How to do Spot Aqueous and Spot Varnish in last unit of the press?

[goldenpress_bahadurgarh]

Hi All,

As per my knowledge, I can do spot varnish using the ink duct and a PS plate, just like printing an additional colour with varnish as my ink.

But is there any way to do a spot aqueous? If yes, how?

Additional info- I do have a dedicated flood aqueous coating machine.

 

[krypt_09]

Hi, I know two ways to do it.

1- if the fit is not critical and there is no small detail, the use of a strippable blanket is the easiest way. Most of the consumable supplier can sell you one and you can cut it with an exact-o.

2- if fit or detail is critical the use of a flexo plate or cyrrel plate is recommended. the advantage of a cyrrel plate is that it can be cut and strip on any plotter. you can either use them like a standard plate gripping system or with your standard blanket bar, depending what are the options on your machine.

hope it helps

 

[goldenpress_bahadurgarh]

Hi, I know two ways to do it.

1- if the fit is not critical and there is no small detail, the use of a strippable blanket is the easiest way. Most of the consumable supplier can sell you one and you can cut it with an exact-o.

2- if fit or detail is critical the use of a flexo plate or cyrrel plate is recommended. the advantage of a cyrrel plate is that it can be cut and strip on any plotter. you can either use them like a standard plate gripping system or with your standard blanket bar, depending what are the options on your machine.

hope it helps

Hi, Many thanks for the reply.

I'm planning to run the aqueous coating through the water train so it hits a blank plate and then reaches the blanket.

Am I thinking in the right direction or I need to retrofit a dedicated coater roller to hit the blanket directly to get it working?

 

[krypt_09]

I don't know about the water train, never tried it. I did run water base in my inking unit with a strippable blanket and a resized packing though. You run it dry and it work's good.

I've worked on 1 machine that had different train of roller that fitted in the water system. switching back and forth would allow us to do water base or ink .

 

[aqazi81]

Hi, Many thanks for the reply.

I'm planning to run the aqueous coating through the water train so it hits a blank plate and then reaches the blanket.

Am I thinking in the right direction or I need to retrofit a dedicated coater roller to hit the blanket directly to get it working?

You can ask for INK DUCT EMULSION from your ink or coating supplier, it runs from ink fountain, they will also supply a retarder which you spray on rollers between pile change or blanket cleanup.
Some people here in my country have tried to run inline coating through water train, it works but creates a lot of mess, better to do on a single color press which you don't want to use for printing in the future.
Heidelberg had offered a retrofit in the past which could be installed on printing unit but I haven't seen that running.

 

[goldenpress_bahadurgarh]

You can ask for INK DUCT EMULSION from your ink or coating supplier, it runs from ink fountain, they will also supply a retarder which you spray on rollers between pile change or blanket cleanup.
Some people here in my country have tried to run inline coating through water train, it works but creates a lot of mess, better to do on a single color press which you don't want to use for printing in the future.
Heidelberg had offered a retrofit in the past which could be installed on printing unit but I haven't seen that running.

When I said varnish, I meant INK DUCT Emulsion, no doubt that's the best available solution.
However, the aqueous coating solution is quite thin and true it can be indeed messy on the press. .

Retrofit seems to be the only solution. We have some local alternatives to Heidelberg for such retrofits.


Thanks for the information.

 

[alibryan]

You can run Aqueous coating in any press ink train but it is only possible to run as a dry flood. The reason is because it is already water based and doesn't separate from water on a printing plate image the way that ink does. The only other way you can coat with Aqueous is to cut your blanket to match the desired image you wish to coat. This acts as a spot coat of sorts, but is only as accurate as your technique is in cutting the blanket. Varnish however, can be run as a flood or spot because it acts just like ink and you can either use it as a dry flood, or with water on any plate that has an image.

As long as they're cleaned up correctly afterwards, either one of these coatings can be run without any damage to the rollers, and you can resume normal printing with that unit after you've finished.

 

[sangcai]

Why not make the printing process much more easier by using UV offset printing machine? Only two steps: design a picture on computer and then print it out.

 

[xfactor printing]

Why not make the printing process much more easier by using UV offset printing machine? Only two steps: design a picture on computer and then print it out.

Impressions per hour?
Cost per print?

 

[sangcai]

Impressions per hour?
Cost per print?

The printing speed is 3.5-22 square meter/hour. Different machine usually with different speed. ECO solvent 8010 with Epson printing head, its speed is 3.5m2/h. The most speed should be with Seiko printing head.
The max resolution ratio: 1440 x 1440dpi
Printing cost is around US$1.0/square meter.