1, the image faint and blank part is not clean. To solve this problem, the glass of the printing machine must first be kept clean. Wipe it off with alcohol, both sides. The transparency of the work is not enough, the penetration of light will be affected, and the version will be blurred. If the film plate and the glass plate are not tightly attached, it will also cause sun filtration.

 

 

 

2, PS version of the network is not real. The solution to this problem is to examine it on film. The dot on the film used for printing should have enough blackness, and the dot structure on the printing plate should be transferred to the printing plate, and the covered part (dot) must not be allowed to pass the light amount, causing the plate sensitive layer to be sensitive. Otherwise, the dot on the plate will not be solid, and the dot will fall off when printing. Dot faint, we know that the absolutely clear dot, the transition between the light plane and the very black covering surface is very steep, is abrupt, and the edge of the dot is actually vertically rising. On the contrary, the blackness of the dot is gradually increased from the edge. So the dot produces an edge with a larger or smaller slope.

 

 

3. It does not reflect the subtle parts of the work. Like a hair strand, there is on the photo, and the printing plate becomes blurred. This is mainly due to the insufficient exposure or the excessive concentration of the solution when the plate is washed off the fine part.

 

 

 

In the gluing process using a low concentration of glue solution, the non-graphic part of the oxidation phenomenon will cause the printing plate dirty. The solution to this kind of problem is: after the dirty injection is used up, it should be covered tightly; The layout should be fully washed after removing the dirt, the glue should be increased when the glue concentration, the glue should be uniform; After gluing the plate, the length of the page is dried before printing.

 

 

 

 

In the baking plate, the high temperature causes the PS plate to deform and bend, and often scratches the plate when sending the plate, and the printing is dirty, and the slight scratches do not break the graphic network can be removed with dirty agent. The baked version is light red. This light red is due to the blank part of the page has a trace of sensitive layer, after baking and become. If the developer is disposed of, it will not be dirty, and if the light red is still left on the page after treatment, it will inevitably be dirty. This condition can be treated with dirt remover. Dark brown or dark brown after baking. Normally the photosensitive layer is reddish-brown after baking. If the color is dark brown or dark brown, it indicates that the baking temperature is too high or the finishing time is too long. This version belongs to the excessive baking version, any photosensitive layer resin has different degrees of carbonization, darkening and brittleness, the result will reduce the printability of PS version.

 

 

PS version after the baking plate dirty is a common fault. There are several reasons for this. The dust, impurities and dirty scratches on the front page of the baking plate were not thoroughly cleaned up in time. These dirt will be firmly adsorbed on the plate after baking, causing the printing plate to be dirty; Insufficient exposure or incomplete development will cause the non-graphic part of the photosensitive resin to decompose inadequately, and the ink will suck on the dirty printing; Don't rub protectant on dirty. PS plate baking plate protectant is easy to precipitate, after placing the solute precipitation to the bottom of the bottle, the protective liquid poured out of the back is thin, with this protective agent will cause the plate protection touch too thin or there is a leak, resulting in dirty PS plate.

 

 

The Photoshop version's task is to make the graphic part as accurate as possible to the rubber blanket. The graphic part is hydrophilic, and the non-graphic part is hydrophilic. But in fact, there is no such private ideal, there will be a variety of problems related to PS version. Some are listed below and discussed.

 

1, the non-graphic part of the layout is dirty, that is, the non-graphic part of the ink. There are several reasons for this.

A. The chemical composition of the moistening solution is improperly configured, which erodes the hydrophilic layer of the blank part. The treatment is to replace the moisturizing solution with one correctly configured according to the manufacturer's instructions. B, the roller sleeve of the water roller is too dirty or has been worn, damaging the blank surface. Treatment: Clean or replace the water roller sleeve by the plate, wet washing can protect the plate. C, in the halftone printing when the ink is too much to cause ink expansion, which will eventually make the non-graphic area sensitization.

 

Treatment: The use of pigments more thin ink film printing. D, there are sandpaper sand retained on the rubber cloth, wear the printing plate. Repair measures: clean rubber cloth, changed paper; Add anti-accumulation agent into the moistening solution; Reduce the amount of water on the plate to a minimum and add more balm, gum Arabic and/or alcohol or alcohol substitutes as needed to keep the non-graphic part of the plate clean while reducing the amount of water; In B-B printing, the pressure between the plate and the rubber cloth is reduced. If an embossing cylinder is present, check the pressure between the embossing cylinder and the paper; If the accumulation mainly occurs in the first printing unit, the water should be increased to help clear the dust on the paper. E, aluminum plate oxidation. When oxidized, the canal looks like a large number of clear dots or doughnut-shaped spots. It often occurs in the area that has been in contact with wet water rollers for a long time. Plates are prone to oxidation if they dry too slowly, or if they are stored in a wet place before development or between two printing productions. If the printing machine is interrupted when the plate is not dry, the plate will also oxidize. Action: Follow recommended plate handling procedures. Store the plate in a dry place. In the process of plate making, cheesecloth is used to dry the plate quickly. If you stop during the printing process, you should leave the plate roller and run the empty car until the plate is dry. F, the water roller and/or ink roller in the ink system work incorrectly, which may cause the printing of dirty bars in the circumference or axis. Measures: Check the pressure, cleanliness, geometric accuracy and overall state of each roll in the ink system. G, the plate is pre-exposed (greying) in the pre-press stage. Measures: Keep the printing plate in a box away from light; Install appropriate safety lighting at the plate making site. H, the ink is too soft, or the oil is too large. Contact the ink manufacturer at this time. I. Too much moistening liquid causes the imprint to be snowy; The ink color actually appears gray, and the color actually darkens; In magnification, the field is uneven and full of tiny white spots. Too much liquid emulsifies in the ink, and when the ink film splits, water droplets are exposed, which prevent the ink from being transferred to the paper. The water supply should be reduced at this time.

2, PS layout text part wear. There are two reasons: first, there is too much resin in the liquid; Second, there is too much acid in the moistening solution. The solution is to reconfigure the solution and check the PH value.

 

3. There are white fibers on the printing plate. This is mainly caused by too much paper wool or fabric falling off by the plate water roller. The method of treatment is to clean the living plate.

 

4, the graphic part of the chart can not be properly inked. There are two reasons: first, there is a resin or retouching liquid cure in the printing plate image area, so only hydrophilic not inophilic; The second is to accumulate ink with too short ink filament or soaked with water on the roller, plate and rubber cloth. The method of treatment is to scrub the layout with a wet cloth, reduce the amount of water, and protect the minimum amount of water required to clean the non-graphic part.

 

5, graphic loss. The reason is that the pressure of the tape drum and the plate drum is too heavy. The treatment method is to check the printing pressure.

 

6, the ink on the plate after baking is too slow. The reason is that the thermosetting adhesive layer is too thick. The treatment method is to clean with phosphoric acid solution or clean with plate cleaner.

 

7. There are scratches on the printing plate. The reason is that there are small sand grains on the outer layer before the paper winding machine, or small sand grains embedded on the surface of the ink roller. The treatment method is to remove two or three layers of paper from the paper roll on the machine and clean the rubber roll.

 

8, plate split. The PS plate may have cracks along the bay line at the head or end of the plate. There are two reasons: One may be the printing plate installation size is not correct. It is not evenly attached to the cylinder body. This may be the bending plate does not pay attention to, the plate material in the bending machine has moved, or the bending machine wear is very serious; The other is that the plate seam of the plate drum is not clean, there is residual ink so that the plate is not installed to the plate, and the plate head or plate tail is seriously stressed.