what is the difference

On the Kirkland thread some discussion has been about the different types of urethane covers.

What is the difference and does it really matter?

Cast seems to be the best??

No. Not to us non touring WRXers.

The easiest technology to implement is to injection mold thermoplastic urethane (TPU) around the golf ball core. When it cools and hardens, the ball comes out and final finishing is done.

The trickier technology (last I heard this was only done at fewer than a dozen factories world-wide) is cast thermoset urethane. The tricky bit is, the components of the urethane are mixed as they are being injected into the mold. Then the actual chemical linking goes on and the urethane material forms in situ. Once formed, this type of urethane can not be heated and molded or remelted. It is a one shot process. And everything has to be JUST RIGHT when the molding takes place.

In terms of golf ball design, I'm not clear on all the subtleties. Dean Snell said in a video that years ago only cast urethane covers could be make really, really thin (as thin as 0.015" or less) while TPU covers were always thicker. He also said that more recently the technology for thinning out TPU covers has approached that of cast thermoset. But still, the tendency is most balls with super-thin covers are cast thermoset and most balls with TPU covers are at least slightly thicker.

I suspect my own snobbery in favor of cast thermoset covers has come about after years of playing thin-cover balls which are cast and thick-cover balls that are TPU. I probably (most likely) just like thin covers better for whatever reason. But there may be more to it than that. Don't know, at this point not sure I really care.

I think at this point, the very good TPU balls are indistinguishable from the cast ones. Bridgestone and Srixon are TPU and they don't seem to have any issues. Companies that have invested in casting though, have no reason to re-tool and move to TPU because the re-tooling would cost them more than any possible savings.

The question though is whether the budget factories can do a TPU ball as good as Bridgestone or Srixon.

And for what it's worth, in my own game I've not cared at all for any Z-Star variant I've tried and I've found all Bridgestone balls other than the (original, first year) B330 to be disappointing. The fact that Bridgestone, Srixon and Callaway balls all have seemed lackluster while Titleist, Taylormade and even the original version of Snell MTB and 4pc K-Sig worked better for me can hardly be conincidence, can it?

> @"North Butte" said:

> The easiest technology to implement is to injection mold thermoplastic urethane (TPU) around the golf ball core. When it cools and hardens, the ball comes out and final finishing is done.

>

> The trickier technology (last I heard this was only done at fewer than a dozen factories world-wide) is cast thermoset urethane. The tricky bit is, the components of the urethane are mixed as they are being injected into the mold. Then the actual chemical linking goes on and the urethane material forms in situ. Once formed, this type of urethane can not be heated and molded or remelted. It is a one shot process. And everything has to be JUST RIGHT when the molding takes place.

>

> In terms of golf ball design, I'm not clear on all the subtleties. Dean Snell said in a video that years ago only cast urethane covers could be make really, really thin (as thin as 0.015" or less) while TPU covers were always thicker. He also said that more recently the technology for thinning out TPU covers has approached that of cast thermoset. But still, the tendency is most balls with super-thin covers are cast thermoset and most balls with TPU covers are at least slightly thicker.

>

> I suspect my own snobbery in favor of cast thermoset covers has come about after years of playing thin-cover balls which are cast and thick-cover balls that are TPU. I probably (most likely) just like thin covers better for whatever reason. But there may be more to it than that. Don't know, at this point not sure I really care.

You are pretty much correct in your descriptions.. TPU are injection molded, and are thermoplastic..meaning they can be remelted and used as regrind over and over again.. the cast urethane is thermoset, which means an exothermic reaction happens, and this liquid heats up, and goes from a liquid to a solid in less than 45 seconds.. and this reaction cross links and creates bonds that cannot be reheated and re-used.. over the years, TPU have typically been a little firmer in hardness, and the covers were always a touch thicker due to the processing.. over the years, improvements have been made and companies can now inject thinner covers. The colors of the TPU balls can be whatever someone wants them to be.. there are color concentrates added into hopper of the injection molding machine, so the covers can be made different shades of white. The thermoset urethanes typically have pigment covers AND pigment paint systems to get the preferred look. One note on the TPU materials, each company has their own specific formulation that has been developed over the years... So one TPU used by one company is not the same TPU used at another. Same is true for thermoset.. each company uses their own version and formulation to meet the specs and performance they are looking for. Bridgestone and Srixon have done a nice job refining their materials, processes and performance using TPU.. Nike also had its own TPU, which was not so successful and eventually they exited the ball market.