Vacuum aluminized paper in green packaging materials

Vacuum aluminum-plated paper is a new type of green packaging material widely used in packaging industry in the world since the 1980s. At present, the largest application market for vacuum aluminized paper is North America and Europe, which account for 80% of the world market. The annual consumption of vacuum aluminum-plated paper in North America is 120,000 tons, and the annual consumption of European vacuum aluminum-plated paper is 90,000 tons. In the past decade, the growth rate of vacuum aluminum-plated paper in the North American and European markets has exceeded 6%. Therefore, the rapid development of vacuum aluminum-plated paper in the Asia-Pacific region has become a trend and the outlook is optimistic.

Vacuum aluminized paper highlights in packaging materials

Vacuum aluminum-plated paper has advantages that aluminum foil composite paper cannot match. The details are as follows:

1. Cost: The cost of aluminizing is lower than aluminum foil compounding. The main purpose is to reduce the cost by reducing the thickness of the metal layer, increasing the speed of the production line, improving the design and material management. First, the thickness of the aluminum layer of aluminum-plated paper is only 0.025um to 0.035um, which is 1/200 to 1/300 of the aluminum used in aluminum foil composite paper, ie, the amount of aluminum used is small; secondly, it is suitable for high-speed printing, and is superior to aluminum foil composite paper. The smoke mark is approximately 200 packets/minute higher; in addition PET film can be reused 6-8 times. Therefore, vacuum aluminum-plated paper can ultimately save 10% in cost and cost compared with aluminum foil.

2. Environmental protection and hygiene: Although aluminum foil gold and silver cardboard and PET composite paperboard have become high-grade packaging materials with good decorative performance and anti-counterfeiting performance, they are non-environmental materials. Aluminum foil gold and silver cardboard is a composite product of aluminum foil and paper, aluminum foil thickness is 7um, so it can not be recycled as aluminum products, can not be recycled as paper, can not be completely incinerated, is not conducive to environmental protection. PET composite paperboard is a composite product of aluminized film and paper. Because plastic film cannot be degraded, it is not conducive to environmental protection. Aluminum-coated paper is due to the use of the least aluminum material, so the aluminum-coated paper is easy to handle and recycled, and it is an environmentally friendly product. In addition, the raw and auxiliary materials used in the production of aluminized paper are odorless and non-toxic, conform to the US FDA standards and are hygienic.

3. Anti-counterfeit: Vacuum aluminum-plated paper is easy to laser holographic processing, vacuum aluminum-plated paper is called laser spray aluminum paper (referred to as laser paper). The laser sprayed aluminum paper is formed by loading a laser holographic pattern or text signal onto the surface of the sprayed aluminum paper by means of molding. The laser brightness of the laser sprayed aluminum paper is several times stronger than that of a conventional laser packaging machine'target=_blank>transparent film, and the laser pattern cannot be wiped off. Moreover, the laser sprayed aluminum paper has a relatively complicated production process, high technological content, and large investment in equipment. Making fake and shoddy products prohibitive, so laser spray aluminum paper has a very good security.

4. Wide range of applications: Aluminized paper is widely used in the packaging of tobacco, wine, food, medicines and daily necessities in daily life. After printing on aluminum-plated cardboard with white cardboard as a substrate, it can be applied to the outer packaging of hard-packed cigarettes and alcoholic beverage boxes. Aluminized paper made from imported wood pulp base paper can be applied to labels on glass bottles. The use of aluminum-coated paper for food and pharmaceutical packaging can solve the problem that powdered medicines packed in composite packaging films are not easily pourable due to electrostatic attraction. Aluminized paper can be divided into low weight (50 grams or less) and high weight (300 grams or more). Low-thick aluminized paper not only has the flexibility of paper, but also has the air barrier property of aluminum foil composite paper. It is mainly used for the packaging of candy, chocolate, chewing gum and other products, but the application on cigarette liners is still in the experimental stage. , has not yet entered the batch use; high grams of heavy aluminum plated cardboard printing transparent colorful ink, can reveal a noble and rich metallic luster, mainly used for moon cake box, cosmetics box, toothpaste box, wine box and Gift Box packaging production, exquisite Luxury, can enhance product value.

