Talking about the Environmental Issues of CTP

Regarding the environmental protection issue of the CTP version, there is a view that the photosensitive silver salt plate will cause environmental pollution, and the thermal plate will have less impact on the environment. The main reason is that the silver salt plate will bring the silver halide tape during the processing. To waste liquids, emissions will cause damage to the environment, so some people think that the silver salt version (including the violet laser printing plate) is not environmentally friendly [ML1]. Is this the case? In the current digital plate technology, except for the thermal abrading plate, the need for rinsing, all types of digital plates (including thermal, photopolymerization, and silver salts) need to be rinsed with potions. The generation of chemical waste does not exist for the rationale of the environmental protection of one type of printing plate over another. In fact, many countries and regions around the world have paid great attention to environmental protection and have prohibited the discharge of waste liquids into public drains. Therefore, regardless of whether thermal, photopolymerization or silver salt plates are used, the waste liquids need to be recycled. As we all know, Europe has a very high demand for environmental protection, but its newspapers use photosensitive CTP. After the use of photosensitive plates, there is basically no impact on the environment.

Therefore, our focus should be on improvement in two aspects: 1. To minimize the production of waste liquid 2. To select some printing plates whose main components can be recovered from the waste liquid. In the first aspect, the market Some suppliers have made a lot of efforts, either through product improvements or introducing new products to minimize the production of waste liquids. For example, Mitsubishi Electric Co., Ltd. designed an eco-friendly P-Alpha 880 SuperEco, which eliminates the need to connect drains, resulting in a significant reduction in waste processing costs. Agfa also improved its flushing system. The amount of waste liquid produced by the new Lithostar Ultra plate processor has been reduced by 40%. Under normal circumstances, flushing per square meter plate produces no more than 300 milliliters of waste liquid (this includes The addition of developer, replenisher, fixer, and water, in addition to making the disposal of waste liquids easier, saves the amount of water and chemicals, and achieves environmental protection.

As for the second aspect, one of the main components of the silver salt coating is silver, and silver can be completely recovered from the waste liquid. The current recovery methods such as precipitation, filtration, centrifugation, etc., further concentrate the metallic silver. These methods proved to be very effective. Many plate processors (such as the Lithostar Ultra above) consolidate three different waste streams into a single container for easy collection and transportation of waste fluids. The waste liquid of the plate processor can be mixed with the waste liquid of the punching machine and stored without any safety problem. The uniform recycling is more convenient. The effluent produced by the general silver salt flushing system has a pH of 6-7, a metal silver concentration of 6-10 grams per liter (depending on the purging capacity), and an aluminum content of 0.5 gram per liter or less. This silver concentration is sufficient for the waste disposal company to recycle with economical benefits. Due to the high concentration of silver, recycling technology is not difficult, so waste disposal companies in many places provide free collection of liquid waste services, customers do not have to pay any fees.

Since the production of silver salt waste liquid has been reduced to a minimum, harmful substances in the waste liquid have also been recovered and there will be no pollution to the environment. On the contrary, the effluent produced by the thermal plate washing system cannot be recovered. The general practice is to discharge it after neutralization and its components still contain harmful substances, which will also have an impact on the environment and ecology. In short, CTP plates with reliable quality, appropriate prices, and environmental benefits will be welcomed by the market. The silver salt version offers the highest exposure speeds, a simple flushing process, and the feasibility of silver recovery, so it is used by thousands of printers around the world. The silver plate version of the violet laser plate can be operated in a near-ambient room with yellow light, high latitude, without preheating or baking version, providing an ideal choice for printers.