Tennis Ball

Tennis Ball - It's Beginning

A tennis ball is the bouncing ball designed for the game of tennis, and is also one of the main components of the game. In the early days, a tennis ball was made of leather, stuffed with the hair or wool. In the 18th century, ¾" strips of wool were wound tightly around a nucleus, made by rolling number of strips into a little ball, and then tied with strings in many directions around the ball, and a white cloth covering was sewn around the ball. At present, this type of ball has a cork core but is still used for the original game of tennis, now called real tennis. In the 1870's lawn tennis was introduced, with the introduction of this new type of tennis, vulcanized rubber was first used to manufacture the tennis balls.

The modern tennis ball has two major parts, the inner core and the outer cloth covering. The inner core is made up of two half-shell pieces of formed rubber joined together with adhesive to form a single core. The outer cloth covering are two dumbbell shaped pieces of cloth that are attached to the ball core by adhesive to give the tennis ball a classic appearance. The tennis ball's cloth density and thickness is matched to the court type which the ball is designed for.

Tennis balls are subdivided into two categories:
? Pressurized balls wherein the core is pressurized with air or nitrogen. This type of tennis ball lose their pressure over time so as their playing properties.
? Non-pressurized balls are made from thicker rubber core where the pressure within the core is equal to its ambient pressure; hence the balls tend to hold their playing characteristics for a longer period of time and only the cloth deteriorates.

In 1999, the International Tennis Federation (ITF) approved an experiment wherein two new types of balls were used in tournaments. These types of tennis balls were designed to have different performance characteristics, differing in their dynamic and aerodynamic properties. With the introduction of these two types of balls, type I and type III, tennis balls have now three types available for play, type I, II and III. These ball types can either be pressurized or pressureless classified through their measurement of diameter and compression test, which measures the forward and return deformation of the ball under an applied load. The type I balls are harder than the traditional type II balls and are designed for slow pace courts such as clay. The type III balls are larger in diameter by approximately 6-8%. This type of ball is slower through the air due to its increased drag properties and have steeper rebound angle giving more time for the receiver to collect the ball.

ITF regulation currently restricts the color of the tennis ball to greenish yellow or white and the seams must be stitchless. Strict limits have also been placed for the mass and diameter for each type of tennis ball. A rebound test was introduced in 1925 to determine the ball's static stiffness and coefficient of restitution (COR), and has remained unchanged since.

Even though the tennis ball is used primarily for the game of tennis, it can be used as a safe substitute for other games as well where a solid ball is necessary.