Drying quality control of the most popular PS vers

Sun quality control of positive PS version (4)

VI. matching developer and its optimal concentration

there are roughly two types of developer materials used with PS version: solid developer powder and liquid developer concentrate. No matter which developing material is used, the developer must be adjusted to the appropriate concentration before it is used for development

different models of positive PS version have development materials used with it. In order to obtain the best development effect, try not to use the developer of other brands and models, otherwise, it may lead to opaque or excessive development

the developer solution has a shelf life. Its production date should be confirmed when using it to avoid using expired developer solutions. The shelf life provided by most manufacturers is one year, but try not to keep the developer solution for too long

the manufacturer will also provide the corresponding proportion of developer. For example, in the instruction manual of a certain brand of developing powder, it is suggested that "a bottle of developing powder is completely dissolved into a concentrated solution with 5:1 warm water, and then the concentrated solution is diluted at the ratio of 1:6 during development". The dilution ratio of 1:6 mentioned here is a widely applicable dilution ratio obtained by the manufacturer through a large number of experiments. For users, it should be used in accordance with the manufacturer's recommendations, and the proportion should not be changed at will

solid developing material is a mixture of developer, inhibitor, wetting agent and other components. For directly mixed developing powder, due to the different specific gravity, particle shape and size of each component, the components with small particle size and large proportion are centrally distributed at the bottom of the container after bumping during transportation. Therefore, when directly taking the developing powder to prepare the developing solution, the developing powder should be fully mixed first

when diluting and preparing developer with developer concentrate, attention should also be paid to the problem of mixing. After the concentrated solution is standing, some components with poor solubility will settle to the bottom of the container due to the action of gravity, and the components in the solution are not evenly distributed. The experiment shows that the developing effect is not good when only the upper solution is mixed in proportion. Therefore, when taking the concentrated solution to prepare the developer, the problem of mixing cannot be ignored

VII. Choose pure water as the water for liquid preparation

generally, there are no special requirements for the water for configuring the developer. Users basically use tap water or deep well water. The developer is an alkaline solution with a pH value of about 13. PU coating technology can be used to enhance and change the performance of various fabrics we usually see. The scaling theory tells us that sodium silicate, one of the components of the developer, is itself a substance that is easy to scale. Coupled with the comprehensive work of calcium, magnesium and other metal ions introduced by water, if the spring is damaged, our measurement will be useless, and it is easier to cause the scaling of alkaline developer. The direct impact is to block the nozzle of the developer, make the developer spray unevenly, or calcify the developing roller, thus affecting the development quality. Therefore, it is best to choose deionized water as the water for liquid preparation to slow down the scaling process of the developer

VIII. Control the appropriate development temperature

heat is required for ninhydrin hydrolysis, salification and salt dissolution in the development process. If the temperature of the developer is too low to provide the heat required for the development process, it will hinder the smooth development; If the temperature of the developer is too high, the unexposed image and text will be dissolved. Theory and practice show that when the temperature exceeds 30 ℃, the binding force between the photosensitive resin and the film-forming resin in the photosensitive layer decreases, and the alkali resistance decreases. Therefore, an appropriate development temperature is one of the prerequisites to ensure good development quality. Generally, it is appropriate to control the developer temperature at 25 ℃± 1 ℃

IX. determination of development time

according to the accurate exposure time measured previously, expose the printing plate, perform machine display, and observe the gray ladder section. When the third ladder is absent, the fourth ladder is retained, and 3% of the dots are guaranteed. It is a natural high molecular biomaterial. 97% of the dots are not sticky, which is the appropriate development time. If it does not meet the standard, re expose it, and adjust the machine display time according to the last development until it is appropriate

X. maintain an appropriate developer concentration

after many times of development, the effective components in the developer are continuously consumed. Coupled with the role of the photosensitive layer constantly dissolved in the developer, the developing ability of the developer is getting weaker and weaker, so that it cannot meet the development requirements, and the developer appears aging phenomenon

in actual production, it can be used to put a measurement and control strip for tracking test every 5 developing plates, and then add an appropriate amount of developer according to the actual situation

in case of serious aging, replace the liquid in time. If the number of developing plates is small, it can be replaced once every two days. If the number of developing plates is large, such as 100 or more, it should be replaced every day

Xi. Correct dirt removal methods

a brand of dirt removal solution may not be suitable for all ps versions. When it does not match, it may cause dirt on the dirt removal part during printing

dirt remover should not stay on the PS plate for too long, otherwise, it will also cause dirt on the printing of the dirt remover

XII. Protective adhesive coating

the maintenance and maintenance of Jinan assay steel bar bending testing machine with protective adhesive is to protect the blank part from oxidation. Therefore, it should be as thin and uniform as possible during coating. If the coating is uneven, the printing will be easy to get dirty, but if the coating is too thick, the graphic part will not be inked

to sum up, in order to achieve the ideal drying quality, we should scientifically analyze and strictly control the influencing factors of each link in the drying process, so as to reduce the waste rate of printing and improve the product quality and printing efficiency

(author/wanghuaming)

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