I am working in a middle-size lab, and we have problem with 1.67 lenses ( mr7 and mr10 materials). When we coat high plus 1.67 lenses convex side of lens gets defects like orange peel, during curing in oven. Does anyone have this problem also?
I am working in a middle-size lab, and we have problem with 1.67 lenses ( mr7 and mr10 materials). When we coat high plus 1.67 lenses convex side of lens gets defects like orange peel, during curing in oven. Does anyone have this problem also?
Last edited by Srejicaleks; 02-09-2011 at 12:46 PM.
Do you use different lacquers for 1.6 and 1.67 ?
I would check the surface after coating if it is ok.. If the coating looks good, try to lower the temperature and incerase the time in oven.
Try to set the oven temperature for 105 celzius degrees and cure time 3.5 hours. I doesn't help try the lower temperature and increase the time only just for chacking what happens.
Was you able to coat 1.67 before or do you have this problem from the beginning? If you have this problem from beginning and test above doesn't help you, try to contact lacquer producer.
The mr7 and mr10 are soft materials, so in case that you use high oven temperature of curing you will get the mentioned surface deformations.
Thanks for reply. We are using the same lacquer for 1.6 and 1.67 lenses. For that kind of lacquer it is recommended 110 celzius degrees and cure time 3 hours. Like I said problem are only 1.67 lenses, convex side, base above 5. I have done some tests, and it is for sure problem with high curing temperature. Defects are more often on mr7 then mr10, because MR 7 material has heat distortion temp 85 ēC and MR10 100 ēC. So I reduced oven temp. at 100-105 ēC , it is better now, but still there are defects from time to time. If I reduce temp. more, adhesion of lacquer will be poor and it will peel of.
I would try to send the lenses to your lacquer supplier to coat them with the same lacquer and you will see the if there is any difference.
I would also try to reduce dipping speed for high index materials about 15% and use the same oven setting and times that you got best results. (we have tried to increase the dipping speed about 15% and we got the same problem you are facing.. )
Hope this helps you and if not try to post your thread in optiboard.com - section of Ophtalmic Optics -the more experienced guys surely help you in this matter, because i do not have any other ideas.
Peter
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