PTP medicinal aluminum foil has become one of the main forms of pharmaceutical packaging because aluminum foil is non-toxic, odorless, light in weight and has excellent shading properties, high moisture resistance and barrier properties.

PTP aluminum foil substrates can be divided into hard aluminum foil and soft aluminum foil. The former is mostly used for the blister packaging of pharmaceutical tablets and capsules, while the latter is generally used as the outer packaging of powder granules and powders for medicines in composite flexible packaging. With the development of the pharmaceutical industry, the quality requirements for pharmaceutical foils are rapidly increasing. For example, as the types of printing colors increase and the types of color registration increase, the surface quality requirements of aluminum foils are getting higher and higher; with the increase of the speed of gluing and coloring equipment, higher requirements are put forward on the mechanical properties of aluminum foils; in order to ensure the quality of pharmaceutical packaging Safety, to prevent drug failure or deterioration, and the requirements for the pinhole of the drug foil are becoming more and more strict.

The base material of PTP medicated foil at home and abroad has always used pure aluminum. It is believed that the higher the purity, the less pinholes. Until recent years, 8 series aluminum alloys have been used more and more widely in PTP medicated foil, mainly because of their mechanical properties. Good, excellent pinhole characteristics, roughness and gloss are far better than pure aluminum foil, which is conducive to printing and decoration. Such as 8011, 8021, 8079, etc.

This paper takes 8011 aluminum alloy as the research object, uses continuous casting and rolling billets to produce 8011-H18 state drug foil, and develops a series of PTP drug foil substrates with different thickness, high performance, high flatness and high surface quality. After being produced in small batches, all of them meet the requirements of users, and now they have been supplied in batches.

The cast-rolled billet was produced by a horizontal casting and rolling mill, and the size of the cast-rolled billet was 6.8 mm × 1280 mm × C, and its chemical composition was controlled according to Table 1. The thickness of the produced medicinal foil is 0.02mm.
According to the internal control composition of 8011 alloy foil, the aluminum ingot and the master alloy are alloyed and smelted in the smelting furnace, and the aluminum alloy melt is degassed and impurity-refined in the static furnace.

Through the continuous bottom blowing of high-purity N2 technology at the bottom of the furnace, the precise control technology of alloy composition, the continuous online degassing of the melt and the double-stage filtration technology, the deviation of the chemical composition of the aluminum melt is controlled within 0.09%, and the hydrogen content in the melt is controlled. Below 0.12 mL/kg, the inclusions above 5 μm were filtered out, most of the gas and inclusions in the melt were eliminated, the content of impurity elements was reduced, and the purpose of improving the metal phase distribution and comprehensive properties of the cast-rolled billet was achieved.

When casting, use high-quality Al-Ti-B wire refiner, control the appropriate range of casting and rolling area during casting and rolling, strictly control the upper limit of casting and rolling speed, and try to cast according to the lower limit of pouring temperature [5]. It is ensured that the low-magnification structure of the cast-rolled aluminum billet is small and uniform, and the grain size is first-class equiaxed grain. And the organization is uniform, without segregation and other internal organization defects.

Meet the requirements of cold rolling process and annealing process of PTP aluminum foil substrate.
Taking the production of 8011-H18 state and 0.020mm thick medicinal foil as an example, the process flow is: billet inspection→cold rolling→intermediate annealing→edge trimming→double rolling→finished product slitting→annealing→inspection, packaging, storage .

Because the user has stricter requirements on the mechanical properties of the medicinal foil, and higher requirements on the surface quality, it is required that the oil should be clean and the surface dyne value should be above 32 × 10-3N/m. The 6.8mm thick cast-rolled sheets were cold-rolled to 2.5mm and 1.5mm, respectively, and subjected to intermediate annealing in different systems. After trimming, the double-coated foil was rolled to a finished product of 0.02mm.