Printed aluminum paper (plate) (below)

The ink should be allowed to dry in the factory, otherwise the residual solvent in the ink will penetrate the surface coating of the aluminum spray paper-(board) to cause problems such as surface coating damage such as surface battering, cracking and the like.

Use oven drying printing ink, the degree of drying can be combined with the following points to consider:

1. Printing speed

2. Oven drying temperature and number of temperature zones

3. Dry wind speed

4. Oven length

5. Printed coating properties (solvent type and solvent release properties of ink resin, solids content)

6. Thickness of the print coating (wet coating print volume, ie depth and number of lines of the printed screen roller, print area)

7. Paper base thickness

Of course, the adjustment of the degree of drying is mainly based on the characteristics of the print coating and the thickness change, and the thickness of the paper base to determine the speed of the printing speed and the level of drying temperature.

It is also advisable to use an ink with a small amount of plasticizer (eg DOP), which can prevent some adhesion problems.

Special gravure inks for plastics and foils are suitable for printing on aluminum foil (board).

Environmental conditions:

In order to avoid edge deformation, 24 hours before printing, the paper and the paper roll are equilibrated to the temperature of the printing shop, and then the package is unpacked before printing. The greater the temperature difference, the longer the required equilibrium time, sometimes reaching several days. The temperature and humidity of the printing shop are kept at 20-25°C, and 50-60% RH is good. During storage and printing processes (such as ink printing drying, cutting, hot stamping, die cutting, finishing processes, etc.), excessive or low temperature and humidity must be avoided. If the time interval between work processes is longer, it is necessary to temporarily seal moisture-proof semi-finished products, which will play a good role in the smooth processing of subsequent processes.

Printing on aluminum paper (plates) is like printing on plastics and aluminum foils. Drying of the ink requires volatilization and/or oxidation. Due to the non-absorbency of the surface, during offset printing, its ink drying is slower than that of normal white paper (board). The increase of the ambient temperature or the decrease of the humidity is of course beneficial to the oxidation and drying of the printing ink on the aluminum spray paper, but it is not favorable for the paper. smooth.

In addition, when the sprayed aluminum paper (board) before printing is stored, the height of the stack should be a knife; when the two sheets of a roll, the aluminum spray paper is stored with the end face down (so-called upturned eyes) to prevent the paper from causing adhesion or surface Damage problem. Because the aluminum spray paper (plate) has a good metallic luster, the surface of the paper is affected more by the external world than ordinary paper, and the surface of the sprayed aluminum paper (plate) is very conspicuously damaged, so the sprayed aluminum paper ( Board) to prevent excessive pressure during transport storage.

Recommendation: There is a process of exploration, familiarization and experience for the printing of aluminum spray paper (board). In addition to the above mentioned, in summary, pay special attention to the following two points.

1. temperature:

During the printing process, the surface temperature of the sprayed aluminum paper (board) is improper (or too high), and its staying heat will soften the surface resin coating of the sprayed aluminum paper (board) and cause deformation, resulting in loss of metallic luster texture.

The use of sprayed aluminum paper (board) metal texture, appropriate mix and use of transparent and opaque inks will make the printed image with a three-dimensional sense, of course, this need to maintain the metal luster in the printing process without loss, in order to achieve beautiful Effect.

2. humidity:

Environmental humidity affects the retention and loss of moisture in the sprayed aluminum paper, which causes curling of the sprayed aluminum paper. If the ambient humidity is too low, moisture in the aluminum spray paper will be lost, and the sprayed aluminum paper will curl toward the reverse side of the aluminum surface. Conversely, excessively high ambient humidity can cause increased moisture in aluminum spray paper, which will curl toward the aluminum surface.

Generally, the relative water content of aluminum spray paper is 4.5-5.5%. With the drying of ink (such as gravure and flexo printing), the aluminum spray paper is affected by the drying. Generally, the relative moisture content of the paper after printing. Will be lower than 4.5%, at this time can be properly filled with water to the paper, the relative moisture content of spray aluminum paper to maintain the level of 4.5-5.5% before printing, in order to prevent the general environment The paper curls toward aluminum and affects the use.

Compared to aluminum spray paper, aluminum spray paperboard stiffness will be larger and less likely to be affected by environmental humidity curling phenomenon (the same 1 gram of moisture changes, 1% for 100 grams of paper, 200 grams of cardboard only accounted for 0.5%).

Conclusion: The printing company uses aluminum-sprayed paper (board) to obtain good packaged printing products, in addition to well-equipped printing machinery and good printing technology; the characteristics of the two raw materials, aluminum spray paper (board) and ink Familiar with understanding, to choose the appropriate ink, combined with the above mentioned points of attention will certainly play a multiplier role in improving the printing quality and reduce costs.