If you are a printer and feel it difficult to make your printing as good as what you expect, your bottleneck might be "Dampening Water" in your printing process. For years, "Dampening Water" has been a function inevitable for offset printing technology; however, it is also a truth that "Dampening Water" has brought to printers many adverse effects. Now, TORAY presents a simple solution to eliminate it; that is the "TORAY WATERLESS PLATE". Its unique structure by Toray's Polymer Science Technology gives incomparable benefits to all printers.
What is Waterless Printing?
Waterless printing is an offset lithographic printing process that eliminates the water or dampening system used in conventional printing. It uses a special silicone rubber coated printing plate, special ink, and typically a means of temperature control on press.
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n waterless printing, the process of printing is changed chemical one involving the use of Isopropyl Alcohol or their substitutes to a simplified mechanical process. Instead of the press operator balancing the delicate relationship between ink and water, all that waterless printing requires is a temperature range for transferring ink to the substrate.
Waterless printing plates offer quick roll-up to color and thereby reduce set-up (make-ready) paper waste. Chemically tainted waste- water from traditional offset printing is also eliminated. Waterless plates are capable of extremely high screen rulings and, as a result, apply more ink to the printed piece. This results in a much larger range of colors in four-color process printing. Since the water dampening chemistry is taken away, the printing ink cannot become emulsified. Thus, cleaner, sharper images are made possible.
Plate-making System
Exposure of the plate is done using conventional vacuum frames and light sources for analog type (photosensitive) plates, or standard infrared laser equipped platesetters for CTP type. Exposure time for the plate material is comparable to most conventional plates. Under exposure, UV light or IR laser passes through the silicone layer of the plate and strikes the photopolymer or heat-sensitive layer beneath. UV or IR exposure activates the photopolymer, causing a break in the bond between the photopolymer and the silicone layers (Negative working type).
After exposure, the plate is ready for processing. Processing equipment for the waterless plate is unique to this system, using specialized chemical and mechanical treatment of the plate. The finished plate now has a non-image area composed of ink repellent silicone. In the image area, the silicone has been removed to expose the ink receptive photopolymer material. This design allows the plate to selectively attract and resist ink without the use of any water, etches or alcohol.
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1) Exposing: IR or UV light weakens the bond between heat (photo) sensitive and silicone layer. (Negative type and CTP)
2) Pre-treatment: Silicone layer of imaged areas are softened by the solution.
3) Development: Softened silicone layer of imaged areas are brushed off.
4) After-treatment: Imaged areas are dyed by the solution.
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2) Pre-treatment: Silicone layer of imaged areas are softened by the solution.
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3) Development: Softened silicone layer of imaged areas are brushed off.
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4) After-treatment: Imaged areas are dyed by the solution.
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Higher Quality
The fountain solution for the conventional offset process dilutes the ink and causes 
the printed dots to soak into the paper and spread. This inclination for dots to spread in size, so called "Dot gain", is reduced when printing with the Toray Waterless plate.
The intaglio structure of the waterless plate provides "ink receptive holes", rather than a "flat" ink receptive surface of the conventional offset plate. These holes provide supportive walls for the ink, and that contributes to unchanged dot size when it is transferred from the plate to the printing blanket.
Thanks to this structure, the printer can also lay down a thicker ink film or densities with waterless printing. This combination of higher ink densities and sharper dots allows for much higher print contrast and bigger color space than can be achieved with conventional wet offset printing.
Superior Productivity
Variations in ink / water balance of conventional offset printing can cause emulsification of ink and lead to inconsistency in color. Operators must have good skills to match and sustain color throughout the pressrun.
Eliminating the need for such ink/water balance by waterless printing changes the printing process from a chemical / physical process to a mechanical one. It thereby eliminates a myriad of process variables.
Roll up to color is nearly immediate since there is no need to achieve ink/water balance at the start. Registration is improved because paper stretch caused by fountain solution is eliminated. Therefore, make-readies becomes easier and faster, and that results in less downtime and less paper waste.
The largest variable is removed from the printing process. As a result, printing without water offers a much higher degree of color consistency throu
ghout the pressrun.
Environmentally Friendly
Water development system … No strong alkaline solution disposal
The development of conventional offset plate is done by the dissolution accompanied with the strong alkalinity developing solution. This solution is degraded soon, and requires frequent replacement, causing huge and inevitable industrial waste. On the other hand, the development system of the Toray Waterless Plate adopts water development system. The developing solution is "tap water", while pre-treatment / after-treatment solutions are all circulated within the processor and need replenishment only. So the industrial waste is dramatically reduced.
Significant VOCs reduction in pressroom
Most dampening-related solutions, such as isopropyl alcohol, are classified as volatile organic compounds (VOCs), which are toxic and linked to the deterioration of the earth's protective ozone layer. Many countries limit its usage by laws and regulations, as well as urging conversion to safer substitutes.
Thanks to elimination of damp ening system, such solutions are not required with the waterless printing, and significant VOCs reduction in pressroom can be achieved.
Waterless printers with ISO 14001 certificated
Many waterless printers nowadays adopt Environmental Management System (EMS) supported by the benefits of waterless printing, and achieve the ISO 14001 qualification.
The implementation of an Environmental Management System (EMS) enables printers to take a systematic and integrated approach in managing and controlling environmental impacts and in ensuring compliance with environmental legislation.
The Butterfly Logo - Assertion of clients' environmental preservation
Waterless printers can use "The Butterfly Logo", by the certification of the Waterless Printing Association, a worldwide non-profit organization based in the United States. The Butterfly Logo gradually obtains the market's recognition, and printers are promoting their products with The Butterfly Logo as a means of clients' contribution to environmental preservation.
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