Labelexpo South China kicks off with flexo debate

‘Flexo is not a simple method and that is why it is still a small part of the Chinese label industry. Service is the key. It is not as simple as I sell you a machine. This is in-line label construction and the service element must include proper configuration of the machine.‘

Joseph Kong of Hong Kong-based pre-press house Flexolutions told the audience of Chinese converters that Esko’s latest HD2 software allows flexo printers to move closer to offset quality in the key areas of minimizing dot gain, maintaining point size, smooth vignettes which fade out to zero, good in coverage of solid areas and Pantone matching. Kong said that the software can also raise the quality of filmsetter-based analogue platemaking in both flexo and letterpress.‘HD2 uses Shifted hybrid screens, which varies dot size to reduce the problems of moiree, while Pillar hybrid screens uses larger highlight dots to avoid dipping into the anilox cell.’

Other features include choking back vector objects to retain detail on small objects and reduce text blurring. New trap types including feathered trapping help further improve print quality depending on individual image requirements.

Kong also recommended digital proofing against analogue, allowing dot for dot output so you can see rosettes and detect morie, with halftone simulation up to 200 LPI. ‘This is now Contract proof quality.’

If all these elements come together, press operators should not have to do any color matching on the press, said Kong.

Jason Zhao from DuPont looked at the effect of new flexo plate types which reduce graininess and mottling. He explained how nitrogen inerting – a controlled atmosphere process which removes air from the plate surface – produces more clearly defined dots, with sharper edges and makes plate more durable.

Sam Chen from Flint Group China looked at how better ink management can reduce downtime and wasteage on press – significant because ink represents between 3-9 percent per sqm of a typical label job costs.

‘We need to increase converter efficiency by reducing the need to clean the press between jobs. Also if there are differences between ink batches this requires adjustment on press - so you need to buy only good quality ink. And good ink inventory management is another critical factor. ‘

Chen also introduced UV-LED – ‘a very hot topic in China’ -  ‘particularly because it can reduce energy consumption, press downtime and allows faster speeds up to 200m/min.’ Chen also explained the REVO 7-color process concept, which allows 90 percent of Pantones to be matched and requires less ink to produce spot colors.

Following the conference sessions there was a highly successful series of technology clinics, allowing converters one-on-one time with industry experts including Josep Roca, Asia Pacific sales manager Xeikon, Fu Quiang, one of China’s leading package print technology experts from the PEIAC trade association, and Lee Jui Ching, director the RFID project team at King Label Adhesives.