Why Are Tennis Balls Sealed?

Why are tennis balls sealed

Sealing of tennis ball, do they have to be sealed. This is the facts you should know.

Why are tennis balls sealed? Tennis balls are sealed in airtight container to maintain the pressure inside the tennis ball at 14psi-16psi for the ball to be bouncy, maintain high speed of movement, and be able to move greater distance desired by tennis players.

Otherwise, if the container was not air tight the ball would easily lose the pressure even before being used in the game and they won’t have the desired bounce.

Pressurized balls are made of rubber. The high quality rubber is often a double layer. The hollow interior is filled with air such as nitrogen. Leaking occurs when the inside pressure is trying to adjust to equilibrium pressure to the outside environment.

Thus, pressurized tennis balls have to be put in air-tight sealed tennis containers to prevent or minimize any possible leak. The rubber nature and the high inside pressure makes a pressurized tennis ball easy to bounce from one place to another.

As a viewer or a player of a tennis match, high chances of you seeing players squeezing a tennis ball or perhaps bouncing it a couple of times before the actual play is common. Normally, the players tests if the tennis pressurized balls still have the much needed pressure to make them good for the match.

Otherwise, if a player feels the ball is not bouncy enough they normally change the ball and throw away the other used ball. A high bouncy ball has high chances of enhancing the overall performance of a tennis player.

There are two types of tennis balls

Tennis pressurized balls:

Pressurized tennis ball outer cover is rubber and the inside is hollow filled with gas. The balls are often stored in an air tight can containing 3 balls. In addition, the hollow balls makes them easily bounce due to being light weight.

Non pressurized balls:

They are compact and not hollow. Can be stored alone and not in an air tight container. Non-pressurized balls last longer since they do not rely on the concept of pressure.

9 Scientific Reasons For Tennis Balls Sealing

Pressurized balls are the ones that are put in an air tight container. Often, the container comes as a package containing three tennis balls. The container is not only air tight but is also pressurized.

That is why when you are opening a new tennis can, it is hard and once opened you can hear a pop sound, whizzing sound, or a fizzy sound as the pressurized gas escape to the outside environment.

1. To Prevent Losing Pressure To Outside Environment

Tennis balls are hollow and are filled with a pressurized gas. So, the pressure inside the tennis ball would always be higher that the pressure in the outside environment during a match. As a result, the balls would easily leak pressure to the outside environment to attain an equilibrium pressure.

2. To Increase Tennis Balls Shelf Life

Losing pressure would make the balls not be bouncy. To prevent loss of pressure, new tennis pressurized balls are often put in a pressurized cans commonly known as tennis ball pressurizer. The tennis ball pressurizer have pressure slightly higher than the pressure of the balls to prevent leaking of pressure from the ball to the container.

In some instance, the pressure of the pressurized tennis ball container can be similar to the pressure of the balls so that the homogeneity of pressure prevents any loss of the pressure.

In that manner, the balls can stay at a store before being purchased for years but still maintain their bouncy nature when bought. Thus, the air tight container increases the shelf life of the tennis balls.

3. To Prevent Deforming of Tennis Balls

Pressurized balls stored in pressurized air tight container often prevent loosing of the tennis ball pressure. As a result, no leaking occurs and the ball does not flatten.

A flattened ball would not go far when hit during a tennis match. Furthermore, a player may have to use too much energy to hit the ball to a desired point.

That is why in a tennis match, new balls are often opened for a new competitive match. After a couple of matches, the balls are no longer in use unless used for warm-up or creative use of old balls.

4. Air Tight Cans Act As Cushion

Normally, when tennis balls get hit on several matches by a racket the ball tends to loose pressure. Reduced bouncy nature can make the game less lively and the ball has to be replaced.

Pressurized air of the pressurized tennis ball container acts as a cushion. So no matter how hard the container falls on the ground or perhaps a hard surface, chances of hitting the ball to make it loose pressure is slim.

