Summary of the hottest metal packaging materials a

Summary of metal packaging materials and their applications (9)

the relationship between the mechanical properties, thickness and moisture permeability of aluminum foil is shown in Table 11 and table 12 respectively

Table 11 mechanical properties of aluminum foil with different thickness

thickness (mm) tensile strength (MPA) elongation (%)

0.0075~0.011 30~100 0.5

0.012~0.04 30~100 2.0~0.5

0.05~0.20 30~100 3.0~0.5

table 12 relationship between thickness of aluminum foil and moisture permeability

thickness of aluminum foil (mm) moisture permeability (g/m2? 24h)

0.007~0.008 7

0.008~0.010 5

0.010~0.015 2.5

0.015~0.020 1.0

0.020~0.025 0

aluminum foil is thin, but as a packaging material, it has the following advantages:

① light weight, which is conducive to reducing transportation costs

② good barrier and shading. It is moisture-proof, airtight and has fragrance retention performance, and can prevent moisture absorption, oxidation, volatilization and deterioration of packaging materials

③ good heat resistance, stable shape at high and low temperatures, and can be used as a baking container, but the quality of the equipment can not be guaranteed

④ it is highly protective, so that the packaging is not vulnerable to bacteria, mold and insects. We have achieved the damage of industry leaders in the sales volume of 2016

⑤ good reflection and gloss of light. It has high reflective ability to heat and light, and its reflectivity is 83~85%, so the exhibition effect is excellent

⑥ good mechanical performance, which can meet the use of automatic packaging machinery

⑦ good secondary processing, molding and embossing

⑧ good adaptability for printing and compounding. Easy to color, easy to fit with paper, plastic, etc

⑨ it is non-toxic and not easy to cause public hazards

although aluminum foil has the above advantages, because its strength is not high, its tear resistance is poor, it is easy to crack when folded, it is not resistant to acid and alkali media, and it cannot be thermally bonded and sealed, so it is very small and rarely used alone. The vast majority of aluminum foil is used in the form of composite materials after composite processing with plastic film, paper and other materials. This not only maintains the excellent performance of aluminum foil, but also makes up for the shortcomings of aluminum foil in some packaging performance. The thickness of aluminum foil used in the composite state can be reduced to 0.007~0.009mm. Compared with the composite without aluminum foil, the composite with aluminum foil has higher barrier, especially shading, and can meet the requirements of vacuum, sterility, nitrogen filling and other packaging technologies. It is a new type of packaging material with strong adaptability and wide application range, which can be used as both soft packaging materials and semi-rigid or hard packaging materials. It has been widely used in food packaging and has replaced some metal cans. For example, in order to save energy and prevent public hazards caused by discarded bottles and cans, tinplate cans and glass bottle beverage containers in the past have been replaced by a large number of vertical aluminum foil bags and paper packaging containers (with aluminum foil Tetra Pak inside)

(2) aluminum foil composite film

aluminum foil composite film flexible packaging material is composed of aluminum foil and plastic film or paper. Commonly used plastic films include polyethylene, polypropylene, polyester, polyvinylidene chloride, nylon, etc. The thickness of aluminum foil is mostly 0.007~0.009 or 0.012~0.015mm, which has enough barrier effect after compounding. According to statistics, 70% of aluminum foil composite films are used for food packaging, 17% for cigarette packaging, and 13% for drugs, detergents and cosmetics. Specific application examples are shown in table 13

Table 13 application of aluminum foil composite film

thickness of aluminum foil for composite structure（ μ m)

aluminum foil/tissue paper

aluminum foil/paraffin/tissue paper

aluminum foil/parchment

cellophane/aluminum foil

aluminum foil/paper/polyethylene

aluminum foil/polyethylene cigarette packaging

fruit candy packaging

butter, margarine packaging

candy packaging

shampoo powder, powdered food packaging

chocolate Drug packaging 9

7

8~9

7~9

8

20

cellophane/polyethylene/aluminum foil/polyethylene drugs, powdered food packaging 7~9

cellophane/polyethylene/aluminum foil/paper/polyethylene tea packaging 7~9

paper/polyethylene/aluminum foil/polyethylene soup, sheep soup packaging 7~9

another representative application of aluminum foil composite film is to make soft containers - cooking bags (cooking bags).Also known as soft can), Its emergence is considered to be the biggest packaging breakthrough since the emergence of metal cans 150 years ago. At present, the general structure of cooking bags is: PET film/aluminum foil/modified PP or high-density polyethylene film. PET film provides excellent toughness and durability in the outermost layer (nylon film can also be used); The middle layer of aluminum foil is the most economical material against moisture, oxygen, light and microorganisms, and it is also the key to maintain the stable shelf life of cooking bags; The inner polyolefin has excellent heat sealing property. Therefore, the cooking bag has the advantages of exploring the influence of growth orientation, thickness, modified substrate and other factors of MOF film on the performance of MOF film, light weight, low energy consumption, no need of refrigeration, convenient transportation, carrying and eating. It is a promising packaging bag. At present, it has replaced some metal and glass cans and refrigerated food

aluminum foil composite film can also be used as trademark material, and the decoration effect is good

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