Strange thing with hot tea in a plastic container



I poured hot camomile tea into a plastic bottle (like from Coca-Cola). The bottle wasn't full, it was about an inch below the rim. The temperature of the tea was less than 100°C (because it was already a while since the water was boiling). I put the bottle with the tea on a steel surface of room temperature, thinking the tea will cool off sooner.

After a few minutes, I noticed that it ran over, the bottle was full and there was for about three soup spoons of tea spilled over.


How can that be?!
Is this a water anomaly?

....I poured hot camomile tea into a plastic bottle (like from Coca-Cola). The bottle wasn't full, it was about an inch below the rim. The temperature of the tea was less than 100°C (because it was already a while since the water was boiling). I put the bottle with the tea on a steel surface of room temperature, thinking the tea will cool off sooner.After a few minutes, I noticed that it ran over, the bottle was full and there was for about three soup spoons of tea spilled over....Was the plastic bottle one like a coke bottle (designed to resist gas diffusion) or some more common one?

I don't think hot water would cool enough in "a few minutes" to absorb significant gas and expand, and I doubt it would expand much even in hours but that is the only thing i can think of and i guess possible if the top of bottle was very small so only small volume change is needed. The hot water was quite gas free and does absorb as it cools.

Sometimes hot water in a metal ice tray will freeze in the ice box faster than cold water but I think this is more due to melting the frost layer below it and thus getting good metal to metal contact.

Can you repeat the observation? Give us more accurate time vs volume data. Use plan water also to see if it has anything to due with tea.

If there were pieces of camomile leaves etc. in the tea, perhaps they were very dry and expand more than the volume of the water they absorb - that is why I want a pure water test also.

The bottle shrank from the heat. When thermoforming plastics, I have noticed this effect- before it starts melting, it shrinks slightly.

I agree with spidergoat. That would be my first guess.

-Dale

Anyone who drinks hot tea from any container besides a real tea cup deserves anything that fate punishes them with. :rolleyes:

Thank you!

Yes, the bottle must have shrunk! It is a regular 0.5 l water bottle, made of light blue PVC, softer than the kind Coca-Cola bottles are made of.
I have another one like that, and I've noticed that the one I poured the hot tea in was chaged, a bit ruffled at the top, before the neck -- as if it shrunk!



Cangas, the tea was for washing my cat's mouth. She has paradonthosis and needs regular rinsing.

water: I also have a cat that I love very dearly.

I was only, though not explicitly stated, as I should have done, speaking of the right way for a civilized HUMAN to consume hot tea. ;)

I sincerely mean this: may God bless your cat and mine.

How can that be?!
Is this a water anomaly?
heh, heh, you almost had me.

to DaleSpam & SpiderGoat & Water:

I hope Water will test your shrinking plastic bottle as I considered this and rejected idea for following two reasons:

(1) The water temp and bottle temp were presumably different when hot tea was poured in and it is the nature most things to expand as the they warmed, so the bottle should have gotten bigger, not smaller if it did not distort shape.

(2) Now lets assume that the bottle became softer and did distort shape: Then the pressure of the water should have made it fatter and shorter - I.e. more sphere like, but this should also increase its capacity to hold water.

There are of course ways to make “expanded” or “heat shrinkable” plastics, but I think this cost money and see no reason why this would be done by bottle maker, especially as he does not know if the bottle will be cleaned with hot water etc or not, and he must specify its capacity - perhaps even a legal problem for him if its capacity becomes less that the “as sold” value.

Of course there may be more important effects I am neglecting, but I want Water to carefully measure bottle capacity (weigh cold water in bottle before and after the hot water is placed in it if high resolution scale is available would work) of the other similar bottle she has and report the facts. I still find her results strange, and until my (1) & (2) thoughts above are refuted, I still think they are reasons to doubt your agree “best bet” as to the cause.

Water - Your cat is not "bottle trained" is it? - that could explain observation also if you were not looking all the time. :eek: :bugeye:

The bottle was not designed to hold hot liquids, or it would have been made of a different or thicker plastic.

Even ordinary plastics have a tendency to shrink sometimes, even though they aren't designed to. My guess is that the polymers contain manufacturing stresses that are released during heating, thus they contract towards an original smaller shape. Continue heating, and they will, of course, slump and, in effect, increase the volume of the container.

