Heidelberg UK last week staged a live interpretation of the debate between conventional litho printing and new generation UV litho. In a shootout at its Brentford showroom, it pitted an XL75 with coater against an SX74 LE-UV press running the same job on uncoated papers. There was little difference in performance: the LE work was completely dry in the delivery while the XL’s had to stand before folding or returning through the press being the main outward distinction.
Heidelberg UK concedes that the UV equipped machine holds advantages for some jobs. It can print on non standard substrates, plastics, metallise boards and such that cannot be printed without UV. However, outside this and printing on uncoated papers and a dominance of same day turnaround work, the conventional press can match the performance of new generation UV without some of the drawbacks. The company has yet to sell a new generation UV press in the UK but has sold an eight colour perfecting XL106 to Lasertryck in Denmark.
“We can also supply the LE UV tuned lamp system as a retro fit,” says sales director Jim Todd. “That is another angle for those wanting to update an older press. It would need a complete roller change as the hybrid rollers do not work with the highly sensitive inks for the narrow UV spectral band.”
At the open house, because of the huge windows looking on to Brentford High Street, the ducts on the SX machine were shielded to prevent UV in sunlight reaching the ink’s photoinitiators. There were also samples of drip off varnish and spot varnish effects that are possible with the UV equipped press and which are beyond the reach of the conventional machine.
The XL75 was printing with a combination of Saphira ink and fount solution designed for fast drying under the most efficient ir/hot air dryer. While this is less energy efficient than the LE UV doped lamp system on the SX, the additional cost is around £1,200 a year when printing 18 million sheets and according to energy tariff.
The big cost difference is in the price of ink which can be three or four times higher than for a conventional process colour set and while prices may fall as competition increases and volumes generate economics of scale, the raw material costs will always be higher than an oxidising ink.
The company has produced a White Paper to explain the issues and costs related to printing with new generation UV, either the tuned mercury lamp approach which is available now or with LEDs to create the UV energy. This will become available to Heidelberg UK next spring.
The company used the open house to demonstrate the new TH56 folder with options to fold pharmaceutical leaflets as well as conventional work and to discuss its recently colour management offerings. The development was put together following requests from customers to help with colour management. The choice of packages ranges from a straightforward health check on a single press to a Platinum package covering a number of machines and full end to end colour management.
This will lead to certification by Heidelberg to the latest version of ISO 12647-2. It also paves the way for a colour evaluation service where printers download and print a test sheet specific to their model of press. This can be assessed in house and once at a satisfactory point will be sent to Heidelberg UK and from there to Germany for final measurement. “Because the printer is doing a certain amount himself, the process becomes a lot faster” says Paul Chamberlain.