Screen printing mesh selection and application
Among the factors that determine the quality of plate making and printing, the screen printing mesh must be correctly selected to determine the type and number of screens. The type of screen should be determined according to the accuracy of the original, the shape of the substrate and the requirements of the printing base. .
According to different materials, the screen can be divided into four types, namely, silk nylon mesh polyester mesh and stainless steel mesh, each of which has its characteristics and quality.
The mesh number of the screen indicates the number of meshes that are present in each linear unit length of the screen. The larger the number, the finer the screen is to select the appropriate mesh size and the quality of the print. Large, the finer the mesh, the higher the number of meshes per cm. On the screen plate, the thinner lines and small dots are easier to copy. If the mesh size is smaller, the thicker mesh plate is used. It is absolutely impossible to print a subtle level. When using a wire mesh, it is not as fine as possible. It depends on many factors in practical applications. The mesh number can be determined according to the following steps. According to the number of screen lines of the positive picture and the number of dot points of the bright tone, the diameter of the printed dot is determined in the screen printing, for some extremely shallow or very dark tone dots. It cannot be printed because the printed dots are limited by the diameter of the screen, so it must be determined according to the range of the tone of the print.
Since the screen printing mesh is interfered by the wire diameter, the small mesh point is easily blocked by the wire mesh, and the degree of loss is related to the position of the wire mesh at the wire mesh.
The number of stages of the minimum dot mesh screen that can be printed by different meshes refers to the thickness of the wire mesh.
According to the thickness of the wire mesh, it can be divided into four different levels of fine, medium and small intermediate.
The diameter of the mesh is usually expressed in microns. When a mesh of a certain number of meshes is selected, the appropriate mesh diameter is selected. In this case, the following factors should be considered: the smaller the wire is, the larger the relative opening area is.
The finer the mesh, the worse the corrosion resistance of the lotion, and the worse the wear resistance of the ink and the squeegee during printing.
The larger the diameter of the mesh, the smaller the relative opening area, and the difficulty in copying fine lines and small dots.
The larger the mesh diameter, the higher the print durability of the screen.
In general, in addition to considering the above factors, the selection of the screen should also take into account factors such as the service life of the adaptive stencil on the surface of the ink substrate.
Only after comprehensive consideration can the correct screen be selected correctly, which will help to achieve the best printing results and economic benefits.