Left side advert image
Right side advert image
Super banner advert image
Subscribe to Print Monthly's RSS feed

Enter your email address here to sign up for our weekly newsletter

Under the Hood

Ryobi 520 GX LED UV

With the development of LED UV, Brian Sims reviews the Ryobi (RMGT) 520GX LED UV and sees how litho has become even more attractive against digital alternatives in this sector

Article picture

The Ryobi (RMGT) 520GX LED UV has a maximum printing area of 505 x 350mm

At the forefront of printing technology

Quite often with technology there is a top down trickle effect where new devices and innovations are introduced on larger flagship models from manufacturers as the costs of the new equipment can be absorbed a little more discreetly in the larger ticket price items. This can seem unfair and preclude some printers from gaining the advantages the new initiatives bring.

In this month’s Under the Hood I am looking at a piece of equipment that bucks that trend, a printing press with cutting-edge equipment not to be found on larger models—the Ryobi (RMGT) 520GX LED UV.

Off limits

In an ever evolving world, the line of what is dedicated to the strict demarcation of a B1, B2, or B3 printer has evaporated. It is likely this is why the Ryobi press has found success in a sector that would have previously been excluded from the flexibility and advantages of UV printing. The technology wrapped up in this press is not only quite surprising but also cutting-edge, and not available in many other traditional sectors.

In an ever evolving world, the line of what is dedicated to the strict demarcation of a B1, B2, or B3 printer has evaporated


The interest on the press itself is the LED UV drying equipment that Ryobi has been pioneering with its technology partners, Panasonic and Toyo. It is not that long ago that the use of LED light sources would not have been considered on a printing system as a component of a drying system. Key developments by Nobel Prize winner Shuji Nakamura of the University of California has made this innovative technology of practical use to the printing industry.

So why is this new lighting source meant to give so many advantages? To understand this, you need to go back to H-UV technology that has found favour and the convention of focusing a specific light spectrum to a matching photo-initiator in the ink or varnish.

LED lamps do exactly the same as H-UV technology in this respect. You need to use the inks or varnishes supplied for the specific lamp so you get all of the advantages of H-UV of immediate drying with reduced temperatures.


One of the first and most obvious advantages of LED UV lamps systems is the ability to turn the light on and off, in an instant



This technology gives the ability to have work dried in the stack ready for reworking immediately, to apply special coatings or effects, such as drip off varnish (if the press uses an optional coater), sharpness of dot giving sharp colour reproduction and possibility of using special colours at will.

One of the first and most obvious advantages of LED UV lamps systems is the ability to turn the light on and off, in an instant. With the LED technology as soon as you turn the lamp on, it is at full luminosity.

Secondly, with regard to the issue of lamp design, the LED system can be used as banks of lamps within the lamp head. This means you can switch down the number of lamps to the desired sheet width which can reduce power usage and improve life. The LED-UV lamps themselves use less power so energy savings are projected on usage alone.

Whilst the variations of H-UV lamps consume significantly less power (hence heat) than traditional UV lamps, it is claimed that the LED versions produce significantly less heat again due to their design. Ozone is also not present, so expensive ducting is also a thing of the past.

Better, faster, stronger

So, what else makes this combination of drying technology and press such an interesting item? Well, previously presses such as this ran at lower speeds, were less equipped, and were selected purely for their paper size and format.

Given we have now demoted the traditional differentiation between press sizes to history, it is refreshing to see that the 520GX has so many of the accepted efficiency options that you would expect to see on a B2 or B1 press.

This press has a unique cylinder configuration of double and triple size transfer cylinders that means the press can cope with paper stock thickness from 0.04 to 0.6mm quite comfortably. The paper sizes are impressive too, sizes as low as 100 x 105mm can be printed, and postcards and envelopes can be easily accommodated on a suction belt transfer system.

After paper sizes each of the units, four, five, or six colours have a number of automated processes. The press comes with semi- automated plate changing, remotely operated plate registration, and a cylinder configuration that does not require a plate bender making the reuse of printing plates quite straight forward.

The inking system on the 520GX has an ink duct which has been updated to have 400 graduations per ink key up from 200. This gives significantly more ink control. The dampening system uses differential gearing which means the form roller runs at a slightly different surface speed to that of the plate cylinder, meaning the form roller scrubs the plate reducing picture framing and hickeys.


The inking system has an ink duct which has been updated to have 400 graduations per ink key up from 200, giving more ink control


















To ensure the press has the optimum efficiency, that would be taken for granted in this day and age, Ryobi has ensured that the 520GX has all the equipment found on other larger presses.

To ensure the press has the optimum efficiency, that would be taken for granted in this day and age, Ryobi has ensured that this small B3 press has all the equipment found on other larger presses


Ryobi has added its PDS-E Spectrophotometer and closed loop system to ensure that ink control is maximized. Ink volume and image data can be converted in their system to allow for the differences in image to be catered for and changed accordingly. This system along with a CIP4 software option will make the taking of a CIP4 file to the printed image as seamless as possible.

As well as inking and unit setting, the press comes with paper and press resizing for a given size of paper at the press of a button. Sidelay, delivery, and all other paper changes are possible from the user interface on the press desk. No more wandering around the press setting it prior to the first pull.

The press series also comes with a coating unit for the application of varnishes and coatings. It has a clever design function of being able to lift the coater blanket and application system out of the way of the paper, such maintenance or blanket changes can be done on the run.

Having looked at this machine, it is refreshing to see that in this day and age, technology is available to all sectors of the printing industry, even more so the LED drying system being also singularly available via Ryobi and its partners.



Brian Sims is the founder of Metis, a specialised business, legal, and technology consultancy for the print industry. To find out more on the issues in this article or his services go to www.metis-uk.eu or e-mail brian.sims@metis-uk.eu

Your text here...
Print printer-friendly version Printable version Send to a friend Contact us

No comments found!  

Sign in:

Email 

or create your very own Print Monthly account  to join in with the conversation.


Top Right advert image
Top Right advert image

Poll Vote

What will be your next business investment?

Top Right advert image