In the packaging and printing industry, printing on paper with aluminum foil on the surface is called aluminum foil paper printing. There are two kinds of aluminum foil: gold foil and silver foil. Aluminum foil printing products are mostly used for packaging decoration, which can make the packaged products more noble and gorgeous, so as to improve the grade of products.Introduction of Printability of aluminum foil paper
Therefore, the printed matter printed with aluminum foil paper has a brighter visual effect than other paper printed with gold and silver processing technology. The history of printing on aluminum foil paper is not long, and it is still very uncommon at present, because aluminum foil paper has obvious printability compared with other ordinary paper.Introduction of Printability of aluminum foil paper
1. Printability of aluminum foil paper
Aluminum foil paper is a kind of non absorbent paper. It is made of aluminum foil pasted on the surface of paperboard. Due to the non water absorption of the aluminum foil surface, it directly affects the drying morphology of the ink layer.
We know that the penetration, curing and polymerization of ink on ordinary paper and the oxidation of conjunctiva are the main forms of ink layer drying. However, in terms of the drying time after the ink layer is printed on the paper, the drying effect of the ink layer penetrating on the paper is rapid and obvious, and the dried vegetable oil in the ink layer contacts with oxygen. The oxidation and polymerization of subsequent film formation is a very slow process.Introduction of Printability of aluminum foil paper.
It takes time to complete the whole process of chemical and physical reactions. It can be seen that the combined action of the two forms the final result of complete drying of printed matter. When printing on aluminum foil, the situation is different. This is mainly because the drying form has changed significantly. Because the aluminum foil paper can not or basically can not absorb the solvent in the ink, the solvent such as dry vegetable oil and high boiling point kerosene in the ink adhesive can not penetrate into the paper, but have to stay in the ink layer on the ink surface. Paper, so that the ink layer cannot be compared.Introduction of Printability of aluminum foil paper
It thickens and fixes quickly, so the ink layer loses its initial drying opportunity. This means that the ink layer polymerizes slowly, and the drying process of oxidized conjunctiva becomes the main drying form of aluminum foil paper ink layer.Introduction of Printability of aluminum foil paper.
The solvent remaining in the ink layer not only can not thicken the ink rapidly, but also hinders the polymerization and oxidation of the ink layer and slows down the drying speed. This phenomenon is often called “don’t do this”. The nature of aluminum foil paper determines that the ink layer cannot be dried quickly.Introduction of Printability of aluminum foil paper.
Another characteristic of aluminum foil paper is high smoothness and poor adsorption. Printed matter sticks easily after printing. Once this happens, the smoother and smoother ink layer will instantly become fragmented or incomplete, which will seriously affect the visual effect of the product and even become waste.Introduction of Printability of aluminum foil paper
The above-mentioned “non drying” phenomenon also leads to more prominent adhesion. Therefore, it can be said that the “quit” phenomenon and the “stick” phenomenon are like twin brothers, which affect and correlate with each other, and have become an important content that we need to pay attention to and care about from the beginning. To the end of the aluminum foil printing process. Around these two problems, it is very necessary to take corresponding technical measures and requirements.
2. Aluminum foil paper printing process
The temperature of the printing environment has a great influence on the drying speed of the ink layer. When the temperature is low, the printing speed is slow, and the drying time increases accordingly.Introduction of Printability of aluminum foil paper.
In order to prevent the “non drying” of the ink layer from becoming too serious, aluminum foil paper has certain temperature requirements during printing. The ideal ambient temperature is above 25 ° C. Printing under such temperature conditions is conducive to the drying of the ink layer and easier to operate.Introduction of Printability of aluminum foil paper.
If the natural temperature (such as winter) cannot meet some requirements, the necessary heating facilities can be used. Because higher ambient temperature can accelerate the movement of material molecules in the ink layer, which is conducive to the contact between vegetable oil and oxygen in the ink layer to produce a film, so as to improve the speed of oxidation and polymerization reaction, so as to meet the requirements and accelerate the drying of the ink layer.Introduction of Printability of aluminum foil paper.
On the other hand, because the drying process of the ink layer is also an exothermic reaction process, the heat generated by the reaction further promotes the drying of the ink layer, thus forming a virtuous cycle in which the ink layer accelerates the conjunctiva. This is very conducive to the drying of printed matter and the complete transfer of ink layer. Introduction of Printability of aluminum foil paper.
Aluminum foil paper is best printed in a relatively dry environment, which is conducive to the drying of printed matter and prevent sticking. We know that the drying of the ink layer first needs to evaporate the water inside, because the water can hinder and inhibit the drying of the ink layer.Introduction of Printability of aluminum foil paper.
Only after the water evaporates, the ink layer can be effectively oxidized and polymerized until it is finally dried into a film. The evaporation rate of water in the ink layer is directly related to the humidity of the environment. When the ambient humidity increases, that is, the air is relatively humid, the evaporation rate of water in the ink layer appears slow, and the drying time of the ink layer increases.
On the contrary, when the ambient humidity decreases, that is, the air is relatively dry, the evaporation rate of water in the ink layer increases accordingly, and the drying time of the ink layer decreases accordingly.Introduction of Printability of aluminum foil paper.
On the other hand, in a more humid environment, the activity of oxygen in the air is not so active during the printing process, which will directly affect the oxygen inhalation of the ink layer, resulting in the slow drying process of the oxidizing conjunctiva, which is another reason why the ambient temperature affects the drying of the ink layer.Introduction of Printability of aluminum foil paper.