Benefits of positive ink feed

[Deleted member 16349]

An article on Whattheythink describes benefits of positive ink feed.

U.S. Newspaper cuts ink waste with Goss - Printing Industry News from WhatTheyThink

The article comments on the benefits of positive ink feed which is provided with Goss's digital inker technology.

Stated in the article:

"An analysis of relevant data provided by Six Sigma led to the realization that a more accurate control over the ink input process could improve print density, ink/water balance and waste levels. Goss digital inking was then chosen as the perfect solution to reducing ink waste."

The Goss digital inker is an expensive technology which provides a positive ink feed to the roller train via gear pumps for ink zones.

The Ink Transfer Blade (ITB) does basically the same thing when used in conjunction with the traditional open ink fountain. The ink keys provide the metering of the ink and the ITB provides the positive ink transfer into the press. Basically performs as a positive displacement pump per ink key.

The much lower cost ITB results in the same positive ink feed as the Goss system but in a way that does not have the slow response of the digital inkers. Also the fact that the ITB can be used with high viscosity inks used in commercial and packaging printing, should be of interest to press manufacturers wanting to gain a competitive advantage.

As time goes on, it will become more and more apparent that positive ink feed is far superior to conventional ink feed systems that in fact have no direct control on the rate of ink feed.

In a process, one can not have predictability without consistency and there can be no consistency if there is no positive control over the variable.

Keep an eye open for articles on how Goss's digital inkers are replacing conventional ink fountains to help newspapers reduce waste and improve consistency. Positive ink feed is a trend that has been slow to start but will grow and can be applied inexpensively to commercial and packaging printing operations. It is the future.

 

[Al Ferrari]

Hi Erik,

That's good news. Here is hoping that your ship comes in.

Al

 

[emanprinting]

Modern Sticker Printing

Modern Sticker Printing

Five types of techniques used in the custom sticker printing industry.

1. Screen Printing

Screen Printing is an uncomplicated form of printing which is trendy for custom stickers printing. This is a type of printing with a still silk screen, is now also done with synthetic material screens. It can be done by hand and is usually monochromatic. For custom stickers, the inks used are identified as ultra-violet cured pigmented colors. The image selected for printing is cut out of a stencil, therefore creating a positive of the image to be printed. This stencil is place over the substrate or the material on top of which the image is to be printed. The screen is then place over the stencil; the suitable amount of ink is direct and then pushed through the screen with a rubber blade. For monochromatic prints this process is only done one time, for prints with several colors the process has to be repetitive for each color after the last color has dried out.

2. Flexography Printing

Flexography is another name for surface printing. This procedure is extensively used for commercial label printing as it let for swift and high volume printing. This is done to some extent like a stamp in that there have to be an inverted master image used to print. A specific quantity of ink is applied to the master for every print; the master creates contact by means of the substrate by gently sloping over it and leaving the projected image. The term “flexo” derived from the flexible character of the printing procedure itself. This method was firstly developed for printing on rough surfaces for instance cardboard, so as to have an excellent print on such a surface it is essential to have a technique of printing that permit regular and even contact with the print surface. Flexographic printing in the sticker manufacturing is largely projected for indoor or limited use; for example in packaging or shipping.

3. Letterpress Printing

Letterpress is another name of relief printing. This means that printed image is taken from a raised surface. The process means from the name itself i.e. you can press the letter to generate the image. This is the method used for portable type printing like bumper sticker printing and for set block printing as well. The first book ever printed was prepared with this procedure in 1456. Johannes Gutenberg was the individual who invented the moveable type block printer. For the next five centuries, this was the standard for printing. Letterpress is designed for easy, bunch printing projects. This process only permits one color to be applied at a time, so these kinds of projects are normally monochromatic or somehow to partial two colors.

4. Offset Printing

Offset printing is the next step in the printing process. The image to be printed is not applied straight; image being transferred goes from the plate drum to the rubber transfer cylinder before it is attach to the real intended print plane. The offset printing process is used in recital with the lithographic printing procedure. Offset printing offers a diversity of tough and vibrant colors that may be used for more striking designs; this effect is formed using a four color process.

5. Digital Printing

Digital printing is the latest development in printing. This kind or printing allows the most elasticity in handling of the print image prior to printing. The print is a duplicate of a digital image. Digital printing is totally customizable from one print to the next, permits for alteration in color, editing of the image and limits the quantity of wasted chemicals and paper used in the procedure. Digital printing inks are not absorbed into the print material so they are dissimilar from other inks used in other processes.

 

[Green Printer]

Can you use inks that skin on positive feed systems? How do you handle inks that tend to skin in 3 or 4 hours. What inking procedure is required to shutdown or restart the press when a new set of plates, smashed blankets or any shut down that last for more than 4 hours?

 

[Deleted member 16349]

Can you use inks that skin on positive feed systems? How do you handle inks that tend to skin in 3 or 4 hours. What inking procedure is required to shutdown or restart the press when a new set of plates, smashed blankets or any shut down that last for more than 4 hours?

Green Printer,

Skinning of inks is a good question and I can't totally answer that. With a system like Goss's digital inker, the ink is totally enclosed within the feed system and therefore skinning would only be an issue at the "rail" where the ink comes out. There are other positive ink feed systems, such as ones from Controls Group Inc. that might be more affected by skinning issues.

My experience is mostly with EB and UV inks so there is no skinning issue, although my ITB has also been successfully tested with conventional ink on a small duplicator type press.

With the ITB concept, there is only a small line of ink contact with the blade tip and that could be quickly cleaned with a quick wipe. Other than that, the rest of the roller train would have the similar problems of skinning as what you have now. In my view, having inks that skin is a bit of a waste. The need to washup at the end of a days production is wasteful. With UV inks, the ink can be left on the rollers for very long periods of time (days).

In general, if one has to stop the press for hours, at restart the densities will almost immediately come back to the previous levels that were being printed before the stop. This is because the ink feed is independent of variations in water, temperature and press speed.

Just think how helpful this would be during a colour OK which has numerous stops and requires minor changes to ink feed. The adjustments would be consistent and predictable. It would also be consistent and predictable for repeat jobs such as in packaging, where the same design will come back to the press again and again. The stored ink zone positions will result in the same results again and again.

 

[Al Ferrari]

If a blanket change after a smash is taking more than 4 hours, you really should put a rake in front of the infeed. Sorry, I couldn't resist.

Those are good questions, actually. Erik's ITB is a modification of the standard open fountain, so no change there. The others, I don't know about. But a 4 hour shutdown with skinning inks is going to require a washup in any case.

Al