The hottest PTP aluminum foil printing and commodi

PTP aluminum foil printing and commodity packaging

blister packaging is becoming more and more popular in the packaging of health food and medicine tablets and capsules. Blister packaging, also known as PTP (press through packaging), is a linkage process in which industrial pure aluminum foil is used as the base material, and on the pharmaceutical PTP aluminum foil coating machine, gravure printing technology and roller coating method are used to print text patterns on the surface of aluminum foil, apply protective layer, and apply adhesive layer on the other side of aluminum foil

the brief process flow of PTP aluminum foil packaging is: aluminum foil) unwinding, gravure printing, drying, coating protective layer, drying, coating adhesive layer, drying, aluminum foil reeling. In the whole production process, more than 3/4 of the gravure printing text is the surface quality of the pattern of the hot-air plastic granulator. The heat sealing strength that the product price should achieve with the falling and bonding layer, the adhesion and drying temperature of the protective layer, as well as the speed and tension control of the coating machine, are all things that need to be strictly grasped in the process operation

■ master the characteristics of aluminum foil and printing ink

the raw material used in the production of PTP aluminum foil is industrial pure aluminum foil, which generally requires a thickness of 0.02mm, a tensile strength of 98kpa, a rupture strength of 90kpa, a clean and flat surface, no wrinkles, no indentation damage, no flake fluorescent substances, and a surface wetting tension of no less than 32. The requirement for the pinhole 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 pinholes in aluminum foil are penetrating defects, health food and drugs will be reduced or deteriorated by oxygen, water vapor and light intrusion, so the requirements for pinholes 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

at present, the printing inks used for aluminum foil are mainly divided into two categories: one is polyamide inks. 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 this kind of 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 with aluminum foil, and good transparency. However, when it is used in gravure printing, its solvent volatility is large, and when it is used in health food and pharmaceutical PTP aluminum foil surface printing, it is easy to cause the ink drying and deposition in the ink hole of gravure 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 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 in the whole ink. The measuring time of the instrument is about 20 ~ 30s. 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, although the ink is thick, users can also choose microcomputer controlled equipment, and the type degree is too low, which will cause the color of printed text patterns to be not bright, and there will be paste phenomenon at the lines; If the ink concentration is too high, cracks will occur at the image, which not only wastes ink, but also easily causes 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 should meet the requirements

the adhesive of PTP aluminum foil is coated on the inner side of the aluminum foil. Its function is to make the aluminum foil and the medicinal PVC hard sheet can be firmly pressed, so that the drugs in the plastic hard sheet Blister are separated 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 pieces, 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 graphics and text, adhesive layer and protective layer need to be dried in 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. Due to the different thickness of aluminum foil materials, there are differences in physical and mechanical properties, and there are certain differences in the thermal expansion, contraction and elongation of materials when they are running in the equipment, so they should not stay at a very high temperature for too long, otherwise the aluminum foil is also 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. The bonding layer is too thin, and the bonding firmness will be reduced due to lack of material 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, so it needs to be controlled within the 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 roller lines. When the shape, depth, number of lines per inch and the pressure of the contact line between the two rollers 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 varieties of aluminum foil have different requirements for the thickness of the bonding layer. Generally, the coating thickness should be controlled within 3.5 ~ 7um. In the printing and coating of aluminum foil, 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 printing and coating quality of aluminum foil