Introduction of Silk Screen Process

 The membrane switch production process is closely linked to the screen printing process. Membrane switches use screen printing as the main process method, one of the few independent screen printing products that can serve the high-tech field.

Here are the advantages of silkscreen printing:

(1) Not limited by the size and shape of the substrate

(2) Strong anti-rotation performance

(3) Soft layout and small pressure

(4) Flexible printing methods

(5) Strong coverage of ink layer

(6) Strong adhesion

(7) Suitable for various types of ink

(8) Suitable for long-term display, the outdoor advertising is expressive

Today, we are going to introduce the working principle of silk screenprinting and its distinguishing characteristics.

Working Principle

Screen printing is composed of five major elements, namely, screen printing plate , squeegee, ink , printing table and substrate. The basic principle of screen printing is to use the basic principle that the screen printing plate's graphic part has a mesh through ink, and the non-graphic part is impervious to ink. When printing, pour ink on one end of the screen printing plate, and use a squeegee to apply a certain pressure on the ink position on the screen printing plate while moving toward the other end of the screen printing plate. The ink is squeezed from the mesh of the graphic part to the substrate by the scraper while it is moving. Due to the viscosity of the ink, the imprint is fixed within a certain range. During the printing process, the squeegee is always in line contact with the screen printing plate and the substrate, and the contact line moves with the movement of the squeegee, due to the screen printing plate and the substrate A certain gap is maintained between them, so that the screen printing plate during printing produces a reaction force against the squeegee through its own tension. This reaction force is called resilience. Due to the effect of resilience, the screen printing plate and the substrate are only in mobile line contact, while other parts of the screen printing plate and the substrate are in a separated state. The ink and the screen are broken to ensure the printing dimensional accuracy and avoid smearing the substrate. When the squeegee is lifted after scraping the entire layout, the screen printing plate is also lifted, and the ink is gently scraped back to the original position. So far is a printing trip.

Distinguishing characteristics

Strong printing adaptability

The three printing methods of flat printing, embossing, and gravure printing generally can only be printed on flat substrates. And screen printing can not only print on flat surfaces, but also print on curved, spherical, and concave-convex substrates. On the other hand, screen printing can not only print on hard objects, but also on soft objects, without being restricted by the texture of the substrate. In addition, in addition to direct printing, screen printing can also be printed by indirect printing according to needs, that is, screen printing on gelatin or silicone plate first, and then transfer to the substrate. Therefore, it can be said that screen printing is highly adaptable and has a wide range of applications.

Strong three-dimensional

The thickness of the ink layer for offset printing and embossing is generally 5 microns, the thickness of the ink layer for gravure printing is about 12 microns, the thickness of the ink layer for flexographic (flexographic) printing is 10 microns, and the thickness of the ink layer for screen printing far exceeds the above ink. The thickness of the layer is generally about 30 microns. Thick screen printing for special printed circuit boards. The thickness of the ink layer can reach 1000 microns. The braille is printed with foaming ink, and the thickness of the ink layer can reach 1300 microns after foaming. The screen printing ink layer is thick, the printing quality is rich, and the three-dimensional effect is strong, which is incomparable with other printing methods. Screen printing can not only print in monochrome, but can also perform color printing and screen color printing .

Strong light resistance

Bright color. Because screen printing has the characteristics of missing printing, it can use various inks and coatings, not only can use pastes, adhesives and various pigments, but also coarser particles. In addition, the screen printing ink formulation method is simple, for example, the light-resistant pigment can be directly put into the ink for formulation, which is another major feature of screen printing. Screen printing products have a great advantage of strong light resistance. Practice has shown that according to the maximum density value range measured after using black ink on coated paper for one impression, offset printing is 1.4, embossing is 1.6, gravure printing is 1.8, and the maximum density value range of screen printing can be Up to 2.0, so the light resistance of screen printing products is stronger than that of other types of printing products, and it is more suitable for outdoor advertising and signs.

Large printing area

Generally, the maximum size of the area printed by printing methods such as offset printing and embossing is the full-sheet size. If it exceeds the full-sheet size, it is limited by mechanical equipment. While screen printing can print large areas, today's screen printing products can reach a maximum range of 3 meters × 4 meters, or even larger.

The above four points are the differences between screen printing and other printing, as well as the characteristics and advantages of screen printing. Understand the characteristics of screen printing, in choosing printing methods, you can maximize the strengths and avoid weaknesses, highlight the advantages of screen printing, and achieve a more ideal printing effect.

Thinking about high-tech screen printing

Screen printing is integrated into high-tech membrane switch manufacturing technology. In addition to the above, there are also many new content that are different from traditional screen printing, such as computer-aided design (CAD) and manual wiring design of membrane switch circuits; isolation The design of the layer window and the air guide groove; the application of insulating ink and its ultraviolet (UV) curing; the application of non-metallic conductor carbon paste; the working environment of the membrane switch with the high-tech computer numerical control (CNC) electronic autofocus precision punch and storage environment. Obviously we should be based on the working environment and storage environment of the membrane switch. Obviously, we should consider the structural design and material selection of the membrane switch according to the working environment and storage environment of the membrane switch.

Today's screen printing has developed into a new modern screen printing technology that integrates high and new technologies such as optics, mechanics, electricity, chemistry, photochemistry, microelectronics, and computers.

Membrane switch technology has not only the color reproducibility and ink color rendering that traditional screen printing pay attention to in the production of its panel layer, which is the decorative function of traditional screen printing, but also the circuit in the production of its circuit layer. The high-tech content is obvious for the conductive performance of the silver paste circuit, the prevention of the oxidation of the silver paste circuit and the migration of silver ions, the production of multi-layer interchange circuits and the reliability of membrane switch products.