These weird reasons of pressurizing tennis balls but it works.
Why are tennis balls pressurized? Because the ball is hollow. Tennis balls are pressurized since the inside of the ball is hollow to allow the ball have high bounce, spin, and speed rate. Also, the pressurized tennis balls are stored in pressurized cans or tennis ball saver to prevent the ball from losing its pressure that can result in a ball going flat before being bought from stores or used in a tennis game.
Main Reasons For Pressurizing Tennis Balls
1. Make Them Bouncy
Compared to pressureless tennis balls, pressurized balls bounce is very high. Thus, in a tennis game the higher the bounce rate of a ball the more lively a match is. Actually when playing tennis, pressurized balls feels real and satisfactory unlike using the pressureless balls.
2. Increase Speed Of Movement
Pressurized tennis balls move faster than pressureless tennis balls. It is because the balls are light weight and when strike they move faster and far compared to pressureless tennis balls.
3. Make Them Light
Since pressurized tennis balls are air-filled, they are generally light weight compared to pressureless balls that are filled with rubber material. Thus, for a high competitive game with constant hitting it is more comfortable to play with pressurized tennis balls than playing with pressureless tennis balls.
4. Increase Durability Once Opened
Pressurized tennis ball have to be pressurized to make them last longer. Since the balls loose pressure over time when removed from the cans, ensuring the initial pressure is high increases their lifespans once in use. Otherwise, if they could be pressured or perhaps have low pressure then the balls would be dead even before playing a match.
5. Increase Shelf Life
Pressurized tennis ball container that have not yet been opened can help the tennis balls stay in good shape even up to 2 years. The pressure inside the ball cannot leak to the can since the can has been pressurized to help maintain pressure equilibrium environment.
Lasting Period Of Tennis Balls Pressurized
Shelf Life Period
As long as the balls have been well stored in a pressurized can as soon as they are manufactured, the balls can stay up to 2 years in good condition when not used or opened at all. It is because there is still some micro leaking that can occur even when in storage.
Besides, a 2 year period is long enough to have the old stock sold out while in good condition. Also, the quality of the can also determines the duration of the ball pressure during storage.
Duration In A Competition
How long are tennis balls good for varies depending with the type of the ball among other factors. However, in a competitive game where there is constant hitting, pressurized tennis balls last 2-3 hours. In a moderate play, the pressurized tennis ball can last about 1-4 weeks of use. So, the balls have to be replaced.
When To Replace The Balls
In a competitive game, new balls are opened for every game. However, in a normal tennis ball practice, manufacturers recommend changing the pressurized tennis ball after using it in 9 games.
Although, some balls may need to be replaced much earlier depending on how efficient they were stored. To know exactly when your ball needs a replacement, do the following
Tests Before Replacing A Pressurized Tennis Ball
1. Squeeze The Tennis Ball
When squeezing a tennis ball, a ball that easily flattens has already lost much of the needed pressure and need to be replaced.
2. Bounce The Tennis Ball
Pro players can easily notice a dead ball by simply bouncing the ball alone. It has much reduced bounce height than a new ball. For a novice player, you can take another new ball and bounce it. Notice the height. Do the same for the old ball, you will notice a much reduced bounce height.
3. Strike The Tennis Ball
A flat or a dead pressurized tennis ball that has lost much of its pressure would result in a thud sound when hit.
Material Construction Of Pressurized Tennis Balls
Pressurized tennis balls are made of double layer of rubber material joined by a seam. The outer covering is a wool material that is also two layer and can be colored yellow or green. In the inside of the ball is hollow.
Pressurized tennis balls have hollow cores that are filled with what gas? Nitrogen gas. Overtime, since the material used in construction are not impermeable to air, the gas leaks.
Pressure Of The Pressurized Tennis Balls
Inside Tennis Ball Pressure
The inside pressure of the tennis balls is about 14psi-16psi. The balls cannot be stored without being put in a pressurized tennis ball container or tennis ball saver because is natural that high pressure air would tend to move to a low pressure in an attempt to attain equilibrium.
Low And High Altitude Tennis Balls
High altitude tennis balls are commonly used in high altitude places where air pressure is low. Thus, the diameter of the high altitude tennis ball is much larger than the low altitude tennis balls.
As a result, the extra circumference of the high altitude tennis balls makes the ball experience an equal amount of pressure just as the low pressure balls used in low altitude.
