| 摘要 |
The tennis ball has a hollowed rubber core (2) covered with a felt cloth (4) for outer skin by mediation of an adhesive (3). The outer skin of the ball is a fabric of pile knitting with the pile yarn being a composite sliver of predyed wool and nylon fiber, the back face of the fabric having at least two portions of back pile by needle punching and the piles bein processed by wool milling. The ball provides good tensility and duration. |
