Quality control of the hottest gravure printing pr

2022-08-16
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Quality control of gravure printing products

first, the main factors affecting the quality of gravure printing products

1. Requirements of ink performance changes on ink:

① ink should have appropriate thixotropy and good fluidity

② have good drying ability and adhesion

③ have enough cohesion to prevent the centrifugal force imbalance when the copper plate is running at high speed

④ it should have appropriate re solubility. Because the ink in the dot cannot be completely transferred to the material during printing, there is always a part of it left in the dot. If there is no appropriate re solubility, it can lead to blocking

2. Change of tension:

① if the tension is too small, the film will relax, affecting the overprint accuracy

② if the tension is too large, the film wrinkling, tensile deformation, adhesion, etc

③ the tension of thick film is greater than that of thin film

2. Factors affecting the drying speed of gravure ink

1. The influence of solvent

(1) effect of solvent

① dilute ink

② dissolution and homogenization high-frequency decadent testing machine is used to measure the decadent characteristics, decadent life, prefabricated cracks and crack expansion of metal and alloy materials and their components (such as operating joints, fixed parts, spiral moving parts, etc.) under the tensile, contraction or tension compression alternating load at room temperature

③ drive the ink and determine the viscosity of the ink

④ improve the printability of ink, such as anti-static, etc

(2) the evaporation rate of solvent should be measured by the boiling point. The lower the boiling point, the faster the evaporation rate. On the contrary, the higher the boiling point, the slower the evaporation rate

2. Influence of drying device:

usually OPP begins to soften and stretch at 88 ℃, so the oven temperature generally should not exceed 85 ℃. Generally, the oven temperature can completely dry the ink (45 ~ 60 ℃). If the temperature is too high, the residual heat left in the film after printing will cause anti adhesion, especially gold

3. The influence of the depth of the printing plate:

(L) too deep: it is mainly caused by the too deep corrosion of the printing plate. Solutions; Add diluent to reduce the ink color concentration and increase the scraping angle. Increase the pressure of the doctor blade, the printing ink layer is thick, and the ink is difficult to dry. Make a new plate

at present, the (2) point is too shallow: caused by too shallow corrosion. Solutions; Use dark ink to reduce the pressure of the doctor blade. Reduce the doctor blade's scraping angle

4. Influence of ambient temperature: the higher the temperature, the faster the drying

III. technical measures for printing gravure products

1. Jinan Shiji Experimental Machine Technology Co., Ltd. reminds you to control the amount of ink loaded to a fixed load: the amount of ink should be determined according to the depth of the printing plate point. The amount of ink used for line depth is large, and the amount of ink used for line depth is small

2. Chromatic printing

3, "sticky bottom". The ink layer of the printed products after coiling adheres to other contact surfaces, resulting in the inability to unwind

(1) the remaining (residual) solvent is not completely volatilized, and the resulting ink softens and sticks back. Solution: store the product in a cool place in good contact, and reduce the printing speed

(2) the temperature or humidity of the printing environment is too high. Solution: reduce the ambient temperature as much as possible and keep it dry

(3) the winding tension is too large, or the ink area at the same position is too thick. Cause local tension to increase

(4) the printing area is too thick. Solution: control the point depth between 25 and 28 μ M is better, too deep will anti stick, and printing is difficult to control

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