Application analysis of pharmaceutical blister packaging printing materials (I)

At present, there are more than 1,500 pharmaceutical packaging manufacturers in China, capable of producing 6 categories and more than 50 varieties. The annual production value is about 150~Lyuan, and annual sales account for about 15% of the pharmaceutical industry's sales, which can meet domestic pharmaceutical manufacturing requirements. 80% of business needs. Among them, there are 165 plastic sheets, membranes (composites), and pharmaceutical aluminum foils used in pharmaceutical solid dosage forms, accounting for 11%. There are 36 PVC and PVDC plastic sheet manufacturers for pharmaceuticals: aluminum foil for pharmaceutical packaging and printing. There are 35 production plants.

The flexible packaging of blister packs formed by the hot pressing of aluminum foil for pharmaceutical packaging and PVC (polyvinyl chloride) or PVDC (polyvinylidene chloride) has developed rapidly in recent years. According to the prediction of Flexib1e Packaging ASSN, “The pharmaceutical packaging market is the new economic growth point for flexible packaging in the next five years. In addition to the strong momentum of medical supplies, it can control the dosage of thermoforming and extrusion blister. The packaging of bulk-packed or bottled medicines will grow rapidly.” According to recent market surveys in China, blisters and pharmaceutical flexible packaging materials will grow at a rate of 5% to 10% over the next five years, exceeding 3% per year in the growth of pharmaceutical products. speed. This is mainly due to the fact that China is changing the form of pharmaceutical packaging for solid dosage forms, from the early use of glass bottles, paper bags of drugs to plastic printing blister packaging, and Chinese medicine granules, powder, powder, capsule packaging, Promote the use of printed plastic film with text patterns, flexible packaging of aluminum-plastic composite materials.

At present, due to the rapid replacement of pharmaceutical packaging materials, old packaging materials have gradually been eliminated, such as glass bottle packaging, iron container packaging, paper bag packaging and so on. The new pharmaceutical packaging has been put into the market in large quantities, such as blister packs, Chinese medicines plastic film (bag) packaging, and aluminum-plastic composite film packaging, which have been widely used. This article introduces the performance characteristics and application scope of these new pharmaceutical packaging printing materials.

First, the characteristics and application of blister packaging printing materials

Pharmaceutical blister packs are also known as Blister Packs, or PTP (Press Through Package). This kind of medicine packaging has many advantages: it can provide patients with a dose of medicine, which is convenient and economical; it has good protection properties for medicines, high production speed, relatively low cost, small storage space, light weight, and convenient transportation. Good safety performance. The aluminum foil used in blister packs can be printed into various colors and medicines, so that pharmacies can avoid the problems of mislabelling and mixed drugs in the distribution of multiple tablets.

The main production process of blister packaging is to first transport the blister plastic sheet under the electric heater to soften it, then place the plastic sheet in the mold, and then fill the mold with compressed air from the upper direction so that the plastic sheet is affixed to the On the mold wall, blister or cavity is formed. If the blisters or cavities are not deep and the plastic sheet is thin, vacuum is drawn from the bottom of the mold to form a plastic part. After molding, it is taken out of the cooling, the tablet is placed in the blisters on the plastic sheet, and the aluminum foil coated with the adhesive is heat-sealed with the plastic sheet containing the tablets under a certain temperature, pressure and time to form a blister pack. . Such packaging has good resistance to chemicals, good chemical stability, tearing by hand, good performance of the drug, and easy access and carrying.

The composition of medicinal blister packaging printing materials mainly includes aluminum foil, plastic hard sheets and heat sealing coatings. Aluminum foil is a sealing material that is sealed on a plastic hard sheet, and is also called a cover material. It is based on hard industrial pure aluminum. It has non-toxic, corrosion-resistant, non-permeable, moisture-proof, moisture-proof, light-blocking and high-temperature sterilization. It has good printing adaptability and can print text patterns on both sides. The thickness of the printed aluminum foil is usually between 0.021 mm and 0.027 mm and consists of an aluminum foil layer, a printing ink layer, a protective layer, and an adhesive layer.

