Polycarbonate Surfacing

[reymundo43]

Hi, I 'm starting to surfacing Polycarbonate Lenses in a wholesale Lab and would like to know if anybody can tell me how to polish the lenses without having to repolish several times to get the perfect lens.
Right now I'm doing a 2 step polishing but has to polish more than 5 minutes to get rid of the circel in the center of the lens.
Can anyone help me with this ?

[HarryChiling]

Their could be multiple reasons. If the center of you lens is not polishing out start with your generator and make sure that the curves coming off f it are right (center no tpolishing means steep curve on lens). If your tool hasn't been changed in a while it's likely this could be your culprit. If they are coming off the generator OK, check to make sure your tool curves are accurate, make sure your pad allowance is being factored in, make sure your pressures are correct. Like I said could be multiple reasons try some of the above. Also poly cuts better with a specific tool, if you have a multiple flute cutter it could be your culprit again if it has any wear or tear to it.

Center not polishing means simply that the lens is too steep or the tools are too flat. Now from their start at your generator and work your way around.

[reymundo43]

Hi, I 'm starting to surfacing Polycarbonate Lenses in a wholesale Lab and would like to know if anybody can tell me how to polish the lenses without having to repolish several times to get the perfect lens.
Right now I'm doing a 2 step polishing but has to polish more than 5 minutes to get rid of the circel in the center of the lens.
Can anyone help me with this ?

Thank you Harry

[The Mighty Mutt]

One major cause of a circle in the center (especially on high-cylinder RXs) tends to be that the axis on the cylinder machines needs to be adjusted. I'm not sure about the newer ones, but the older machines can get knocked off axis fairly easily...for instance if the sleeve of your lab coat snags the switch, sending the lens clamp slamming down.

Good Luck!
~Rob