You would be amazed to see how many processes are required for making a perfectly shaped, seamless ping pong ball fit for the best players in the world. According to the International Table Tennis Federation, ping pong balls must have a diameter of 40 mm and weigh 2.7 grams. Although highly flammable celluloid was the material used for many years, the ITTF changed to a plastic compound of camphor and nitrocellulose. It still has some celluloid characteristics, but it is less combustible.
What are the steps in making ping pong balls?
Although mechanical equipment carries out some manufacturing processes, many steps need the human sense of touch to ensure top-quality results. The six primary steps include shaping, trimming the edges, gluing hemispheres together, quality control, adding printed logos and packaging.
How are ping pong balls shaped?
The first step involves workers who scan and weigh the nitrocellulose to ensure uniform quality and weight. Some manufacturers cut the sheets into discs for shaping, while others use the sheets. After soaking the sheets or discs in an alcohol solution, they are soft and pliable. Next, they are placed onto hemispherical molds, and copperheads press them down, each forming one-half of the ball, while dripping hot water keeps them pliable. Trimming the edges is the next step after which the hemispheres are left to harden.
Pingsider | How Table Tennis Balls are Made
How do they join the halves to form a ping pong ball?
The adhesive used to glue the halves together is an alcohol-based binding agent. Workers place the halves into individual molds, ready for the adhesive application. The machine then joins the hemispheres in pairs to form balls before a mechanical process agitates them to smooth the glued seams.
How do they grade the quality of the ping pong balls?
Grading of the balls is a mechanized process; however, human hands do the final test for smoothness. Measurement machines grade and separate balls according to weight, roundness and hardness. Workers then check smoothness by hand examining each ball’s surface. The slightest irregularity will disqualify balls for use by professional ping pong players. However, ping pong balls have a three-tier grading system, so those who do not make the three-star grade might be suitable for one or two stars. Before the balls are packed and shipped, they must be kept in storage at a specific temperature and time to finalize the solidification process.
Do they fill the balls with gas that can make you “high?”
Typically, ping pong balls are filled with nothing other than air. However, people might have reason to think they are filled with some kind of gas. A reaction between the plastic polymer material and the adhesive leaves gassy fumes into the ball’s interior. The odor inside the ball could be likened to that of modeling glue or photographic film. Claims that inhaling the residue causes a “high” might be justified, but beware, the vapors are sure to be toxic — although ping pong balls are not poisonous.
To wrap it up
Next time you play ping pong, spare a thought for the workers whose sense of touch ensured the high quality of the balls.