| 摘要 |
<p>A water bouncing ball includes a gel core made of plastic material and an elastic porous plastic material adjacent the gel core and covering and centering the gel core in the middle of the ball. The ratio between the diameter of the gel core and the thickness of the elastic porous plastic material is in the range between 0.66 and 2.8. In this way a soft floating ball having good bouncing ability is provided.</p> |