Due to the sensitivity of drugs to moisture and light transmission, blister pack printing materials are required to have high barrier to water, vapor, and light. The commonly used materials are polyvinyl chloride (PVC), polyvinylidene chloride (PVDC) or composite materials, such as: PVC/PVDC (polyvinyl chloride/polyvinylidene chloride), PVC/PE (polyvinyl chloride/polyethylene) Ethylene), PVC/PVDC/PE (polyvinyl chloride/polyvinylidene chloride/polyethylene), etc. During use, it was found that polyvinyl chloride materials are not ideal for moisture barrier and gas barrier properties of drugs, and PVDC and its composite materials have been widely used. Compared with the same thickness of material, PVDC has 1500 times more oxygen barrier performance than PVC, 100 times that of polypropylene (PP) and 100 times that of polyester (PET). It also has superior water vapor and odor resistance properties. In PVC. For example, some use PVC-coated vitamin E capsules, which have been viscous when they have not been used. There are also some proprietary Chinese medicines that require high barrier packaging, especially oxygen-blocking packaging medicines, such as inhalation and analgesic creams. If PVDC membranes are used, the odor will not be lost and will not affect the efficacy. In addition, the ink used for pharmaceutical aluminum foil printing should have good adhesion properties, good heat resistance, good gloss, and no toxicity to aluminum foil substrates. Currently, alcohol-based polyamide inks and aluminum foil-based inks mainly composed of polyethylene vinyl acetate copolymer resin acrylic are used.

Second, the main features of aluminum foil printing and coating equipment

The aluminum foil material printing and coating equipment is mainly composed of a printing system, a drying system and a retractable roll system.

1. Printing system of medicinal aluminum foil material

The system is characterized by printing a text pattern through the concave surface of the printing roller. The printing plate roller is processed into a printing plate graphic by external processing, and the graphic part is eroded into ink holes or pits on the copper plating surface of the printing roller. The non-graphic part is the surface of the copper coating on the outer layer of the roller itself. . During printing, the plate cylinder rotates in the ink tank, filling each ink hole with thin ink. When the roller rotates out of the surface ink tank, the excess ink on the surface is installed on the surface of the plate cylinder. The squeegee scrapes away. When the printing roller rotates and the substrate is in contact with the aluminum foil, an elastic embossing roller presses the aluminum foil against the plate cylinder so that the ink in the ink hole is transferred to the surface of the aluminum foil and the aluminum foil printing is completed. In this way, the surface of the aluminum foil is printed as a continuous text pattern.

2. Pharmaceutical aluminum foil coating system

The system refers to a device for coating (dip coating) an adhesive or protective agent on an aluminum foil substrate. Most devices use a gravure roll coating method, also known as a wire roll coating method. This coating device is characterized by the concave shape engraved on the surface of the roller. The anilox roller is immersed in the roller groove. When the roller rotates, the excess paint is scraped off by the scraper and remains on the surface of the anilox roller. The coating was transferred to the aluminum foil substrate between the nip roller and the nip. The gravure of the textured roll has different shapes, such as pyramidal, quadrilateral, truncated prismatic and triangular threads. The amount of coating depends on the depth and density of the indentations, and the degree of intensiveness is like that of a sieve. The coarser the sieve holes, the greater the diameter and depth of the indentations, and the more coating that is contained. For example, with a pyramid of 200 pyramids, the paint has a storage capacity of only 1000 square feet and weighs about 0.5 pounds, ie, 2.4 grams per square meter. With 24 triangular threads, the paint stock can reach l3 pounds per 1,000 square feet, which is 63 grams per square meter. In production, the viscosity of the fluid-like coating must be as low as possible to ensure that the coating can be smoothly transferred from the anilox roll to the aluminum foil substrate under nip pressure.

3. Drying, retracting and unwinding systems for medicinal aluminum foil materials

Drying system uses far-infrared plate drying, and is divided into five drying areas, each area is set with different temperature gradients, so that the printed graphics and coating layer can be evenly dried. Retracting and unwinding device uses magnetic powder clutch and brake device to ensure the stability of retracting aluminum foil roll tension.

(to be continued)