What’s Required to Increase Press Speed?
In order to understand what is necessary to improve press speed, it is helpful to step back and remember the big picture. If you look at print growth over the years, the real issue with press speed has simply been a lack of technology. As knowledge and machinery abilities have increased, so has press speed. The machines coming out now are not as gear-driven as the presses that came out in the 60’s, 70’s, and 80’s.
Colour printing is not what it seems, nor is it simple. To obtain full colour, the three processes (letterpress, lithography, and gravure) all depend upon printing only the primary colours (yellow, red, and blue, plus black), and precisely superimposing them so that all the other colours of the spectrum (orange, green, purple, etc.) seem to appear. Black adds the type, and some crisper ‘modelling’ to the colours. The final apparent printed colour is therefore a tone made up of one or more primary colours, where the tone ranges from the palest (highlight) tones to the darkest (shadow) tones.
The challenge with that growth has been finding ways to get more scientific data with the numbers that involve line screen and volume.
Along with the improved ability to harvest this data, the increase in press speeds can also be attributed to the advancement of plate technology, pre-press, and higher quality inks. Press speeds in the past were less than 800 feet, but now they’re close to 3,000 feet. Some CI presses are averaging speeds of 1,200 to 1,400 feet, and still looking to increase, and a few are even running 2,000 feet already.
I believe that these increased speeds are a result of five areas in which there has been great improvement over the years:
- Enhanced art work
- Thinner plates with better ratios of anilox cell to dot-on-plate
- High line-screens with more volume due to higher-wattage lasers
- Servo drive machines instead of chain driven – tailor made for the customer
- Cad cam designs from press to anilox with tighter tolerances
While growth in any of these five areas nearly guarantees improved speed and quality, it is impossible to get repeatability without correct and consistent equipment. Are you using the optimal gear for what you want to print? Do you have the proper anilox roll engravings for the volume you need? Take the time to find out what works for you.
The angle of the cells, the carrying capacity of the cell and the number of cells per linear inch.
I think banded roll testing is important to increase press speed because it will help you find exactly the right anilox roll for what you want to print. The anilox is known as the “heart of the press” for good reason. Choosing the right roll helps to create a good foundation for a variety of printing challenges. When it comes to increasing press speed and maintaining quality, finding the right anilox is a critical step.
