Over the past 50 years, the production of tennis balls
has not changed. Instead, materials and technology have changed which
now allow us to obtain higher levels of performance.
This is the path that Sphera has chosen: to play on
the field of quality. A quality that is guaranteed by numerous tests and controls throughout every stage
of production.
step
1
Natural rubber is mixed with additive substances that make them more resistant to gas leakage in order to get the perfect pressurization of the ball.
step
3
Pellets are loaded into a hydraulic press and pressed into concave shells that will be joined to form a ball.
The shells are then cooked for about 2 minutes at 150 ° C so that the rubber can reach the mechanical and elastic ideals.
step
5
And now the most important and delicate, the pressurization process. The inflation by the use of chemicals occurs through the release of nitrogen, produced by the optimal balance of sodium nitrate and ammonium chlorite. The quantity and the combination of these, gives the level of pressurisation the ball will retain.
step
7
The final step is the print applying the logo. Now the balls are ready to be packaged in pressurized cylinders, ensuring they get to the tennis player in perfect condition.
step
2
The rubber compound is heated and extruded into a soft loaf which will then be cut into pellets.
step
4
The shells are treated to make the surfaces abrasive and better able to retain the adhesive solution that will be applied later on the shells edges to be joined to make a perfect sphera, furthermore to ideally bind the glue of the felt.
step
6
A solution of liquid rubber is applied to the
surface of the ball to adhere the felt coating: a mix
of wool and synthetic fibers, which guarantee the maximum softness and
minimizes the felt’s
loss during play.
The fabrics are cut into a shape that resembles an 8: two of these shapes are combined to cover the entire surface of the ball.
