What Is Silk Screen?
一、 What is silk screen printing?
The screen printing process is also called the screen printing process, and the screen printing is a main printing method in orifice printing. It stretches silk fabrics, synthetic fabrics or wire mesh on the screen frame, and makes screen printing plates by hand engraving paint film or photochemical plate making, and makes the ink pass through the screen of the graphic part through the extrusion of the scraper. The holes are transferred to the substrate, resulting in the same graphics as the original.
Screen printing equipment is simple, easy to operate, easy to print and plate-making, with low cost and strong adaptability. Screen printing has a wide range of applications, and common printed materials include: color oil paintings, posters, business cards, bound covers, commodity signs, and printed and dyed textiles.
二、the advantages of screen printing
(1) Not limited by the size and shape of the substrate
General printing can only be carried out on a flat surface, but screen printing can not only be printed on a flat surface, but also on special shaped moldings such as spherical curved surfaces. Anything with a shape can be printed by screen printing.
(2) The layout is soft and the printing pressure is small.
Silk mesh is soft and elastic
(3) Strong coverage of ink dust.
Can be used for pure white printing on all black paper, with a strong three-dimensional effect.
(4) Suitable for various types of ink
(5) Strong resistance to optical rotation
Can make the gloss of the printed matter unchanged. (Temperature and sunlight have no effect) This makes printing some stickers without additional lamination and other processes.
(6) Flexible and diverse printing methods
(7) Plate making is convenient, cheap, and the technology is easy to master
(8) Strong adhesion
(9) It can be screen printed by hand or machine printed
(10) It is suitable for long-term display, and the outdoor advertisements are expressive
三、 Disadvantages of silk screen printing
1. It is difficult to screen-print multi-color patterns
Silk screen printing can only print one color at a time, which is well known. For multi-color printing, it is necessary to carry out complex and cumbersome color registration. Color registration has relatively high technical requirements. There are relatively few technical personnel in this area. It is better if there are fewer colors. If you need to print 4 or 5 colors at a time, It is inevitable that there will be inaccurate color registration. This increases the scrap rate of the product, and the cost increases accordingly. But like the pattern with more than 4 colors or gradient colors, silk screen printing is only far behind.
2. The cost of small batch proofing is high
Everyone knows that if you want to print a pattern in silk screen printing, you must have a set of processes that cannot be saved. That is plate making and film production. If the quantity is small, then these costs are quite high. Therefore, generally silk screen companies do not accept small jobs, mainly because the cost is too high.
3. Radian limit
Screen printing, this process can only be used for relatively flat products, if there are some bumps, it can’t be solved completely.
4. The amount of ink cannot be controlled
As we all know, some products need to keep their original state while printing, especially textile products. After printing, many customers want to keep the texture of textiles, which is difficult to do with silk screen printing.
四、the silk screen process
Screen printing consists of five major elements: screen printing plate, squeegee, ink, printing table and substrate;
Ink: divided into crude oil, diluent, curing agent, toner; screen printing ink is generally divided into UV ink and PU ink, PU ink is not wear-resistant, so it can only be printed on the primer, and then sprayed with topcoat for protection; UV ink is attached Both strength and wear resistance are relatively good, and it can be screen printed on the topcoat to greatly improve production efficiency. It is currently widely used in production.
五、 Bad screen printing and countermeasures
(1) Sawtooth burrs on the edge: 1. The screen itself is not fully developed. 2. The screen is not clear and the mesh is blocked. 3. The distance between the screen and the substrate, the angle of the scraper, and the printing pressure should be appropriate.
(2) Orange peel on the surface: 1. The viscosity of the ink is too high and the leveling is not good. 2. The distance between the screen and the substrate is too small, and the printing is not separated in time.
(3) Vibration and wear-resistant paint: 1. The printing thickness does not meet the requirements, 2. The baking is not complete, 3. The UV energy is too low.
