# Optical Forums > Ophthalmic Optics >  Spin coat vs Dip coat

## Websta

Hi all,

I am trying to find out some information on the best type of coating to use with AR coating. We currently do dip coating, but I have heard that in the USA they mostly use spin coating for AR coated lenses. 
Is this true and what is the quality like? What are the long term disadvantages?
What has the experience been like for users of this site?

look forward to your comments.
Thanks

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## AWTECH

Companies in the US use spin coating for a couple of reasons.

One it is easy to get into.  No big equipment costs.

Another is the use of UV cured hard coatings.  These UV hard coats have improved over the years but are still no match for a good polysiloxane thermal hard coating.

UV is fast no 2 hour or more curing time.

For any volume production the dip coating method would be much better.

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## Chris Ryser

> Hi all,
> 
> *I am trying to find out some information on the best type of coating to use with AR coating.*


While some UV cure materials provide a much harder coating ..........they can not be made with silicone polymers which are *the only compatible ones* for good AR coating adherance which have to be thermocured.

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## Jim Stone

> Hi all,
> 
> I am trying to find out some information on the best type of coating to use with AR coating. We currently do dip coating, but I have heard that in the USA they mostly use spin coating for AR coated lenses. 
> Is this true and what is the quality like? What are the long term disadvantages?
> What has the experience been like for users of this site?
> 
> look forward to your comments.
> Thanks


By dip coating, do you mean a thermally cured coating or the snake oil stuff you put in tint units?  Most AR now require both surfaces to be hard coated.  For safety reasons. I don't know any lab that has the capability thermally cure a hard coat.  I am sure they exsist.  The UV cure is just more popular and easier. This snake oil stuff will not do for AR caotings.  You may get by with them in a retail situation.   It really is not much good.

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## AWTECH

Jim;  I am sure he is referring to dip coatings using polysiloxane thermally cured coatings.  These thermal cured dip coatings are the used in most developed countries of the world including Austrailia.

The US is the only country that is using so much UV cured spin coatings.

As far as the tint tank coatings, which you may have correctly identified, I have no experience with these.

Our polysiloxane thermal hard coatings have a Bayer rating of greater than 5.

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## Ace

> While some UV cure materials provide a much harder coating ..........they can not be made with silicone polymers which are *the only compatible ones* for good AR coating adherance which have to be thermocured.


Really? Can you send me data on this. You have test results, and field results that support this? What is thermocured? Or do you mean thermally cured?

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## dochsml

There are many UV cured hard coats that are compatible with AR. The non-tintable ones seem to work better depending on the particular AR stack. Ultra Optics for example seems to work just fine.

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## Ace

> By dip coating, do you mean a thermally cured coating or the snake oil stuff you put in tint units?  Most AR now require both surfaces to be hard coated.  For safety reasons. I don't know any lab that has the capability thermally cure a hard coat.  I am sure they exsist.  The UV cure is just more popular and easier. This snake oil stuff will not do for AR caotings.  You may get by with them in a retail situation.   It really is not much good.


 There are quite a few labs doing thermal cure dipcoating. There are also a few good quality UV lacquers as well that have good AR compatability. However there are lot of UV lacquers that aren't compatible. Equipment and lacquer maintenance is key for success, as with any lacquer system

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## Ace

> There are many UV cured hard coats that are compatible with AR. The non-tintable ones seem to work better depending on the particular AR stack. Ultra Optics for example seems to work just fine.


 The next generation of UV lacquers for AR will be non-tintable solvent based.

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## hipoptical

> There are many UV cured hard coats that are compatible with AR. The non-tintable ones *seem* to work better depending on the particular AR stack. Ultra Optics for example *seems* to work just fine.


Depends on how far out you are looking. At first glance, there are some non-tintables that are good, but that is only when comparing them to another UV-cured coating. The best spin-coat is still no match for a thermally-cured dip coat. When looking at AR compatibility, one must take into account the fact that your front and back coats will not match unless it is dipped. This can be problematic if you intend on the front and back color match, the scratch-resistance match, the durability match.... it's just never really a good idea. Then one must take into account the fact that UV-curing makes ALL lenses more fragile, and less impact-resistant. But hey- if money is the only important thing, then by all means, save yourself a few pennies and buy yourself a spin-coat unit.
Just my opinion.... based on facts, knowledge, experience, documented testing...

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## Websta

Hi all,


Thanks for your replies. We have tested the ultra-optics UV cured spin coat, but found many problems with adhesion and long term degradation.
We currently use thermally cured dip coating processes, but were looking to cut down on time. It is evident, from the many replies, that there is still much debate over dip vs spin coats.

If anyone manages to find and use a spin coat system, that can be verified by someone like Colt laboratories, then I will be happy to pursue this. I guess for now we will continue with what we are doing.

Thanks

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## dochsml

> Hi all,
> 
> 
> Thanks for your replies. We have tested the ultra-optics UV cured spin coat, but found many problems with adhesion and long term degradation.
> We currently use thermally cured dip coating processes, but were looking to cut down on time. It is evident, from the many replies, that there is still much debate over dip vs spin coats.
> 
> If anyone manages to find and use a spin coat system, that can be verified by someone like Colt laboratories, then I will be happy to pursue this. I guess for now we will continue with what we are doing.
> 
> Thanks


Dip coat is good if you have the room in your lab and time for the curing. I agree that dip coat is the best option for AR but even it has it's drawbacks. Spin coats do a better job of covering scratches than dip coaters for one. I would be curious as to which Ultra Optics coating you used. UV NV is compatible with most AR and is tintable. UV NVC works great as well but is non-tintable. There will be a mis match from front to back but this can also be compensated in the AR process so that the color matches closer. To sum up, dip coaters are best if you are careful with your cosmetics and have the space, time, and money. Spin coaters, however, will get you into AR at a fraction of the cost and allow you to AR pretty much anything. I would stick with the dip coater if it is working for you and maybe only get a spin coater as a backup and not a replacement.

