Quality Control in Aluminum Foil Printing for Pharmaceutical Packaging

The rapid development of China's packaging industry is a fact obvious to all, and the packaging materials used for special commodities - medicines have also been completely replaced. Aluminum foil for pharmaceutical packaging is an essential packaging material for solid dosage form pharmaceutical packaging. On its surface, it can print a variety of novel and beautiful text patterns that are required by customers to reflect the good efficacy of the packaged pharmaceuticals. In order to avoid problems related to printing quality in the process of production, the personnel involved in operation and management can try to exclude factors that will lead to unsatisfactory printing quality and further improve the economic efficiency of the company.

First, the quality of raw aluminum foil for printing substrate monitoring

The original aluminum foil substrate for printing must have good gloss and surface wetting tension value, in addition to having fewer pinholes, no oxidation, good flatness, and uniform thickness. Wetting tension value can not meet the requirements, printing ink can not be well attached to the original aluminum foil substrate, resulting in non-uniform printed text pattern; To achieve a clear text pattern of the printing effect, you must monitor the surface of the original aluminum foil oil In case of using the original aluminum foil whose surface tension value fully meets the requirements. In addition, the original aluminum foil must also have a good gloss to reflect the high grade of the packaged drug.

Second, the quality of aluminum foil printing ink for pharmaceutical packaging

First you must choose the ink that is suitable for foil printing. The surface of the ink cannot be crusted and stratified. The ink measured with the fineness meter must meet the technical requirements. The ink film coated on the surface of the original aluminum foil with the specified model of adhesive tape should not be separated from the base material and has good abrasion resistance, scratch resistance, heat resistance, high temperature resistance, and gloss. If the gloss of the ink does not meet the requirements, the printed text patterns will appear obsolete and dark, and even make people suspect that the efficacy of the packaged drugs, therefore, the strict requirements of the gloss of the ink is necessary.

The viscosity of the ink has a direct effect on the quality of the print. The ink viscosity required for production is determined by the specific printing process parameters. The viscosity of the ink can be adjusted by the special ink thinner specified in the process technology until the viscosity of the ink meets the printing requirements. Different inks use different formulations of ink thinners; different printing speeds use different amounts of ink thinners, the amount of diluent is too large, the dried ink film is thin, and the abrasion strength and wear resistance are weakened. Misprinted ink formulations 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 the customer needs a special color, the ink of the same type must be used for deployment until the color of the ink sample is exactly the same as the sample supply. . The depth of the ink color can be adjusted by adding the same type of varnish, without affecting the viscosity of the ink.

Third, the quality of roller monitoring

The experience summarized by the printing experts is "seven-point making, three-point technology and production", which shows that the quality of the printing roller has a decisive influence on the quality of the printing.

We must ensure that the new rollers of the new plant have good grinding quality, good concentricity, an increase in diameter of 0.02-0.04mm, and the hardness, thickness, and finish of the chrome plating layer meet the requirements. Electric sculptures are clear and uniform. Then proofing, you need a full pattern of the roll circumference, proofreading text, patterns, whether there is additional leakage in the hue, to determine whether the ink sequence and the feed exactly the same. According to the requirements of the national standard, check whether the color registration mark is complete and complete, and whether the color registration accuracy meets the standard.

The roll used for printing on the machine is also inspected for defects such as bumps and scratches.

After passing inspection, the printing roller that has not yet been machined or printed has to be cleaned with the ink cleaning agent specified in the process technology and placed in a ventilated and dry place.

Fourth, strict process drying place

The quality of the surface of aluminum foil used for medicine packaging has a great relationship with the setting of process parameters.

We need to set the proper speed and tension according to the characteristics of the original aluminum foil. The excessive printing speed will affect the drying degree of the ink. If the tension is too large, the base material may be easily broken, and if the tension is too small, wrinkles may easily occur, which may affect the winding quality.

The printing temperature must also be strictly controlled. If the temperature is too high, the ink layer will swell easily, the surface layer will be dry, and the inner layer will not have dried yet, which will cause adhesion between the layers. The temperature is too low and the air volume is insufficient, resulting in poor drying and a second color change.

The most important thing in the production process is the adjustment of the doctor blade. Strictly adjust the good transfer of the ink. Excessive pressure will cause the ink to squeeze out; when the pressure is too low, excess ink on the roll will not be cleaned. The squeegee will wear out after a period of time. Therefore, it is necessary to adjust the angle of the squeegee from time to time and replace the squeegee as required to ensure that the printing production runs normally.

In addition, the inspector of the printing production process must monitor the production site, take samples of aluminum foil in a timely manner (samples can not be lower than the two patterns), detect all aspects of quality under the light, and contrast with the sample color, text patterns, etc., found problems Timely process adjustments. Then establish a process file, record the hue of the ink used this time, leave a print sample and the temperature, humidity, etc. of the production environment, to prepare for the next life without reference or use for technical research such as aluminum foil printing for pharmaceutical packaging.

Companies engaged in the production of aluminum foil for pharmaceutical packaging use, as long as they can strictly monitor production in accordance with the above aspects, the quality of the products will inevitably be further improved, and at the same time it will increase the competitiveness of the company in the market.

Reprinted from: China's packaging industry Author: ZhangJiXia Wei Xing