Professinonal Cosmetic Packaging Supplier
NEWS CENTER
If you want the quality of the plate to be good, you can’t control it in three time.
Page view
In order to complete a good quality printing plate, it is necessary to control exposure time, plate washing time, and drying time. Faced with different printing plates, there are different times to control. How do you control these three kinds of time? Need to pass the test version to test.
Determination of back exposure time
The back exposure time should be determined according to the thickness of the desired substrate. As shown below, if the required thickness is C, the corresponding back exposure time is 12 seconds. We can divide a printing plate into many pieces and then use different exposure times to obtain different thicknesses. Based on the thickness of this test plate after exposure, a comparison chart was established. With the beta version, a print version that meets the requirements can be produced very accurately when the official version is made.
Determination of the main exposure time
Through the test version can also determine the main exposure time, for example, we take four plates, use different times to expose, after the completion of the percentage of Yin Yin picture points, compared to measure the Yin and Yin pictures to choose. If the dot is larger than the negative image, reduce the exposure time; if the dot is small relative to the negative image, increase the exposure time so that the optimal main exposure time can be determined.
Plate process parameters
Through the beta test, you can get a range of exposure references:
Plate elongation compensation
In the process of making plates, pay attention to the compensation of the elongation of the plate. As shown below, the normal pattern (flat printing) is a circle. But the printing plate is wrapped on the printing roller. Since the radius of the printing roller is not the same, its arc will not be the same, so the dots will become elliptical and the ellipticity will be different. Therefore, it is necessary to correct the printing plate for different roller radii.
Compensation of the length of the photosensitive resin plate
How to modify the plate, there is a correction formula can refer to:
∮=R/(R+r)×100%
r=a+b+c
In the formula,
Reducing rate
R is the roller radius
a is the thickness of the paper
b is the thickness of double-sided tape
c is the plate thickness
This formula can be used to calculate the compensation of the stretch dimension, which will make our printing more accurate. Therefore, when making a printed version, it is necessary to be very clear about the elongation of the plate.
Previous article:
Printing and packaging industry
无
Next article: