Definition of screen printing

Screen printing, also known as screen printing, is a printing technique that is often used in the field of textile printing. It is a process in which ink is transferred to the material to be printed through a fine-mesh fabric (screen). This mesh is traditionally made of silk, but nowadays other materials such as polyester or nylon are also used.

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The screen printing process

1. Preparation of the screen: A fine-mesh fabric is stretched on a frame and then the screen is covered with a light-sensitive coating.
2. Exposing the screen: A design is printed on a transparent film and placed on the prepared screen. The screen is then exposed to light, making the exposed areas harder and the unexposed areas softer.
3. Development of the screen: The screen is washed to remove the soft, unexposed areas and to create the print openings.
4. Preparation of the printing process: The prepared screen is placed over the material to be printed (e.g. a piece of textile) and ink is applied to the screen.
5. Printing: The ink is drawn over the screen with a squeegee, so that it only reaches the material through the open printing holes.
6. Drying: After the printing process, the printed material is dried to fix the ink.

Advantages of screen printing

High durability: Screen printing produces robust and long-lasting prints.

High ink coverage: Vivid and clear prints can be achieved even on dark or colored backgrounds.

Cost-effectiveness in mass production: The use of specially manufactured screens and machines means that large quantities can be produced efficiently and cost-effectively.

Disadvantages of screen printing

Limited attention to detail: Fine lines, complex patterns or subtle color transitions cannot be reproduced as precisely as with digital printing.

Higher set-up costs: Screen printing requires the production of special screens for each design and color.

Not economical for short runs: Due to the higher set-up costs, screen printing is not economical for short print runs or single prints.

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Equipment required for screen printing

1. Screen: A fine-mesh screen made of metal or plastic on which the design to be printed is created. The screen is coated with a light-sensitive emulsion.
2. Exposure unit: An exposure unit is used to transfer the design onto the screen. This exposes the screen with UV light through a positive template of the design.
3. Squeegee: A squeegee is used to spread the ink evenly over the screen onto the material to be printed. There are different types of squeegees, including rubber blades of varying degrees of hardness.
4. Screen printing ink: Special inks for screen printing that are matched to the material to be printed. There are different types of screen printing inks, including water-based, solvent-based or UV-curing inks.
5. Printing table or printing machine: A printing table or printing machine is used to stabilize the material to be printed and to facilitate the printing process.
6. Drying device: After the printing process, the printed materials must be dried. A drying device or drying station speeds up this process.
7. Cleaning chemicals: Special chemicals are required to clean the screens after the printing process and prepare them for the next use.

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Time required for screen printing

The time required for screen printing depends on various factors, including the complexity of the design, the number of colors, the drying time and the production quantity. A simple design with few colors can be printed relatively quickly, while complex designs with many colors and intricate details can take more time. Screen setup and exposure time can also affect the overall time required. Overall, screen printing can be more time consuming than some other printing techniques, especially when it comes to short runs or customization.