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## Websta

> I would be curious as to which Ultra Optics coating you used.


We have tried the UV NV. However this was done some time back. Our biggest drawback to both options is the many various lens materials and manufacturers lenses we hold stock of. If we could narrow down our search on the most effective UV spin coat, we may be able to decrease the amount of manufacturers lenses we have, but that also has its pros and cons.
As you stated, we have the space and time, but would like to increase our competitive advantage in some areas.

thanks for all the info though.

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## dochsml

> We have tried the UV NV. However this was done some time back. Our biggest drawback to both options is the many various lens materials and manufacturers lenses we hold stock of. If we could narrow down our search on the most effective UV spin coat, we may be able to decrease the amount of manufacturers lenses we have, but that also has its pros and cons.
> As you stated, we have the space and time, but would like to increase our competitive advantage in some areas.
> 
> thanks for all the info though.


http://www.satisloh.com/site/index__...05-51-387.html

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## Websta

I have tried to find info or pics of the satisloh spin coater, but have not seen much. There is some technical information, but that is about it.

Our surfacing department uses 2 ultra optics BSC machines, but may be looking to update (we have had them for close on 4 years). I have spoken to satisloh reps about their spin coaters, but have always been refered to their website, which does not have much.

If you of where I can get some comprehensive information, it would be appreciated.

Thanks

ps. Thanks to "awtech" for recognising that Australia is not as backward as people think or presume. Cheers Mate!

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## dochsml

> I have tried to find info or pics of the satisloh spin coater, but have not seen much. There is some technical information, but that is about it.
> 
> Our surfacing department uses 2 ultra optics BSC machines, but may be looking to update (we have had them for close on 4 years). I have spoken to satisloh reps about their spin coaters, but have always been refered to their website, which does not have much.
> 
> If you of where I can get some comprehensive information, it would be appreciated.
> 
> Thanks
> 
> ps. Thanks to "awtech" for recognising that Australia is not as backward as people think or presume. Cheers Mate!


My suggestion would be to send Larry Clarke an email. He is the CEO of satisloh North America. I'm sure he could get you pointed in the right direction. His email is on the link.

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## AWTECH

Here is a link to another spin coater manufacturer that is based in the US.  This system I think allows the use of up to three different coatings

http://www.lescouv.com/products/Opti.../flexcoat.html

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## rinselberg

Ultra Optics has already been mentioned on this thread.
http://www.ultraoptics.com/coatings.htm

Chemalux offers spin-coat machines that can apply either a SR (scratch resistant) or AR coating.


> Scratch resistant coatings are the basecoats for AR coatings. Chemalux offers the best UV scratch resistant coating technology to our customers. By working with Ultraoptics, Chemalux designs and fabricates Model 100O system for both AR and SR coatings. Chemalux 100O system is ideal for optical retailers and small wholesale labs to do in house SR/AR affordably. In addition, Chemalux distributes Ultraoptics' Model Mini II and MR III along with Chemalux AR coating systems (150A and 300T). Deposition of Chemalux AR coatings onto Ultraoptics' UV-NV in-house yields the best in-house AR coatings.


http://www.chemalux.com/AR%20Equipment/SR.htm

I have no other information or experience to add - I am only offering the links to these Internet webpages.

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## Ace

> I have tried to find info or pics of the satisloh spin coater, but have not seen much. There is some technical information, but that is about it.
> 
> Our surfacing department uses 2 ultra optics BSC machines, but may be looking to update (we have had them for close on 4 years). I have spoken to satisloh reps about their spin coaters, but have always been refered to their website, which does not have much.
> 
> If you of where I can get some comprehensive information, it would be appreciated.
> 
> Thanks
> 
> ps. Thanks to "awtech" for recognising that Australia is not as backward as people think or presume. Cheers Mate!


I have seen them both at a tradeshow. There are 2 models, one is called a G4, which has a steamcleaner attached, and has 2 lacquer tanks. The other is just the 2 lacquer spincoater without the steamcleaner.

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## jrctx

I second all those listing thermally cured dip coating over UV as the best.  Do however keep in mind that there still remains a difference between quality in each of the two groups.  
In UV applications there are many actual coatings and coating systems as well as training and inspection methods.
With thermally cured dip coating as well as A/R coating your product is only as good as your technician.  There may also be a chance that a branded product is different if purchased from the branded lab vs. a licensed lab.  The licensed labs typically do not have the expertise and training to identify potential problems or remedy problematic situations.

Utilize the source (coating developer, R&D, etc.) for consistent quality every time.

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## Chris Ryser

> *The next generation of UV lacquers for AR will be non-tintable solvent based.*


Got to disagree with above statement. I have been making a non tintable solvent based UV curable coating material since 1984, so this would rather classify it as old generation rather than next generation.

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## LKahn

There seems to be some confusion between application processes and coatings.

Spin, dip, bath or spray are processes for applying the coating. The application process is a function of the nature material being coated and the function of the coating and coating viscosity.AR, Hard-Coat and Scratch Resistant are all different types of coatings performing different functions.We are just about to introduce a revolutionary new scratch resistant coating, LensArmor which is applied at room temerature, applied in a bath, spin-coat or spray process (1 step), cured with or without heat, Non-Toxic, Non-Flamable and does not require a primer.

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