I often find myself watching stuff that’s completely unrelated to a particular sport; for example, I could say with confidence that I have seen more than my fair share of videos of funny incidents involving soccer, cricket and tennis. Another time, I came across a video featuring a bowl filled with hundreds of table tennis balls, producing massive flames that were far too big to be produced by such tiny balls.
However, after doing some research, I found that table tennis balls always burn very rapidly, even when exposed to a small spark. The question is, why does that happen?
Are table tennis balls filled with flammable gas?
There is a tendency of table tennis (also known as ‘ping pong’) balls to burn up in a fireball as soon as they’re lit by a match, or even burst into flames during a live match (which looks pretty cool, by the way). This might make a lot of folks believe that ping pong balls are filled with highly flammable gas that causes the balls to burn up so rapidly, but as it turns out, that’s far from the real reason.
A standard table tennis ball is 40 millimeters in diameter, weighs 2.7 grams and usually has a matte finish. Contrary to what the instant flame eruption of the ball might lead you to believe, the ball is filled with nothing but regular air.
Although there is no explicit rule stating that balls be filled with air or some other gas, air is used because it presents the most economically viable option when manufacturing table tennis balls on a large scale. You can check out the international standards regarding the dimensions of table tennis balls here.
Why do table tennis balls burn so rapidly?
The material of the ball is usually celluloid (or some other plastic), which is the real reason why it burns up so rapidly when lit. Celluloid is a highly flammable substance, and since table tennis balls are made of celluloid, they burn up easily too. Moreover, old table tennis balls consisted of acidified celluloid, the instability of which increases over time. Hence, the slightest source of heat (even a tiny spark) can cause it to go up in flames.
Why is celluloid so flammable?
To answer that, we’ll have to take a quick look at the composition of celluloid itself. For starters, celluloid is not a specific substance; rather, it’s the name given to a class of compounds that are created from nictrocellulose (or cellulose nitrate), camphor, dyes and other agents. More specifically, a typical composition of cellulose is nitrocellulose (74%) and camphor (24%). It’s considered to be the first ever thermoplastic, is very easily shaped and molded, decomposes rapidly and is highly flammable.
Its high flammability can be attributed to its chemical structure. In the presence of heat, the nitrate groups present in celluloid break off from the structure and release nitrogen gases (like nitric oxide and nitrous oxide) in air. Hence, nitrocellulose doesn’t need oxygen externally to continue burning, as the reaction itself produces oxygen.
So the next time you’re engaged in a hotly contested game of table tennis and the ball suddenly turns into a ball of fire, you can take a break from the game while you find another ball and enlighten the other players about what just happened!