui]

Hi.
On YouTube there are a lot of videos that show how to make a foam spray from a simple garden spray. One example you may see here: https://www.youtube.com/watch?v=yh54gle5DQA

They make that by piercing a small hole in the small tube (which in general,is used to suck the water from the bottle and they add a piece of aquarium filter or a piece of scotch brite(which is more common used on other videos)inside the nozzle to increase the thickness of the foam. I know that the 3 base components to make a foam are:soap,water and air(besides other chemicals that increase the foam formation),so i understand that the air which is mixing with the soap/water is making that foam,but how does the aquarium filter/scotch brite piece inside the nozzle make the foam thicker?What is the science explanation behind that?
Thanks.

[billnotgatez]

your link is not in English language so fellow members may not respond

[xchcui]

It is not really important what is said in the video.The only part in the video that matter is the 1:40 point in time,when the aquarium filter pad/scotch brite is insert into the nozzle.
I also don't understand the language,but it is very simple to understand the process.It is just an ordinary garden spray that its small tube has been pierced in order to mix air+water/soap mixer to create a foam.My question is related only to the scotch brite/filter in the nozzle.(1:40 in the video)thats all!
How it makes the foam thicker?
science explanation.
Anyway,here is another video in English:
https://www.youtube.com/watch?v=kKUX5H7-xu0
You may skip to 5:55 point of time to see the relevant
part.

[Borek]

My guess is it is just helps in mixing of the air and liquid by adjusting the pressures and speed of the flow. Filter pad obstructs the flow, slowing it down and making it much more turbulent (as compared with mostly laminar flow in the straight tube).

[xchcui]

Okay,so the turbulent action is what makes the thicker foam.
Are the obstructing of the flow and slowing it down the only things that make the turbulent action or it may related,also to the structure of the filter pad itself?
I can understand how the filter pad creates the turbulent as it is built from many many small cavities,
but how does the scotch brite making the same results(thicker foam)?
BTW,before they put inside the piece of scotch brite,they opening it a bit by pulling the scotch-brite fibers with both hand's fingers.

[Borek]

As far as I can tell scotch brite is not much different when it comes to blocking the flow - it slows the flow down by making it much more turbulent.

[xchcui]

Thanks,Borek,for your explanation.