Indigo 5500 ink scratching

[RGPW17100]

I have been working with Indigos as a production manager for 10 years. I am familiar with the Indigo 2000,3050 and now the 5500. Our main operator left a week ago and I am currently the new operator of this machine. Indigo says that a color build of over 260 percent is bad and it will scratch or the ink will not stick to the substrate. We use exclusivly GPA stock which is the best substrate for indigo. What can I do to minimize scratching. We see it in rich black and real dark blues like 2757, 301 and similar inks. We can aqueous coat sheets but I see minimal sucess with this. Is there an offline coater that will help? I have received mail pieces that were printed on an indigo and I can not scratch them. I am open to all ideas.

 

[jay12345]

We suffer from the same issues as anyone who owns an indigo. Ink scratching/picking/scuffing. We have tried AQing the sheets afterwords to see if this would help but no it does not. UVing the sheets is really the only option and i wish they would have told me that before i bought the machine but if they had they would not have sold a machine so i understand why they did not. My biggest complaint with the machine is the chipping on the edges after the job is cut. The edges of of job printed rich black look like hell. Even with UV there is no stopping this. We use GPA stock when we absolutely have to because there prices seem to be double everyone else's. From what i gather a stock being indigo approved does not really mean anything other than that manufacturer having paid hp a sum of money to grant them permission to market as such. They claim that R.I.T tests the stocks and gives them there approved status if they meet the requirements but i have heard this is BS from people within hp. Well. sorry i cant help other then vent my frustrations. I do love the quality of the prints. just as long as i can keep them on the sheets.

 

[RGPW17100]

GPA uses a new formula of coating the replaced the old sahpire coating. So if a stock is going to work GPA should be the best solution. We are set up on consignment with GPA and because of the amount of stock we purchase from them we get a pretty good discount. I guess I dont understand why UV would work better other then it is a thicker harder coating.

 

[jinthebay]

Scratching, especially on uncoated stocks is probably the biggest complaint from Indigo operators. We try to avoid using any build higher than 250. But designers will never understand why this is a problem and continue to do what they do. That said, increasing your blanket temperature can help as well as adding null cycles. If you do increase your temperature make sure to run a new first transfer. If you've been using Indigos for ten years this shouldn't be anything you don't already know though.

 

[DigitalMike]

I have also been using HP Indigo technology for 10+ years, operating all series of presses. I will tell you that yes HP Indigo Inks are a little soft but there are many things you can do to help. I have successfully printed many jobs that exceed the recommended ink density from HP. Substrate has a lot to do with it. I also had a GPA consignment program and was extremely happy with the substrates and the results.

Keep in mind that if Ink adhesion is an issue you fight, UV coating the sheets are only masking the problem and if a tape test were to be performed it would pull off the UV coating along with the ink. I have some first hand experience with the RIT certification process and it is way more involved than vendors simply paying for their items to get a stamp of approval.

Please contact me offline should you wish to discuss this further.

 

[SherrySpencer]

Hey, I found good and useful information here regarding Indigo 5500 ink scratching. Thanks for sharing it.

 

[Lukew]

What I take from this thread is you indigo guys, who take the work from offset presses. Can:
1) Do the job quick with minimal waste or time
But
2) can't actually deliver that job throughout bindery to client without issue.

Great to see technology going in leaps and bounds. Only the other day I had a job done digital instead of offset, only issue was the latest and greatest digital machine that is phasing out offset, couldn't register the double sided form. Let alone allow it to be recycled for reuse within the industry.

 

[Schnitzel]

If this technology wasn't successful at meeting customer quality demands, it wouldn't "take the work from offset presses". You sound as if offset printing has no limitations and problems...

 

[Lukew]

If this technology wasn't successful at meeting customer quality demands, it wouldn't "take the work from offset presses". You sound as if offset printing has no limitations and problems...

The latest indigo machines available may well have solved a lot of the initial indigo problems, But there are many a print shop in my region that jumped on the indigo bandwagon and sold their presses. Issue with that was they near lost there business due to the indigo issues and constant breakdowns of the indigo presses. Some of these shops have had to reinvest in presses again.

The quality of digital copiers is poor, the digital printed work is slippery always causing issues for folding and saddle stitching. It doesn't register, and the colour is never the same.
Press a button and what ever comes out the finish tray is whats excepted from digital.
If a offset printed job had those imperfections it would be reprinted and the printer would cop and earful from management.

ow did I mention this digital technology thats taking over offset, can't be de-inked.

 

[RGPW17100]

Interesting how a simple question about scratching totally bashed the digital print industry. Negitive comments from anyone on this thread has no clue as to the importance of digital printing. I run probably 20 jobs a day on the Indigo and maybe have problems with 3 or 4 a month. Most of these is because designers build their ink to over 250 percent and then problems happen. All of the other jobs go like clock work and seldom do these jobs bounce. I came from a quick print background and am an accomplished press operator on most printing presses from an Ab Dick to a SM52 5 color with extended aqueous and CIP 4 technology. Our shop has two 40 inch presses, 6 color MO and a 5 color SM52. If your customer needs 100 copies of high quality 4 color printing digital is the way to go. As far as I have seen Indigo is so far ahead of any other digital press that it is impossible to do a comparison. So instead of bashing digital on this thread maybe you can just stay focused on the original topic and post solutions to help prevent scratching.

 

[Lukew]

The indigo sheet can be Varnished via a small offset press from memory?
This may stop the scratching issue your having.
Ive heard of shops that do it here. Can't recall if its a unique varnish done via offset pre-indigo print or a high solids varnish done offset after the job has been printed indigo.
Some use little ITEK 985's to do it.

My post was not to bash indigo, but more a gripe against digital copier machines, which you would be well aware are far below the quality of indigo or offset press.

