Since the advent of aluminum paperboard, with its special surface visual effects - flat gloss, noble and beautiful, and love for the packaging industry, have used as high-end products packaging materials. In the manufacture of aluminum cardboard packaging, the first thing involved is its design and printing.
First, the design problem Compared with general packaging materials, aluminum cardboard has its unique printability: high surface finish, poor ink absorption. In view of its visual characteristics and printing characteristics, when designing such packaging products, we should strive for a simple pattern with a small number of colors and make full use of its own visual aesthetics. We must also consider the smooth progress of printing production and ultimately achieve the desired packaging. effect. In general, the number of colors should not exceed four colors. The number of printing should be reduced as much as possible to prevent damage to the product surface during the production process and affect the visual effect.
Second, India ink issue 1. Ink selection In view of the printing properties of aluminum paper, we should pay special attention to the selection of ink, the drying mechanism must be mainly oxidized conjunctiva, the drying speed is not easy to dry on the ink roller, and the paper can be quickly dried on the paper (generally within 8h) is appropriate. At present, the inks with better adaptability to aluminum paperboard have the following types: "Hanghua" brand JP ink, "Tiens" brand TCT ink and so on. In addition, some people designed an aluminum foil ink, the effect is also relatively good.
2. Adjustment of Ink Printing Applicability Aluminum cardboard printing requires thin, plain prints. In principle, original ink printing should be used. The benefits of this are: 1 dry quickly, generally within 8 h can be dry; 2 full ink; 7 back is not easy to stick dirty.
However, in the case of wet-press wet-overprinting, the post-color must be filled with a small amount of sizing agent in order to satisfy the conditions for transfer of the imprint. But do not add more, otherwise it will delay the drying speed of the imprint, lighten the ink color and increase the possibility of sticking.
Third, the lining issue Aluminum cardboard printing should adopt a neutral hard lining, avoid soft lining. Because of the use of medium-soft liner printing, the dots are easy to paste and affect the screen level. More importantly, it will cause the blot to dry slowly, usually taking 2 to 5 days to dry. This will not only affect the cycle, but also easily cause the back of the dirty, affect product quality. Why does this happen? I think that this is because the pressure of the soft liner is not level, the binder contained in the imprint is more, and the surface absorption of the aluminum cardboard is very poor, and the oxidized conjunctiva is dry. Very slow. The use of a neutral, hard-backed lining is different, and its blotting is thin and flat, and contains relatively few binders, generally only 8 h to completely dry. In this case, we have tried many times.
Fourth, the pressure problem In view of the printing properties of aluminum cardboard, imprint must be thin and plain, in order to ensure the smooth progress of the printing work to obtain the desired printing effect. This means that the pressure of such products must be larger than normal products (usually greater than 50 ~ 100mm). The pressure increases, there are two ways: 1 reduce the center distance between the impression roller and the blanket roller; 2 thick rubber roller lining.
Fifth, anti-sticking dirty problem In the aluminum cardboard printing process, although using the original ink, and the ink layer is thin, but do not pay much attention, it is very easy to occur on the back of the dirt, and therefore need to take some measures to prevent. There are two commonly used effective measures:
1. Spraying powder. Using a powder jetting device of the printing press, a thin layer of powder is sprayed on the surface of the printed sheet to “separate†the printed sheets from each other, which can effectively prevent the cooked food from being burned. The finer the sprayed particles, the better.
2. Add a separator. Each sheet of 200 to 300 sheets is placed on a sheet separator so that the printed sheets are layered to prevent sticking.
How to improve the quality of aluminum cardboard packaging products, involving design, materials, machinery, processes and other aspects of the problem, we have yet to further study and explore. I have talked about the above, for your reference only.