Screen-printing is the most flexible printing process. It can be used to
print on a wide variety of substrates, including paper, paperboard,
plastics, glass, metals, fabrics, and many other materials including
paper, plastics, glass, metals, nylon and cotton. Some common products from
the screen-printing industry include posters, labels, decals, signage,
and all types of textiles and electronic circuit boards. The advantage
of screen-printing over other print processes is that the press can
print on substrates of any shape, thickness and size.
An important characteristic of screen-printing is that a greater thickness of ink can be applied to the substrate as compared to the other printing techniques. This allows for various interesting effects that cannot be achieved through the other printing methods. Because of the simplicity of the application process, a wider range of inks and dyes are available for use in screen-printing than for use in any other printing process.
Utilization of screen printing presses has begun to increase because production rates have improved. This has been a result of the development of the automated and rotaryscreen printing press, improved dryers, and U.V. curable ink. The major chemicals used in screen-printing include screen emulsions, inks, and solvents, surfactants, caustics and oxidizers used in screen reclamation
Overview of the Screen Printing Process Screen-printing consists of three elements
Many factors such as composition, size and form, angle, pressure, and speed of the blade (squeegee) determine the quality of the impression made by the squeegee. At one time most blades were made from rubber, which, however, had a tendency to warp and distort. While blades continue to be made from rubber such as neoprene, most of them are now made from polyurethane, which can produce as many as 25,000 impressions without significant degradation of the image.
If the item is to be printed on a manual or automatic screen press the printed product will be placed on a conveyor belt, which carries the item into the drying oven or through the UV curing system. Rotary screen presses feed the material through the drying or curing system automatically. Air-drying of certain inks, though rare in the industry, is still sometimes utilized.
The rate of screen-printing production was once dictated by the drying rate of the screen print inks. As a result of improvements and innovations in the printing technology, the production rate has greatly increased. Some specific innovations, which affected the production rate and have also increased screen press popularity include:
Once the artwork is transferred to a positive image that will be chemically processed onto the screen fabric (applying the emulsion or stencil) and eventually mounted onto a screen frame that is then attached to the printing press and production begins
An important characteristic of screen-printing is that a greater thickness of ink can be applied to the substrate as compared to the other printing techniques. This allows for various interesting effects that cannot be achieved through the other printing methods. Because of the simplicity of the application process, a wider range of inks and dyes are available for use in screen-printing than for use in any other printing process.
Utilization of screen printing presses has begun to increase because production rates have improved. This has been a result of the development of the automated and rotaryscreen printing press, improved dryers, and U.V. curable ink. The major chemicals used in screen-printing include screen emulsions, inks, and solvents, surfactants, caustics and oxidizers used in screen reclamation
Overview of the Screen Printing Process Screen-printing consists of three elements
- The screen which is the image carrier
- The squeegee
- Ink
Many factors such as composition, size and form, angle, pressure, and speed of the blade (squeegee) determine the quality of the impression made by the squeegee. At one time most blades were made from rubber, which, however, had a tendency to warp and distort. While blades continue to be made from rubber such as neoprene, most of them are now made from polyurethane, which can produce as many as 25,000 impressions without significant degradation of the image.
If the item is to be printed on a manual or automatic screen press the printed product will be placed on a conveyor belt, which carries the item into the drying oven or through the UV curing system. Rotary screen presses feed the material through the drying or curing system automatically. Air-drying of certain inks, though rare in the industry, is still sometimes utilized.
The rate of screen-printing production was once dictated by the drying rate of the screen print inks. As a result of improvements and innovations in the printing technology, the production rate has greatly increased. Some specific innovations, which affected the production rate and have also increased screen press popularity include:
- Development of automatic presses versus hand operated presses, which have comparatively slow production time.
- Improved drying systems, which significantly improve production rate.
- Development and improvement of U.V. curable ink technologies
- Development of the rotary screen press, which allows continuous operation of the press. This is one of the recent technology developments.
Screen Preparation
Screen (or image transfer) preparation includes a number of steps. First the customer provides the screen printer with objects, photographs, text, ideas, or concepts of what they wish to have printed. The printer must then transfer a "picture" of the artwork (also called "copy") to be printed into an "image" (a picture on film) which can then be processed and eventually used to prepare the screen stencil.Once the artwork is transferred to a positive image that will be chemically processed onto the screen fabric (applying the emulsion or stencil) and eventually mounted onto a screen frame that is then attached to the printing press and production begins