This is easy to test, hold a plastic coke bottle over a burner, and watch it contract before it eventually melts. (be careful)

...Even ordinary plastics have a tendency to shrink sometimes, even though they aren't designed to. My guess is that the polymers contain manufacturing stresses that are released during heating, thus they contract towards an original smaller shape. ...This is easy to test, hold a plastic coke bottle over a burner, and watch it contract before it eventually melts. (be careful)Now that you remind me of this, I am inclined to Join you and Dale in your view. I have noticed plastic bottles thrown in open fires do appear to shrink before burning.

Just see if Radio Shack gets any more of my money for heat shrink tubing that I thought must be hard to make. :D

CANGAS,


Indeed, may God bless our beloved cats. :)



* * *


Billy T,


Numbers!

The volume difference between the heated bottle and the normal one is 90 ml.
The sight is interesting, it's obvious right away how different they are -- the heated bottle is 1 cm shorter and measures 20.1 cm around, while the normal bottle measures 21.3 cm at the same level.
Whew, I didn't think this was possible!

(Someone please tell me the English word for that measure around a body. I know what diameter and radius are, but I don't know that other word. English is my third language.)


Water - Your cat is not "bottle trained" is it? - that could explain observation also if you were not looking all the time.

Hm? Do you know what it means to rinse a cat's mouth? You prepare camomile or salvia tea (salvia is better, but it tastes too awful for most cats), and a big syringe, or a water bottle with a "sport cap" (the one you can drink from by sucking it, or by squeezing the bottle). Then you wait for the tea to cool off to a proper temperature, not too hot, not too cold. Then you go out on the veranda (because the cat hates the bathroom), and one person holds the cat, we are all bent over, and the other person opens the cat's mouth a bit, and flushes the tea in at one side. Repeat on the other side. The cat isn't supposed to drink the tea, the tea is supposed to just run through her mouth, rinsing it.

It's not nice, but it helps, as the meds aren't enough.


* * *


spidergoat,



The bottle was not designed to hold hot liquids, or it would have been made of a different or thicker plastic.

Even ordinary plastics have a tendency to shrink sometimes, even though they aren't designed to. My guess is that the polymers contain manufacturing stresses that are released during heating, thus they contract towards an original smaller shape. Continue heating, and they will, of course, slump and, in effect, increase the volume of the container.

This is easy to test, hold a plastic coke bottle over a burner, and watch it contract before it eventually melts. (be careful)

I have noticed that! I just haven't made the connection between that and the bottle with the hot tea.

(Someone please tell me the English word for that measure around a body. I know what diameter and radius are, but I don't know that other word. English is my third language.)

It's circumference.

Hm? Do you know what it means to rinse a cat's mouth?

I think he was making a "potty trained" kind of joke, implying your cat peed in the bottle when you weren't looking.

My vet gave me some kind of solution to apply to rinse my cats mouth with (he's currently on a diet to prepare for a thorough teeth cleaning). The solution is supposed to taste good to them, but it's peppermint flavoured?? This sort of thing is never fun, I feel your pain and concern for our felines.

Oddly the vet said that he used the solution on his own teeth.

It's circumference.

Thank you. But -- when you go to the tailor to measure you, does he measure the circumreference of the waist?


My vet gave me some kind of solution to apply to rinse my cats mouth with (he's currently on a diet to prepare for a thorough teeth cleaning). The solution is supposed to taste good to them, but it's peppermint flavoured?? This sort of thing is never fun, I feel your pain and concern for our felines.

Oddly the vet said that he used the solution on his own teeth.

Yes, humans can take a lot more yucky medicines than cats -- and think if it's alright for humans, it's alright for the cat -- but it isn't!

Why don't you make the tea out of catnip?

Thank you. But -- when you go to the tailor to measure you, does he measure the circumreference of the waist?

Yes, circumference will work there.

Why don't you make the tea out of catnip?

Because we don't have it ...
Does catnip tea have good antiseptic qualities and is good to ease inflammations?

I don't know...but cats love it.

Nix on catnip tea.

It may make the cat sick.

www.vet.purdue.edu/depts/addl/toxic/plant07.htm