Question...Why do 'Table Tennis' balls burn to complete nothing

Air, most likely. I know you can buy tennis balls filled with pure nitrogen, which may make them keep their bounce a bit longer. (There's no need for that though, since for a few bucks you can buy a simple screw-type ball repressurizer.) There would be no advantage to putting nitrogen in a table tennis ball.
 
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78% Nitrogen, 21% Oxygen, ~1% Argon plus a smidge of CO2 and other trace gases.

There's no obvious advantage to filling ping pong balls with anything other than plain air (maybe dried air to prevent internal condensation if playing in cold weather)

ETA. What Gravy said...
 
De_Bunk said:
SeanDamnit...

Nice one...Impressive that you knew where to find a vid...thanks!...

I also never thought that they were filled with gas...Are they really under pressure ?...(I doubt it tho'...they can't be...surely not)

But try a white one...the normal standard ball...

Are they made differently?...(i know about the hardness of them 1, 2 or 3...)

DB
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I figured that any cheap, common item that burned the way you described HAD to have been recorded ablaze on YouTube at some point. There are actually several videos if you search for "ping pong burn" or something like that.
 
anor277 said:
From what Wiki says, modern table tennis balls are made up of polymeric nitrocellulose (this is also the basis of guncotton!). The products of combustion of this sort of polymer are CO2, H2O, N2, all gaseous materials (note that the nitro group provides oxygen in situ to aid combustion; further note that the combustion of anything organic is CO2 and H2O); complete combustion would leave no solid residue.
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Most combustion results in all gaseous products in theory. The reason you usually get ash and charcoal left behind is that things don't usually burn completely. I suspect the main reason you don't see much from a table tennis ball is simply that there is only a small amount of material spread over a relatively large surface area, so it burns very efficiently. Of course, any black smoke you see is in fact just particles of ash that are small enough to float in air.

Gravy said:
Air, most likely. I know you can buy tennis balls filled with pure nitrogen, which may make them keep their bounce a bit longer. (There's no need for that though, since for a few bucks you can buy a simple screw-type ball repressurizer.) There would be no advantage to putting nitrogen in a table tennis ball.
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Are tennis balls actually airtight? And why would nitrogen make them any bouncier than regular air?
 
arthwollipot said:
I've never purchased table tennis balls. Are they marked as flammable on the packaging? Is it legal to board a plane with a set of balls in your hand luggage? Are there restrictions on transporting them?

Inquiring minds want to know!
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A better question might be "Is it legal to board a plane with a set of balls in your hand?" And, if you do, whose are they?
 
fuelair said:
A better question might be "Is it legal to board a plane with a set of balls in your hand?" And, if you do, whose are they?
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I always take my balls onto a plane. Never been stopped. dont know about playing with them mid-flight. Might get you arrested when you land.
 
anor277 said:
From what Wiki says, modern table tennis balls are made up of polymeric nitrocellulose (this is also the basis of guncotton!). The products of combustion of this sort of polymer are CO2, H2O, N2, all gaseous materials (note that the nitro group provides oxygen in situ to aid combustion; further note that the combustion of anything organic is CO2 and H2O); complete combustion would leave no solid residue. From the youtube film, there seems to be a flammable gas present inside the ball. I don't know what this is; methane and hydrogen are both ligher than air.
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I never knew table tennis balls were made of nitrocellulose! Nitrocellulose is highly flammable and very, very "clean burning". As noted, that's what flash paper is made of, and it's also used by biologists as a substrate onto which to transfer proteins and DNA that we're detecting. Once you're done doing the detection, you're left with all this lovely, highly flammable paper.

We used to collect big stacks of used nitrocellulose, then light a piece at a time, throw the pieces in the air, and watch them *POOF* in a big burst of flame. Very clean -- no visible residue.

(And yes, lab work is awesome.)
 
sanguine said:
We used to collect big stacks of used nitrocellulose, then light a piece at a time, throw the pieces in the air, and watch them *POOF* in a big burst of flame. Very clean -- no visible residue.

(And yes, lab work is awesome.)
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The tech service lab I used to work in used nitrocellulose filters for quantifying metallic fines in metal-working fluids. The idea being you could trap out the metals then just burn the whole lot and weigh what was left. Nitrocellulose being so clean burning meant whatever was left must be metal.

Of course when us technicians found out they were so much fun to set fire to and throw at one another*, the consumables budget for filter papers trebled overnight.

*no real danger as they burned up before travelling more than a foot
 
"Tortoiseshell" guitar picks are made of the same stuff and burn the same way- like a shingle factory, leaving behind only a very small quantity of fine black ash.
 
Junior scientists, cut a new one open and smell and report back.

That is not air inside the ping-pong ball.

Anyway, ping-pong and tennis skills are mutually exclusive.

Tennis balls are airtight to a degree. The inner rubber layer is permeable to gas, which is why storing them under pressure keeps and restores their bounce.
 
Cuddles said:
Are tennis balls actually airtight? And why would nitrogen make them any bouncier than regular air?
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Tennis balls aren't completely airtight, which is the reason for the nitrogen. It supposedly leaks out more slowly than plain air. Since air is about 78% nitrogen, I would expect the difference, if any, to be quite small. Automobile tire purging/refilling with nitrogen is a current fad.

ETA: found a car tire test:
The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim.

http://blogs.consumerreports.org/cars/2007/10/tires-nitrogen-.html
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As I keep getting an annoying message telling me that I have not posted in some time I would just like to say....Balls.
 
The answer is very simple. Because it is made of plastic, nothing to do whit the gas inside, because the gas inside is air. If you pierce a ping pong ball it doesn’t flat out at all.
Plastic is organic material (special kinds of molecules of it). Basically made out of carbon and hydrogen (and a couple of less significant elements that are mainly non-existing). Carbon burns into CO2 (gas), and the hydrogen in H2O (water vapour), so they basically evaporate away, and when the energy is not enough to continue the chain reaction, the reaction stops leaving remains (or debris) of organic material that did not chain reacted and impurities (and other elements) in the material that are not combustible.
 
The fact that ping pong balls are flammable has nothing to do with what is inside them. The material they are made from is essentially the same as nitrocellulose lacquer, except it is solid.

Nitrocellulose lacquer is a wood finish. It is used commonly in finishing guitars and it is extremely flammable. As a matter of fact, in a pinch you can make your own nitrocellulose lacquer at home by dissolving ping pong balls in acetone.

Laquers for finishing are made by dissolving nitrocellulose, plasticizers, and pigments in volatile solvents. When the solvents dissolve, you're left with a hard finish, which means your nitro-finished guitar is basically coated with a ping pong ball!
 
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I don't believe there's a mystery here to solve. In the video someone linked to, I saw that there was indeed a solid left behind, and it didn't seem to be an especially small amount, given the fact that the ball only started as a very thin hollow shell of solid anyway. I see no reason to think that the original mass's conversion to gases was any more complete than with many other flammable solid objects.
 
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