Naked Science Forum

General Science => General Science => Topic started by: Don_1 on 21/11/2011 18:58:21

Title: Why do tea bags float?
Post by: Don_1 on 21/11/2011 18:58:21
First thing in the morning I just must have a cup of tea, well, mug actually.

Like many others, I whack a Typhoo tea bag (other tea bags are available) in a mug and pour on boiling water. The tea bag is full of perforations to 'let flavour flood out' (other slogans are available).

Now here's the question, if my tea bag is full of perforations, why does it blow up like a balloon? Even when I push it under the water, it just bobs back to the surface like a, like a........ floaty thing. Why doesn't the air just escape through those perforations and the tea bag sink?

Please write your answers on the back of a tea bag.

To assist you in finding the back of a tea bag, here is a typical tea bag.

 [ Invalid Attachment ]  Front of tea bag

 [ Invalid Attachment ]  Back of tea bag
Title: Why do tea bags float?
Post by: Geezer on 21/11/2011 19:00:16
Aren't you supposed to take them out of the plastic bag first?
Title: Why do tea bags float?
Post by: Don_1 on 21/11/2011 19:01:41
Look, I'm not that stupid...... Oh! I dunno though!
Title: Why do tea bags float?
Post by: CliffordK on 21/11/2011 22:58:04
Here in America...  we dumped all our tea into the Boston Harbor 200 years ago.

And just drink coffee now   [:-\]  Problem solved   [;D]

I think there are both paper and plastic tea bags, or whatever the difference between the old and new bags.

Perhaps the new teabags have smaller pores, and are thus more restrictive to the flow of air. and perhaps water too.  The plastic might also be more hydrophobic, and thus more restrictive to the passage of polar compounds than one might otherwise expect.
Title: Why do tea bags float?
Post by: Geezer on 22/11/2011 02:24:54
The plastic might also be more hydrophobic, and thus more restrictive to the passage of polar compounds than one might otherwise expect.

See, there you go Don. Your teabags are obviously rabid.
Title: Why do tea bags float?
Post by: Don_1 on 22/11/2011 03:01:35

 Your teabags are obviously rabid.

Strewth! I thought it was just my tooth paste.........
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F1.bp.blogspot.com%2F-1Ql7_Gp04gs%2FTYVGFxDauZI%2FAAAAAAAAETw%2FI8Orp9PScoU%2Fs1600%2FCamel%252Bfoaming%252Br.jpg&hash=5dea0e677e53a3c4e46b25263c6efefd)
Title: Why do tea bags float?
Post by: Geezer on 22/11/2011 04:56:44
Looks like Mrs Don_1 is impregnating them with Fairy Liquid.