5. Maintain The Needed Ball Pressure

Before a match, tennis balls should have a pressure of about 14psi to 16psi. As a result, having the balls kept in air tight can helps maintain the balls pressure until it is opened a few minutes to or during the match.

Besides, hitting the ball across the net makes the ball loose some pressure. So, it is safe to play with new balls which a player is certain is still in good condition that try luck with used balls.

6. Maintain Tennis Ball Speed And Bounce

A tennis pressurized ball that has not yet leaked any pressure has high speed. When hit by a racket, the tennis ball can move fast and far. Besides, the ball can bounce off from one place to another as aimed by a player.

However, a tennis ball that has already lost some pressure is less likely to be less bouncy, have reduced speed of movement, and cannot move far when hit. That is why the sealed cans containing the balls get opened before the match.

7. Maintain High Spin Speed

Pressurized balls in a sealed can maintains their pressure. As a result, they remain light in weight and can easily be spin during a match compared to a tennis ball that has already lost pressure of perhaps a pressureless tennis ball.

8. Maintain Game Competitiveness

Whether a pro or a beginner player in a tennis match competition, using a pressurized tennis ball that has no leaks increases one’s competitiveness other than relying on individual skill and expertise. New balls opened at the field have the desired speed, and bouncy.

9. Sealed Tennis Balls Can Stay Inside A Refrigerator

Have you also wondered or know why are tennis balls stored in the refrigerator? Tennis balls are often stored in the refrigerator to prevent the balls from losing their internal pressure. Air circulation of cold air is much lower than the air circulation of hot air.

As a result, chances of pressure loss in cold air is much lower than the rate at which pressure can be lost when exposed to hot air. Thus, the main reason for storing tennis pressurized balls in a refrigerator is to reduce or perhaps prevent the balls from losing their pressure.

More About Sealed Tennis Balls

Benefits Of Tennis Balls Being Sealed

A brief summary of having pressurized tennis balls tightly packed in a tennis ball pressurizer can results in the tennis ball being

  • More bouncy
  • Having a greater speed of movement
  • Being lighter and easily spins

Reasons Why Some Sealed Tennis Balls Are Bouncy Than Others

Pressure Leaks Inside The Cans

The higher the air tight container, the lower the risk of the tennis ball loosing pressure. Thus, in the instance a new opened ball tends to be less bouncy that others could be because of a little loss of pressure during storage.

Poor Storage

Not not all sealed tennis balls can have the same durability. Tennis balls that were well stored in pressurized cans can last longer than those that were not properly stored.

Quality Of The Sealing Can

Besides, if the container is of poor quality seal then chances of the container pressure being lost is high and the balls would in turn loose pressure. In the end, such balls can be less bouncy than others.

How To Test Sealed Tennis Balls

In order to know how long are tennis balls good for, there are three commonly used methods for testing the wellbeing of a tennis ball. They include:

1. Bounce method:

Once you open the can, bounce the ball. A ball that has enough pressure can bounce high enough. You can compare the bounce with an already used ball.

2. Squeeze method:

Use your hands to squeeze the tennis ball. A ball that has already lost pressure will give in and deform. Pressured tennis ball in good condition is hard to get deformed.

3. Sound method:

Strike your tennis ball. A deflated tennis ball will have a funny sound when hit by a racket. As a tennis player you can easily tell the difference in sound of a good tennis ball and a bad ball. A thud sound can be heard when you hit a flat ball.

How Long Can Tennis Balls Stay Outside Sealed Cans

Once the tennis pressurized balls get opened, they can be used in a competition match for up to 9 matches. Normally, a maximum duration of about two weeks is good to maintain the balls bouncy and speed when moderately used.

However, if a ball is used for a highly competitive match whereby the ball experiences high rate of being hit by the players, a maximum of 2-3 hours is allowed before the ball loses its bouncy nature.

As a result, the ball has to be changed in a real competition match frequently. In fact, some players change the ball after every new game.

However, the balls are not just discarded once the bounce is lost. The balls can be used for learning by beginners for some time including enhancing your grip skills. Once the balls have lost their bouncy nature, they can be recycled.

