TENNIS BALL
Discover the composition and specific characteristics of the Artengo pressure ball
Contents
Composition of the pressure ball
Core : rubber, around 4mm thick.
Pressure : pressurised to around 0.8 bar.
Seal : silicon.
Felt : made of wool, cotton and synthetic fibres. The felt cover represents 20% of the weight of the ball (it is around 3mm thick).
Two types of felt can be used to cover tennis balls and they heavily influence the aerodynamic behaviour of the ball:
- "Needle" = mainly non-woven synthetic (acrylic) felt.
- "Woven" = "warp and weft weave " rich in cotton, wool and polyamide.
Pressure tennis balls are made from two rubber pieces that are pressed together, with air then being injected into the ball to create a level of pressure that influences the aerodynamic behaviour of the ball and the extent to which it bounces.
Given that the rubber shell is not airtight, balls are packaged in pressurised sealed cans to ensure they retain the correct air pressure prior to use.
The four main characteristics of a tennis ball
Diameter: ITF regulations state that a tennis ball must be between 6.54 and 6.86cm in diameter. The size of the ball influences both responsiveness and control.
Weight: ITF regulations state that a tennis ball must weigh between 56 and 59.4 grams. The weight of the ball mainly influences feel on the racket.
Deformation: we measure the effort required to deform the ball by 2.54cm. The level of deformation mainly influences the responsiveness of the ball.
Rebound: the ball is dropped from a height of 2.54m and we measure the height of the first bounce. ITF regulations state that a tennis ball must bounce between 135cm and 147cm high. The size of the ball influences both responsiveness and control.