German Printer 02-2007

Surface Sealing widens range of paper choices

Finishing Solution

Papers used in digital printing are usually exposed to a high level of stress. In order to achieve a reliable quality of the finished print despite this stress, GP Stratum developed a coating technology, which adds more functions to paper and simultaneously minimizes the impact of factors such as temperature, humidity and dust. Detlef Amsel calls his company’s innovation "product-friendly paper sealing". Amsel is director of Norwegian GP Stratum AS - formerly known as GP Tinter – a company which specializes in surface refining of papers for the digital printing industry. Its focus of interest is the roll-fed digital press for all technologies and speed categories.

: Transeo

Coating

The newly developed product of GP Stratum AS is a system designed for in- and offline coating of paper for toner- or inkjet- prints. The unit called Transeo is based on the principle of flexo printing and can be connected - as a new Surface Finishing Solution - to any endless digital printing press unit. All parameters required for coating, such as speed of paper, temperature and humidity of the paper and the environment, are gathered per sensor in a control unit. The configuration of the amount and density of the applied substance is completely automatically. In the coating unit the actual sealing is done with up to 4 systems for double-sided coating with multiple fluids in one step, or with one fluid in two steps. The assignment and operation of the particular units are dependent on whether watery solutions, emulsions, lacquers or even other substances are being used. Transeo has a self-cleaning and auto-load system to guarantee a user-friendly handling of the unit.
The emulsion "Tune up" can be used as a coating fluid, which has been specifically designed for digital printing. According to the manufacturer, this fluid not only seals the paper surface but also diffuses into the paper.

An additional drying unit is not required. Coating unit and coating fluid are technologically aligned and are able to minimize or eliminate production impact of factors such as temperature, humidity, static and dust. Thus even almost desiccated papers can be reanimated for further print processing.

Range of Application

Relative humidity can be more than 30% increased, without any static effect on the paper. The formation of dust from preprinted and perforated papers is therefore prevented. A big benefit of the inline- coating with Transeo is the wide range of choices for printing materials that can be used. Even standard offset paper (which is usually cheaper) can thus be used without any problems, though it actually does not comply with specifications for digital printing lines."Test results provided by independent test laboratories like "Pira" in Great Britain have shown that the product specifications required for transport systems are met after treatment" says Detlef Amsel. Test criteria included effects of adhesion and sliding friction, as well as abrasion resistance. Problems of static are resolved, and the planity of the paper improves demonstrably. The technology also meets the standards of security printing. A complete printing line including Transeo and the emulsion "Tune up" is planned to be introduced by GP Stratum at the event “Emergo”. The latter will take place on March 27th and 28th in Cologne. Technical presentations will complete the program. Being in use by selected test customers, the Transeo is planned to be ready for production use this year.

TRANSEO`S FEATURES

Impact of environmental factors like humidity and temperature on the digitally printed paper will be minimized through dehumidification

More choice of printing materials in digital printing, as standard offset papers, can be used

Improved planity of paper for further print processing

Reliable quality of the prints, due to refining takes place after printing and problems with the printing materials can be eliminated later

Time saving due to a possible inline connection

Functions to enhance security of the printed product

German Printer No. 02/2007
Published om 1.2007