How DHS table tennis balls are made
Balls are the main element in many sports, including table tennis. Without them, this sport would not exist. However, the unique characteristics and behavior of a table tennis ball sets it apart from other sports balls. In recent years, due to the transition from celluloid balls to plastic, the production process has evolved significantly. Let’s take a detailed look at the table tennis ball manufacturing process.
Shanghai. China. Ittf is visiting the world’s largest manufacturer of table tennis balls – Double Happyness and Mr. Yang Junwei, the factory director, is with us.
“Welcome to DHS. Today’s visit will give you a better understanding of the DHS ball manufacturing process. The life of a table tennis ball begins in this small hall located in the western part of the factory. At the beginning of the journey, we see only thin sheets of plastic, which by the end of the working day turn into something more definite. Our production starts here, for DHS 40+ balls we use CA as the adhesive. We also recently launched a new series of DHS D40+ balls, which are made from a different material with a different seam bonding technology. To familiarize yourself with the process, I will give you a short tour of the factory, where you will see the entire production process of DHS 40+ balls. Before shaping, all plastic sheets are weighed, measured and quality controlled to ensure that they meet the standards of both halves of the ball.
The first stage of production is shaping the halves of the ball. With the help of round copper heads, the leaves acquire the desired shape. Hot water supplied to them prevents cracks.
2. The resulting halves have a large edge, which is then cut off during the next fully automated step.
3. After trimming the edges, the halves of the ball are ready for gluing. It’s happening here. The individual halves find their match and enter the gluing machine. The adhesive substance is evenly distributed and after that the finished ball takes on its final shape. The balls are placed in these hanging bags and then transferred to the next hall where they are finished. How exactly the balls get their perfectly even shape is the secret of the factory.
“We store finished balls in a warehouse at a certain temperature and humidity. In the past, due to the instability of natural cotton, which is the main ingredient of celluloid, it was necessary to store balls here for up to 60 days, but now, thanks to new environmentally friendly materials, this process has been reduced to 15 days. As you may have noticed, I’m sweating in this storage room as the temperature here reaches 45-50 degrees Celsius.”
Once the balls are in storage, it’s time for quality control. Each ball is carefully controlled on an automatic assembly line. Among the balls that have passed the automatic control, we select balls for the competition and send them to the next control stage – manual control. To ensure the best quality, DHS always double checks the quality of the balls manually by our staff.
In 5 steps it will be determined whether our ball will receive a trademark.
The first step is to check the quality of the ball surface. To do this, we hold the ball along the seam and check the inner and outer surfaces under the lamp, paying attention to the two top points of the ball at the same time. This ball, for example, has an uneven seam and will be rejected. The next step is to check the ball for agility. One by one, they are sent to the table at a certain angle and for a certain length, and if the deviation of the ball from the center line exceeds 175 millimeters, the ball gets into a marriage.
Step 3 is hardness. A special device measures the hardness of the ball at various points. The ball along the seam line is placed parallel to the round base and its hardness is measured at the upper points. The balls are then categorized by hardness.
Fourth step – the balls are carefully weighed on accurate scales and must fall within the range of 2.68-2.76 grams in order to pass control.
The last step is roundness. After determining the size, the allowable deviation on the device can be within 2-2.4mm, and the size of the ball should be 40.00-40.40mm.
We caught up with Wayne Lee Chin, three-time world champion, one of the best players of the last decade and member of the ITTF Sports Commission, to get his take on how balls have changed in recent years.
» From my point of view, plastic balls have had a significant impact on the game of athletes. In my opinion, the new balls from the very beginning differed from the presidential celluloid balls in terms of stability and wear. And thanks to innovative technologies, development and research, the new material from which DHS produces modern high-quality balls provides the best game for athletes in world-class tournaments.”
In the meantime, at the factory, all QC balls are ready to be stamped with the DHS logo.
In two stages, a two-color logo is applied to the balls.
The balls are ready for packaging and shipping. The packing machine is fully automatic and can pack up to 1200 balls per minute. The whole production line can produce up to 600,000 balls per day, equal to an annual production of 200 million balls. Class 40 balls are now ready to ship worldwide.
Table tennis is an accessible sport with hundreds and millions of active players around the world, but as you’ve seen in today’s edition, table tennis ball production is no easy task.