Aqueous Coating Gloss...

[kdw75]

On our GTO we use the 5th color station to aqueous coat jobs. While this give a nice shine, it is nothing compared to what one of our competitors is doing. They aqueous coat on a 2010 Speedmaster CD74 with a coating unit, and theirs looks like it is put on about 2 or 3 times as heavy. Just beautiful.

Now if I try to put it on any heavier it starts sticking together. Does this sound like they have a different coating, or does their machine have better drying, so that they can run it heavier?

 

[Cornishpastythighs]

They(your competition) are using a dedicated unit designed to apply coating either by with an Anilox system or 2 roll application. They can indeed apply more coating than you and probably have an extended delivery to allow for 'flow out' to improve gloss. Have you converted your print unit to apply coating via the dampening unit or are you using a Duct coating applied through the roller train like a Kentucky Shine I think it's called.
You are comparing apples and potatoes with your unit and the competition I doubt you can ever match the gloss of a dedicated coater no matter what coating you use.

 

[kdw75]

They(your competition) are using a dedicated unit designed to apply coating either by with an Anilox system or 2 roll application. They can indeed apply more coating than you and probably have an extended delivery to allow for 'flow out' to improve gloss. Have you converted your print unit to apply coating via the dampening unit or are you using a Duct coating applied through the roller train like a Kentucky Shine I think it's called.
You are comparing apples and potatoes with your unit and the competition I doubt you can ever match the gloss of a dedicated coater no matter what coating you use.

We are indeed using Kentucky shine through the ink train, and yes the competition has an extended delivery.

We can always tell their work from everyone else in town, because of the tremendous shine.

 

[Cornishpastythighs]

You might want to look at being able to apply AQ through your dampening unit although with no extended delivery and good dryer you may run into your loads ending up as solid blocks of coating and sticking.

 

[turbotom1052]

Are you sure your competition isn't using an inline uv coater or perhaps even an offline UV coater? you will NEVER achieve the gloss levels of UV coating with an aqueous coater, even applied with a dedicated coating unit. Its been a long time but i seem to remember using a aqueous printing unit coating that had higher gloss levels than the Kentucky shine product. I can't remember the product name but I think it was made in Japan. If i remember the product name I will post it.

 

[kdw75]

Are you sure your competition isn't using an inline uv coater or perhaps even an offline UV coater? you will NEVER achieve the gloss levels of UV coating with an aqueous coater, even applied with a dedicated coating unit. Its been a long time but i seem to remember using a aqueous printing unit coating that had higher gloss levels than the Kentucky shine product. I can't remember the product name but I think it was made in Japan. If i remember the product name I will post it.

It's not UV.

It really bugs me that the GTOs have such a short delivery.

 

[Ret Heidelberg Instructor]

It's not UV.

It really bugs me that the GTOs have such a short delivery.

The GTO is out of production and someone did make an after market coater. I don't know if it caught on. If you can afford a used SM52 with coater and extended delivery you will be further ahead. It can be a money maker and a dream to operate.

 

[Ret Heidelberg Instructor]

Consider this; regardless of whether or not you're using an ink train or a dedicated coating unit, you're still applying the coating to the sheet via a blanket. So the method of getting the coating to the blanket isn't as much of an issue as the type of coating you're actually using. I've never used Kentucky Shine (although I've heard of it) but there are plenty of different brands of aqueous coatings out there that run in ink trains to choose from. Heck, you could probably even use the same coating they're using out of the barrel and it would still run okay, you just have to get your viscosity correct and may have to run short lifts.

Your competition may have an IR dryer and an extended delivery to assist with delivering the sheet, but using an IR dryer doesn't always guarantee quicker drying and in some cases can actually do more harm than good. And an extended delivery gives you about two to three extra seconds before dropping the sheet, so that may not be the entire reason for their superior product either.

I would look into coating brands and experiment with your viscosity. It may not completely solve your problem. but it's a step in the right direction.

From my past experience with coatings with and without dryers. I ran a Miller press with an Epic coater that
had no heat drying. It sealed the sheet (instead of using over print varnish). It dried reasonably well but left a strong ammonia odor in the delivery area of the press. Many changes have happened since 80 regarding coatings. Mind you a lot of the paper substrate we ran was coated on one side. Since coatings were water based you had to get the hot air knives in the delivery to aid in evaporation of the water that was in the coating. It was hot air that dried the coating. In press rooms with high heat and humidity, drying was an issue if you coated both sides of the sheet. It sometimes required that the printed material be re-piled to avoid the sheets sticking together.