Fineness of the ink is an important indicator directly related to the rheological properties and economic benefits of the ink. Fineness generally refers to the extent to which solid powdered substances such as pigments and fillers mixed in a binder are dispersed. The ink is too thick, which can cause prints to be destroyed or stenciled, and is not suitable for high-grade prints with finer printed wire. Finer inks with finer pigments have higher coloring power than those with finer fineness.
At present, the method for detecting fineness of ink in domestic companies is mainly based on scraper fineness metering. The following uses offset printing ink as an example.
Take a certain amount of ink on the glass plate, add a certain proportion of No. 6 oil according to the size of the ink fluidity, and use the ink-adjusting knife to adjust the uniformity and place the evenly-distributed ink in the depth of the groove on the scraper fineness meter. Place, then use the thumb and heavy finger of both hands to hold the blade, vertically across the ink in the depth of the groove of the scraper, scrape the blade from the top down to the shallowest position of the scraper, immediately scraper The instrument surface is inclined at a 30 degree angle to the light source, and the ink fineness is observed.
In the inspection process, due to instrumental error, human error, and environmental conditions, the same factors often cause ink fineness detection, there is a dispute between the production control company and the company quality center, the company quality inspection center and the printing plant. . How to measure the fineness? In other words, what are the main factors that affect the fineness test results?
First, the impact of scraper fineness meter Scratch fineness meter can be measured to the Institute of Technology (institute) for verification. The company-level quality inspection center, production control inspection, and printing factory all have several scraper fineness gauges, which are regularly replaced due to frequent use, and generally only a scraper fineness meter at the company's quality testing center is sent for inspection. Then pass on other scraper fineness gauges.
Scraper fineness meter is composed of scraper and scraper.
1. Scraper scraping accuracy:
(1) The plane flatness on the squeegee is 0.003 mm.
(2) The flatness of the bottom plane of the chute is 0.003 mm.
The squeegee was calibrated using an optical comparator. However, the users of the scrabble meter did not have an optical comparator. Usually, they were only tested at the factory. Check the plane flatness on the chaos for a limited number of points. A certain micrometer scale line plane is 0 μm, and the groove depth is measured; another micrometer scale line plane is 0 μm, another groove depth is measured, and so on. There are two things to note:
(1) Whether the micrometer number of the reference plane of any micrometer scale line is 0μm, in short, whether the two sides of the squeegee groove are plane? Producers generally talk about how to grind the plane and ensure that the plane error is within the number of users and bring the user to the wrong zone. There are simple ways to overcome.
Using the method described above, use a calibrated scraper to scrape the adjusted ink from top to bottom. If the two sides can scrape off the ink, generally the surface is considered to be flat; if the scraped surface is adjacent to the edge of the groove Can scrape clean, away from the groove surface position is not judged as medium high; the other hand is concave. If there is a pattern on the surface of both sides of the scraper, the surface on the scraper is not a flat surface.
(2) Assume that the surface of the squeegee is flat, and the flatness of the bottom plane of the chute is 0.003mm. For ink workers, the acceptable error whether the plane flatness on the squeegee or the flatness of the bottom of the chute is acceptable ≤± 1μm. The ideal squeegee instrument except for the middle groove, the surface of the entire squeegee is a plane, the zero point is trimmed, and the error between the groove depth and the marked value of each point does not exceed ±1 μm. Even if the fineness value is within the allowable range, there is an error.
2. Scraper Scraper Accuracy: Scraper two blades straightness 0.002mm.
In order to achieve the blade straightness index, some manufacturers grind the knife edge into facets perpendicular to the blade. Although the flatness of this knife reaches the target, but the detection can only scrape the ink when the knife edge is completely vertical, and other angles are not applicable. In severe cases, the ink on the two sides of the clear groove is not scraped, which is the kind of "full house" scraper. Using this squeegee can not get accurate test results. (To be continued)
At present, the method for detecting fineness of ink in domestic companies is mainly based on scraper fineness metering. The following uses offset printing ink as an example.
Take a certain amount of ink on the glass plate, add a certain proportion of No. 6 oil according to the size of the ink fluidity, and use the ink-adjusting knife to adjust the uniformity and place the evenly-distributed ink in the depth of the groove on the scraper fineness meter. Place, then use the thumb and heavy finger of both hands to hold the blade, vertically across the ink in the depth of the groove of the scraper, scrape the blade from the top down to the shallowest position of the scraper, immediately scraper The instrument surface is inclined at a 30 degree angle to the light source, and the ink fineness is observed.
In the inspection process, due to instrumental error, human error, and environmental conditions, the same factors often cause ink fineness detection, there is a dispute between the production control company and the company quality center, the company quality inspection center and the printing plant. . How to measure the fineness? In other words, what are the main factors that affect the fineness test results?
First, the impact of scraper fineness meter Scratch fineness meter can be measured to the Institute of Technology (institute) for verification. The company-level quality inspection center, production control inspection, and printing factory all have several scraper fineness gauges, which are regularly replaced due to frequent use, and generally only a scraper fineness meter at the company's quality testing center is sent for inspection. Then pass on other scraper fineness gauges.
Scraper fineness meter is composed of scraper and scraper.
1. Scraper scraping accuracy:
(1) The plane flatness on the squeegee is 0.003 mm.
(2) The flatness of the bottom plane of the chute is 0.003 mm.
The squeegee was calibrated using an optical comparator. However, the users of the scrabble meter did not have an optical comparator. Usually, they were only tested at the factory. Check the plane flatness on the chaos for a limited number of points. A certain micrometer scale line plane is 0 μm, and the groove depth is measured; another micrometer scale line plane is 0 μm, another groove depth is measured, and so on. There are two things to note:
(1) Whether the micrometer number of the reference plane of any micrometer scale line is 0μm, in short, whether the two sides of the squeegee groove are plane? Producers generally talk about how to grind the plane and ensure that the plane error is within the number of users and bring the user to the wrong zone. There are simple ways to overcome.
Using the method described above, use a calibrated scraper to scrape the adjusted ink from top to bottom. If the two sides can scrape off the ink, generally the surface is considered to be flat; if the scraped surface is adjacent to the edge of the groove Can scrape clean, away from the groove surface position is not judged as medium high; the other hand is concave. If there is a pattern on the surface of both sides of the scraper, the surface on the scraper is not a flat surface.
(2) Assume that the surface of the squeegee is flat, and the flatness of the bottom plane of the chute is 0.003mm. For ink workers, the acceptable error whether the plane flatness on the squeegee or the flatness of the bottom of the chute is acceptable ≤± 1μm. The ideal squeegee instrument except for the middle groove, the surface of the entire squeegee is a plane, the zero point is trimmed, and the error between the groove depth and the marked value of each point does not exceed ±1 μm. Even if the fineness value is within the allowable range, there is an error.
2. Scraper Scraper Accuracy: Scraper two blades straightness 0.002mm.
In order to achieve the blade straightness index, some manufacturers grind the knife edge into facets perpendicular to the blade. Although the flatness of this knife reaches the target, but the detection can only scrape the ink when the knife edge is completely vertical, and other angles are not applicable. In severe cases, the ink on the two sides of the clear groove is not scraped, which is the kind of "full house" scraper. Using this squeegee can not get accurate test results. (To be continued)
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