Application of aluminum material in packaging industry.

Aluminum is a rich white light metal, second only to steel in the world.Its application in packaging industry is the first in nonferrous metals.As a packaging material, aluminum, aluminum and aluminum foil are generally used.Aluminum plates are usually used as canning materials or cover materials;The aluminum block is used to create a can of extrusion forming and thinning drawing.Aluminum foil is generally used for moisture-proof internal packaging or production of composite materials and flexible packaging.
The packaging boards are all anti-rust aluminum alloy, and manganese and magnesium mainly improve the strength of materials and improve the processing performance.Copper can also improve the strength of materials, but also reduce the corrosion performance and processing performance.When adding zinc, especially in the same day as copper and magnesium, the heat treatment effect is better, but the corrosion resistance and processing will decrease.The addition of silicon is mainly to reduce the melting point of aluminum, increase the strength and melt fluidity, and reduce the coefficient of thermal expansion.Aluminum foil is made from a thickness of 0.4-4).7mm(more with 0.5mm) industrial pure aluminum sheet is made of flexible metal sheet after repeated cold rolling.
A.The characteristics of aluminum material.
Compared with other packaging materials, aluminum materials have the following advantages:
(1) aluminum has a very small density of 2.7g/cm, only 35% of steel.This makes the container easy to achieve lightweight.The surface of the aluminum can naturally produce a dense layer of alumina thin film, which can prevent further oxidation.
(2) aluminum is non-toxic and tasteless, conforming to the hygienic standard of packaged food.
(3) high gloss of aluminum surface, easy to stain and good printing effect.
(4) the open cover made of aluminum is better than that of tin plate.
(5) excellent reflectivity and conductivity of aluminum to light and heat can improve the effect of sterilization and low temperature treatment of canned food.
(6) the mechanical properties of aluminum can remain unchanged at low temperature, especially for frozen food packaging.
(7) the composite film made of aluminum foil is completely impervious to air and light, which can effectively protect the food inside.Aluminum foil can also improve the strength of the composite film.
(8) the waste can be recycled and reused, which can save energy consumption and prevent the pollution caused by waste, and meet the requirements of environmental protection.
But there are some deficiencies in the aluminum material, mainly:
(1) aluminum production is much more energy intensive than tinplate and TFS, so the price is more expensive.
(2) aluminum is non-magnetic material, so the original equipment used to absorb raw materials must be modified.
(3) aluminum materials have poor corrosion resistance and should not be used for food with acid, alkaline and salt content.
(4) aluminum has a soft texture, which is lower in strength than that of tinplate, and is prone to deformation and surface abrasion due to collision in manufacturing and transportation.
(5) aluminum welding is difficult, so it can only be made by stamping or bonding.
Some defects of aluminum can be made up by compounding with other materials.For example, aluminum foil with paper or plastic compound, can increase its stiffness and tensile strength;In order to overcome the disadvantages of low stiffness of thin-walled aluminum cans, a small amount of liquid nitrogen can be filled before the closed container, and the internal pressure generated by vaporization of liquid nitrogen can increase the stiffness and compressive properties of the container.Aluminum foil with nitrocellulose and modified polyolefin coating not only enhances the chemical properties of aluminum foil, maintains a good printing appearance, but also provides heat to fit.
2.The application of aluminum material in packaging.
1 aluminum anti-theft bottle cap.
China's current packaging liquor, wine, liquor and beverages, etc. Most of them still is given priority to with glass bottles, about 50% of the JiuPingGai use aluminum manufacturing security caps, anti-theft caps in China will grow at an annual rate of 10%, by 2010, anti-theft cover consumption will reach 15 billion, 60000 tons need aluminum strip.There are nearly 200 aluminum bottle cap production plants in China, with an annual design capacity of about 9 billion. Among them, 30 production lines are introduced, and the production capacity is more than 5 billion, which can produce nearly 100 kinds of bottle caps.More than aluminum bottle cap in a high degree of automation production line processing, so on the strength of the material is very strict, elongation and dimensional deviation, otherwise it will produce rupture or crease in the deep drawing process.In order to ensure that the bottle cap is formed and easy to be printed, it is required to have flat surface, no rolling marks, scratches and spots, and the commonly used alloy materials are 8001 HI4, 3003, H16, etc.The general thickness of the material is 0.20 to 43.23mm, tolerance plus or minus 0.1%, width 449-796mm.The production of aluminum bottle cap can be made by hot rolling or continuous casting and rolling.The production practice shows that the hot rolling stock is better than the casting billet.
2 aluminum plastic bubble wrap packaging.
At present, the health food and medicine tablet, capsule Packaging is more and more common in the form of blister Packaging, the aluminum plastic bubble cover is also known as the blister eye package, or PTP.The aluminum foil used in blister packaging is the sealing material used in pharmaceutical plastic polyvinyl chloride (PVC) hard film, so it is also called cover material.Almost all the requirements in the modern packaging not pervious to light or high barrier composite aluminum foil products are used as the barrier layer, this is because the aluminum foil have highly dense metal crystal structure, can cut off any gas completely, so the application is very extensive.It is expected that the packaging of pharmaceutical bubble wrap will account for about 60% to 70% of the tablet and capsule packaging in the future, which is one of the best pharmaceutical packaging materials in the future.
