Frame: The basics of screen printing

Frame Features and Maintenance In many companies, visiting the screen production workshop is like remembering the Sherwood Forest Tour: The rows of frames are like the long bows of Robin Hood and his clowns, with crooked frames everywhere visible. However, these curved frames do not allow the arrow to reach the intended target, but rather preserve the image's registerability and appearance. The frame is the most basic element in screen printing. The printing plate in screen printing is a screen image with a template. If the screen cannot be fixed on a stable frame, it is not used at all. The frame has many sizes, shapes, and characteristics. They consist of several different materials, mainly woody, aluminum, magnesium, and steel. Regardless of their composition, shape or style, all screen frames perform the same important functions in screen printing. In summary, these functions include the following sections: Provide tools to support the wire; 2. Understand the tension of elastic mesh; 3. To withstand the external forces encountered in printing; 4. Keep flat and square; 5. Must be light enough to facilitate treatment. Among the elements that printers care about in screen printing, the frame is more important than other elements. To evaluate whether it is good or bad is to look at its tensile strength. The screen tension is measured in N/cm (Newtons per centimeter) and the tension at 1 N/cm is equal to 0.22480894 lbs/cm (pounds per centimeter). Assuming a 40 x 40 inch screen reaches a tension of 20 N/cm, this will cause the frame to receive approximately 455 pounds of tension on each side, ie 40 in. x 2.54 cm/in. x 20 N/cm x 0.22480894 lbs/N. = 456.8 lbs. With the increase in the size of the frame, the pulling force is also proportionally increased. A 60 x 80 in. screen version had a tension of 20 N/cm, with 915 pounds on the long side and 685 pounds on the short side. If these tensions can be controlled, screen printing has a solid foundation. If they cannot be controlled, they will destroy the printing process. This article will discuss the importance of forming a frame, what problems will occur when the frame is deformed, factors to consider when buying a frame, and when the frame will be used. Not just a box in the early days of commercial screen printing, no one really valued the structure or material composition of the frame. Most of the frames are wooden, and although the metal frame has been greatly developed, the wooden frame still occupies an important position. Although the performance of the new improved wooden frame is much higher than that of the original flexible natural wooden frame, the inherent instability of wood adds a challenging variable to the screen printing, especially when the screen tension When it is very large and registration accuracy is high, it is more prominent. Although many screen printers have achieved good results in demanding low production, this chapter does not introduce them. This chapter mainly introduces metal mesh frames. Once the tension is applied to the screen, the screen is stretched over the frame, and the flatness of the frame becomes an important factor. Screen tension is a “potential energy” in screen printing. The role of the frame is to resist the force from the tension. A suitable frame will be able to resist tension without being deformed in the time required for printing, and will remain flat and square.