The city of Jundiaí, in the state of São Paulo, is responsible for the monthly production of over 30 thousand tennis balls, which are destined for global export. The manufacturing combines industrial processes with artisanal finishing to ensure the quality of the ball's ideal bounce.
These balls are supplied to various sports brands that sponsor major tennis tournaments held outside the country, meaning that products originating from the interior of São Paulo frequently feature in world sporting events.
José Osvaldo Osti founded the factory four decades ago, combining his engineering knowledge with his passion for tennis. He reported that he started after receiving a book from a chemist containing a basic formula for manufacturing tennis balls.
Murilo Osti, a chemical engineer, highlighted the achievements of the family business over the years, specifically mentioning that the factory obtained certification for a beach tennis ball from the ITF, which represents great satisfaction to have its products used by top athletes in important competitions.
The production process of a tennis ball involves several stages, starting with the molding of the rubber and subsequently, the application of the felt cover. A crucial aspect is the bounce test, which must reach a height of up to 1.51 meters.
Before reaching the final product, production begins with a precise combination of 25 chemical compounds, responsible for giving the rubber the correct pressure. After being molded into semi-spheres, the pieces go through a high-temperature press and are sanded, culminating in the stage of gluing the two halves together to form the complete ball.
Next, wool felt comes into play, covering the ball and defining its color. This felt is cut and glued manually in Jundiaí before being taken to the final oven.
Finally, after a production cycle exceeding 12 hours, the ball undergoes the definitive quality test. When dropped from a height of 2.54 meters, it must bounce and reach a minimum height of 1.38 meters or a maximum height of 1.51 meters.