Besides, some high quality pressurized tennis balls can stay outside a can for up to 6 months without losing their bouncy nature. However, such balls can only be used in normal training. New sealed can tennis balls have to be used in a real competition match.

Getting Best Deals For Sealed Tennis Balls

Normally, pressurized tennis balls are more costly than non-pressurized tennis ball. It is because manufactures have to ensure:

1 The pressure inside the ball meets standard pressure

2. The cans are of high quality to withstand environmental impact that can break them causing a leak.

3. The cans have to be pressurized enough to maintain the quality of the stored tennis balls.

4. Shipping canned tennis balls is much costly since they occupy more space compared to non-pressurized tennis balls.

Order Tennis Balls In Bulk Whenever Possible

Thus, in order to save some cost it is worth shipping the balls in bulk in terms of box or boxes rather than shipping a single can containing 3 balls.

Lager packs ensures you have extra balls to use for future as long as you only open when you want to use, and perhaps after the expected bouncy nature has reduced. Otherwise, if you end up opening the cans even when not in use you will end up with less bouncy balls.

Why Pressureless Tennis Balls Are Not Airtight Sealed

Non-pressurized balls are also made of several layers of rubber material and are not hollow. The thicker rubber makes the non-pressurized tennis ball harder. In most cases, the non-pressurized balls are used for practice to sharpen the skills and expertise of trainees.

Since the ball may need more energy and techniques for training, a player finds it much easier to play with a pressurized ball in a real competition match.

However, when training with a non-pressurized tennis ball caution must always be taken since the balls are hard you can easily injure yourself.

Pressurized tennis balls are light in weight since they are hollow and injuries caused by pressurized balls are less severe than that of a non-pressurized cans.

Frequently Asked Questions

Why are tennis balls fuzzy?

Tennis balls are fuzzy because of the fuzz of the nylon felt outer layer. Tennis balls outer cover that is often yellow in color can either be of woolen felt or nylon felt. As tennis ball moves through air, the fuzz on the ball brings about a fuzzy effect as the fuzz tries to resist the air movement around it.

Why are tennis balls yellow?

Tennis balls are colored yellow to make them easily visible by the tennis players in a court and spectators who watch tennis game live or through their television. Yellow color is a standard color for tennis balls set by the International Tennis Federation for purposes of enhancing visibility of the ball.

Why do tennis balls smells so good?

Tennis balls smells good when opened because the storage containers normally have chemicals such as the lid glue, and chemicals used in making the felt and rubber during tennis ball manufacturing. When these chemicals are released upon opening a new ball, a good smell can be smelled.

Why are tennis balls bad for dogs?

Tennis balls are bad for dogs because the ball can easily choke a dog to death. Besides, the fuzz felt causes wear and tear of the dogs teeth as the dog tries to bite and grip the ball. Thereafter, worn out teeth can trigger open pulp and can result in poor feeding of a dog due to pain.

How are tennis balls made?

A tennis ball is made of layers consisting of a rubber material enclosing a hollow gas often nitrogen gas. The rubber material is then covered with a layer of wool for the high end tennis balls but nylon case can also work. Pressureless tennis ball layers consists of several layers of rubber material enclosed in a woolen felt. The processes of making a tennis ball entails combination of several techniques.


Main reason why are tennis balls sealed is to maintain the pressure of the tennis balls. Pressurized tennis balls are bouncy and have high speed of movement making them lively during a match. Be sure to open a new can before a real competition so you can experience the best out of the pressurized tennis balls. Balls that have lost pressure end up being less bouncy and less speed. Actually, pressureless tennis balls feels dead and are not bouncy since you have to use a lot of energy to get the ball moving.

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Brett Haber

My goal is simple: to immerse you in the world of tennis like never before. Whether it's analyzing the strategies of top players, delving into the history of the sport, or offering insightful commentary on current events, my words aim to entertain, inform, and ignite your own passion for tennis. Join me on this thrilling journey through the courts, and let's ace this adventure together!

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