What is the difference between No. 20 and No. 22 sponges?
No. 20 sponge was successfully developed by DHS in 2000. It has a close inheritance with No. 22. The control ability of the sponge is strengthened mainly by adding plasticizers and changing the process. Therefore, it feels softer and the surface treatment is neater. However, the two are similar in basic performance. The surface pores of No. 20 sponge are fine and closely arranged to increase its potential energy, making the ball's arc longer and faster. No. 22 sponge has high tensile strength and strong rebound force. It can maintain a lower arc and create high-speed rotation and strong forward thrust through force friction...
In the era of separation of rubber and sponge, everyone is already very familiar with DHS's "Yunhai" sponge, first No. 22, then No. 20. Including the transition from organic to inorganic, the sponges used in the new Kuangbiao and the new Tianji have a common feature, which is a dense hard sponge. Hard sponge + sticky rubber is a prominent feature of Chinese rubber. This is also the consistent advantage of DHS, which is easy to rub and spin, the arc of the ball is cunning, and there are many changes in the front rush of the table. In 2008, the ITTF banned glue, and the use of inorganic glue reduced the rotation and speed of the ball. Under the condition of glue filling, the advantage of high elasticity of No. 22 and No. 20 sponges after full expansion was limited, so DHS immediately developed the NEO series of Kuangbiao and Tianji, using tension sponge, and rediscovered the advantages in speed and rotation. The No. 25 sponge used in the Hurricane 8 in 2018 is also a dense sponge, but after adopting the high-elastic particle penetration technology, near-nanoscale particles are added to reduce the energy loss in the sponge, so it becomes softer, but not losing elasticity. It is a high-elastic micro-foaming technology.
The sponge technology types of German and Japanese rubbers are very different from those of Chinese sponges. In the past, DHS has always focused on the development of Chinese rubbers. Later, high-elastic white sponges appeared. In the Tiangong series of rubbers, we named the sponges 50#, 60#, and 65# respectively. The faster one is No. 60, which is designed in yellow, and the one that emphasizes control is No. 50, which is designed in orange. 65# is between 60# and 50#. All three sponges are open-pore sponges (large-pore sponges, or cake sponges).
The No. 80 sponge (red) that appeared in 2021 is also a large-pore sponge, mainly used for backhand...
Why does DHS sponge use Shore hardness?
What is the difference with other hardness standards? The fundamental reason why the Shore hardness standard is different from other sponge hardness standards is that the testing equipment and methods are different. DHS uses Shore A type, which is measured by a needle probe, while other sponge standards use spherical probes (C type). The two measurement methods can be used separately according to the density of the sponge, and they cannot be converted to each other. However, it can generally be roughly estimated by C-13~15=A. (Jin Gong 5 & Jin Gong 8 use Shore C hardness measurement) The needle measurement method is suitable for sponges with high density and has high measurement accuracy, while sponges with low density have high accuracy under the spherical measurement method. The Shore hardness standard is a sponge testing method used by DHS for 60 years and has been recognized by the market. From the comparison between the DHS sponge hardness system and the perception of athletes, the use of Shore hardness by DHS sponge has its regularity and scientificity. Whether it is a dense sponge or a large-pore sponge, the same hardness parameter is used, which is conducive to a clearer product system...
Is a soft sponge more elastic or a hard sponge more elastic?
The elasticity of a sponge has no direct relationship with its hardness. For the same type of sponge, the higher the hardness, the greater the elasticity. However, if it is too hard, it will be dead. On the contrary, the elasticity will decrease. Whether it is too hard depends on the swing strength. For example, a 43-degree blue sponge can maximize its power in Wang Liqin's hands, but for players with relatively weak strength, such a high hardness will make it dead and unable to hit through...
What are the differences in performance between national sets, provincial sets, and hurricane sets? What are the common specifications for national team members? What is the difference between star national sets and national sets?
National hurricane sets, provincial hurricane sets, and general hurricane sets use the same formula. The main difference between the three is the tolerance accuracy of the indicators. For example, the hardness requirements of national team athletes can be accurate to 0.5 degrees and the thickness can be accurate to 0.05mm, so the detection tolerance range of national sets is smaller. The detection tolerance range for general athletes is slightly relaxed.
In addition, in different periods, top-notch players such as Ma Long will have different requirements for the viscosity of the rubber or the hardness of the sponge, which requires fine-tuning. Therefore, there are slight differences in the national sets of different stars, and there are also differences in the same star player in different technical cycles or event cycles....
Blue Provincial Madness seems to have increased in weight? Is it due to the formula adjustment or the glue? Starting from 2021, the blue sponge rubber used by the national team, provincial and municipal teams has been toughened. After the sponge toughness is improved, the sponge will withstand more and more intensive impact force and increase the service life of the sponge. After the blue sponge is toughened, the bottom strength is stronger, and the weight is slightly increased, generally 3-5 grams heavier.
