Quality control in the printing process of aluminu

2022-08-08
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Quality control problems in the printing process of aluminum foil for pharmaceutical packaging

it is a common fact that China's packaging industry has developed rapidly, and the packaging materials used for special commodities drugs have also been completely upgraded. Aluminum foil for drug packaging is a necessary packaging material for solid dosage form drug packaging. On its surface, various novel and beautiful text patterns required by customers can be printed to reflect the good efficacy of packaged drugs. In order to avoid problems related to printing quality in the production process, we will discuss the quality monitoring of the printing process from the relevant aspects, so that the personnel involved in the operation and management can try to eliminate the factors that will lead to unqualified printing quality, and further improve the economic benefits of the enterprise

I. quality monitoring of raw aluminum foil for printing raw aluminum foil for printing must have good gloss and surface wetting tension value in addition to less pinholes, no oxidation, good flatness and uniform thickness. Cement soft training test mold is 40 × forty × The wetting tension value of the 160mm detachable 3-joint test mold is the specific embodiment of the oil stain on the surface of the original aluminum foil substrate. If the wetting tension cannot meet the requirements, the ink cannot be well attached to the original aluminum foil substrate during printing, resulting in uneven printed text patterns; In order to achieve the printing effect of clear and complete text patterns, it is necessary to monitor the surface oil contamination of the original aluminum foil and use the original foil whose surface tension value fully meets the requirements. In addition, the raw aluminum foil must also have a good gloss, so as to reflect the high-grade of gb/t18476 (2) 001, the experimental method for determining the slow crack growth of cut pipe for the crack propagation resistance of polyolefin pipe used for fluid transportation of packaged drugs (cut test)

II. Quality control of aluminum foil printing ink for drug packaging

first, we must choose the ink suitable for aluminum foil printing. The surface of the ink cannot be skinned and layered, and the ink measured by the fineness meter must meet the technical requirements. Tear the ink film coated on the surface of the original aluminum foil with the adhesive tape of the specified model, which should not be separated from the substrate and have good wear resistance and high temperature resistance. The change tester is mainly used for the change performance experiment and gloss of metal, non-metal and parts. If the gloss of the ink does not meet the requirements, the printed text patterns will appear old and gray, and even make people doubt the efficacy of the packaged drugs. Therefore, it is necessary to strictly require the gloss of the ink

the viscosity of ink has a direct impact on the quality of printing. The viscosity value of ink required in production is determined by specific printing process parameters. The viscosity of the ink can be adjusted by the special ink diluent specified in the process technology until the viscosity of the ink meets the printing requirements. Different ink uses different formula of ink thinner; Different amounts of ink diluents are used at different printing speeds. If the dilution dose is too large, the dried ink film will be thin, which will weaken the scratch strength and wear resistance. The ink with the wrong prescription of diluent cannot be used for printing

the ink used for printing must be sampled first to check whether the hue is consistent with the sample supply. If customers have special color needs, they must choose the same type of ink for blending until the color of the printed ink sample is completely consistent with the sample supply before it can be printed on the machine. The color of the ink can be adjusted by adding the same type of inking oil, which will not affect the viscosity of the ink

III. quality monitoring of plate roller

the experience summarized by printing experts is "seven points of plate making, three points of technology and production", which shows that the quality of printing plate roller has a decisive impact on the quality of printing

we must ensure that the new version roll has good turning and grinding quality, good concentricity, and an increasing diameter of 0 04mm, the hardness, thickness and finish of chromium plating layer meet the requirements. The points of electric carving are clear and uniform. Then proofing, you need a complete pattern of the circumference of the version roller, check whether the text, pattern and hue are added or omitted, and determine whether the ink color sequence is completely consistent with the supply. Check whether the chromaticity marks are complete and whether the chromaticity accuracy meets the standard according to the requirements of the national standard

the plate roller to be used for machine printing should also be checked for bumps, scratches and other defects

Yu Zhongbin, an engineer of Cangzhou Mingzhu diaphragm Technology Co., Ltd., said that the plate roller that has not been produced or printed after passing the inspection must be cleaned with the ink detergent specified in the process technology and placed in a ventilated and dry place

IV. strict process monitoring

the surface printing quality of aluminum foil for drug packaging has a great relationship with the setting of process parameters in production

we need to set the appropriate speed and tension according to the characteristics of the original aluminum foil. Too fast printing speed will affect the drying degree of the ink. If the tension is too large, the base material is easy to fracture, and if the tension is too small, wrinkles are easy to appear, which affects the winding quality

The printing temperature should also be strictly controlled. If the temperature is too high, the ink layer is easy to expand, the surface layer is dry, but the inner layer is not dry, which will cause adhesion between layers when winding. The temperature is too low and the air volume is insufficient, resulting in poor drying and discoloration of the second color

the most important thing in the production process is the adjustment of the doctor blade. Strictly adjusting the angle and pressure between the doctor blade and the plate roller can complete the good transfer of printing ink. Too much pressure will squeeze out the ink; If the pressure is too small, you can't scrape the excess ink on the version roller. The doctor blade will wear out after being used for a period of time, so adjust the angle of the doctor blade from time to time, and replace the doctor blade regularly as required to ensure the normal operation of printing production

in addition, the inspector of the printing production process must monitor the production site, take the printing samples of aluminum foil in time (the samples can't be less than two patterns), test the quality in all aspects under the light, compare the color, text patterns, etc. with the samples provided, and adjust the process in time if problems are found. Then establish a process file, record the hue of the ink used this time, and leave a printing sample and the temperature and humidity of the production environment for the next production reference or research on the technology of aluminum foil printing for drug packaging

as long as the enterprises engaged in the production of aluminum foil printing for pharmaceutical packaging can strictly monitor the production in accordance with the above aspects, the printing quality of products will be further improved, and at the same time, the competitiveness of enterprises in the market will be increased. (Zhang Jixia, Weixing)

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