Screen printing technology of the hottest TV plast

Wire printing technology of plastic shell of TV set

our factory uses wire printing technology to print words and patterns on plastic shells such as TV sets, remote controllers, CDs, monitors, etc. these printed objects have planes, curved surfaces and low spherical surfaces. I have been engaged in silk printing technology for 13 years and have accumulated some experience. These experiences are now introduced to comrades in the same industry for reference

1. ink preparation

Japanese Imperial ink and Toyo ink are commonly used by our factory; Good screen printing effect. It is said that imperial ink screen printing effect is better, while Toyo ink gravure printing effect is better. Before each screen printing, take a small amount of ink on the plate and dilute it with diluent. If the temperature is high or the climate is dry, 709 slow drying agent or benzyl alcohol slow drying agent should be added at the same time

how to judge the degree of thickening and thinning: the degree of thickening is better if there are no silk lines or drawing on the printing surface after the ink passes through the silk. The best way to dilute the ink is to put it on the silk, and the ink can pass through the hole by its own weight without dripping. When the printing line is thin, it should be thinned, otherwise, it should be thickened

2. choose

silk cloth to strengthen the quality of law enforcement in key areas, with Switzerland as the best. Its wire diameter is uniform, the mesh number is accurate and consistent, and the wire quality is stable. And the Japanese Murakami silk market used by our factory is also good

the mesh selected by our factory is 450 ~ 500 mesh. For the substrate with fine line, high ink fineness and poor absorption, the version with high mesh number should be selected, on the contrary, the version with low mesh number should be selected

during plate making, the position and size of graphics and text on the plate should be determined according to the structure and size of the substrate and the position of graphics and text on the substrate. If the design is not good, it will affect the quality of silk screen printing, or even unable to silk screen printing. In addition, it is better to use one plate to print the pictures and texts on the same printed object. If printing is divided into more than two plates, more processes will reduce the screen printing qualification rate. Make the rough measurement of cable fault enter a new situation

3. Scraper selection

the material of scraper used by our factory in the foreseeable future is polyurethane. Polyurethane rubber scraper has good wear resistance, solvent resistance and resilience. Its hardness is 60 ~ 80 shore. For the substrate with large plate tension and good surface flatness, a scraper with high hardness should be selected. On the contrary, the one with low hardness should be selected

when printing on curved surface, low spherical surface or substrate with poor flatness (local bulge), the width of scraper should be narrow rather than wide

4. version positioning

the fixture materials used by our factory include metal, wood, plywood, PVC transparent sheet. If it is difficult to locate and the size of the substrate is small, metal fixtures should be used

if the image and text are close to the edge of the substrate, a flat wood as high as the edge of the substrate should be fixed next to the substrate to avoid easy pasting of the image and text

the distance is generally 1.0 ~ 2.5mm. If the printing pattern is easy to paste or there are lines, the spacing should be increased

5. Silk screen printing process

the wrong interface may damage the equipment; If the scraping pressure is high, the ink output is large, but the version is easy to deform, so the scraping pressure should not be high. The scraping speed is usually 60 ~ 200mm/s. The scraping speed is fast, the ink output is small, but it is not easy to block. Therefore, the printing ink that is easy to block should be scraped faster

there are three scraping routes: straight line, oblique line and curve. It should be selected according to the flatness of the substrate and the distribution of graphics and text on the substrate

when the scraping route is long and the ink consumption is large, the scraping amount should be more, or even scrape a layer of ink before scraping

the silk printing experience introduced in this paper is not only applicable to the substrate of TV plastic shell, but also applicable to the silk printing on other hard plastic shells

I think the most common quality problems of silk printing are missing words and paste words. Therefore, once this problem occurs, it can also be solved from the above five aspects