Esko CD Crystal 5080 XPS
Flexo plate making is still mostly a process with many manual steps, but automation is arriving at every stage, from pre-press to processing, finds Michael Walker.
Whether you’re a flexo pre-press specialist making plates for a range of printers, a converter that has the volume and turnaround demands to justify having the whole process in-house – or somewhere in-between, making some plates for simple jobs yourself and outsourcing the more tricky ones – there are plenty of plate making and processing options available to you, whether analogue or digital, solvent or water-washable.
Increased product diversification and shortening lead times mean that the pressure is constantly on to find ways to speed plate production and get jobs on press faster. Many of the recent developments in plate imaging, processing/washing and exposure are aimed at precisely this, as well as improving overall quality and consistency of press-ready plates.
Arguably, platemaking begins before anything is imaged via any means, at the pre-press stage. Getting the job right for the type of substrate, ink, plate and roller begins here and there are a number of interesting software developments that aim to tackle this.
Perfecting it in pre-press
One of the great strengths of flexo – the range of substrates it can be used to print on – can also be its weakness. For converters who produce multiple label or packaging types, this can mean having to stock a range of plate types to suit the different substrates, and artwork content – large solid areas and coarse type, or fine lines and/or halftone, for example. While some plate suppliers are increasing the range of application-specific products they are offering, this does also increase the amount inventory that needs to be held, with cashflow implications, as well as introducing the possibility for error in plate selection.
Kodak’s DigiCap NX Patterning
An alternative approach that is being pursued by Kodak is to effectively customise the same plate for different applications via software and digital imaging control techniques. Shown at drupa, Kodak’s Flexcel NX System ’16 combines the company’s expertise in imagers, software and plate materials to allow the imaged plate surface to be customised during imaging to provide what it describes as ‘optimum ink transfer capabilities for a specific application’. The benefits are said to be greater precision, consistency and on-press performance compared to engineered plate surfaces, as well as the ability to support a range of applications with a small plate inventory. Kodak uses a small set of imaging patterns and some patented edge definition technology to optimise plate characteristics for different substrates, ink types and anilox volumes.
Esko too is looking at ways to increase productivity through process and inventory simplification, but via reducing the number of inks and wash-ups by standardising on a fixed palette extended gamut. Using 5, 6 or 7 colours and avoiding wash-ups between jobs, Esko estimates that its Equinox system can help achieve a 34% reduction in printed waste per job and a 25% ink saving in flexible packaging.
Esko’s rage of pre-press tools and workflow solutions is also offered by Fujifilm, whose water-washable Flenex NX plate (reported in the July issue) and accompanying processors offer platemaking times of around one hour. Fujifilm also offers flexo customers pre-press tools from PACKZ Software, which includes a native PDF editor that supports trapping, separation, object-based screening, barcode creation and recognition capabilities amongst others for efficient preparation and checking of artwork.
Put in on a plate
To boost productivity in the platemaking process itself, Esko has introduced a new flexo plate UV LED exposure device, the XPS Crystal 5080, and a new plate imager, the CDI Crystal 5080. The two units can be connected to act as one single device, combining plate imaging and exposing into a single operation, halving the number of manual handling steps that would otherwise be necessary and reducing the time to produce a press-ready plate by almost 70%, according to Esko. The company claims greater plate consistency through the use of LED main and back exposure compared to UV frames that use light bulbs, while both units connect to Esko’s Automation Engine Device Manager to allow job status information to be gathered for more efficient production management.
Screen PlateRiteFX1200
Screen’s CTP technology that was originally developed for offset plate production has long been adapted to suit flexo purposes, enabling the firm to offer a range of models for applications from narrow format labels through to carton board. The range includes the entry-level FX870 IIE which offers imaging resolutions up to 4800 dpi with Screen’s Flexo Dot screening for improved detail and halftone quality, and imaging rates of 2 sqm/hour, with plate sizes from 100 x 200 mm up to 870 x 762 mm supported; higher productivity models are also available.
Xeikon’s digital platemaking systems for the flexo market are marketed under the ThermoFlexx brand name. They provide high-resolution plate exposure including screening, colour management and workflow management capabilities. The ThermoFlexx range covers the gamut of flexo printing applications, from an entry-level model suited to narrow web tag and label print via units that meet the needs of more general label and flexo packaging production, up to high-volume platemaking for large shops or prepress sites.
One of the most recent additions to the Xeikon portfolio is the ThermoFlexx 48, which can image plates up to 900 x 1200 mm with standard resolution of 2540 dpi and optional resolutions up to 5080 dpi, making it suitable for labels, flexible substrates and carton board printing. It offers continuous production at between 3.5 and 6 sqm/hr via FlexTray, a mobile table that feeds plates fed by the operator into the drum for imaging to begin immediately; imaged plates are fed automatically into an external online LED back-and-top exposure unit for consistent exposure, ready for processing.
High performance plate imaging at up to 6.5 msq/hr is offered by Lüscher, whose Xpose! FlexLine model features a novel combination of internal and external drum technology that allows for faster operating as it does not require tension rails or taping of plates onto the drum, since plates of any supported size or thickness are held static.
Due process
On the plate processing side, AV Flexologic is focusing on the growing popularity of water-washable plates with its Cosmoline and Aquasupreme models. The former is an inline washer and dryer unit that uses a combination of round brushes and a large plate brush for increased coverage on plates up to 900 x 1200 mm. An optional membrane filter can be used to filter photopolymer from the wash water; a centrifugal cleaning system is standard. The Aquasupreme comprises separate plate processing and dryer/exposure units in a choice of sizes up to 900 x 1200 mm. These have low maintenance requirements thanks to automatic cleaning functions with a two-stage wash water filtering process. A touch-screen display provides control of back, main and post-exposure plus washing parameters.
Touch-screen control of all critical plate processing parameters is also a feature of the Titanium processor launched by Heights at drupa. Available in three models, the Titanium processors are compact high productivity designs for conventional or thermal plate types and can be configured for online or offline use via a wide range of platesetter interfaces.
DuPont’s Cyrel range of flexo products includes platemaking equipment and workflow solutions in addition to plates. Both analogue and digital plate types are offered, the latter including the Cyrel FAST dry thermal plate processing system that allows press-ready plates to be produced in an hour or less. The dry system in said to save time, money and materials in operation and maintenance as well as providing improved process control, product quality and consistency and offering a more sustainable way of working.
For high-throughput plate processing sites, Vianord has introduced a modular fully automatic plate processing system. Aiming at full automation of the flexo plate making process, Vianord’s Easy to Plate concept revolves around modules that can be bought separately with the option to upgrade and connect subsequent units to build a complete automatic system, from plate input via laser imaging, back exposure, processing and drying, to light finishing and stacking ready for mounting on press. Plate status information is provided continuously by internal cameras located after the wash-out section and this capability also facilitates remote diagnostics and support.
For those who are new to flexo platemaking, it’s becoming a less daunting task to achieve reliable and consistent results that will produce sellable print, and for those who are familiar but just need to do it all faster, or to aim for higher quality to attract new customers, the technical advances to help do that are here now.
