Why the screen plate between the substrates and like to leave a gap?
Silk screen printing and printing content to be kept a certain gap between is determined by the characteristic of silk screen printing office.Silk screen printing is silk screen version of the base, silk screen are strung on the net frame, when the screen in a state when a certain level of sag.Especially in the printing process, sag value will increase, in order to make the substrates at the time of scrapping printing at the end of the stick to ensure the quality of printing ink, screen plate must leave the lowest part of the substrates.In screen printing, scraper and the screen plate is mobility line contact, screen plate with the scraping board in prepress and post-press can't contact with the substrates, especially the silk screen plate left substrates with scraper movement, if the screen plate hand has not left before printing graphic part returned to a printing ink continue to penetration and diffusion caused by line size expansion, the dimensional precision printing fell, the distortion of substrates.
Screen to have a certain space between the plate and substrates, it also has close relationship with substrates movement forms, substrates when printing, especially in the forming surface (such as container) printing, printing substrates in printing at the same time will do circular motion.Have certain gap not cause substrates by deformation phenomenon such as fuzzy or lines.
How to determine the clearance between the substrates and silk screen printing plate?
It has talked about the silk screen plate between the substrates and why order must leave a gap when printing, but the size of the gap can't follow one's inclinations.Silk screen printing plate between the substrates and if the clearance is too small, prone to penetrate along scraper movement direction and glue phenomenon.If the gap is too big, can't recover after screen plate embossed, relaxation and prolapse, make the picture size is less than the silk screen after printing plate screen size.Serious which will make the silk screen plate breakage and cannot be printed.If is to use elastic small stainless steel screen will appear page contact less than the surface of the substrates to implement printing..
Determine the amount of clearance between screen printing and printing substrates mainly according to:
(1) the size of the screen plate size.
(2) the size of the stretch mesh tension.
(3) the center of the screen plate sag.
(4) the shape of the substrates.
(5) substrates of the nature of the material.
6 substrates surface morphology.
All landowners ink viscosity, etc.
Silk screen printing plate and the clearance between the substrates, because printing condition is different, and the clearance value is different.Generally on a less ink absorption ceramics, glass, metal surface, rigid plastic substrates, such as a hard object surface requirements for printing the clearance value is higher.For cloth, paper and ink absorption force soft plastic substrates, such as surface soft objects would not be so strict with printing gap value.Is presented, which is usually printed in the printing requirement gap value between 1-3 mm.For ordinary print its clearance for 2-6 mm.When surface printing clearance value is smaller, and print time interval values are larger.