Flexo plate material characteristics and process three

Second, the paste process

The process of a sticker is generally divided into two processes: preparation and specific operation.

(a) the preparation process:

Before the plate-laying operation, it is necessary to understand and check the relevant technical requirements, the accuracy status of the plate-attached device, and the status of the plate.

1. Master the technical requirements. It is necessary to fully understand the mastering of technical requirements, such as the size of the plate cylinder, the position of the printing plate, the number of printing colors and color sequence, the printing on the front side or the back side, and the position, size, color, and marking of the photocell. Rules and other relevant conditions and technical requirements.

2. Check and adjust the accuracy of the sticker proofer. First of all, should focus on checking whether the geometric accuracy of the impression roller meets the requirements, such as the radial runout of the impression roller (should be controlled within 25UM), ellipticity (should not be greater than 25UM) and so on. The second is to check and adjust the mutual positional relationship between the plate cylinder and the impression cylinder of the proofer, which is mainly parallel to the center line of the two rollers. If the middle and the two ends of the two rollers are the same, then parallel, the traction resistance is uniform, otherwise Parallelism should be adjusted.

3. Check the status of the plate cylinder and its transmission gear. The main task is to check whether the working face of the transmission gear is clean, whether there is damage, whether the gears on the plate cylinder are firmly connected, whether the surface of the plate cylinder and drum shaft is dirty (such as ink), whether there are scratches, pits, and strokes. Wounds and other defects, the dimensional accuracy of the plate cylinder (roll diameter tolerance +25 UM), geometric accuracy (elliptic tolerance tolerance 13 UM) meets the requirements, if the above defects should be repaired. At the same time, check whether the registration symbols on the layout are clear. If the markings are not clear, relabel them.

(B) General Methods and Steps for Stickers

Due to the different equipment, plates and technical conditions of each printing factory. The method and steps of the sticker cannot be exactly the same. Here, according to relevant information, the general methods and steps are introduced for reference. The specific operation should be determined according to the specific conditions of the factory. To ensure the quality of the stickers.

1. Ordinary plate material sticking method

(1) Cut double-sided tape, the width of which is 10 cm larger than that of the printing plate, and the length is such that it can be wound on the roller and there is overlap.

(2) Do not remove the protective paper on the double-sided adhesive tape. Wipe the surface of the roller with gasoline or nail polish. After drying, place the double-sided adhesive tape face down and carefully place it on the roller. At this time, it is necessary to pay attention to aligning the edge of the plate with the grid lines on the roller, in order to achieve the overlap of the ruler of the available plate-setter. To avoid storing air in the area under the double-sided adhesive tape, the plate should be slowly affixed while rotating the roller. After the tape is attached to the roller, the overlapped portion of the tape should be removed with a knife (this is to make the seams neat). Inside, use the polyethylene roll roller, so that the double-sided tape and roller do close together.

(3) Peel off the protective paper from underwater or in the vertical direction and tear one piece every 2.5CM. It is best to never peel, and the seams and edges are finally peeled off.

(4) After the protective paper is peeled off, remove the line hair, paper residue and other specialties attached to the surface. If there is any bubble, it should be pierced and broken with a needle.

(5) In order to activate the stickiness of the double-sided adhesive surface, it can be roughly rubbed with gasoline or armor.

(6) If a sticker is not used, it is necessary to use a grid line on the roller. For this purpose, you can use a thin ball to smile on the adhesive lining to draw a line.

(7) If there is a margin in the size of the plate, it can be cut with scissors or a knife, and the cut mark should be beveled to prevent the plate edge from curling up.

(8) Hold the diagonal or both ends of the plate, and place the center of the plate on the double-sided tape. In order to prevent it from skewing and warping, use the plate from the center to the head and from the middle to the end by hand. Xuan flattened.

(9) If air bubbles are trapped between the double-sided tape and the plate, the air must be discharged from the non-graphic area.

(10) If you want to take down the plate attached to the roller, you should take it slowly. If the plate is stuck tightly, you can pull it up. Use a smile to dip a small amount of gasoline or paint on the plate and both sides. Between, soften the glue and peel it off little by little. To repost or save the plate, wait for the solvent to clear.

(11) In the case of large printing batches or repeated use of printing plates, special ink tapes may be used to seal the edges of printing plates in order to prevent ink or solvent from dipping into the bonding surface from the end of the printing plate.

(12) Wipe the plate slightly with alcohol before printing, as oil, fingerprints, and other foreign materials will cause loss of print quality.

2. Paste with double-sided adhesive lining

(1) Prepare plates and rollers.

(2) Remove the protective sheet on the adhesive surface and observe if bubbles are present between the double-sided tape and the plate.

(3) Through the observation holes on the plate, align the alignment lines on the plate with the grid lines on the roller.

(4) The subsequent operations are the same as those for the conventional flexo.

(5) Finally, cut two 2.5CM wide double-sided adhesive tapes and stick them one by one around the drum. This is to enhance the firmness of the printing plate to avoid creeping in the printing.

3. Pre-curved paste

(1) Prepare plates and rollers

(2) Follow the regular version of the sticker program.

4. Paste of metal north liner

(1) Follow the ordinary flexo sticker program.

(2) For the normal north metal lining plate, the version line is engraved on the back of the plate, and the plate line should be overlapped with the ruled line on the roller. If it is a version with a positioning pin, then the metal back The two positioning holes of the plate cylinder correspond to the pins.

(3) Fix the corresponding ends flat on the roller. Otherwise, twisting may occur during printing.

5. Color cable version paste

There are two basic requirements for the paste of the color cable version. One is the normal registration of the printing plate. The second is to ensure the thickness accuracy of the printing plate. In order to obtain the correct registration accuracy, the mechanical accuracy of the equipment must be maintained. Of course, it depends on the technical level of the operator. The paste method of the color cable version is the same as that of the line version, but it must be handled with care.

6. Proofing with sticker proofing machine

For the multi-color fine prints with high requirements for printing quality, with the general paste method, it can not reach the accuracy requirements, and it is necessary to use a special sticker proofing machine and proofing. To ensure the accuracy of the board. The method steps used for the general color proofing machine proofing are detailed in the machine description. Please follow the instructions in the manual to apply the technique.