Pharmaceutical packaging aluminum foil printing process and precautions
The brief process flow for pharmaceutical packaging foil printing is: Aluminum foil unwinding → gravure printing → drying → coating protective layer → drying → coating adhesive layer → drying → aluminum foil winding. During the entire production process, the surface quality of the gravure printing text pattern and the heat seal strength to be achieved by the adhesive layer, the adhesion of the protective layer and the drying temperature and the speed and tension control of the coating machine operation are the process operations. Need to strictly grasp. Therefore, in the "Aluminum Foil for Pharmaceutical Packaging" national standard, there are clear requirements for the surface quality of printed aluminum foil for medicinal use, and there are physical and chemical indicators for the performance of the protective layer and the adhesive layer, so as to protect the medicinal PTP aluminum foil with good barrier properties. , Hygiene safety, heat sealability and good physical and mechanical properties. To achieve the above-mentioned requirements in the PTP aluminum foil printing and coating production process, it is still necessary to be familiar with the applied raw material properties, and the following issues should be noted in the operation process: 1. Grasp the characteristics of aluminum foil and printing ink The raw material for the production of PTP aluminum foil is industrial pure aluminum foil. The general requirement is that the thickness is 0.02mm, the tensile strength is 98kPa, the rupture strength is 90kPa, the surface is clean, smooth, no wrinkles, no indentation damage, no fluorescent material, The surface wetting tension is not less than 32. The requirement for the pinhole degree of medicinal aluminum foil is that the pinholes with a diameter of 0.1-0.3 mm are not more than 1/m2. Since the pinhole in aluminum foil is a penetrating defect, the penetration of oxygen, water vapor, and light by medicines will reduce or deteriorate the efficacy of the drug. Therefore, the requirements for pinhole degree are very strict; if the thickness of aluminum foil exceeds the required deviation ( When 10%), the coating amount of the adhesive layer and the protective layer is affected, and the operator's attention needs to be paid. Printing inks for aluminum foils are currently mainly divided into two categories: one is polyamide inks. This type of ink has good adhesion, dispersibility, gloss, abrasion resistance, good solvent release, and softness for printing on various types of materials, and is often used for the printing of plastic films. When used in the printing of aluminum foil materials, the excellent performance of the ink can be expressed, and its heat resistance can also meet the requirements of aluminum foil printing. The other type is based on vinyl chloride vinyl acetate copolymer resin / acrylic resin as the main ingredient of aluminum foil ink, its holding point is bright color, high concentration, and aluminum foil adhesion is particularly strong, with good transparency, but Because it is used for gravure printing, the volatility of the solvent is large, and it is easy to cause the ink of the gravure roll ink to dry and deposit in the intaglio printing ink foil when it is used for printing the medicinal PTP aluminum foil, resulting in stencil printing phenomenon. Therefore, it is necessary to perform the necessary pretreatment on the deposition and freezing of the ink by stirring or increasing the temperature (water bath) of the deposited and frozen ink. If the ink storage time is too long, the ink will appear to deposit, resulting in the ink upper resin solution, the lower pigment, the upper color light, the lower color, it should also be used after stirring. 2, the amount of solvent added to the ink to be appropriate When a large-viscosity ink needs to be diluted with a large amount of diluent, it should be stirred while adding a diluent so that the diluent is evenly distributed throughout the ink. The degree of measurement is about 20-30s. The indoor temperature and humidity have an influence on the ink concentration. It is better to use an ink concentration detector to determine the amount of the added solvent, and determine the ink concentration at regular intervals according to changes in temperature and humidity. When gravure printing is used to print aluminum foil products, the ink concentration is too low, which will cause the printed text patterns to be not bright and the web patterns will be stenciled; if the ink concentration is too high, cracks will occur at the map, which will not only waste ink, but also Can easily cause the printing surface to be uneven and not beautiful. In addition, better inks should be selected based on the speed of the aluminum foil coater and the ink hole depth of the gravure roll. 3, adhesives should meet the requirements The adhesive of PTP aluminum foil is coated on the inner side of aluminum foil. Its function is to enable the aluminum foil and the medicinal PVC hard sheet to be firmly pressed together, so that the medicine in the plastic hard film blister is isolated from the outside and the medicine is sealed. purpose. In the process of filling the medicines for heat sealing, the adhesive layer is activated by the heat and pressure, so that it is firmly bonded with the PVC plastic hard sheet, which requires that the adhesive layer and the PVC resin have good heat-sensitive properties and the substrate Compatibility. 18MM Snap-off Blade Plastic Safety Utility,Heavy Duty Snap-off Blade Cutter,18mm Snap-off Plastic Box Cutter Shangqiu Acer Measuring Tool Co.,Ltd. , https://www.acertoolshn.com