Advances and innovations in printing plate technology

“Market forces are driving the printing plate market in several directions,” observes John Wilson, northern Europe market manager for MacDermid Printing Solutions. “On the one hand, costs need to be reduced, and liquid polymer can meet this need more than the industry realises. On the other hand, more productivity and high quality is tending to accelerate the move towards sleeve technology, including digital continuous photopolymer sleeves. On both counts, MacDermid is ideally placed as the world’s only manufacturer of all the technologies involved,” he boasts.

The company recently introduced the Flex-Light ULT 5.0 – as the “ultimate plate” for the narrow web market. It can be used for a broad range of applications, including labels, folding cartons, flexible packaging, and multiwall bags. Tom Caplinger, director, New Product Introductions, comments: “After the successful introduction of Encore, some customers were asking us for a product that was a little softer, but that would still provide the same great print results. ULT 5.0 is that product.”

The new plate is available in 0.45, 0.67, 0.107, and 0.112in thicknesses, and sizes up to 52 x 80in. It will process in most safe solvents used for flexo plate making, and can be used with conventional and point-light imaging processes. Its rapid dry and shorter light finishing times are claimed to provide substantial improvements to plate making productivity.

According to Asahi Photoproducts, whilst the trend towards digital plate making has meant heavy investment programmes for some companies, over the past two years alternative imaging systems have also taken major steps – offering flexo plate makers a lower investment, and similar or better quality. Both techniques produce outstanding printed results, the company maintains.

“Continuous sleeves by direct laser engraving appears to be the wish of every printer since DRUPA 2000,” it continues. “The obvious savings in time and labour will have to be balanced against quality and capital investment, and the flexibility flexo has at present in changing part of the image (such as for promotional flashes).” Asahi is developing a material for trade houses that want to produce continuous laser engraved sleeves. Commercial trials are due early in 2003.

The company recently introduced two new products to its AFP range of photopolymer flexo plates. Both the SG and SH materials have been designed to give value added performance on slow or fast presses. SG also has a higher than normal resistance to solvents and when used with catatonic UV inks printing onto film, the density and quality of printed result is said to be excellent. SH has a black coating to enable CTP users to evaluate the product. Sharper printing results and good transfer of ink densities is claimed.

Asahi has also launched a second generation AFP exposure frame designed to give faster plate production and control “never seen before” over the exposure of plates.

The first Esko-Graphics CDI flexo imager with PowerBeam optics to be installed in the UK is now at MCG Graphics. It is the third CDI system for the Hull based company – already one of Europe’s largest users of photopolymer plate materials – and the PowerBeam, which operates at a speed of 4m2/hour, will handle increased demand for high quality flexo plates.

“It is a reflection of the company’s confidence in the on-going developments in flexo printing,” says sales and marketing director Steve Buxton. “CTP plates offer flexo printers the kind of quality, consistency and printing stability that until recently had only been available through gravure or litho printing. We expect the extra capacity to provide clients with shorter lead times.”

Claimed to be proven the fastest flexo imager at over 150 sites, the third generation CDI with the PowerBeam optics is said to boost productivity by 60 per cent. It is said to be ideal for high quality, fast turn-round packaging products such as snack foods. In just over 20min, it images a full size, 1,067mm x 1,524mm flexo plate on DuPont Cyrel or other brands of digital flexo plate, independent of plate thickness.

The YAG laser is said to combine high output powers with extreme durability – over 5,000 hours. It also features fully variable imaging resolution between 1,800-2,800ppi.

Faster imaging

DITP Gold, Kodak Polychrome Graphics’ latest advance in thermal imaging of plates was shown in Europe for the first time at IPEX 2002. This plate is said to have a faster imaging time, needing 25 per cent less exposure. Its high resolution is claimed to make it ideal for quality printing and stochastic screening for sheet-fed printers. IPEX also saw the European debut of the Sword no-preheat, no-postbake thermal plate with long run capability. It is said to be highly solvent resistant.

With the demands of environmental legislation in mind, AV Flexologic has designed the Aquasuper MK II 500 x 700 machine for processing water washable flexo plates. Apart from elimination of solvent use, it is claimed to be up to three times faster than conventional systems, so well suited to shorter runs. The automatic washout unit can handle photopolymer material with thicknesses of 1.14, 1.70, 2.30, 2.54 and 2.84mm.

Plastotype reports that several UK label and narrow web printers/converters have taken delivery of the Flex-E 760 photopolymer plate processing system. This incorporates exposure, wash-out, drying and finishing components in a single, compact unit. It is said to offer improved operator safety and an environmentally friendly production. The Flex-E 760 also provides fast throughput, according to Plastotype, producing the first press-ready plate in under two hours, with subsequent plates available every 10-12min. Exceptional plate quality is also promised, with an isolated dot of just 0.5 per cent and minimal plate swelling.

BASF’s nyloflex LD is said to be the first polymer plate designed for direct laser engraving, which eliminates the time consuming steps of pre-exposure, wash-out, drying and after-treatment. Environmentally friendly plate making without chemicals, good ink transfer, smooth tonal gradations, and excellent abrasion resistance are all claimed .

Designed for printing with UV inks, it is said to provide sharp edges and fine details with brilliant area coverage and high contrasts. Resolution up to 60 l/cm is possible, at a tonal value range of 2-95 per cent, says BASF. The plate is available in a standard size of 610 x 762mm, and 1.14mm thick.

On the sleeve front, BASF’s nyloflex 1600 processing system can accommodate both conventional nyloflex plates and the digitally imaged digiflex plates on sleeve lengths of 400-1,650mm, and diameters from 64-400mm ID, 70-420mm OD. An electronic control system provides the user with the option for entering customized programs for different types of plates. Post exposing and after-treatment can also be programmed automatically. The wash-out unit incorporates round brushes said to provide a particularly gentle but thorough relief wash-out. Additional features include a programmable memory for input of processing parameters, plus a ‘user friendly’ electronic control system.

The equipment is said to occupy minimal floor space. Only one operator is required to run the system: a special mounting device means that heavy components otherwise used for slipping the sleeves on can now be dispensed with. In addition, a pneumatic support facility allows the sleeve exposure/light finisher to be opened and closed with one hand.

Seven Worldwide, producer of visual brand communications for packaging, has installed a Creo ThermoFlex 5067F flexo computer to plate system at its Newcastle, UK, site. The Newcastle operation has been using a Misomex Omnisetter for the last four years and so appreciates the benefits a digital environment delivers.

The TIFF front end supplied with the ThermoFlex 5067 comprises software for quality control, permitting verification of file integrity and inspection of full resolution screened files before output. This allows the operator to check screen angles, traps and dot shapes before committing to the media itself. The front end also has tools to allow operators to make the best use of the polymer media, should they wish to use off-cuts or full sheets.

“The new system has fitted seamlessly into our Nexus RIP workflow and accepts all of our file formats,” says Geoff Smith, operations director.