The most obvious impression of prints is their color, vividness, and authenticity of reflection. Except for the structure of the pattern and the level of printing, almost all of them are expressed by color. Because there are a lot of printing plants, printing a fixed product every month requires that the color of the ink be the same, otherwise it will lead to inconsistencies in the color of printed materials. Therefore, the inspection of the ink color is very important. There are two main ways to detect ink color: The conventional test method is a method of parallel observation and comparison by the person's eyes on the target (quasi-) and test (inspection) samples. This method is relatively simple, but it cannot be represented by numbers. The tristimulus value can be measured by the instrument method and used to calculate the main wavelength, purity and brightness in the CIE system or the hue chroma and brightness in the Munsell system, and can also be represented by the color difference data through calculation; Next, introduce the instrument inspection method: (1) Tools and Materials a, small tune ink knife; b, squeegee; c, scraping paper (or printed with a black cross, length 11 cm, width 6.5 cm). d, colorimeter (such as CS-200, CS-210, CS-220) (2) Inspection method: a. Take a small quantity of standard sample and a small amount of ink sample, place each sample on a glass plate and mix it thoroughly. Then use a small adjustment key to take a small amount of the standard sample on the upper left side of the scratch paper, and then take a small amount of the sample. At the top right, the two should be adjacent and not connected. b. Use a squeegee knife to force the ink to form a thin layer from the top to the bottom of the sample paper. After scraping it to 3 to 5 centimeters, the squeegee is gradually leveled (that is, the angle formed with the paper becomes smaller). The small pressure causes the ink to coat a thicker layer of ink on the paper. c. After the ink layer is cured, measure the color information of the sample and the standard with a color difference meter to obtain the difference between the two. (3) Precautions: a. Scratching is one of the important basic functions of ink makers and inspectors. Thin and highly fluid inks are easier to scrape. Thick (thick) and high viscosity inks are not easily scratched. Thick, short and rough inks have an untidy shape (which is often the case for engraved gravure inks), making them look ugly. b. When the blade of the blade is sharp, the ink layer scraped on the paper is relatively thin. On the contrary, the ink layer scraped is thicker. c. When the thin ink is scraped, the angle of the knife can be smaller to ensure that the scraped ink layer is thicker. When scraping thick sticky inks, the angle of the knife should be made larger so that the ink remaining on the paper is thinner. d. The quality of the paper has a great influence on the scratching. It is generally appropriate to use a paper with a uniform fiber and a smooth surface, or a high-grade forest paper. The color of the paper should be neutral white, no fluorescence, no watermark. Internationally, the background color generally refers to the color of a thin layer of ink printed on paper. The complexion refers to the color of the thick layer ink; e. Solvent-based inks can also be sampled by this method, but they can also be sampled using a wire rod method. f, lithographic ink and letterpress ink focus on the face color and background color; mesh version of the ink, gravure ink focus on the face color and ink. g, in order to more accurately view the color, you can use the printability test implementation (for example, IGT printability testing machine and RI-1 type printability testing machine) after printing and judge it. Coating Service,Metal Spray Coating,Flame Spray Coating,Thermal Spray Coating Luoyang Golden Egret Geotools Co., Ltd , https://www.xtc-thermalspray.com
One is the instrument inspection method; it is measured by colorimeter, spectrophotometer and other instruments.
A conventional inspection method is to apply ink to a base material for comparison and judgment.