Actual printing ink penetration:
1. The thickness of the film layer (determines the amount of ink). If we use photosensitive glue to make the screen, we must also consider the solid content of the photosensitive glue itself. After the photosensitive glue with low solid content is made, the film will be volatilized and the film will become thinner. So we can only use a thickness gauge to detect the overall thickness of the screen.
2. The viscosity of the ink (indirectly affects the thickness of the ink layer). The lower the viscosity of the ink in the printing process, the thicker the ink layer will be, because the ink itself contains less solvent, on the contrary, the thinner.
3. The mouth of the scraper (directly affects the amount of ink). If the blade of the squeegee is at a right angle, the ink volume is small. The ink volume is large if it is at an obtuse angle.
4. The pressure of the squeegee (directly affects the amount of ink). During printing, the greater the pressure on the squeegee, the smaller the ink drop. The reason is that the ink has been driven away before being completely squeezed out of the mesh. On the contrary, it is small.
5. The tension of the screen (affects the size of the opening, the number of screen meshes, the wire diameter, and the thickness of the screen). In the process of stretching the screen, as the tension increases, the technical parameters of the screen itself will change accordingly. First, it affects the mesh number of the wire mesh, the higher the tension, the greater the drop in mesh size (until the mesh is plastically deformed). Next, it will affect the hole width of the screen, the mesh will become larger, the wire diameter will become thinner, and the mesh fabric will become thinner. These factors will eventually lead to changes in the amount of ink.
6. Ink type (indirectly affects the thickness of the ink layer). We know that after solvent-based ink is printed, the solvent will evaporate and the final ink layer will become thinner. After printing, the resin is cured immediately after being irradiated by ultraviolet rays, so the ink layer remains unchanged.
7. The hardness of the squeegee (indirectly affects the thickness of the ink layer). In the printing process, the higher the hardness of the squeegee, the less easily deformed, the smaller the amount of ink, and vice versa.
8. The angle of the scraper. (Indirectly affects the thickness of the ink layer). When printing, the smaller the angle between the squeegee and the screen, the greater the amount of ink, because the squeegee and the screen are in surface contact. On the contrary, it is small.
9. The pressure of the ink-return knife (the amount of direct ink). The greater the pressure applied to the ink-returning knife, the greater the amount of ink, because a small amount of ink has been squeezed out of the mesh by the ink-returning knife before printing. On the contrary, it is small.
10. Printing environment (indirectly affects the thickness of the ink layer). One issue that we have always overlooked is the change in temperature and humidity of the printing workshop environment. If the temperature of the printing environment changes too much, it will affect the ink itself (such as ink viscosity, mobility, etc.).
11. Printing materials. (Directly affects the thickness of the ink layer). The flatness of the substrate surface will also affect the thickness of the ink layer, and the rough surface ink will seep out (such as braid, leather, wood). The opposite is greater.
12. The speed of printing (indirectly affects the thickness of the ink layer). The faster the printing speed, the smaller the ink drop. Because the ink has not completely filled the mesh, the ink has been squeezed out, causing the ink supply to be interrupted.
we know that if a certain link changes during the printing process, it will eventually lead to inconsistent ink volume. How should we calculate the thickness of the ink layer? One method is to weigh the weight of the wet ink. First, try to keep every link in the printing unchanged. After printing, weigh the weight of the substrate, and then subtract the original weight of the substrate. The data obtained is that of the wet ink. For weight, another method is to measure the thickness of the ink layer. Use a thickness gauge to measure the thickness of the substrate after covering the ink, and then subtract the original thickness of the substrate. The data obtained is the thickness of the ink layer.
How to control the thickness of the ink layer in the printing process of the screen printer has become a problem faced by screen printers. The first thing we have to do is to use the existing measuring equipment to ensure the correctness and objectivity of the measured data; The premise factory can use an automatic coating machine to complete the gluing process to ensure the thickness of the glue layer. The next thing to do is to ensure that every link in plate making and printing remains unchanged as much as possible. Each printing parameter should be well documented to provide ideal data for finding the right ink layer thickness, so that the screen printer can print better.
Post time: Jan-21-2021