Ultraoptics coater chipping backside of Transitions 1.50

[snowmonster]

I'm really sorry to double-post this, but I forgot this forum existed until somebody else mentioned it. Here's what's already been discussed in the other forum:

http://www.optiboard.com/forums/show...546#post317546

So I've got a Ultraoptics Mini II coater that we've had absolutely no trouble with until about 2 months ago. All of a sudden, most Sola Transitions 1.50 SV and FT lenses were developing either little chips or very small "dents" in the center of the lenses after the wash/dry cycle (before coating). We haven't had any trouble with polycarb or regular CR39. All of the chips/dents were within a central 1.0 cm of the lens (meaning at the OC of the lens). I can assure you the lens is not hitting the wash/dry heads or coating nozzle.

We fine on low speed for 2:15 with a 7-leaf 3M 15 micron 1-step pad from PSI, we polish for 4:00 on low speed. We really haven't changed anything except for switching from IPA for the wash cycle to deionized water but that was about 3-4 months before we started having trouble with the chips. DragonLensmanWV suggested we polish for 6 minutes for the Transitions 1.50 lenses, could that really make a difference?

Since we have no trouble with polycarb and CR39 and we've always used Sola's Transitions 1.50 products, I'm starting to think we've run into a bad batch of products.

Or perhaps there's simply too much pressure being used by the coater. Is there a way to modify how much pressure the Haskell pump puts out?

[Jim Schafer]

Hi Steve

The lenses you are having problems with are what we call generic product.

This generic product line is 1.50 standard index Gray and Brown FSV, SFSV and ST28. This product is mass produced and labeled with the name of the manufacturing partner who bought them from Transitions Optical. SOLA, Essilor, Younger, HOYA and X-Cel Optical all carry the same product in generics. X-Cel Optical offers extended ranges that they cast, but that is considered a specialty product.

The odds of getting the same batch in a pair is pretty high.

Has the travel of the oscillating spray head changed? Is it lingering in the center? That or pump pressure to high.

Jim

[snowmonster]

Okay, so I tossed a regulator with filter on the coater and cranked it down to 80 psi.

Ran a 1.50 Transitions FT28 of the same curves that was generated, fined and polished the same exact way through the wash/dry cycle 10 times with absolutely no dents/chips/defects as viewed with a slit lamp microscope and naked eye.

Still strange since we had no trouble until a few months ago and nothing really changed, but at least it worked so that's cool.