how do they make pool balls?

[VictorMeldrew]

google, ask, yahoo, all can’t tell me. i know they are made from resin, but how do they make them seam free and perfectly round?

[Majikthise]

It’s not exactly billiard balls, but this site has some historical information about the manufacture of glass marbles, including links to a few patents. Some of the methods might be applicable to billiard balls, “industrial spheres”, etc.

It looks like they are manufactured with either seams or cut marks at the ends, which are then polished away.

[DSYoungEsq]

@Majikthise

It’s not exactly billiard balls, but this site has some historical information about the manufacture of glass marbles, including links to a few patents. Some of the methods might be applicable to billiard balls, “industrial spheres”, etc.

It looks like they are manufactured with either seams or cut marks at the ends, which are then polished away.

The videos in the link you gave show no such thing. The marbles are made by allowing a “gob” of molten glass to enter a space between a screw mold that has a hemispherical groove spiraling down the length and a “reciprocating shear device” that, in essence, keeps the molten glass gobs seperate from the next gob and pushed into the molding screw. The result is that the gobs form spheres as they are taken down the length of the screw form, and ejected cool at the bottom as round pieces of glass.

[chrisk]

Huh. I think I believed until today that the majority of billiard balls were still made of Ivory. :eek:

[fortytwo]

Here’s how they used to do it in olden times but I’m sure balls are not polished by hand anymore.
The accuracy required to make them completely spherical must have meant the polisher/sander were quite skillful.
I couldn’t find a modern process though.

[C_K_Dexter_Haven]

This seems to be more of a General Question than a comment on a Staff Report, so I’m moving it to a forum where I think you’ll get more/better responses…

[Mister_Rik]

@Vetch

Here’s how they used to do it in olden times but I’m sure balls are not polished by hand anymore.
The accuracy required to make them completely spherical must have meant the polisher/sander were quite skillful.
I couldn’t find a modern process though.

Did you see that? That woman is not wearing eye protection! Where the hell is OSHA?

[minor7flat5]

As others have aluded to, they probably use some variation of extrude, chop, mold, and polish, with the polishing being done using traditional ball-bearing manufacture equipment. Here’s a question about ball bearing manufacture at HowStuffWorks. According to their response, “Manufacturers use a very similar process to make metal pellets for air guns, plastic balls for bearings and even the plastic balls used in roll-on deodorant.”

If they use this process for roll-on balls, why not billiard balls?

[David_Simmons]

I’m not at all sure but I suspect that they are molded and then polished by a variety ofcenterless grinding,. Ball bearings don’t have a seam and that’s the way they are finished.

[David_Simmons]

Here’s a note onball bearing ball making.

High speed, cold heading machines take a wire or rod feed, chop it to length and cold forge a ball to fairly close limits of size and sphericity. Basically this is done by taking a cut slug of the right volume and “bonking” it between two hemispherical dies.

For billiard balls, replace this with the operations of molding a blank to the approximate, slightly over, size.

Then the balls are fed in a continuous stream to a series of grinding and
lapping machines. These look like the old flour grinding mills…two discs
contra-rotating (or rotating at differential speeds) the balls feed in the
center and sphericity is 'Generated" just as you would form a ball of play-do by
rolling it between your hands.

This describes a centerless grinding and lapping procedure.

[David_Simmons]

Well great. I see that I just repeated minor7flat5. I’ll just quietly slither off now.

[GIGObuster]

minor7flat5 is on the right track: this billiard ball manufacturer for example also does… Ball bearings:

http://www.saluc.com/html/industry-en/index.php?idlien=2

Here is a machine that is made for plastic balls following a ball bearing design:
http://www.noonanmachine.com/pages/Plastic_Balls.htm

It looks though that for some high quality billiard balls, makers use a different method, the strip and colors are a solid core that runs all the way through the ball:
http://www.saluc.com/html/billiard/index.php?idlien=4

Phenolic resin, polyester or other polymers are the materials for the modern billiard ball, it looks like in this case the plastic material is put in molds under pressure and heat cured with grinding machines doing the final polishing.

http://www.saluc.com/html/billiard/index.php?idlien=6

The 13-step production process lasts 23 days and includes casting and curing processes combined with unique grinding and state of the art polishing technology.

Being Memorial day, a mention has to go to the camo set:
http://www.saluc.com/html/billiard/index.php?idlien=34

[Mister_Rik]

That Aramith site reminded me of a question I had a while back, after watching a pool tournament on TV. Why are the “TV” balls oddly colored? The purple and orange balls are pink, and the burgundy balls are a sickly yellowish-brown.

[cckerberos]

@Phase42

That Aramith site reminded me of a question I had a while back, after watching a pool tournament on TV. Why are the “TV” balls oddly colored? The purple and orange balls are pink, and the burgundy balls are a sickly yellowish-brown.

It’s so they’ll be easier to distinguish on TV (at least, according to Wikipedia:

Some balls used in televised pool games are colored differently to make them distinguishable on television monitors. The 4 ball used in such games is colored pink instead of purple, while the 7 ball is colored sienna (or a lighter shade of brown) rather than brown. The stripes on the 12 and 15 balls are colored the same way. Likewise, cue balls used for televised matches may depart from the norm by having spots or stripes on their surface so that spin placed on them is evident to viewers.

[ParentalAdvisory]

@chrisk

Huh. I think I believed until today that the majority of billiard balls were still made of Ivory. :eek:

I don’t think new ones are made from Ivory, but if you ever see a set of old yellow stained balls (and no I’m not talking about Dick Cheney), those were probably made from Ivory, so I’m told.

[R.P.McMurphy]

Lo and behold! I reading through the Aramith site and see a picture of a Logitech trackball just like the one I’m using.

I guess it makes sense. Where is Logitech going to get their trackballs? From a billiard ball manufacturer, of course.