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Hello everyone,
we are having "ghost Images" on the back side of cut lenses. This means tat during a "Steaming Up" Situation, the Image of the machine block appears. In Winter this is more perceptible. When a sudden Change in temperature occurs it appears.
Also when breathing on the lens the Image appears.
We have tried eveything to clean the lenses but without success.
Does anyone have the same Problem?
Thanks for the help!
All lenses or AR only? Most likely a chuck pressure issue. Also could be worn chuck pads and/or base curve/block mismatch.Quote:
Originally Posted by dirceu
Hi lensmanmd,
with all possibilities, AR , Top coated, Super topcoated. We have ajusted the chuck pressure but it still cotinues. We also changed the chuck pads and no success.
Look at lenses with slit lamp and see if you've got minute scratches where block was attached
We had these issues with the top coated super hydro. The ghosting that you are seeing may be related to the anti slip top coat. Clean both sides with ink remover and check again.Quote:
Originally Posted by dirceu
This may also be related to your water quality. You didn't mention whether it was dry or wet edging. Too much anti-foam, hard water, etc. Again, a gentle wipe with ink remover on both surfaces prior to glazing may solve these issues.
Good luck
Quote:
Originally Posted by lensmanmd
..................................perfect solution, probably some residue left on surface.
You can also clean the surfaces with one of the new type marking removers.
I get that from time to time. Put the lens in the salt pan for a few minutes and it will disappear.
Too much chuck pressure on you edger. Try putting a blocking pad on the back side of the lens to ease the pressure.Quote:
Originally Posted by dirceu
Really? I was always told AR is susceptible to 130F and above.Quote:
Originally Posted by CME4SPECS
Wouldn't a slat/bead pan be much too hot?
lower than that for 167.Quote:
Originally Posted by Uncle Fester
I've done it many times, I posted that before and got negative responses. I do it and will continue to do it, because it works. My chuck pressure is on the lowest setting, from time to time blocking pad marks show up.Quote:
Originally Posted by Uncle Fester
That it does. Typically, it shows up on undercured hardcoats, and is a temporary fix. What you are “fixing” with heat is the micro crazing of the hard coat stack. Once that stack cracks, it will return, AR or not.Quote:
Originally Posted by CME4SPECS
We use multiple chuck pressure settings based on material and AR. If my tech uses the incorrect settings or incorrect blocks and crazes the AR, we redo the job. Better to fix it before it gets to the wearer than redoing it after the fact.
Hi, will do. IŽll let you know!
We did the tests wth the ink remover and it only disappeared on lens with AR Coating only. We use dry Edging.Thank
Hi, the Problem is that we Edge 5000 to 6000 lenses a day.
We also have diferent chuck pressure Settings depending on material. We have tried all type of values but with no success.
OK, this means that you are using robotic edgers, most likely an MEI Racer. Since AR coated lenses are now resolved with ink remover, that leaves non-AR. I would take it one step farther and guess that this occurs on surfaced lenses, not FSV. This would point to the backside coating.Quote:
Originally Posted by dirceu
Are you using spin, dip, or both? i would venture a guess that these are occurring on spun lenses, which would indicate curing.
We edge about 350 pairs a day, both wet and dry on different edgers depending on fit and finish, all manual, including our MEI. We did see this last year, and changed our curing process and times. The issue went away. I don't believe this is an edging issue.
Why everyone isn't supporting Steve Machol and Optiboard with at least a Bronze paid subscription is beyond me for the knowledge and stories (see latest post by Chris on the "In defense of" thread) that we get for "free" here. :smile:
Always learning...
Preach Fes!
We only have dip Coating.
Now we are getting somewhere. When is the last time that you looked at the curing process and times? Have you sent any lenses out for testing? Those chuck marks from the edger means that your coating is undercured and/or too thick. i'm no expert here, just so you know, but your coating is suspect.Quote:
Originally Posted by dirceu
We are Looking at all possibilities. As soon as i have a answer iŽll let you know.
Thanks to all for the feedback and ideas.
Where do you guys send these lenses and what are they looking at?Quote:
Originally Posted by lensmanmd
What other tests can "they" do?
What do they charge?
We have this issue with 1 Customer and only in winter. We can do all the tests as refferd earlier from Lensmanmd.
The Costs always depend on how many Hours our process engineers take to come up to a conclusion.