Factors affecting the quality of medium and high-grade wrinkle ink screen printing
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
At present, with the rapid growth of commodity economy and the diversified development of printing technology, packaging and decoration printing products have entered a new development realm in China. In the past 20 years, the share of packaging and decoration printing in all printing output has increased from about 20% to about 70%, accounting for the first place in China's printing industry. While lithographic, letterpress and gravure printing are the main printing technology of packaging and decoration printing products, due to the complicated technical process and special quality specifications of packaging and decoration printing products, special printing technology must be adopted, which accounts for the output value of packaging and decoration printing. 5% to 10%, and the application of screen printing is catering to this trend, filling the gap in packaging and decoration printing.
In terms of market segmentation, screen printing is not a major printing process in the field of packaging and trademark anti-counterfeiting printing. However, according to the recent development of the domestic and international packaging market, screen printing has been shown in the field of packaging anti-counterfeiting printing. With stable growth, Screen Printing has occupied an extremely important position in the packaging and printing market with its own characteristics. Wrinkle ink came into being in this trend. The ink is printed on gold-plated paper, silver cardboard and other substrates. After UV wrinkle drying, it will produce a special wrinkle effect on the surface, due to UV wrinkle ink. It has the characteristics of strong stereoscopic effect, luxurious and elegant, full ink film and good visual effect. Its application field has been extended to printing high-grade cigarette packets, wine boxes, gift boxes, health care products packaging boxes and other fields. However, in the actual printing operation, due to the short time of this ink, the wide application and research discussion are still lacking, so the printing quality of UV wrinkle ink will be affected by many factors, such as mesh number, Stretching angle, printing pressure, blade angle, printing speed, drying speed, etc., if these factors are not well controlled, will inevitably affect the quality of the final product.
In addition, UV wrinkle inks are difficult to obtain the desired wrinkle effect after printing, which is the biggest problem encountered in UV wrinkle ink printing. Any change in parameters during the printing process may lead to printing failure, which requires a lot of experiments to determine the quality. The printing conditions required for the print.
1. experimental method
Based on the preliminary analysis of the factors affecting the printing quality of UV wrinkle ink (mesh mesh, stretch tension, stretch angle, photoresist thickness, printing pressure, printing speed, blade angle, mesh distance and drying speed), first Carry out rough experiments, preliminarily determine the most important influences and determine the general scope; then carry out optimization design to determine 16 sets of printing schemes; finally, carry out fine tests to obtain printed matter, and draw conclusions through analysis and evaluation of printed matter.
2. experiment procedure
2.1 rough experiment
2.1.1 Specific experiments
The main purpose of the rough experiment is to screen the main factors and determine the general scope of the main factors.
The mesh parameter is set to 150 mesh;
The maximum air pressure of the air pump used in the experiment is 1Mpa, and the empirical value during use is 0.6-0.8MPa, so the experiment is selected 0.7MPa;
At present, the commonly used method of coating photosensitive adhesive for screen printing enterprises is to apply the printing surface 3 times and the back side coating once. Therefore, the printing surface is set to 3 times.
Rough experiment (1): Determine the range of wrinkle speed
Fix the stretch net tension, the blade angle, the printing pressure, the printing speed and the mesh distance, and determine the wrinkle speed range through experiments.
Rough experiment (2): Determine the range of the mesh distance
Fix the angle of the net, the angle of the blade, the printing pressure, the printing speed and the wrinkle speed.
Rough experiment (3): test the influence of printing pressure on printing effect
Fix the angle of the stretcher, the angle of the blade, the speed of the wrinkle, the printing speed and the mesh distance. The effect of printing pressure on the printing effect is determined through experiments.
Rough experiment (4): Determine the effect of printing speed on printing results
Fix the angle of the stretch net, the angle of the scraper, the speed of the wrinkle, the mesh distance and the printing pressure, and determine the influence of the printing speed on the printing effect through experiments.
Rough experiment (5): The effect of the test blade angle on the printing effect
Fix the angle of the stretch net, printing pressure, printing speed, wrinkle speed and mesh distance, and determine the influence of the blade angle on the printed product through experiments.
Rough experiment (6): The effect of testing the angle of the stretcher on the printing effect
Fixed printing pressure, printing speed, wrinkle speed, mesh distance and scraper angle. The effect of stretch angle on print quality was determined experimentally.
Rough experiment (7): further testing the effect of stretch angle on print quality
From the rough experiment (6), it can be seen that when the angle of the stretcher is 45°, the moiré is the most serious; when the angle of the stretcher is 60°, 75°, the moiré is also serious; when the angle of the stretch is 30°, There is basically no moiré. In order to determine a further range of stretch angles, the experiments listed in Table 7 were specifically performed.
2.1.2 Conclusion of rough experiment
(1) mesh number
The higher the accuracy required for the print, the higher the mesh size, and vice versa. In the choice of mesh size, the manufacturer recommends using 100, 150, 200 mesh screens. If the precision of the printing equipment is high, the screen with higher mesh height can be selected appropriately. At the same time, considering the limited experimental conditions, the mesh size selected in this experiment is 150 mesh.
(2) stretch angle
The experiment shows that the angle of the stretched net is 0°, the print does not produce moiré; when the angle of the stretcher is 30°, the moiré is lighter; when the angle of the stretched net reaches 45°, the torography is the most serious; the angle of the stretch is 60°, 75 At °, the print produces a lighter moiré.
In further experiments, it was confirmed that no moire was produced when the angle of the stretcher was 10°, 20°, or 25°.
Therefore, in the following fine experiment, the range of the angle of the stretcher is set between 0 and 30 °.
(3) Net distance
When the mesh distance is less than 5mm, the image can be completely displayed on the substrate; when the mesh distance exceeds 5mm, as the mesh distance increases, the image presented on the substrate becomes less and less.
Also, the minimum value of the mesh distance adjustment in this experiment is about 1.5 mm. 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, and only changes 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.
Since the size of the pattern is not included in the scope of quality evaluation, the factor of printing speed is not considered in the fine test.
(5) scraper angle
The change in the angle of the blade also does not change the quality of the print, only the size of the pattern. The blade angle is small and the pattern is small. On the contrary, the pattern is large.
Also, since the size of the pattern is not included in the scope of the quality evaluation, the factor of the blade angle is not considered in the fine test.
(6) ink wrinkle, drying speed
The wrinkle speed is too slow and the print cannot wrinkle. It is experimentally determined that when the wrinkle speed is less than 14 m/min, the ink cannot wrinkle, and when the speed reaches 14 m/min and 14 m/min or more, the ink wrinkles.
Therefore, the range set in the fine test is 14 to 20 m/min.