Vacuum aluminum plating paper

The vacuum aluminum-plated paper is heated in a high vacuum of 1.33×102 Pa or more by resistance, high frequency or electron beam, and the aluminum wire is heated to about 1400° C. and vaporized and then adhered to a paper substrate. According to its production process can be divided into direct method (paper plated aluminum) and transfer method (film surface aluminum) two. The direct method is to pre-coat the surface of the paper to improve the flatness and brightness of the paper surface, and then the paper is directly placed on a vacuum aluminum plating machine for aluminum plating. This method has a high requirement for paper, and is suitable for 40 to 120 g/m2 coated paper, white board paper, cardboard, and the like. The transfer method uses PET and BOPP films as transfer substrates, which are coated, colored, sprayed, compounded, and peeled to make aluminum sprayed metal layers with metallic luster transferred to the surface of paper or cardboard through adhesive action. method.

The aluminized paper produced by the transfer method, the aluminized layer is transferred by PET film to the paper, and the aluminum film has good flatness, strong metallic luster and high smoothness, and is more suitable for packaging printing. Compared to the direct method, the transfer method has the following characteristics: (1) The aluminum layer has firm and reliable adhesion, and can produce aluminum-plated paper of any thickness (40-450g) of paper or paperboard. (2) It can make full use of the flatness of PET film. The paper surface metal luster is brighter and the appearance quality is greatly improved; (3) Laser anti-counterfeiting vacuum aluminum-plated paperboards of various patterns can be produced.

The problem of vacuum aluminum coated paper

Although vacuum aluminum coated paper has many advantages over other flexible packaging materials, it is still time for vacuum aluminum coated paper to replace the original non-environmental materials. There are mainly the following deficiencies:

First, compared with composite aluminum foil materials, vacuum aluminum coated paper has stringent requirements in terms of transportation and storage. During the transportation process, plastic film must be used to protect the aluminized paper. The protective measures such as the upper and lower boards and the angle protection board are used to prevent the aluminized paper from wrinkling and warping, so as to avoid affecting the flatness due to stacking. In the storage area, it should be stored in a warehouse with constant temperature and humidity. The room temperature should be controlled at about 25°C and the humidity should be 60% to 70%.

Second, vacuum aluminum-plated papers have defects in replacing PET film materials, and there is still a gap in brightness. The brightness of the aluminized paper depends mainly on the quality of the paper base. It requires ultra-bright paper and good flatness. The visual white is above 96 to 116 degrees. The brightness of the aluminized paper can reach the level of PET composites. At present, the Swedish "Iggesund" smoke is used in white. Jams meet this requirement.

Third, the aluminum layer is too thin to be suitable for some printing methods and complicated processes. Although gravure printing is the most suitable printing method for aluminized paper, it cannot be fully applied to screen printing at present, because screen printing is mainly applied to non-absorbent materials (such as composite gold, silver cardboard and PET film, etc.). There are certain requirements for the thickness of the material, but the aluminum layer of the vacuum-coated aluminum paper is too thin, which can easily cause scratches on the material and increase the scrap rate of the printed product.

Fourth, after changing to aluminum-plated paper, the ink must be adjusted. Otherwise, the original hue cannot be maintained and the ink is prone to explode, especially when the printing ink is dark. This is mainly because the surface coating is chemically incompatible with the molecules in the ink. Therefore, pre-coating is performed before the aluminized paper is printed, such as water-based varnish before printing, and high-toughness inks should be used as much as possible. UV inks are particularly suitable for the printing of aluminum-plated paper, and it is an environmentally friendly ink. In addition to the use of aluminized paper, its original equipment, processes, all aspects should be comprehensive adjustments, which for the daily production tasks with a heavy printing plant, there is a test machine deployment process.

V. Outlook

In short, vacuum aluminum spray paper not only looks gorgeous, but more importantly, it has anti-counterfeiting and degradable properties. It is an environmentally friendly product that meets international trends. Today, more and more well-known enterprises have realized and started to apply this new type of packaging materials to high-end packaging such as cigarette cases, gifts, and alcohol, which will certainly bring new development opportunities to the Chinese packaging industry.

Author/Tang Defang Nie Xiaoan
Source: China Packaging