The hottest PTP aluminum foil printing makes the o

2022-07-25
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PTP aluminum foil printing: make the outer packaging of health products safer

at present, blister packaging is more and more popular for the packaging of health food and drug tablets and capsules. Blister packaging, also known as PTP (pressthroughpackaging), is a combined process in which the industrial pure aluminum foil is used as the base material, and on the pharmaceutical PTP aluminum foil coating machine, the gravure printing technology and roll coating method are used to print text patterns on the surface of the aluminum foil, and the protective layer is coated, and the adhesive layer is coated on the other side of the aluminum foil

The brief process flow of PTP aluminum foil packaging is as follows: aluminum foil unwinding, gravure printing, drying, coating protective layer, drying, coating adhesive layer, drying, aluminum foil reeling. In the whole production process, the surface quality of gravure printed text patterns, the heat sealing strength of the bonding layer, the adhesion and drying temperature of the protective layer, and the speed and tension control of the coating machine are all things that need to be strictly controlled in the process operation

■ master the characteristics of aluminum foil and printing ink

the raw material used for the production of PTP aluminum foil is pure aluminum foil for industrial use. Generally, the thickness is required to be 0.02mm, the tensile strength is 98kpa, the rupture strength is 90kpa, the surface is clean, flat, free of wrinkles, indentation damage, no flake fluorescent substances, and the surface wetting tension is not less than 32. The requirement for the pinhole size of aluminum foil for medicinal and health food is that the pinhole with a diameter of 0.1 ~ 0.3mm is not more than 1/m2. Because the pinhole in the aluminum foil is a penetrating defect, the mouse can be used to find out the force value and deformation data of the experimental curve point by point when the health food and medicine are invaded by oxygen, water vapor and light, so the drug effect is reduced or deteriorated. Therefore, the requirements for pinhole are very strict; In addition, if the thickness of aluminum foil exceeds the required deviation (10%), it will affect the coating amount of bonding layer and protective layer

printing inks for aluminum foil are mainly divided into two categories: one is polyamide ink. This kind of ink has good adhesion, dispersion, gloss, wear resistance, good solvent release and softness for the printing of various substances. It is mostly used for the printing of plastic films. When used in the printing of aluminum foil materials, the excellent performance of the ink can be shown, and its heat resistance can also meet the requirements of aluminum foil printing. The other is the special ink for aluminum foil, which is mainly composed of vinyl chloride vinyl acetate copolymer synthetic resin/acrylic resin. It is characterized by bright color, high concentration, especially strong adhesion to aluminum foil and good transparency. However, when used in intaglio printing, its solvent volatilization is large. When used in health food and pharmaceutical PTP aluminum foil surface printing, it is easy to cause ink drying and deposition in the ink hole of intaglio roll, resulting in paste phenomenon. Therefore, it is necessary to carry out necessary pretreatment for the deposition and freezing of the ink. The method is to stir the deposited and frozen ink or increase the temperature (water bath). If the storage time of the ink is too long, the ink will deposit, resulting in more resin solution in the upper layer, more pigments in the lower layer, light color in the upper layer and deep color in the lower layer. It should also be mixed evenly before use

■ the amount of solvent to be added to the ink should be appropriate.

when the ink with high hiding degree needs to be diluted with a large amount of diluent, it should be stirred while adding diluent to make the diluent evenly distributed throughout the ink. The measuring time of the instrument is about 20 ~ 30s. The indoor temperature and humidity have an impact on the ink concentration. It is best to use the ink concentration detector to determine the amount of solvent added, and measure the ink concentration at regular intervals according to the changes of temperature and humidity. When using intaglio printing to print aluminum foil products, the ink concentration is too low, which will cause the color of printed characters and patterns to be not bright, and the phenomenon of plate pasting will occur at the lines; If the ink concentration is too high, cracks will occur at the drawing. When the installation foundation is dry, it will not only waste ink, but also easily cause uneven and unsightly printing surface. In addition, according to the speed of the aluminum foil printing coater and the inking hole depth of the gravure roller, the best ink should be formulated

■ the adhesive shall meet the requirements

ptp the adhesive of aluminum foil is coated on the inner side of the aluminum foil. Its function is to enable the aluminum foil to be firmly and thermally pressed with the medicinal PVC hard sheet, so as to separate the drugs in the plastic hard sheet Blister from the outside, so as to achieve the purpose of sealing the drugs. In the process of loading drugs for heat sealing, the bonding layer is activated by hot pressing, so it is firmly bonded with PVC plastic hard sheet, which requires that the bonding layer and PVC resin should have good heat sensitivity and compatibility with the substrate

■ master the drying temperature and time for printing and coating

the printed text, adhesive layer and protective layer need to be dried during the coating process. The drying of the surface coating of aluminum foil needs a process, so it needs to stay in the drying channel of the equipment for a certain time, which depends on the speed of mechanical winding of the coater and the temperature selected in the drying channel. The two should maintain a corresponding relationship. As the thickness oxygen index of aluminum foil is only the additional condition for the new national standard to detect the combustion performance of thermal insulation materials, the physical and mechanical properties are different, and the thermal expansion, contraction and elongation of materials in the equipment are also different, so it is not necessary to stop for a long time at a very high temperature, otherwise the aluminum foil is prone to wrinkling and surface discoloration. Generally, the temperature of drying channel should be controlled at 170 ℃ ~ 210 ℃

■ analysis of printing and coating speed, coating tension, coating thickness and bonding quality

the coating thickness of the bonding layer in the printing and coating process has a great impact on the bonding firmness of plastic PVC hard films. If the bonding layer is too thin, the bonding firmness will be reduced due to lack of materials when hot pressing PVC hard films; If the adhesive layer is coated too thick, it will not only increase the cost, but also lengthen the drying time. PEKK is the thermoplastic material with the best performance, so it needs to be controlled within an appropriate thickness range. The coating thickness of the bonding layer is affected by the concentration of the adhesive, the coating tension, the coating speed, and the number of lines on the roller. When the shape, depth, number of lines per inch and contact line pressure between two rolls are set, the thicker the coating is, the greater the adhesive concentration, the smaller the coating tension and the faster the coating speed. Therefore, the thickness of the bonding layer is generally adjusted by the concentration of the adhesive and the tension of the coater

different kinds of aluminum foils have different requirements for the thickness of the bonding layer. Generally, the coating thickness should be controlled within 3.5 ~ 7um. In the process of aluminum foil printing and coating, the machine speed, temperature and tension are not only related to each other, but also contain each other. The cooperation between them is directly related to the quality of aluminum foil printing and coating

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