UV Varnish adhesion over Konica Minolta digital prints

[Jools1968]

Hi
We supply all types of pressroom consumables and small machinery such as digital foilers, folders, guillotines and small desk top UV flood coaters. We are having a real issue trying to find a UV varnish that will adhere to prints produced by Konica Minolta machines and I wondered if anyone had a similar experience? if so have you found a solution? We currently sell UV coating from two suppliers and have tried several others which all run fine with every other manufacturer other than KM.

Any help would be greatly appreciated!!

[Emtri]

I have not heard of any issues regarding KM machines
What sorts of jobs where you adding a uv coat to?
What happens when to the sheet when the UV is laid over?

[Jools1968]

Hi there

The issue is that only over KM prints we see the UV varnish simply peel or flake off as it does not seem to get the adhesion required. Any other digital print is fine with either of the varnishes we supply but the KM gives us real problems. Our machines are designed as an all over flood coater and as such are quite simple devices.

Thanks

[effeegee]

Could be the 'microencapsulation' toner which KM use. In effect the release/fuser oil is in the toner making the image areas repel the varnish. If the varnish releases from dense image areas more quickly than light image areas and not from non-image areas that will be the underlying explanation.

That said UV varnishes are available which adhere to KM microencapsulated toners - check with a/your varnish supplier for one suited to the curing system on your machine

[buckeye]

We just got done experimenting with different coatings for our KM C8000 digital prints. The Konica needs a coating that is specifically designed for the wax based toner that it uses. We tried TecLighting and DryTac and both worked. Also, we had to turn the IR temperature up and slow the speed down on our Duplo coater.

XtraCote Hi-Gloss UV Coating #2709

Erik

[KopyBoss]

We have the KM C800 & 6500. Having great success with the blend we purchase from here:
Finishes

[hondarr9]

We have the same problems with coating KM prints. We are using a coating specifically designed for KM and added an additional UV lamp to our Graphics Wizard machine (helped a little). Still get a very weak coat. Especially over black toner. Its frustrating to hear that other people have no problems.

[SnappySteve]

Have not heard of any table top units that will coat this type of toner. You definitely need a fluid that is made for the wax adhesion andthe coater needs an IR lamp pre-UV lamp.

[Erniek]

The temperature to apply the UV coating needs to be quite a bit higher to get good adhesion with the KM toner.