What is screen printing: How it works?

Screen printing technology has a long history and is widely used in many industries. As we all know, there are many different printing technologies, but why screen printing technology are so popular in the world wide? Today, let’s explore the whole process of screen printing together. That will also help us have a better command of its use in daily life.

Step 1: Picture Processing

Before printing, we need to get a clear and preferred picture to print it on the clothes or other items. After getting the right design, we need to print it on the inkjet film. To get the best results open your print menu and change your image settings to “best quality photo” or “best image.” Set your paper settings to “premium glossy photo paper.” And then, we will get an inkjet film with design on it.

Step 2: Plate-making

In this step, you need to prepare screen printing mesh, screen printing frame, mesh glue, manual screen stretcher, exposure unit and so on. We can also bought the finished screen printing screen which is made by polyester mesh and screen printing frame. That helps a lot, especially for beginners. First, choose the suitable screen printing mesh. Screen Printing Mesh is one of the vital parts of screen printing, and choosing the correct mesh fabric depends on your desired printing result. After getting a finished screen printing screen, how can we transfer the design from inkjet film to the screen printing screen?

Next, cover the screen printing screen with photosensitive emulsion and remember the entire wire mesh needs to be dried in a darkroom or in an environment free of ultraviolet rays. Then put the inkjet film tightly on the screen into the exposure unit to make the design transferred on the screen well. Thirdly, the excess parts are removed by using the scouring technology to present a clear image of the wire mesh. Finally, we will get a good plate after dried.

Step 3: Print

This step is most interesting part in screen printing process. Screen printing can use a variety of pre-mixed inks, among which the most common are water-based or water-soluble inks. Vacuum tables can help draw away air through fine holes, thus ensuring the flatness of the paper during the printing process. The screen is firmly fixed in the screen frame, and the four corners are fastened with screws to ensure that the screen does not shift during printing.

Before printing on the fabrics, we need to test first to confirm the print result of the design. During the printing process, newsprint or smoothed waste printed materials are often used as test paper to check whether the images are printed clearly. First, place the test paper at the predetermined position, and at the same time, move the screen to the appropriate printing position. Then scoop an appropriate amount of ink, places it at the bottom of the screen, gently lifts the screen, and uses a screen printing squeegee to evenly and smoothly apply the ink onto the screen. When the screen is in the printing position, exerts force with both hands while maintaining a 45° Angle of the squeegee. Next, lift the screen again to allow the ink to flow back slightly to ensure that the screen does not dry out. After completing these steps, the first printed matter can be obtained. Subsequently, the printed matter needs to be moved onto the dryer and the above process should be repeated until one round of printing work is completed.

In the printing process, printing color is a key link. When multiple colors need to be printed, special attention must be paid to the printing of the second color. To ensure the printing quality, transparent plastic film or acetate will be evenly adhered to the paper, so that the second color can be directly printed on the plastic film, maintaining the correct arrangement with the previously printed color.  After confirming the registration position, we can fix the guiding marks and start a new round of printing. This process will be repeated for each different color until the entire image is finally printed.

Step 4: Clean the screen

After printing, clean the screen is also important. When the ink is moist but not completely dry, evenly apply a large amount of plate remover over both side of the entire screen. After a few minutes of decomposition, the high-pressure water pipe was used to thoroughly rinse away all the photographic emulsion until the screen was completely clean, thus completing the entire process flow.