That would be grand


We are used to seeing larger and larger signage adorning the fronts of shops and buildings. I recall being amazed on a visit to Berlin where they are rebuilding the original Schloss (translated as palace) which was replaced post-war by the DDR’s 1950’s modern “workers” version.  Whilst the site was being cleared, the contractors had a life-size version printed on sheeting which protected the site. This gave a quite amazing view of what was coming out of the ground.

My wife asked “how ever do they print that?”, well the answer being quite likely on the equipment SignLink is reviewing this month, the baby-grand from Mimaki, the UJV55-320.

This inkjet printer is capable of seven colour production on a very wide substrate width of up to 3.25 metres. Whilst this could be considered as limiting any printer to projects such as the Berlin Schloss, the clever part of the design of the UJV55-320 is the printer can produce off two reels simultaneously of up to 1.524m wide.  


This means a printer can upscale to large projects and production but can equally be at home with far smaller reels and products. The UJV55-320 is a very adaptable printer that can help any business step up to large markets whilst protecting more embedded smaller variations.

The UJV55-320 comes from the well-proven manufacturer, Mimaki. There is a thorough-bred theme running through the printer from piezo-electric heads and the associated technology such as MAPS, WCT, NCU and NRS which are described in detail later. All these components are well-proven in other Mimaki printers and as such are naturally found in the UJV55-320.  

The heads have Mimaki’s staggered inkjet layout which can print four colours with each of the process set meaning you have a total of 5,120 nozzles (1,280 nozzles – 320 nozzles x 4 lines). In seven colour mode half of the heads are set aside for white (twice) plus light cyan and light magenta. This means the UJV55-320 prints 2,560 nozzles of CMYK and 2,560 nozzles of WWLcLm.  

The UJV55-320 can produce at a number of speeds and resolutions. At the maximum output level of 110sq m/h in four colour mode and at a print quality of 3,000 x 600dpi. A large number of levels under this is the highest of quality at 1,200 x 1,200dpi (three layered) and a production area of 1.2sq m/h.


There are number of different formats the UJV55-320 can print such as four-colour banner, vinyl and backlit and a complimentary version for seven-colours. Add white printing to the mix and both a number of passes and layers can be programmed.

The LED-cured ink used on the UJV55-320 is the newly developed LUS-120 range. In this day and age when there is an added need for traceability or compliance, these inks are underpinned by the GREENGUARD gold standard.

GREENGUARD certification is part of UL Environments ecological compliance program. UL Environment is part of Underwriters Laboratories (UL) and acquired GREENGUARD in 2011 which provides purchasers with assurances the products being supplied will comply with the highest of ecological standards.

To satisfy the GREENGUARD gold standard, the inks supplied must meet the stringent emissions standards based on established chemical exposure criteria. Specifically the LUS inks meet the UL2818 standard which is for low chemical emissions for indoor production.

The LUS inks used in the UJV55-320 which hold the GREENGUARD Gold certificate meaning they have passed the most rigorous testing and have a very low impact on the environment and contain very low levels of volatile organic compounds (VOCs) and are nickel free.

Ink deployment is enhanced by a key Mimaki gadget the Mimaki Advanced Pass System (MAPS). MAPS disperses the ink pattern on the sheet in such a pattern in a very specific array to allow the even drying of the product. Obviously the even drying of the sheet means consistency across production and happy clients.

Further to MAPS the UJV55-320 models come equipped with Mimaki’s Waveform Control technology (WCT). With this system, the print heads are able to round nearly perfect circles of ink droplet rather than the deformed circles that can form once the ink is deployed. The benefit is to allow the UJV55-320 to produce high quality images with sharp letters and line and almost perfect sized dots.

Finally there is a Nozzle Check Unit (NCU) which checks and cleans each nozzle automatically but if the cleaning process has not been successful, the Nozzle Recovery System (NRS) monitors and swaps nozzles when any become clogged or blocked. Both NCU and NRS allow the Mimaki to keep production stable metre upon metre.

When printing large signage and banners, the use of white inks can be used on transparent substrates and an over or under layer. White inks can suffer from pigmentation separation which then ends up deposited in various parts of the machine, normally in the inkjet heads which then affects quality and production.

The UJV55-320 overcomes this issue when deployed in seven colour mode by the use of Mimaki Circulation Technology (MCT). MCT agitates the white ink by recirculating it through a device prior to passing it onto the print head. In doing this, the pigments that may be inclined to drop out of the carrier medium, stay in place as required.

The use of transparent material is a growing market and can bring unique issues with it. Marking and other surface issues can be a bigger issue on this substrate and previously on a reel to reel device, you were unable to see any problems until it was unwound.

Mimaki have understood this issue and have used a clever inspection device to allow checking of work on the fly. There is an inline LED Lightbox which allows you to back light production so you are able to see the affect and any issues with the print whilst in production.

The Mimaki UJV55-320 is a very large width reel to reel inkjet printer capable of printing some of the largest jobs, but cleverly with the simultaneous two reel mode, it allows a growing printer to step up to the larger markets but still maintain a production capability in small size markets.     

Brian Sims, principal consultant, Metis Print Consultancy, www.metis-uk.eu