 

[RGPW17100]

I have no malice towards you Luke. We have used stocks that have something like a saphire coating that has helped indigo ink stick to non approved stock. We have tried aqueous but never varnish. These inks are very high in hydro carbons and because of it figured varnish would have negative effects on it. Any time I speak to one of the Indigo techs they always ask the build of the ink and in most cases it exceeds 250 percent. Just wish there was a way to avoid this because most designers want to pop the ink and that is when the problem starts

 

[Mark Flanders]

HIya,

late posting, but on the initial topic... to be clear. "Scratching" is something I think of as a press problem. Like a piece of paper in paper path dragging on the sheet as it passes by. What you're talking about is post production scratching, particularly on direct mail. (as opposed to posters, brochures etc) This is essentially an adhesion problem and it is most pronouced in over-rich blacks. Give desingers a spec for rich black: 100 K, 60C, 50 M, 40 Y. This adds up to 250 and is a very solid rich black. Setting a color to "Registration" or 100% of everything is incorrect on any press. Regarding adhesion, the liquid toner ink adheres to the surface of sheet with heat and pressure, and the excess oil is removed. A number of things contribute to a good final piece. A good substrate is first. Some sheets have chemicals from the mill which casue a resist to the inks, which is why they have HP coating and certification. Papers withouth certification can work fine. You have to test for yourself. Use scotch tape on a printed job, pull it off and see how much ink is left behind. If it comes off clean as a whistle, you have a problem. Next up is heat and pressure. If there is a real problem, change papers to see if it improves. I you have to, calibrate your ITM temperture, and bump it up 3-10 degrees to improve adhesion. (put back down to a spec of 160 after a trouble job) Also, lie to the press about how thick the paper is. Tell it that it is .32mm when it really measure .41, for example. this increases the pressure on the sheet. Also, set the press in "Heavy Substrate Mode" in blanket/machine parameters. This changes the duplexer to run slower, but prevents the sheets from scuffing each other as they pass in the duplexor. This slows your machine down, but give heavy coverage a chance to cure. Also, do not overhandle sheets right off of the press. let them sit, untouched for 15 minutes before jogging. Then, if your customer has to have a perfect piece after being kicked around the post office, upsell them to UV coating. Yes, an offline UV coater is great. Finally, make a call to HP and have you Field Service Tech look at your press around this issue. You may need to change your ozone filters, or make sure the more subtle environmental issues (too much oil in the ink) are looked into. Good luck.

 

[DigitalMike]

All,

As I mentioned in my earlier post I have run HP Indigo Presses for over 10 years. Models S2000, 3050, 5500, 7500 and have done a lot of testing with the new 10000. I will tell you that although HP does not recommend that you don't exceed 250-280 total ink density I have had great success printing at ink density levels over 300% when using the right materials. Substrate is a HUGE part of this discussion and is a bigger part than most people are willing to admit or test.

There are 3 types of material that all HP Indigo users print on.
1.) "RAW" - These are stocks that were cut down from master sheets in their offset environment with the expectation that they will perform well on their HP Indigo. Based off of the substrates acidic/PH balance, it's a 50/50 shot at best that it will perform at all. Don't expect great results with these products in finishing processes.
2.) "OPTIMIZED" - These substrates have a specific proprietary chemical added into the mixture of the substrate before it is formed that aids in the HP Indigo ink adhesion characteristics of the substrate.
3.) "TREATED" - These materials have a liquid surface treatment applied to them after they are in their finished form that aid their ability to receive the HP Indigo ink. Not all treated materials are treated with the same surface treatment. There is a lot of R&D that goes into developing the right surface treatment to match up properly with the right base material.

Keep in mind that the HP Indigo ink does not penetrate the substrate as in the offset world. The ink is virtually sitting on the surface, therefore making it EXTREMELY important to select products that have been engineered specifically for the HP Indigo technology. If you select the right material the results can be incredible.

Also, note that the HP certification process done at RIT does not include any type of scratch test.

I would also like to clear up some information that was in another posting.

1.) The 160 degree celsius temperature that was noted earlier does not apply to all HP Indigo Presses. 3000, 3050, 3500, 3550, 5000, 5500 & 5600 all have default temperatures of 160. 7000, 7500, 7600 & 10000 all have default temperatures of 110 degrees celsius.

2.) Heavy substrate mode does not aid in ink adhesion. This mode is intended to keep sheets from passing each other during duplex printing of jobs. Using heavy substrate mode prints both sides of sheet one before delivering sheet two into the press, therefore keeping the sheets from passing in the "PERFECTING UNIT" not the "DUPLEX CONVEYOR" as earlier mentioned. If you are looking to aid ink adhesion I would recommend you utilize the "INK TRANSFER MODE" options located in the job properties window of each job.

3.) If you are going to perform ink adhesion test using tape and are looking to see if a substrate is performing in-line with the RIT certification results, DO NOT USE SCOTCH TAPE!!! This tape is much more aggressive than people think. This is not the tape that is used in the lab at RIT when performing the HP Indigo substrate certifications.
You should be using SCOTCH 3M 230 Drafting tape for anything PAPER and SCOTCH 3M 610 tape for anything SYNTHETIC!

As far as consistency and matching color comments made earlier, I worked in a high end offset print shop for many years. I ran and managed our digital department of 3 indigo presses and I will tell you that our quality and consistency was so good off our indigo presses that our sales people and customers couldn't tell the difference in side by side comparisons. We were even at the point where customers were ASKING for their jobs to run on the indigo. In my opinion, consistency, quality and results boils down to the operators understanding of the technology and how to harness the capabilities of the equipment. That includes maintenance procedures that can keep the press from breakdowns as mentioned.

I am more that willing to share my experiences should anyone want to discuss this topic in more detail.
Mike