Immediately following the successful introduction of Thermal CTP, attention turned to the promise of “Processless” CTP plates. Removal of the developer and the processor from the pre-press area would provide welcome cost, time and space benefits to printers. Many iterations of technology have been attempted in laboratories and also in the market. However, until recently no single technology has successfully delivered a commercial, “processless” plate with these customer benefits. A new technology will be discussed which has allowed the introduction of the first Thermal CTP plate which requires neither a developer, nor a processor, nor a debris-collecting platesetter, and which still provides a traditional printing background. The plate is a “Develop-On-Press” (DOP) plate. It has presented the plate designer with a new set of challenges; how to prevent press contamination, and how to develop-on-press without increasing make-ready time. The solution represents a technological advance in the application of photopolymers in litho plates. Polymers will be described which provide a unique chemical effect to allow a novel, single layer coating to be used. This helps to minimize coating weight and reduce contamination. The same polymer also provides a particulate structure, which contributes to excellent developability in fountain solutions.
展开▼
