The application of aluminum foil inks and material

Abstract: This paper focuses on the characteristics of PTP aluminum foil printing and coating equipment for drugs, and looks forward to the use and development of pharmaceutical aluminum foil, pharmaceutical PVC hard film, printing ink, adhesives, etc. from the perspective of end-users

key words: Medical aluminum foil and medical PVC have become an important member of this goal. Hard film, printing ink and adhesive

aluminum plastic blister packaging of drugs is also called blister packaging, which is abbreviated as PTP (press through packaging). This kind of drug packaging has many advantages: first, it can provide patients with a single dose of drug packaging, which is convenient and economical. Secondly, the aluminum-plastic blister packaging protects drugs with good performance, fast production speed, low cost, small storage space, light weight and convenient transportation. Third, the safety is good. Because the blister packaging aluminum foil is printed with text instructions, the drug dispenser can avoid the wrong drugs and mixing drugs in the distribution of many tablets. Therefore, the pharmaceutical industry will significantly increase the packaging volume of high-quality blister drugs. Some experts predict that the packaging of blister materials for drugs will account for 60% to 70% of the packaging of tablets and capsules in the future

in the national standard aluminum foil for pharmaceutical packaging, health food, 4 There are clear requirements for the surface quality of the printed words of the medical aluminum foil for the double-layer explosion-proof glass window, and there are also physical and chemical indicators for the performance of the protective layer and the bonding layer, so that the protective PTP aluminum foil has good barrier property, health and safety, heat sealing property and good physical and mechanical properties. In order to achieve the standard performance in the production process of Pt p aluminum foil printing and coating, we still need to be familiar with the performance of the applied raw materials, and pay attention to some problems in the operation process. At present, blister packaging is becoming more and more popular in the packaging of health food and medicine tablets and capsules. Blister packaging is also known as a linkage process in which pure aluminum foil for industrial use is used as the base material. On the pharmaceutical PTP aluminum foil coating machine, the gravure printing technology and roller coating method are used to print text patterns on the surface of aluminum foil, and the protective layer is coated, and the adhesive layer is coated on the other side of aluminum foil

blister packaging of drugs rose from Europe in the 1930s. The blister packaging materials used in China in the early 1970s mainly depended on imports. In the 1980s, Guangzhou, Lianyungang, Jinzhou and other places in China successively introduced Japan's pharmaceutical aluminum foil gravure coating equipment and its application technology, but the main materials such as substrate aluminum foil need to be imported. By the 1990s, China has been able to manufacture monochrome or multicolor aluminum foil printing and coating equipment, and can print aluminum-plastic products with golden series of drug outer packaging, while the pharmaceutical aluminum foil materials, printing inks for aluminum foil, protective agents for aluminum foil and adhesives used in blister packaging have been localized and can meet domestic needs

I. characteristics of pharmaceutical PTP aluminum foil printing and coating machinery

the equipment is mainly composed of printing system, coating system, drying system, receiving and releasing system, etc. In the whole production process, the surface quality of gravure printed text patterns, the heat sealing strength of the bonding layer, the adhesion and drying temperature of the protective layer, as well as the speed and tension control of the coating machine need to be strictly controlled in the process operation

1. Aluminum foil printing system: its principle is to print text patterns through the concave surface of the printing roller, commonly known as intaglio printing. It is to process the plate cylinder to make plate graphics and text. The graphics and text part is corroded into ink holes or pits on the surface of the copper layer of the cylinder, and the non graphics and text part is the copper surface of the outer layer of the cylinder itself. The printing cylinder rotates in the ink tank, and each ink hole is filled with thin fluid ink. When the cylinder rotates and turns out of the surface ink tank, the excess ink on it is scraped off by the doctor blade installed on the surface of the printing plate cylinder. When the printing plate cylinder rotates and contacts the aluminum foil of the substrate, the surface has elasticity. The embossing cylinder presses the aluminum foil against the printing plate cylinder, so that the ink in the ink hole is transferred to the surface of the aluminum foil. The whole process is the technological process of aluminum foil printing

2. Aluminum foil coating system: the so-called aluminum foil coating system is a device for coating (dipping) adhesive or protective agent on aluminum foil substrate. Most equipment uses concave roll coating, also known as line coating. The characteristic of this coating device is that the surface of the roller is carved with a concave shape, and the corrugated roller is soaked in the roller groove. When the roller rotates, the excess paint (adhesive or protective agent) is scraped away by the scraper and retained in the corrugated roller. At present, the main electronic testing machines of the factory include: liquid crystal display electronic tensile testing machine The coating in the dimple on the surface of the microcomputer controlled electronic universal experimental machine is transferred to the aluminum foil substrate between the dimple roll and the impression roll

the concave lines of the coating roller can be pyramidal, quadrangular, truncated prism and triangular thread according to the specific needs. The coating amount depends on the depth and density of the pit. The density is like a sieve. The coarser the sieve, the larger the diameter and depth of the pit, the more paint it contains, and the larger the coating amount. For example, there are 200 pyramid shaped pits, that is, there are 200 pits per inch and about 8 pits per millimeter. The storage capacity of the coating is only 1000 square feet and weighs about 0.5 pounds, that is, 2.4 grams/square meter. For the 24 triangle thread shape, the coating retention can reach 13 pounds per 1000 square feet, that is, 63 grams/square meter. The viscosity of the fluid coating must be as low as possible to ensure that the coating can be smoothly transferred from the corrugated roller to the aluminum foil substrate under the pressure of the roll gap

able to protect and spot check

3. Drying and rewinding system: the drying system adopts far-infrared plate drying, and is divided into five drying areas. Each drying area is set with different temperature gradients, so that the printed text and coating can be evenly dried. The magnetic powder clutch device is used in the winding system to ensure the stability of the tension of the aluminum foil winding

