Note The Following Points in Paper Tube Boxes For Cake Printing

Note the following points in Paper Tube Boxes For Cake printing

 

1. The difference between the proofing version and the machine version

In fact, for proofing and printing, two different sets of plates should be printed. For proofing, from the structure of the proof press itself, it generally belongs to the platform, the proofing pressure is smaller than the printing pressure, and the speed is slower than the printing speed. At the same time, the dot increase caused by proofing is small, and when printing, the dot between 2% and 3% is retained, and 98% of the dot can not be pasted. For printing, due to large printing pressure, fast speed, printing ink than proofing ink soft (small viscosity), easy to cause dot increase, and can increase to 30%-40% at most, so the same plate for proofing and printing effect is not the same, and for a long time this contradiction has not been solved. Therefore, when printing the printed version, it is required to retain 4% to 5% of the dot, 96% of the dot is not paste, leaving room for the expansion of the dot caused by printing, and the print is easy to access the proof.

 

2, the phenomenon of losing ideas when printing

The loss of dot should first look at the degree of dot reduction of the film itself, such as whether 50% of the dots on the film are square, whether 4% and 5% of the dots are complete, in short, to check the quality of the phototypesetting film, and then according to it, and then determine whether the dot is lost in the process of printing. Due to the problem of printing operation and lost points often appear, which has a direct relationship with exposure time, development time, developer temperature, concentration and so on. Excessive exposure and excessive developer concentration will cause the loss of the dot that should be retained on the layout or the thinning of the text strokes. Strictly speaking, the printing staff should control the exposure and development through the printing test strip and the gray ladder, and test out their own test data.

 

3. The layout is empty

Investigate the cause of the printing plate deficiency, the first may be related to the printing plate film, if the output film exposure is too much, it will lead to the printing plate on the dot deficiency, the printing plate naturally also weak.

 

From the point of view of the printing operation, it may be because there are foreign bodies or dirt on the glass or film of the printing machine; Or the liner of the printing machine is not suitable; Or the vacuum is not real, so that the film and plate close enough; Printing film collage improper; The light is too strong before exposure (when punching) or after exposure to development, etc., may cause the straight plate to be weak; There are too high developer temperature, too high concentration, too long development time, too much developer supplement liquid caused by excessive development is also the cause of the page deficiency cannot be ignored.

 

At this time, the glass or film should be cleaned with a cleaning agent; Adjust the liner to flat; The tape leaves the image part 3mm away from the collage, and confirm whether the film is close to the plate; Work under safe light, such as anti-fading fluorescent lamps, yellow lights, fluorescent lamps with safety lampshades, etc. For the problem of inappropriate development, it should be implemented according to the standard.

 

4. Uneven development

Uneven or poor development is often caused by reduced activity of the developer, which is mainly reflected in several aspects: the developer is not replenished in time; Development time is too short; Developer temperature is too low; At this time, in addition to standardizing the development conditions, the developer should also be supplemented in a timely manner according to the quantity.

In addition, dirty spots or foreign bodies on the plate will also hinder development, which requires the staff to regularly check the developer and plate printing machine, and clean the machine in time.

 

5. The layout is dirty

There are different situations and different causes of dirt on the page. The layout is dirty, may be underexposure, which has two possibilities, one is the transparency of the film is not good or the film expired haze; The second is that the exposure light source is used for too long, resulting in aging. In the first case, you can only re-make the film; If the exposure light source is a problem, you should use the gray ladder to adjust the exposure time appropriately, or directly replace the exposure light source. Of course, poor development may also cause dirty layout, at this time it is necessary to check the specific reasons for poor development, and adjust to standard conditions in time.

 

In the production, sometimes you will also encounter spotty soiling. Analysis, its "culprits" are really many. If ① there are dirty spots on the glass of the printing machine, dust or dirty spots on the film; ② When collage printing plate film, the tape on the film printing plate, leaving tape impressions on the plate layout; ③ During development, poor development is caused by blister attachment (developer spray hole bubbles due to blockage); ④ In the printing operation due to dirty hands, leaving fingerprint traces on the page; ⑤ Protective glue liquid thin; ⑥ The protective glue is not dried and stored on top of each other, making each version stick together, causing the protective glue layer to peel off when used; After plate making, the plate is kept under high temperature and high humidity conditions.

