Options, Technologies & Key Features for Printers to Consider When Buying a Flexographic Press

Printing, like all manufacturing, is about increasing production, reducing waste and improving quality. All flexographic printers look for ways this can be done, especially when it comes to investing in a new machine. Truth be told, all major press manufacturers subscribe to similar sets of key performance indicators (KPIs); they simply identify them by different names. At FTA member Poly Print Inc, long, small and medium jobs are all accommodated. Job value on small- and medium-sized runs is not usually high, and margins tend to be very tight. As such, changeover time and reduction of setup waste are extremely important.

They say presses come down to two major things: tension and ink. That isn’t too far from the truth. It is a printer’s challenge to conquer the art of matching target color on the first pull, sustaining consistent color throughout the printrun and maintaining clean print. Many offline tools help measure quality and color, as well as help report on it. Over the years, spectrodensitometers have become more sophisticated, as has the software accompanying them.

Prepress has made progress by leaps and bounds with software that helps manage separations. Evolution of anilox technology for better ink laydown, higher linescreen printing, and even the methods to clean and maintain the rolls allow printers to hit targets and lay down vibrant colors. Continual improvement of printing plate technologies has made flexo a force to be reckoned with when compared to gravure, litho and offset. Flexo can now print at linescreens for which all the other printing methods were known.

There are so many different options available when designing and building a new press. It seems that most press manufacturers have an answer for nearly everything you could want or think you want. As a printer, it’s important to evaluate which options are going to be best for the markets you currently serve or want to serve. Most of these options come with heavy price tags, so while you may want to have every feature available and be able to say to your customers you can do something, be aware that it’s very expensive to do so. If you don’t have the market for it, it’s likely not worth spending the money on.

For some of the markets Poly Print Inc services, including food packaging, pet food and beverage, we noticed traction with spot gloss or matte varnish overprint. In some cases, we have had interest in printing on both sides of the web. With that, we invested in a re-insertion feature that allows us to print one side of the web and then put the roll back on the machine to print the other side. This is very popular in premium snack food brands and pet foods.

Press Features & Functions

Having all the right offline tools in place is just one important piece to solving the printer’s challenge. By themselves, and even together, these tools are useless. A press is what brings them all together to do their jobs. Having a machine that works in tandem with these tools is really the foundation to take a printer to the next level.

Our newest press, a 10-color, 44-in. Uteco Onyx, did a good job addressing the issues, thanks to some new features—one of them being an automatic wash-up system. This was a major jump from having to manually wash each individual deck, one by one. Wash-ups are done in a fraction of the time, are much more thorough and are performed with the touch of a few buttons.

Next on the list was setting registration and impression. Traditionally, that was accomplished with a skilled operator standing or balancing in an area at the press where there was good visibility of the web. Here, the operator could make adjustments via pendants to alter registration up and down and side to side. For older presses, this was accomplished with knobs to move the decks in and out. The process was done with the press moving, slowly, addressing each individual color one at a time. Either simultaneously, or after the operator had the job in register, the impression setting for each print deck was done.

The speed of this process was heavily reliant on operator experience and skill. With most press manufacturers recognizing this as a major area for improvement, their sights were set on making this process more efficient and accurate. The results of their focus work quite well and for the most part can set up jobs of up to 10 colors in record times. There are occasional jobs that do require adjustments to be made by an operator. The key to making these technologies work to their design is operator training, implementation and enforcement.

In addition to the wash-up and auto-register and impression-setting systems, there are a host of other new technologies and parts that help with fast changeover, short runs and waste reduction. Specifically, a completely redesigned and re-engineered doctor blade system that allows for consistent ink flow to and from the buckets, within the chamber and from the chamber to the anilox, has reduced ink starving, anilox scoring and chamber pressure. Toolless doctor blades allow for faster changing of worn blades and seals, and reduced downtime. Viscometers now measure ink viscosities based on vibrations and require little to no maintenance.

We opted for shaftless turrets at both the unwind and rewind. What we noticed here is that loading and unloading rolls is much faster and much safer. Gone are the days where the helper “forgot to put air in the shaft” and rolls at the rewind would exhibit telescoping or have poor conformity. Although this was quite a large expense, we are in here for the long run and wanted to make the job easier for current and future operators.