Photosensitive resin details

In recent years, water-soluble solid photosensitive resin plates have the advantages of simple plate making process, low cost, no pollution, good ink transfer performance, high printing rate, light plate material, and short plate making cycle, and can be matched with computer laser photocopying system. Being favored by small and medium printing manufacturers, it is gradually replacing the zinc plate.

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 of the text, lines, patterns, lines too thin, too small, small words and independent points off, small lines bent on the resin plate making, common thin lines and small text, separate points off and other issues.

Main reasons: l, resin plate exposure time is insufficient; 2, the film contrast is small, there is fog, not clear; 3, baking resin plate and thermal curing improperly; 4, brush resin version when the water temperature is low, rinse time is long, bristles Excessive hardness, too thick brush plate; 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 reasons: 1, overexposure; 2, vacuum adsorption is not true when the sun; 3, the 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

The main reasons: l, the resin plate version of the material has exceeded the shelf life, or any production, storage, transportation, light leakage, resin photolithography hardened; 2, flushing brush version when the water temperature is too low; 3, film darkroom processing is not good, The backsheet has poor light shielding and low density.