Developments at Dantex

Dantex demonstrated the first water-wash flexo plate at drupa at the turn of the millennium. Although the plate took more than two hours to prepare, ‘the race was on’ according to Simon Cosh, the company’s business development manager. ‘The objective was to produce a plate with low carbon dioxide emissions and still maintain a low non-renewable energy consumption especially when compared to the average solvent platemaking process.’

Aquaflex is Dantex’s flagship water-wash flexo plate. The plate material is created from a unique formula of NBR rubber and graft polymerized, plasticized, bi-functional monomers. Advanced technology means fast plate washout, from imager to dry in under 40 minutes, as well as enhanced resolution, press life and reusability. It is compatible with all ink types including UV, water and solvent.

A specially formulated water-wash compound results in a linear screen reproduction with near zero dot growth through production, reducing bump up requirements and lending itself to consistent print quality through the whole print run. On press, the ink release characteristics of Aquaflex plates reduce anilox and plate cylinder pressure. This helps extend the life of the plate and reduces plate-related stoppages during print runs.

Says Cosh: ‘The further practical advantage to the end user is the elimination of having to make duplicate plates. On long run jobs it is quite common to manufacture two sets of plates and may involve a number of colors. If replacement plates are not available, the lead time on a solvent plate would be 90-120 minutes. The press operator now has the dilemma as to whether to lift the job off or wait until the replacement plates are made.

‘A further environmental concern here is the creation of waste – consumables such as print stock and inks – if the job is lifted off the press. Duplicate plates therefore have a value, but this practice not only increases plate consumption, but also requires the chemistry and energy with the ensuing environmental impact.’

Growth in dry film systems is another development seen by Dantex. These systems remove the need for traditional methods such as imagesetter film with its associated chemistry, hence reducing the environmental impact.

The Star Plate dry film system is a digital imaging option designed for direct inkjet to film, with the ability to produce high quality halftone screening. Using the Actual Dot analytical engine, the system analyzes and reproduces the dots of the RIPped 1-bit data. Many systems are being used with Smart Screen screening technology to produce negatives for screen printing, flexo and letterpress platemaking. The resultant plates display sharp dots, fine lines and visually superior tonal ranges on press, particularly in highlight areas, claims Dantex.

Star Plate preserves text attributes, right down to 1pt type, and is capable of imaging screen rulings up to 200 LPI. A user-friendly interface allows for multiple calibration curves to be generated to suit various press conditions. A range of CtF nano-porous films are completely reusable just like imagesetter film, available in various gauges and able to produce a D.Max of between 3.0 and 4.5.

Cleaning

Dantex offers a range of plate processors, including the new DigiWash System. This has a dual-action wash for ‘superior cleaning results’ and automatic brush height adjustment for different thicknesses. To allow for easy loading, it has a fastening section on a table with permanent sticky plate and automatic opening. Tank levels, water temperature and dryer temperature are monitored via the new D.I.G.I touch screen operator interface system. The dual tank system for black mask and plate wash debris ensures plate waste is handled efficiently.

Also new is the Aquaclean Pro Filter System, which works on a closed loop concept. Following processing of plates, water containing waste polymer in suspension is transferred from the plate processor to the main filter and then filtered through the second tank where the finer particles of polymer are removed via a series of ceramic filters. What remains in the third holding tank is the clean water with surfactant ready to be used in processing of plates again. Solid waste polymer removed from the system is collected in a holding tank and can be disposed into the drain (dependent on local water authority laws) or can be sent for disposal. Dantex Aquaclean polymer is classified as household waste so no special waste collection is required.

‘Cleaning and maintenance is often neglected,’ notes Cosh. ‘Proper photopolymer plate care prolongs optimal print quality and reduces costs. Plates should be cleaned correctly and immediately after use. If neglected, cleaned incorrectly or improperly dried prior to storage, they can stick to each other and develop cracks. Effective cleaning requires suitable brushing using the correct brush type and the correct amount of pressure, along with a compatible wash solution to loosen and remove ink deposits. We have seen an increase in demand for AQFC cleaning systems for optimum cleaning.’