Discussion on Screen Printing Quality of High-grade Wrinkle Ink (3)

Coarse experiment (7): Further testing the effect of stretch angle on print quality

From the rough experiment (6), it can be seen that when the stretch angle is 45°, the moire is the most serious; when the stretch angle is 60° and 75°, the moire is also severe; when the stretch angle is 30°, Basically no moire appears. In order to determine the further extent of the stretch angle, the experiments listed in Table 7 were performed.


2.1.2 Rough experiment conclusion

(1) Screen mesh number

The higher the precision required of the print, the higher the number of screen meshes, and vice versa. In the selection of screen mesh number, manufacturers recommend the use of 100, 150, 200 mesh screens. If the precision of the printing equipment is high, meshes with a higher mesh number can be properly selected. At the same time, taking into account the limited experimental conditions, the mesh size selected for this experiment was 150 mesh.

(2) Stretching angle

The experiment shows that the stretch angle is 0°, and the print does not produce moiré; when the stretch angle is 30°, the moire is lighter; when the stretch angle reaches 45°, the moire is most severe; the stretch angle is 60°, 75 At 0°, the print produces a lighter moiré pattern.

In a further experiment, it was confirmed that no moiré was produced when the stretch angle was 10°, 20°, and 25°.

Therefore, in the following fine experiment, the range of the stretch angle is set between 0 and 30°.

(3) Network distance

When the net distance is within 5 mm, the image can be fully displayed on the substrate; and when the screen distance exceeds 5 mm, the image displayed on the substrate becomes less and less as the net distance increases.

And because the minimum value of the pitch adjustment in this experiment is about 1.5mm. Therefore, in the following fine test, the setting range of the mesh distance is 2 to 5 mm.

(4) Printing speed

The change in printing speed does not bring about a change in quality. It can only change the size of the ink wrinkle pattern. The printing speed is fast, the pattern is small; the printing speed is slow, and the pattern is large.

Because the size of the pattern is not included in the scope of the quality evaluation, the factor of the printing speed is not considered in the precision test.

(5) Scraper angle

The change of the blade angle can not change the quality of the print, just change the size of the pattern. Scraper angle is small, pattern is small, on the contrary, the pattern is large.

Also because the pattern size is not included in the scope of the quality assessment, the scraper angle is not considered in the precision test.

(6) Ink creping and drying speed

The speed of wrinkling is too slow and the print cannot wrinkle. Experimental measurements When the wrinkle speed is less than 14m/min, the ink cannot wrinkle. When the speed reaches 14m/min and 14m/min or more, the ink will wrinkle.

Therefore, the range set in the precision test is 14 to 20 m/min.

(The author / Wu Jun Yu Yurong)
Source of information "screen printing"