PRINTING PLATES
Back in the 1800s during the early days of offset lithography, limestone slabs were used as the original “printing plate.” Nowadays, printed images are transferred from a thin plate (usually aluminum or polyester), onto a blanket, and then to the substrate. Plates can also be made of metal, plastic, rubber or even paper, depending on the process used. These plates are attached to a press cylinder and are used to transfer the inked image that will appear on the printed material. In general, metal plates are more expensive, but they usually last longer and have greater accuracy. As run lengths are decreasing, the latest developments in plate-making increasingly revolve around ways to make the process more environmentally-friendly by reducing or eliminating the chemicals used in the imaging process. This section will take a closer look at some of the most recent developments in printing plate technology.
Epson DirectPlate technology
Epson used Graph Expo as a launching pad for this new plate-making technology, designed for small and medium commercial print shops. Epson says the plates are part of a recent breakthrough in chemical engineering and plate coating, which allows them to be imaged with a standard Epson Stylus Pro printer. No special inks are required either – the process uses Epson’s standard UltraChrome HDR inks. The high-resolution aluminum plates can be used to produce up to 20,000 impressions at 175 lpi. The plate-making process is water-based, eliminating the hazardous chemicals often associated with traditional plate-making solutions. The company says that these plates are extremely smooth for superior water retention.
Agfa :Amigo TS plates
Also at Graph Expo this year, Agfa debuted its :Amigo TS plates for the first time in North America. As a successor to the original :Amigo plates, the TS model can run up to 50 percent faster. Run lengths of up to 200,000 impressions are possible without baking. This plate is best suited for commercial printing applications on both sheetfed and web presses.
The :Amigo TS plates are eco-friendly due to the use of Agfa’s Thermofuse technology. During the exposure process, thermoplastic pearls absorb energy, melt and fuse together. They bond to the aluminum substrate. Unexposed areas are removed by washing the plate surface with a mild clean out solution – not a developer.
Another important aspect about the TS plates is that they can be imaged on any suitable 830nm thermal plate setter and can tolerate fluctuations in laser energy with little or no effect on quality.
Kodak Trillian SP plates
These plates from Kodak were revealed at IPEX this year and hit the market over the summer. Designed for commercial printers, publishers and offset package printers, Kodak says these plates aim to lower the cost of use for printers by using up to 70 percent less chemistry than previous systems – a significantly lower amount. They also eliminate the use of preheat and post-bake ovens, even for long jobs in harsh chemical environments.
These plates have a proprietary negative-working coating that provides high sensitivity, consistency, chemical resistance and durability without baking. And, 500,000 impressions for standard press conditions are possible. They are best suited for high-quality medium- to long-run sheetfed, heatset web and offset packaging applications.
The fact that they use up to 70 percent less chemistry means that the cost of storage and disposal of these plates is less, and their impact on the environment is reduced.
HUMIDIFICATION SYSTEMS
Controlling pressroom humidity is vital to the quality of the printed job. When humidity fluctuations occur, problems like paper curl and static are the result. This type of issue doesn’t just affect the look of the job – it also affects your press. Printers can’t run a press at top speed when the stock’s properties are affected by dampness or dryness. Paper jams can occur causing costly and time-consuming shut downs and repairs. A lot of printers don’t realize these types of issues stem from pressroom humidity since it is difficult to feel slight changes in the air. It’s important to really do your research when investing in a humidification system for your company. Some require a lot of energy and water, making your monthly overhead bills pretty steep. You should also make sure the system is hygienically safe since there is a risk of bacteria buildup anywhere there is standing water. This section discusses a couple of the key humidification suppliers in the industry.
DRAABE
DRAABE offers several different types of humidification systems, depending on an individual company’s needs. The TurboFog is an example of a DRAABE product that would suit a printing environment. Its micro-fine atomization nozzles ensure that no expensive compressed air is used, which also reduces unwanted noise. Its stainless-steel build means it’s corrosion-resistant, and features a BioSafe germ elimination system for hygienic purposes.
ML SYSTEM
The humidification systems from ML are known for their low energy consumption and for being very hygienic. The Princess is an example of an ML System product that would suit a printing environment. They are high-pressure and require less power to operate than older, conventional steam machines. The water used is always treated to ensure bacteria and mold don’t build up – the water is never stagnant and is flushed every few seconds. ML System products are suited for both medium- and large-size printing companies.
