Selection of photosensitive materials
Screen printing screen screen is required to reproduce the image.An important factor in determining reproducibility is the selection of a good photosensitive material.The so-called screen printing plate reproduction refers to the screen screen of the original image reproduction ability.It is shown in screen printing plate precision, clarity, differentiation and other aspects.
oneScreen printing plate accuracy.
Screen printing plate precision refers to the printing plate image, text, symbols and so on the position and size accuracy.It is when the plate-making materials and methods, such as manual coating and cutting the accuracy of plate is often lower than the photosensitive plate;The accuracy of indirect plate-making is higher than that of direct plate-making.
twoScreen printing plate clarity.
In photography, definition refers to the degree of image edge density variation on the soft plate, in screen printing, it refers to the degree of horizontal and vertical alignment of the film image edge.It consists of three elements: sharp shoulders, bridged shoulders and flat shoulders.
1.Shoulder and sharpness.Is refers to the plate film image shoulder squared degree.Square shoulder (90 degrees) has good three-dimensional imprinting;Shoulder collapse, the ink edge of the imprint is uneven, and there is a phenomenon of expansion of the imprint.
2.Bridge.Is refers to the plate film image edge across the wire mesh also when the performance of the original image shape.Good bridging, good reappearance of the image edge, the image edge will be deformed across the network, the degree of deformation is related to the plate film material, production method and the position of the image edge and the mesh, the impression is serrated.
3.Smoothness.The flatness of the film surface (the side in contact with the substrate).Flatness determines the degree of sealing between plate film and substrate in printing.Good flat, printing on both sides of the joint, ink flow will not cross the boundary, print clean;When the flatness is poor, the surface of the plate film with the silk screen, the hole and fluctuation, ink flow will flow into the non-sealing part, so that the impression edge appear serrated, and every two mesh appear a serrated, the beginning of the teeth and the size of the approximate non-sealing range.The roughness of the plate surface can be measured by the roughness meter.If the difference is large, the flatness is poor.The difference value is between 3 and 7 meters, so you can get good legible marks on all kinds of substrate surfaces.
4.The thickness of the printed mask.The thickness of screen film on the printing surface affects the thickness and clarity of the ink layer, especially on the small image, and even changes the step value and color of the dot.When the product requirements of ink thickness, thick line, the corresponding requirements of the plate film should be thicker.Therefore, the role of the plate film to meet the thickness requirements.
5.Screen printing plate resistance.Resistance to printing refers to the ability of a printing plate to withstand the number of times it is printed.There are many factors that affect the printing force, from the perspective of plate-making, mainly depends on the printing plate itself mechanical force and chemical strength, and its combination with the screen fastness.Printing plate resistance should be suitable for the screen printing task, some only a few dozen copies, some more than 100,000.
6.Screen plate of the film.Demulsification refers to the film from the printing plate screen screen removal of the degree of difficulty.The standard of plate-making quality is not the higher the better, but under the premise of meeting the task needs, the more economic the better.
To meet the above requirements, make a more qualified printing plate, we will choose the quality of sensitive materials, printing fine photo effect, KFG non-ink we require the use of photographic pulp is oily, thick film photographic pulp (preferably imported).