Process Technology Of Medicinal Aluminum Foil

- Dec 29, 2018-

The medicinal aluminum foil adopts electrolytic aluminum ingot with purity of more than 99%, which is made by calendering process.

Usually includes casting and rolling (hot rolling)-cold rolling-intermediate annealing-rough rolling-double-joint rolling-split-cut-finished surface heat treatment-inspection-packaging and other processes.

Due to the production process using smelting, casting and calendering production, by the metallurgical quality, roll surface quality, rolling oil physical and chemical properties, process operation technology and production site environment and many other factors, the medicinal aluminum foil inevitably appears a variety of quality defects: 

(1) Pinhole: is one of the most important defects, the size and number of medicinal aluminum foil pinhole has a decisive impact on the moisture resistance, gas resistance and shading of pharmaceutical packaging.

Because the pinhole in aluminum foil is a penetrating defect, health food, medicine by oxygen, water vapor and light intrusion will reduce the efficacy of the drug or spoilage, so the requirements of the pinhole degree is very strict. 

(2) Thermal Stability: In the use of the process, if the mechanical properties of medicinal aluminum foil is low, in the production will often appear broken foil and rupture, thus affecting the continuous printing and coating.

If the aluminum foil is broken in the baking channel of the printing press, because the temperature of the baking channel is very high, generally need to cool down before connecting, thus affecting the production schedule.

The original production of medicinal aluminum foil alloy grade is industrial pure aluminum foil, with the continuous development of pharmaceutical packaging technology, aluminum processing enterprises have developed a higher alloy performance of alloy grades, including continuous casting and rolling billet process commonly used 8011 alloy grades, hot rolling billet process commonly used 8021 and 8079 alloy grades. ·

8011 alloy Grades increase the content of FE-SI elements, more than 1% of the total alloy elements, its mechanical properties corresponding to a higher advantage; ·

8021 contains a high amount of iron elements, with better mechanical properties, barrier capacity, light avoidance and moisture-proof properties, non-toxic tasteless, safe and hygienic; ·

8079 aluminum foil contains a higher amount of iron content, grain more refined, is higher strength, elongation and pressure better aluminum foil, the surface color is beautiful, easy to process a variety of colors of beautiful patterns and patterns.

(3) Surface wetting performance: aluminum foil appearance surface oil, poor wettability, not only will affect the printing, text pattern clarity and integrity, and even will appear discoloration, drop words and affect the quality of coating, reduce the adhesion of protective agent adhesives and aluminum foil, affect the sealing performance of finished aluminum foil and composite materials, reduce the safety of drug packaging.

(4) Thickness deviation: uneven thick and thin, deviation if exceeded the required (10%), affecting the finished aluminum foil coiling tightness and end flatness, but also affect the packaging quality of the product, and the medicinal foil coating process of the bonding layer and the coating amount of the protective layer has an impact.

(5) Control the metallurgical quality of the billet, such as alloy composition, grain size, hydrogen content, slag clamping, etc., in order to ensure the mechanical properties of medicinal aluminum foil and pinhole degree and other indicators.

(6) in the cold rolling and aluminum foil rolling process, to ensure that the production environment is clean, air cleaning, workshop configuration air Circulation Filtration system, to maintain the workshop micro-positive pressure production, improve the surface quality of medicinal aluminum foil, reduce the pinhole rate.

(7) in the process of aluminum foil rolling, clean the roll, Arch, and inlet Guide road in time to prevent the mixing of sticky aluminum and impurity foreign bodies.

(8) The selection of the base oil of rolling oil, the selection of additives and the use of the ratio: the control of the physical and chemical properties of rolling oil, including the viscosity of rolling oil, saponification values, hydroxyl value, acid value and other indicators should be appropriate to ensure the surface quality and wetting properties of medicinal foil.

(9) Control the speed of the rolling mill when rolling aluminum foil finished product to control the surface oil content and surface brightness.

(10) In the cutting process, control the tension and cutting speed, to ensure that when cutting aluminum foil edge part is neat, can not appear the wrong layer, side burr, Lotus leaf edge and other quality problems. 

(11) If annealing treatment is required, in the annealing process, the annealing time and annealing temperature should be controlled to ensure mechanical properties and surface oil removal clean.