Magnetic Printing Technology and Mechanical Discussion--Gravure Printing (I)

Second, gravure printing

(A) The basic characteristics of gravure printing

The gravure printing plate layout is opposite to the relief plate layout, the graphic part is concave, and the blank part maintains the original plane. The graphic part is concave and receives the ink layer. After the pressure of the impression cylinder, the ink layer is transferred to the surface of the printed matter and is reproduced as a printed matter.

The main features of gravure printing products compared to those produced by letterpress, lithographic, flexographic or other printing methods are summarized as follows:

Good quality, thick ink layer, three-dimensional, colorful, rich layers, especially suitable for a variety of exquisite color printing;

2 The production speed is fast, the printing plate printing rate is high, the drying is rapid, the printing speed is fast, it is suitable for all kinds of large-format, bulk product printing;

3 The cost is low, and the printing material has a wide adaptability and can withstand large printing surfaces, and is particularly suitable for the printing of various commodity packaging and decorating materials.

With the continuous development of the production of goods, the requirements for packaging and decorating materials have become higher and higher, both in terms of output and in variety and quality. The use of gravure printing technology to develop the packaging and decoration of goods is growing.

(B) The basic principle of gravure printing

The layout of gravure plates is similar to that of seals, and the printing method is similar to that of rubbing or stamping.

Earlier seals were usually written in graphic form as concave inverted negative images. They were printed on soil or on paper (known as closed mud). After the method of extension or smashing, they formed the negatively written characters. If the image of the seal is engraved into a positive image (projection is highlighted), the positive text is written after the method of extension or deduction.

The surface of the stone (stone) engraved with a concave image (an overcast image) is coated with a wet, soft tissue paper, and then a slight pressure is applied to the surface of the paper (slight brushing) to engrave the paper. In the recessed graphic part, after the paper is dried slightly, brush it with a soft-bristle brush (or use a soft cloth) evenly. Due to the fact that the indented part of the text does not contain ink, the white-on-black-on-white (Yin-Yi-Wen-wen) extension, commonly known as the Rubbing inscription, is obtained. If the image on the stone tablet is engraved into positive writing (part of the graphic and text is highlighted), the rubbing of the positive image (black text on white) can be obtained in the same way.

In gravure printing, the principle of rubbing is used to sculpt images on a flat or cylindrical metal surface to make a gravure plate. Then the ink is applied on the plate and the ink on the surface of the plate is scraped off. Then, the printed material is applied, the printing pressure is applied, and the ink layer embedded in the graphic is transferred to the surface of the printed object, thus obtaining a gravure printed product, as shown in FIG. 2-30.

With different depths of concaves and concaves, the depth of the ink layer can be accommodated. When transferred to the surface of the printed matter, thick and vivid printed images are obtained.

The main features of gravure printing products are rich layers, thick ink layers, and rich three-dimensional texture (the thickness of the ink layer of the lithographic printing products is 0.7~1.2μm; the thickness of the ink layer of the topography printing products is 1.0μm; and the ink of gravure printing products The thickness of the layer can generally reach 8-15 μm).