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Silk screen printing may appear net template ricochet off substrates, part of the screen grain ink will follow web version of wool cloth with soft nap of "silk" was pulled from the substrates, floating.When the screen continue to push up, it is the "silk" before and after the wind drift were spattering on the substrates, the substrates surface smearing, texture edge is not sharp.This kind of phenomenon is very annoying is any printing workers don't want to see, this is a static phenomenon.

In the compact disc printing, silk screen printing is a so-called relative movement and scraping plate through the screen mesh in a certain blow pressure transfer ink to a process on the substrates.The network version (screen) and scraping board blow (polyurethane) is an insulator, they do on location in the screen printing relative shift rub against each other, especially in a low humidity will generate static electricity affect the substrates of surface charge distribution state. Especially insulation materials, such as cd-rom with PC substrate, touch the PET sheet, as well as the name on the medallion, advertising the use of PVC, PP, PE plastic bottles, and so on basic belongs to the insulator, they once do not pay attention to in the operation of the screen printing will produce static electricity.Such as screen printing ink membrane switch decoration, because PET film base after production, surface layer of PVC dry film on its surface protection, such as to make it from scratch in the cutting, packaging, and so on.

But the material must be stripped before screen printing after the protective film, often some of the operators when torn off the protective film exposed film very fast, what does not know it at the moment of this quick jie film, protective film and PET especially under the low humidity in the process of fast separation of PET produce electrostatic surface, the results on the screen printing ink on the edge of the handwriting FeiMao, and sinks down on transparent PET sheet shape of wool cloth with soft nap on the pattern of the ink silk and so on quality issues.This is a typical example, screen printing workshop of membrane switch units have much confusion.

One, because of the existence of static electricity, because in the printing production difficulties caused by static electricity, etc for the body, in the screen printing performance are:
1. Screen printing after wide imprinting on ink is plush pull up together as screen, artifacts "FeiMao" out with the ink silk had broken phenomenon;
2. Overprint, color before and after the color ink word edge and texture edge are mutually exclusive, not a good match, not between the two color ink printed ink;
3. The screen printing, workpiece stuck on the screen, especially stick to the scraper to move the end the screen position;
4. The substrate together;
5. Scrapping printing process, the ink on the screen smooth, agglomerate together.
6. Substrates dust absorption, screen printing ink to produce defects, pitting, rough surface is not smooth, etc

Above problems are mainly the existence of static electricity, but sometimes in electrostatic exist at the same time is also associated with printing process do not meet the requirements.

For example: when in low humidity environment and ink solvent quantity shortage, on the one hand, low humidity electrostatic cannot be passed on the moisture in the air, less ink solvents at the same time, the viscosity, the viscosity of the ink itself with such chance natural produce wire drawing;Again, such as in the process of silk screen printing speed is accelerated, the scraping plate and screen strongly friction generates static electricity.

Especially under the condition of high tension network edition, polyurethane scraping scraping pressure on the screen move speed and fast, can cause the occurrence of electrostatic, most people say triboelectrification, is this truth.

Screen printing because of the existence of static electricity can cause a lot of quality problems, and even make printing can't continue, so the electrostatic and how to avoid and eliminate screen printing?

First from process conditions to control the screen itself, under the network version of high tension, as far as possible to reduce network distance.Network distance is reduced, the pressure of the scraper is reduced, scraping the surface mesh version of the friction reduce the possibility of electrostatic generation.

In cd-rom screen printing, in order to ensure accuracy and reduce the printing grain texture of turtle grain and overprint text accurately on at the same time to avoid static electricity production, so the disc tension up to 26 n/cm, while net from small to around 1.0 mm.If the screen printing in the above conditions may also appear small static, this time can be adjust can avoid scrapping printing speed.

The matching screen printing environment conditions, screen printing is better printing environment temperature in 23 ℃ + 2 ℃ relative humidity of 60% ~ 70%, the solvent ink solvent volatilization of speed control, good for UV light solid ink viscosity good control, stability of the ink viscosity, can satisfy the ink printing eligibility, printing ink printing eligibility good can not be because of the ink itself appear wiredrawing phenomenon.

More than two, if get control of technical conditions, then the power to control methods are:
1. The workpiece itself has been charged.At this point, you can use in addition to static brush, or in addition to electrostatic cloth in front of the screen printing on the surface to deal with the electricity.Method is very simple: use in addition to electrostatic brush to brush the workpiece or use to electrostatic cloth to wipe the surface of workpiece, a direction after processing can print.
2. Screen printing plastic workpiece with static electricity.Prior to adding antistatic agent in the plastic recipe, which requires the production of plastic raw materials suppliers.
3. It can also be in with electrostatic surface of workpiece increase a coating of antistatic coating method to eliminate static electricity.
4. The rational use of ink solvents.Even if the ink solvent mixture performance is good, and good electrical conductivity solvent deployment of ink viscosity.
5. Increase the artifacts from the screen printing equipment grounding, make its release and eliminate static electricity charge.
6. In the absence of control measures of wet screen printing workshop, increase to the ground water in low humidity season surplus, China local surface evaporation process printing environment humidity regulation.This method in the absence of damping device, crude production unit with more, it besides damping, as well as control of dust prevention role.

In a word, for the generation of static electricity and eliminate should according to the specific circumstances and conditions analysis and the corresponding measures, make the printing work under ensure the quality of products can convenient and smoothly continue.

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