Six Common Problems in Printing Resin Plate Making

The photosensitive resin plate uses a synthetic polymer material as a film-forming agent and an unsaturated organic compound as a photocrosslinking agent to produce a relief plate material having a sensitization performance. Almost all photosensitive resin plates are under the irradiation of light (mainly ultraviolet light), and a cross-linking reaction occurs between molecules, thereby forming an embossed image with a certain insolubility. Photosensitive resin plate from the plate making process can be divided into solid and liquid type two. The solid-type prefabricated plates made of saturated photosensitive resins are relatively costly, but they are of relatively good quality. They can be used to make product packages, trademark plates, and cable screen plates; liquid series consisting of unsaturated polyester resins are The coated plate (simplistically, the photosensitive liquid used for substrate preparation, and then coated with resin, sensitized and manufactured) is relatively inexpensive and is suitable for rough text lines.

In the actual operation of plate-making process of solid photosensitive resin plate, there are often the following problems. Only comprehensive analysis, different treatment, and identify the source of the problem can solve the problem.

First, the resin version text, lines, pattern lines are too thin, too small, small words and independent points off, small lines bent

In the making of resin plates, there are common problems such as thin lines, fine text, and detachment of individual dots.

main reason:

l. Insufficient exposure time of resin plate;

2, the film contrast is small, there is fog, not clear;

3, baking resin plate and thermal curing improperly;

4, when the resin version is low, the water temperature is low, the washing time is long, the bristles are too hard, and the brush plate is too deep;

5, when the pressure on the machine printing is too large, improper adjustment.

Solution:

1, in the production of resin plate, encounter small text, lines, patterns, independent points, to grasp the correct exposure time. 3kw iodine lamp, exposure time is about 20min, must be longer than the normal version of the extended exposure time, so that small lines, text, independent points can stand, do not fall off. Due to the long exposure time, the slope of the resin plate on the side of the system is small (about 70°), and the substrate is firm.

2, baking resin, drying and thermal curing, under normal circumstances, the oven temperature is controlled at 60 to 80 °C, the purpose is to evaporate the plate and the water; drying temperature is too high, the resin plate is easy to blistering.

3, requires the operator darkroom technology is perfect, the contrast of the film processing should be as far as possible, no fog, text, smooth lines and smooth, no shortage of strokes.

4, in the system of solid resin version, whether it is plate-making machine automatic brush plate, or manual brush brush version, the water temperature should be controlled at 50-60 °C, flushing until the substrate is exposed. Brush resin version to rotate the brush, single brush on one side, it is easy to side slope and brush people, resulting in small lines of bending, off; brush version to choose those soft and suitable hair brush, if the bristles are hard, it will make Small text brush damage; brush resin version should pay attention to master version of the brush depth, brush version does not necessarily have to wash see the base, brush version is too easy to the version of the text, lines, patterns are brushed version, in addition, pay attention to brush Do not wash the plate for too long.

5, when the resin plate is printed on the machine, the pressure between the ink roller and the resin plate, the resin plate and the platen roller must be withered, and the pressure for adjusting the resin plate is less than the pressure for adjusting the copper plate and the printed plate type. some. To avoid excessive pressure, the ink roller and the impression roller will crush the small text lines of the resin plate, which will affect the printing rate.

Second, the text, line version is not clear when the resin version

main reason:

1, excessive exposure;

2. Vacuum adsorption is not true when drying;

3, film contrast is small, not clear.

Solution:

1, to master the resin exposure time, in particular, hollow text, lines, the most likely to paste version, design graphics as much as possible a little bold.

2. The inhalation of the printing machine should be strong. If inhalation is not true, there will be a gap between the resin plate and the film, and the ultraviolet rays will be injected from around, resulting in a photosensitive paste plate.

3, before the printing version to carefully check whether the apricot film paste version, good light transmission, contrast, clear, in order to meet the needs of plate quality.

Third, the resin version does not move

main reason:

l. The resin plate has exceeded the shelf life, or leaks in the process of production, storage and transportation. The resin plate is hardened.

2. The water temperature is too low when flushing the plate;

3, film darkroom processing is not good, negative film poor light, low density.

Solution:

1, the resin version of the preservation period is about half a tablet, printing manufacturers should be based on the factory's production capacity and the amount of purchase, do not blindly buy overdose, otherwise it will cause extended failure.

2, the resin version is a photosensitive material, most afraid of the production, storage, transport links appear light leakage. When saving the resin plate, the plate that is not used for the moment should be placed in a sealed box and sealed with a black plastic bag; the resin plate should be stored in a dry, damp-proof place.

3, when the brush version of the water control at about 60-70 °C. If the water temperature is too low, it will affect the dissolution of the unsensitized resin film when it is in contact with water. When the water temperature is high, dissolution is accelerated.