The Naked Scientists

The Naked Scientists Forum

Author Topic: Why do tea bags float?  (Read 2000 times)

Don_1

  • Neilep Level Member
  • ******
  • Posts: 6487
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Why do tea bags float?
« 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.

Front of tea bag

Back of tea bag

Geezer

  • Neilep Level Member
  • ******
  • Posts: 8416
  • "Vive la résistance!"
    • View Profile
Why do tea bags float?
« Reply #1 on: 21/11/2011 19:00:16 »
Aren't you supposed to take them out of the plastic bag first?

Don_1

  • Neilep Level Member
  • ******
  • Posts: 6487
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Why do tea bags float?
« Reply #2 on: 21/11/2011 19:01:41 »
Look, I'm not that stupid...... Oh! I dunno though!

CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6379
  • Site Moderator
    • View Profile
Why do tea bags float?
« Reply #3 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.

Geezer

  • Neilep Level Member
  • ******
  • Posts: 8416
  • "Vive la résistance!"
    • View Profile
Why do tea bags float?
« Reply #4 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.
« Last Edit: 22/11/2011 04:39:30 by Geezer »

Don_1

  • Neilep Level Member
  • ******
  • Posts: 6487
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Why do tea bags float?
« Reply #5 on: 22/11/2011 03:01:35 »

 Your teabags are obviously rabid.

Strewth! I thought it was just my tooth paste.........

Geezer

  • Neilep Level Member
  • ******
  • Posts: 8416
  • "Vive la résistance!"
    • View Profile
Why do tea bags float?
« Reply #6 on: 22/11/2011 04:56:44 »
Looks like Mrs Don_1 is impregnating them with Fairy Liquid.

 

SMF 2.0 | SMF © 2011, Simple Machines
 
Login
Login with username, password and session length