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Digital Plate Primer : Enviro Plate Considerations

November 2010 By John Zarwan

(Editor’s Note: This article is a condensed version of the 2009 report by J Zarwan Partners titled “The Environmental Impact of a Printing Plate.” A revised report, including the new Kodak Trillian SP thermal plate, will be published later this year.)

Printers around the world increasingly are paying attention to reducing the environmental impact of their operations. Owners want to be good citizens. Governments are focusing more on environmental compliance and the reduction of emissions and waste. Customers are demanding “green” policies and procedures. 

Even aside from these societal pressures, there are still very good reasons for printers to focus on improving operations and reducing waste. Simply put, waste of any type does not add value. Reducing it means increasing efficiency, shortening turnaround time and lowering costs.

One process that has received a great deal of attention—and that all printers can focus on—is that of plates and plate making. All major plate suppliers have made great strides in reducing the amount of chemistry and waste required to process offset lithographic printing plates.

That said, a number of claims are being made, and there is a great deal of confusing information. This report is an attempt to bring some clarity to the issue. While environmental considerations are only one factor in the choice of a plate, it is important to be aware of the differences and the amount of chemistry and other waste involved. 

Sources of Waste 

Processing of plates consumes three primary resources: chemistry to develop or process the plates; energy to run the processing unit; and water to rinse the plate, dilute the chemistry or clean the unit. Similarly, processing generates waste, which must be disposed of, in the form of spent chemistry, waste water and containers. Some plates, such as silver-based violet plates, also require a silver recovery system. Each plate type and process consumes different amounts of these resources, depending on the imaging laser, emulsions used, and chemical and physical reactions required to develop or wash-up the plate.

In addition to the direct resources used in the processing of plates, there are indirect resources used. Plates and processors must be manufactured and delivered, all of which require materials, energy and water. Each of these also has a carbon footprint. 

There are a number of different technologies available for digitally imaged plates:

1. Conventional chemically processed 

2. Reduced chemistry 

3. “Chemistry-free” 

4. Processless 

Each of the major plate manufacturers offers a variety of options within each of these broad categories. Here’s a breakdown.

Conventional Chemically Processed. There are two main technologies for conventional chemically processed digital plates, using thermal or violet (visible light) lasers. After imaging, these plates need to be processed with chemistry in a processor. Violet plates tend to use more chemistry than do thermal plates. Within each of these broad categories, however, chemistry consumption is essentially similar across manufacturers.

This category is most sensitive to assumptions and plate volumes. The amount of chemistry used depends on the size of the processor; developer needs to be replenished to maintain proper strength; and it must be changed based on volume and time.

In this category we included thermal plates from Agfa (Energy Elite); Fujifilm (Brillia HD LH-PJ/PL); and Kodak (Sword Excel and Electra), and the violet Agfa Lithostar Ultra LAP-V.

Reduced Chemistry. This category is characterized by clever plate or processor design, which helps to reduce chemistry usage. There are a number of options for chemistry reductions, including the use of “intelligent processors,” such as the Fujifilm FLH-Z “ZAC” processor with the Brillia HD LH-PJ/PL plate, or a reduced chemistry plate, such as the Agfa Amigo. With an intelligent processor, the replenishment system delivers the correct chemistry and water solution according to the activity of the developer bath. This provides longer developer life with consistently higher quality and a concomitant slight reduction in chemistry and waste. 

The Agfa Amigo plate uses “ThermoFuse” technology, the same as its “chemistry free” Azura. Agfa positions the plate as a reduced chemistry option rather than chemistry-free. We can see, however, that its chemistry usage is nearly as high as that of conventionally developed Fujifilm and Kodak thermal plates, and higher than those plates using an intelligent processor. (Kodak also offers an optional “Chemical Conservation Unit” for its preheat plate products, offering up to 40 percent savings on chemical usage for high-volume plate users.)  

Chemistry-free. These solutions require post-imaging processing or finishing before mounting on-press. The most common of these require a finishing solution or gum to fix the plate image prior to being used on-press. Here, we look at the Agfa Azura thermal plate and the violet Fujifilm Brillia Ecomaxx-V (also known as HD PRO-V in some regions), both of which use a finishing solution rather than a traditional chemical developer. Both use less chemistry for this process than either the reduced chemistry or conventional options, but more than processless plates.

Processless. Finally, we examine the option of processless plates, looking at two thermal solutions, the Fujifilm Brillia Ecomaxx-T (also known as HD PRO-T in some regions) and Kodak Thermal Direct. As both are developed on-press, they involve neither additional chemistry nor a processor.

All plates use resources in their development that have an impact on the environment. The major resources include chemistry for processing, water and energy. Plate processing also affects the ambient air through, for example, the release of VOCs. Let’s focus on chemistry, water and energy, and the waste resulting from their consumption.

• Chemistry. Most digital plates require the use of chemistry for development or washout. There are, nevertheless, a variety of options available to reduce the amount of chemistry used, including intelligent processors, reduced chemistry plates and processless plates.

• Water. Plate processing uses water both to wash the plate and, in some cases, dilute the chemistry. Water is a scarce resource in many geographies; many systems allow for water to be recirculated. Water recirculation is particularly beneficial for conventionally developed plates. Chemistry-free and processless plates use little if any water.

• Energy. Plate processors all require energy to operate. The most power is used when the plate is being developed or processed. However, the processor also requires power during the non-processing times, to keep the temperature “ready” for processing, and somewhat less in “sleep” mode. In our example, this would be weekends and nights. 

There are very few differences in power consumption by plate. Violet processors tend to have slightly higher energy consumption as they are more powerful to accommodate the pre-heating requirements of violet plate processing. (Plates that require baking naturally use much more energy for the baking oven. Ovens can use 24 kilowatts or more per hour of operation.) The Agfa Azura is not temperature-sensitive. Its wash unit, therefore, requires less power and uses less energy. With no processor, processless plates consume no additional energy for development. 

• Waste. All of these resources need to be disposed of after use. For most systems, this is essentially chemistry and the empty containers. The amount of waste generated closely tracks the amount of chemistry used, except in those cases where chemistry is diluted. Depending on local regulations, water can be treated and disposed of safely. For silver-based plates from Agfa and others, a silver recovery system is required before the waste can be disposed of locally. The environmental impact of and legal requirements for disposing of chemistry and even wash water for your particular region should be investigated as part of the analysis for each plate solution you consider.

In summary, printers are rightfully concerned about lessening the environmental impact of their operations. Environmentally-conscious printers can make a more informed decision by looking at the amount of chemistry, water and energy required by each plate they are considering. Reduced chemistry plates, “chemistry-free” plates and processless plates can further reduce the environmental footprint. While performance on-press will remain a key factor in plate selection, we hope the information presented here will enable printers to take into account the environmental impact of their decision. PI

About the Author
Dr. John Zarwan is a founding partner of J Zarwan Partners, an independent consultancy that specializes in business development, market strategy, and product planning and positioning. His 2003 paper, “CTP Platemaking: Understanding the Real Costs,” was the first attempt to quantify the cost of chemistry. Prior to founding J Zarwan Partners, Dr. Zarwan was principal of State Street Consultants and held senior management positions in finance, marketing and product management at NEC and Agfa (Compugraphic). To find out more or get a copy of the full report on which this article is based, visit: www.johnzarwan.com.


 

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