II. Aluminum foil for drug packaging

the aluminum foil used in drug blister packaging is a sealing material sealed on a hard plastic sheet, also known as a capping material, which is usually called PTP pharmaceutical aluminum foil. It is based on hard industrial aluminum foil, which has the advantages of non-toxic, corrosion-resistant, impermeable, hygienic, heat resistant, moisture-proof and so on. It is easy to carry out high-temperature disinfection and sterilization, and can block light, which can protect drugs from the damage of light. Before sealing the aluminum foil cover with the plastic hard sheet, the text and pattern instructions should be printed on the brush coater, coated with protective agent, and the other side of the aluminum foil should be coated with adhesive

the purpose of coating protective agent is to prevent the mechanical wear of ink and text on the surface of aluminum foil, and also to prevent the pollution caused by the contact between the outer ink and the inner adhesive during mechanical winding of aluminum foil. The function of coating adhesive is to make aluminum foil and plastic hard sheet have good bonding strength

the raw material used in the production of PTP aluminum foil is pure aluminum foil for industrial use. Generally, the thickness is required to be 0.02mm, the tensile strength is 98kpa, the rupture strength is 90kpa, the surface is clean, flat, without wrinkles, indentation damage, no flakes of fluorescent substances, and the surface wetting tension is not less than 32. Aluminum foil material is made of 99% electrolytic aluminum by means of post-processing, non-toxic and tasteless, with high-quality conductivity and shading, as well as high moisture resistance and gas resistance

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, there is still a gap in the application of pharmaceutical aluminum foil in China compared with imported products in terms of quality, mainly in the following aspects:

1. The number of pinholes of pharmaceutical aluminum foil can not meet the use requirements. The number of pinholes in aluminum foil is a penetrating defect, which seriously affects the barrier property of aluminum foil. Especially when applied to the outer packaging of drugs, it is easy to let oxygen, water vapor and light penetrate and reduce the efficacy

2. Domestic medicinal aluminum foil has uneven thickness and low tensile strength. Different thickness will affect the uniformity of the coating amount of adhesive, and then affect the thermal bonding strength of aluminum foil and plastic hard sheet. The low tensile strength will cause the foil to break after tension is applied during the unwinding and winding of aluminum foil during the printing process, and the continuous printing operation cannot be carried out

3. Residual oil stains on the surface of aluminum foil. Oil stains are often found in the finished aluminum foil products because oil is used to cool and set the aluminum foil in the process of calendering and stretching. This kind of oil stain on the surface will affect the adhesion between aluminum foil printing ink and protective agent and aluminum foil material, causing a series of quality problems, such as unclear handwriting, peeling of protective agent and aluminum foil, etc. Especially when gold is coated on the surface of aluminum foil or color patterns are printed, due to the existence of oil stains on the surface of aluminum foil, there is almost no adhesion between words and patterns and aluminum foil, resulting in color fading and word dropping, which seriously affects the product quality

III. blister materials for drug packaging

at present, most blister materials for drug packaging use polyvinyl chloride (PVC) hard sheets and polyvinylidene chloride (PVDC) hard sheets. Because drugs are sensitive to moisture, moisture and light transmission, they are easy to deteriorate or fail due to this influence. Therefore, plastic hard sheets are required to have good barrier properties of water, steam, light, etc. polyvinyl chloride (PVC) is not ideal in terms of moisture and gas resistance. Some manufacturers have applied polyvinylidene chloride (PVDC) or its composites to this field

polyvinylidene chloride (PVDC) or its composites have good barrier properties to oxygen, water vapor and carbon dioxide (CO2) in the air. Compared with materials of the same thickness, PVDC has 1500 times the barrier capacity of polyethylene (PE), 100 times that of polypropylene (PP) and 100 times that of polyester (PET). Its water vapor barrier performance and air barrier performance are better than PVC. In addition, the sealing performance, impact strength, tensile strength, durability and other indicators of PVDC can meet the requirements of drug packaging

another trend is to gradually adopt plastic composites such as pvc/pvdc/pe and pvdc/opp/pe to replace plastic hard sheets. Its comprehensive advantages of drawing on others' strengths can be reflected in one, which will greatly meet the packaging requirements and performance indicators, and is the direction of future development

IV. ink for aluminum foil printing

ink for aluminum foil printing should have good adhesion to aluminum foil, the printed text and pattern should be firm and solid, at the same time, the solvent release performance should be fast, heat resistance, wear resistance and gloss performance should be good, and non-toxic, will not pollute the packaged drugs, and the practical viscosity should meet the requirements of speed and drying during aluminum foil printing

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, particularly strong adhesion with aluminum foil, and good transparency. However, when used in gravure printing, its solvent volatilization is large, so it is used in health food