 

Different causes should be targeted at the "right medicine". Among them, the dirt caused by tape adhesives and tape impressions is the most common, and it should be prevented first. Thin and clean transparent tape should be used as far as possible when making plates. If the tape adhesive comes to the printing plate, it should be gently wiped off and then developed. When printing, it is necessary to fully pump air to minimize the air layer around the tape and the original film to minimize the possibility of light interference. If there are tape marks on the page after exposure, you should manually remove the dirt with dirt remover or double exposure to remove the dirt.

 

For other aspects of dirt removal, dirt removal agent, retouching knife, pumice rod can be used to remove dirt, you can also use scattering film exposure to remove dirt or remove dirt cover plate.

 

6. Poor ink on the printing plate

If it is not caused by the low content of the photosensitive adhesive of the plate, it should be found from the relationship between the inking force of the plate and the exposure time and the developer concentration. If the exposure time is too long or the developer concentration is too large, the printing plate inking force is easy to appear. Because the photosensitive layer of the PS plate exposure is not absolutely soluble or absolutely insoluble, but between the two, the control is not good, it will make the photosensitive layer of the printing plate the solution of the solution, the solution that should not be dissolved, the deinking rate is increased, and the inking is poor. In addition, if the protective glue does not meet the requirements, the glue liquid is too thick, and the manual glue is not uniform; (2) The drying temperature of the plate is too high or too low, resulting in poor ink absorption or poor film forming performance; ③ The printing plate is in contact with strong light after gluing; ④ After plate making, the printing plate is stored in a high temperature and high humidity environment, which will cause the ink force to decrease. At this time, the plate should be used to specify the protective glue, appropriate dilution of the glue, a reasonable drying temperature, generally should be 60. C or so; After gluing, prevent light and store the good plate in a qualified environment. If the printing plate is found to be poorly inked during the printing process, it should be checked whether there is too much glue in the plate liquid, or whether there is no water after the use of cleaning agent.

 

7, the printing plate printing resistance is reduced

The main reason for the decline of plate printing resistance lies in two aspects: plate printing operation and printing. In terms of printing: ① before exposure or before development; The density of the film is not high enough; (3) Due to the high temperature and concentration of the developer, the development time is long or excessive supplementation causes excessive development; (4) There are strong acids, alkali, organic solvents, dirty liquid and other agents attached to the printing plate; ⑤ The number of times of wiping with plate cleaning agent is too much, and so on, which will affect the printing resistance of the plate. In terms of printing, if the printing pressure is too large or the paper powder is too much, as well as the use of strong plate cleaning agents and drum cleaning agents in UV printing, it will inevitably cause a decline in print-resistance.

 

In particular, it should be pointed out that in order to prevent light running, yellow safety lights should be used for ordinary PS versions to fully block harmful light.

 

8. There is a bottom blue on the printed plate

In production, a plate is exposed, whether it is because of the problems of the plate material pre-production, or the matching conditions of the exposure and development time of the printing plate itself are not suitable, and the printed version has a bottom blue. The "secret" of the bottom blue is: ① When the plate is made, the sand mesh is too coarse, and the current of electrolytic oxidation is not matched; (2) Insufficient exposure or insufficient developer concentration when printing, or these two conditions do not match properly. The bottom blue phenomenon makes many operators headache, this problem, more development is not good, less development is not good.

 

Multiple development, the need to retain the dot will be reduced or lost; Less development, it will affect the entire page. Under the condition of moderate exposure and development, after showing the bottom blue to repair dirty, but a dirty, there will be a watermark on the page, to finish the watermark plate, machine printing, and the watermark swimming around and dirty, if you use the dirty solution to repair this circle of dirty, and will swim out another circle of dirty, if the picture, text or network cable, the plate can not be used at all. To solve this problem, it is necessary to apply a thin layer of glue before cleaning, and high-quality prints can not use this version.