In the end, the resultant speed of movement of both low and high altitude tennis balls is the same since they experience same amount of resistance in ideal condition.
Using high altitude tennis balls in low altitude areas can significantly reduce the speed of movement due to more air resistance of the ball because of its larger circumference.
Prevention Of Pressure Leak
As a result, unsealed tennis ball would leak their pressure which is higher than the outside environment and would end up being flat. So, the balls have to be stored in a pressurized container.
Characteristics Of Pressurized Tennis Ball Container
Pressurized tennis ball container is commonly referred to as tennis ball saver. Often, manufacturer pressurize the cans to a pressure equivalent to the pressure of the manufacture tennis balls.
In that manner, tennis ball saver helps maintain an equilibrium pressure of the ball and the outside environment to prevent pressure losses during storage.
In that manner, there is no way pressure leak can occur since the pressure is homogenous. At times, manufacturers put a slightly higher pressure in the cans.
In that manner, the balls end up becoming a low pressure zone while the can becomes a high pressure zone. Pressure leak cannot occur from a low region of pressure to a high region of pressure.
Thus, the shelf life of the balls since the time of production is maintained even when at the stores until the day the balls would be opened for a match.
Opening Tennis Ball Pressurizer
Once the tennis ball can is opened, pressure starts leaking even if the ball is not hit. In fact, after 6 months of complete no use the ball would start becoming flat for losing its internal pressure to the outside environment to attain equilibrium.
Extending Durability Of Tennis Balls As Pressurized
A fact is, once the ball is opened they start loosing some pressure. The rate of pressure loss depends with the frequency the ball is being hit. The higher the use of the ball such as in a competitive match, the faster the pressure loss.
So, you have opened the ball. The cans have already lost pressure. There is no way you can put the pressure back unless in rare cases you are skilled enough.
However, all is not lost. There are still ways you can extend the durability of your ball when not using it.
Ways To Extend Tennis Balls Durability
1. Put The Pressurized Tennis Balls In A Fridge
Yes. Put the balls in a refrigerator. The reason for doing so is because we are taking advantage of the cool air circulation inside the fridge. Cold air circulation is much slower than hot air circulation.
Since pressurized tennis balls have air, the rate of the air circulation as well as leaking becomes much reduced when stored in a cold environment. The ball can last much longer than a ball that was stored in the outside normal environment even if the balls were opened the same time.
2. Put The Ball In A Tennis Ball Pressurizer
Tennis ball pressurizer or tennis ball saver for storing tennis balls are available in the market. A pressure ball-tube allows you to set the pressure of the tube to 14psi which is often the pressure inside the tennis ball.
You connect the tube to a pump such as a bicycle pump, then looking at the gauge you pump air inside until the gauge reads the desired pressure.
Besides, since the ball would already have been used, its inside pressure would be lower than pressure in the tube. There is no way leakage can occur.
What Manufacturers Test In A Pressurized Tennis Balls
Before manufacturers can ascertain that a tennis ball meets all standards set by International Tennis Federation, the following tests have to be conducted on each manufactured tennis balls.
1. Durability Test
Manufacturers have to ensure that the tennis balls manufactured can last about 9 games of moderate use. Thus, both the quality of the rubber and the woolen outer cover quality must be tested and be of high durable quality.
2. Ball Diameter Test
Standard diameter of a tennis ball ranges from 65.4mm to 68.6mm.
3. Rebound Test
Using a standard height of 2.54 meters, a new tennis ball used on a normal court should cover a rebound distance of about 135-147cm. Rebound distance for tennis balls used in high altitude environment should be about 122-135cm.
4. Tennis Ball Weight Test
The weight of a standard tennis ball should range between 56g to 59.4g.
5. Pre-compression Test
The ball gets compressed at various angles and monitor its ability to “wake up” after compression. The test is to ensure that whichever the compression environment of the ball storage or perhaps shipping, the ball can regain its ideal shape as soon as possible once the compression pressure is lifted.
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 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 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 are tennis balls pressurized? Tennis balls are pressurized in order to maintain their bounce, speed, spin, and high durability. That is why tennis balls are stored in a pressurized can to also prevent loss of pressure of the ball to the outside environment. Loss of pressure of the balls can make the ball less bouncy, have reduced speed of movement and spin, and can become dead. That is why you have to replace the ball after about 9 games of moderate playing.