Characteristics of ordinary hot stamping and three-dimensional hot stamping in printing
(1) Ordinary hot stamping plate
High-quality hot stamping plates are the guarantee of hot stamping quality. The production of ordinary hot stamping plates is relatively simple, mainly using photo-etching plate-making technology and electronic engraving plate-making technology. Commonly used plates are copper or zinc plates. Copperplate is currently the mainstream hot stamping plate because of its fine texture, smooth surface, good heat transfer performance, wear resistance and pressure resistance, and not easy to deform. Using a high-quality copper plate can improve the gloss and clarity of the hot stamping. In the custom book printing factory, the zinc plate can also be used for hot stamping with a small quantity and low-quality requirements.
(2) Three-dimensional hot stamping plate
The production principle of the three-dimensional hot stamping plate is the same as that of the ordinary hot stamping plate, but it is more complicated than the ordinary version because it needs to form a three-dimensional embossed pattern. The deeper the printing plate, the higher the precision. At present, the printing companies in China mainly use the copper plate photo-etching method. The advantages of this method are low cost and simple process, but it is only suitable for flat bronzing. Due to the poor three-dimensional effect, short service life, and only about 100,000 prints, it is often used in some that do not require high relief effects such as paper box printing.
At present, engraved brass plates have been widely used abroad. The pattern to be hot stamped is first scanned with a scanner, the data is stored in the computer, and then three-dimensional engraving is carried out through the control of the computer and software; forming a negative mold intaglio with rich three-dimensional patterns. Because it is controlled by a computer, it can form very fine patterns, which is ideal for the performance of subtle parts, and the printing endurance can reach more than 1 million prints. Die intaglio. Of course, due to the need to be equipped with high-end electronic engraving machines, scanners, computers and software, engineering and technical personnel, etc., the production cost is higher than that of the photographic etching method. Therefore, for some high-quality products that require anti-counterfeiting functions, such as cigarette packs, wine packs, health care product packaging, and greeting cards, it is very suitable for three-dimensional bronzing. At present, a small number of printers in China can process this hot stamping plate, which effectively reduces the cost and achieves the effect of cheap box printing.
(3) Bottom die relief
Three-dimensional hot stamping is different from ordinary hot stamping. The bottom plate of ordinary hot stamping is flat and does not need to be specially made, while the bottom plate of three-dimensional hot stamping must be a positive relief plate corresponding to the hot stamping plate, that is, the concave part of the hot stamping plate should be on the bottom plate. It is raised, and the height of the protrusion corresponds to the depth of the depression of the hot stamping plate. The method of making the bottom mold relief is the same as that of the embossed male relief.
The bottom mold relief plate is used to form a three-dimensional relief pattern with the hot stamping gravure, which must correspond exactly to the hot stamping plate. However, three-dimensional bronzing is different from the embossing. Most embossing does not require heating, while three-dimensional bronzing must be heated at a high temperature. During hot stamping, as the temperature increases, the hot stamping plate will expand, while the temperature of the bottom mold relief basically remains unchanged, which will cause the hot stamping plate and the bottom mold relief to not match, resulting in crushing the bottom mold. Or the phenomenon that cannot be stamped. Therefore, the expansion rate of the hot stamping plate should be fully considered when making the bottom mold relief, so as to make an accurate bottom mold relief.