2007-10-19 04:05:21 · 3 answers · asked by CST 1 in Science & Mathematics ➔ Physics
Some are injection molded. That involves blowing a bubble of liquid rubber inside a spherical cavity and letting it vulcanize (harden). Others have a seem along the equator where they're fused together by vulcanization.
2007-10-19 06:19:52 · answer #1 · answered by Dr. R 7 · 0⤊ 0⤋
It could be done with blow molding, vaccu-forming, or injection molding with a bit of rubber welding. A quick look at the ball would tell you what you need to know. If it has a small indentation or plugged hole, then it is blow molding. If there is a seam line completely arond the ball, then it is injection molding. I would bet on this method, injection molding.
With blow molding, a small hole would need to be in the ball somewhere, but as long as the ball was still relatively warm, the hole might be able to seal itself.
With vaccu-forming, you might not be able to get a consistant thickness, but i would imagine that it would works faily well.
With injection molding, you'd have to make each half of the ball and then using some form of plastic/rubber welding to combine them. FYI, plastic welding is a much different process than metal welding, if you didnt know. Or they could glued. There are some very good high strength glues for plastic/rubber out there.
2007-10-19 04:19:59 · answer #2 · answered by Toledo Engineer 6 · 0⤊ 0⤋
I guess there many ways, may depend on the company and the type machines they use.
The link is a Video on YouTube and shows how a tennis ball is made. Takes about 7½ miuntes to watch.
http://www.youtube.com/watch?v=oICVzJj8EUM
2007-10-19 04:24:25 · answer #3 · answered by Snaglefritz 7 · 0⤊ 0⤋