However, the ball material was swapped from celluloid to “plastic” by the International Table Tennis Federation (ITTF) for all of the international events held after July, 2014. Here, plastic balls were defined as “balls which do not contain celluloid” (Küneth, 2015). This new material was introduced because celluloid balls were thought to be expensive and flammable, therefore creating a fire hazard during transportation. Even though the ITTF set the specifications for the newly approved official plastic balls similar to those of the previously approved celluloid balls, it was anticipated that there would be a few differences between the two. As mentioned above, since players have accumulated information concerning the behavior of celluloid table tennis balls, considering that this behavior changes due to the new material, the players’ prediction scales need to be adjusted …show more content…
Seams were present in the celluloid and plastic balls alike, had same quality ranking and were produced by the same company (3-Star, Stiga). For this study, three balls were selected by random from a container of celluloid 3-star Stiga balls, along with three balls from a container of plastic 3-star Stiga balls. All of the balls were evaluated under the various conditions described below. For celluloid balls, the mean diameter was 3.94 ± 0.00 cm; the mean diameter of the plastic balls was 4.00 ± 0.03 cm. Celluloid balls had a mean mass of 2.738 ± 0.009 g, and that of the plastic balls was 2.722 ± 0.006 g. In this experiment, table tennis balls were fired from a table tennis ball robot that controls the velocity, along with the spin, of the ball using three rotors (Ozaki et al., 2013). By way of adjusting the rotors to produce differing spin rates, five different sets of velocity conditions were created, ranging from 15 to 115 km/h. Back-spin was applied to the table tennis balls for all velocity conditions. Using two coordinated high-speed cameras, the behavior of the table tennis balls prior to and following collision with the table was