Arrachement / grabbing problem on CR39

[Etienne]

Dear,

I use a VFT Compact Satisloh for surfacing my lens. I have some problem on CR39 ( polarized lens). I have a grabbing problem only on the cr39 polarized and not on the other Cr39 (white or trnasition).
The material CR39 on the polarized must be different.
Can you give a parameter Peak height , chip thickness and workpiece speed max for increase the quality on this lens?
I use 2 tool different for thePre process and finish process.
I know the tool quality is very important but I can product the other lens whitout problem when I see the grabbing problem on polarized

Regard

[Dantech]

Pitting is always more noticeable on Cr39 polar, it is probably happening on clear and trans you just aren't noticing it. First thing you need to focus on is water flow. If any of your milling or fast tool nozzles are clogged or misdirected you have identified your issue. If your nozzles are not clogged or misdirected, make sure your flow looks strong. After time the ports in these machines collect debris and the water flow can be choked up a bit, this will cause pitting and undesired center features in your lenses. If your water flow is strong and your nozzles are hitting the correct point on the tooling, you need to look at your thickness calibration, scratch test, true curves on both tools and milling motor height calibration. If none of these help it is possible you have an untrue milling disk or hub. Let me know what you have done so far to try and resolve this.