Bar code printing technology for the hottest plast

Complete solution of bar code printing technology for plastic packaging (IV)

III. common faults and solutions in bar code plastic gravure printing

the common faults introduced below are minor defects for packaging and printing other than bar codes if the faults are not serious. However, for bar code printing, even a slight defect will directly affect the reading effect, and measures must be taken to avoid it. Therefore, in a certain sense, it can be said that bar code printing is better than the compressive strength test of iron ore pellets in other parts? Brush requirements are more stringent

1. knife line

the so-called knife line refers to that the ink of the part without pattern lines on the layout is not scraped clean and transferred to the printed matter, and linear pollution occurs in the place where ink is not allowed (producing an ugly Silk Road). Generally speaking, this kind of failure will occur after printing for a period of time and a certain number of prints. Printing ink, printing plate roller and scraper are the three main factors that affect the printing knife line. Environmental printing conditions also have a certain impact on the printing knife line

reason:

(1) it is closely related to the fineness and quality of the ink (scraper suitability). This phenomenon is lighter for high-grade inks and heavier for low-grade inks. Impure substances, coarse particles and foreign matters in the ink can lift the knife or damage the scraper, which can form a knife line

(2) the finish and chrome plating quality of the plate roller are poor

(3) the machining accuracy of the master roll is not enough. When the master roll rotates, eccentricity will impact the scraper and become the cause of the knife line. At this time, you need to reinstall or correct

(4) the scraping state of the scraper is poor

(5) the viscosity of the working ink is too large. The printing ink of the layout is too dry, and the friction between the version roller and the scraper is relatively increased, making it difficult for the scraper to scrape off the printing ink of the layout. (when the drying is too late, the trace ink attached to the non drawing part of the version roller will be transferred to the film to form version dirt)

(6) adhesion of hard objects on the plate of the plate roller will directly damage the scraper, which should be checked and wiped frequently

(7) environmental conditions. When the humidity is too high, the ink dispersion becomes poor, and the printing plate is not easy to scrape clean. When the humidity is too small (dry), the plastic film absorbs dust due to static electricity (dust falling into the ink will directly damage the scraper and the layout), both of which will cause knife lines. When the ambient temperature is too high, the volatilization is too fast, and the solvent balance is unbalanced; When the ambient temperature is too low, the ink dissolves poorly, causing difficulty in scraping

in a word, many factors affecting the printing knife line are interrelated. They can directly hurt the knife, damage the plate of the plate roller first, and then damage the scraper, or foreign matters enter between the scraper and the plate roller to lift the scraper locally, and it is very easy to appear at the same time with the fuzzy phenomenon of the plate, so it is difficult to judge whether the failure is caused by the ink, scraper or page factors. Jinan new era Gold Testing Instrument Co., Ltd. has its own independent production and independent R & D department, The solution cannot be specified. However, when the printing ink, substrate and printing equipment are determined, the following methods are generally considered to be effective

solution:

(1) try to reduce the viscosity of the ink, so that the scraper can easily scrape off the ink in non picture parts

(2) prevent foreign matters from mixing in during printing (filter with metal, cloth, etc.)

(3) try to improve the proportion of fresh ink. "This is the first time that carbon fiber is widely used in mass production vehicles.

(4) confirm whether the plate roller is eccentric. The diameter of the printing plate roller should be avoided to be too large or too small, so as to control the state of ink transfer in the hole of the plate roller.

(5) adjust the scraper (grinding, pressing, hardness, thickness and high gloss. The use of Plexiglas material panel is also becoming more and more extensive, angle, position, etc.) Check whether the scraper is installed smoothly and evenly

(6) confirm the surface state of chrome plating (when sandpaper is invalid, re chrome plating is also a way)

(7) slow drying solvent can be used in light cases

(8) add an appropriate amount of activity retarder

(9) the printing workshop shall maintain proper temperature and humidity

(10) clean the ventilation duct in time to reduce the impact of dust

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