However, the quality of Chinese medicinal aluminum foil is far from that of imported aluminum foil.According to the actual situation reflected by several enterprises producing PTP pharmaceutical packaging in China, there are two main problems.
(1) the number of pinholes of medicinal aluminum foil is far from being required.Aluminum foil pinhole is a penetrating performance defect, which affects the barrier properties of aluminum foil, especially for drug packaging. It is very easy to make the drug's drug effect decrease with oxygen, water vapor and light penetrating.Pharmaceutical aluminum foil in national standard requires that the diameter of pinhole is not greater than 0.3mm, the diameter is 0.1 to 0.3mm can not be more than 1 / m2, currently domestic aluminum foil rarely meets this standard.
(2) the thickness of medicinal aluminum foil is uneven and the tensile strength is low.Due to uneven thickness of aluminum foil, easy to cause in the process of mechanical inhibits PTP aluminum foil coating adhesive coating weight coating weight range to meet the standard, and influence of aluminum foil and PVC plate heat Huo strength.Due to the uneven thickness, low tensile strength leads to the production of broken foil in the actual process, which is not conducive to the normal production of production. These problems need to be taken seriously by the raw material manufacturers.
3 aluminium beverage cans.
At present.The development of aluminium beverage cans has three characteristics, namely, easy to pull cover, special tank, self-heating/self-cooling beverage can.For a long time, while metals such as aluminum cans packaging has been the challenge of tinplate and PET materials, but due to its light weight, and it has advantage of recycling, still is one of the main forms of beverage packaging, not only to get stable development, but also in constant development and innovation.
Recently, COINS packaging company has successfully developed EPOL (open cover).The tank cover is made of a polymer coated steel ring and anti-corrosion aluminum foil, which can be used for existing filling equipment. The aluminum foil cover can be opened safely and is more suitable for the elderly and children.Because of the competition of PET bottles, in recent years, the demand for aluminum cans in the Japanese market has been decreasing, but the demand for aluminum cans has started to rise.At present, the company has entered the production field of aluminum cans, including the punching industry, daiwa tank and mitsubishi materials, and the lid of the aluminum cylinder developed by the company is also put on the market.
Daiwa can company to complementary advantages, focus on the PET bottles and aluminum cans and the advantages and disadvantages of the two kinds of beverage packaging container, foster strengths and circumvent weaknesses, take the lead in successfully developed in the world can give back to metal cans for tightness of beverage packaging new container "new bottle type metal cans (new bottles).
New bottles is beyond the existing two piece cans and three cans of structural framework and develop a new packaging container, it is not only used the compound technology of three pieces of metal cans, edge with technology, but also applied the two cans of deep stamping technology made body, and then reusing existing canned contents and match with the threaded cap processing technology, so as to realize the use of metal aluminum, processing formed a bottle mouth and 28 mm diameter drink new metal bottle packaging container.The new container has both the advantages of a metal can and a PET bottle, and has overcome both inherent shortcomings.Considering the environmental problems, the new bottles are made of a single metal aluminum alloy material. On the surface of the material, the inner and outer surface of the tank body are combined with the PET film material.The inner surface of the bottom cover is also composed of a composite PET film, and the outer surface is coated with PET.The bottle cap is coated with low density PET, and the outer surface is coated with printing.The inner layer of the new bottle can avoid contact with the content, without the use of various coatings that are traditionally used in metal cans.After the success of the new bottle trial, it was exhibited at the Australian canning industry exhibition in 2000 and won the grand prize in the name of the Japanese company.The technology is also striking internationally, and the demand for a PET can is likely to expand further.
According to the Japan aluminum cans recycling association, the number of aluminum cans sold in 2002 reached 1.5 billion, up from 2 last year, as the four companies went into the production of aluminum cans.Five times, in 2003, it increased by about 20%.
The beverage packaging market is one of the largest markets in the metal packaging market.To improve the brand effect, in addition to use aluminum silver characteristics, the appearance of aluminum cans is becoming more and more important, so the metal molding equipment manufacturers also talking about the aluminium cans, molding and embossing technology.More prone to forming of aluminum and meet the requirements of shape, researchers are exploring extension forming, spinning forming aluminum cans scroll and rheological forming technology, in the near future will be in beer can be used in the first place.
The use of aluminum cans for drinks such as beer and soda has increased the use of aluminium products, while other industries are considering using aluminum cans.Industrial information resources according to the information provided by the company, more than a year ago, Japan's largest aluminium cans manufacturers and aluminium cans company to produce aluminium cans for beer and tea company, the company has produced four last year.The 800 million aluminum cans, plus two other Japanese aluminum cans, are expected to double in the next two to three years.Aluminium cans, which are favored by the beverage industry because of its light weight and easy to recycle, have recently spread to other industries and have replaced glass and metal bottles.
3.conclusion
Experts believe that new market share in aluminum materials will also make new progress with the promotion of so-called active packaging.Due to the application of new technology of aluminum products, the demand for aluminum will be further expanded.