Analysis of the hot stamping of self-adhesive labels
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: 860681365@qq.com
1. Hot stamping method
According to the processing method of the self-adhesive label, the hot stamping method is divided into a single sheet of hot stamping and a web stamping. Sheet-fed gilding is the same as the traditional bronzing process and is processed on a dedicated bronzing machine. Web bronzing is done on the label linkage and is the most widely used processing method. At present, there are several ways to gilt the reel material:
1 label machine flat pressing bronzing
For the letterpress label printing machine, whether it is flat flat or round flat type equipment, since the roll paper is intermittently fed, the bronzing is all flat and flat. Under normal circumstances, the bronzing station is an independent unit, and some models are gilded to share one unit with die-cutting and used separately.
2 multi-station flat pressing bronzing
Some models have a two-station bronzing unit, such as Japan's Shiki's SMHC-45-MWL labeling machine, one unit close to the plate, complete horizontal bronzing, and the other unit is a separate unit, complete vertical bronzing. This model can perform two-color bronzing at the same time.
3 processing machine flat pressing bronzing
The machine is designed for the processing of printed roll labels and labels that do not require printing. Bronzing is a function of the processing machine. The bronzing device on the processing machine generally adopts the flat pressing method, and its working principle is the same as the above labeling machine.
Round press on the 4 rounds
The bronzing plate used for round pressing and bronzing is a roller-shaped plate. When bronzing, it is in contact with the impression cylinder to achieve hot stamping. Round press bronzing is suitable for use on the continuous transfer labeling machine of continuous paper feeding, but there are certain requirements for the feeding speed, that is to say, the printing speed is affected. However, compared with the flat pressing and ironing, the efficiency is greatly improved. The round-pressed hot stamping rolls are expensive to manufacture, so they are only suitable for long-running hot stamping.
Cold bronzing on 5 rounds
This is a new hot stamping process. Instead of using a heated metal plate, the printing foil is used to transfer the metal foil to achieve hot stamping. The process flow is: first print UV pressure sensitive adhesive at the position where the printing needs to be bronted, dry the adhesive through UV drying device, then use special metal foil to composite with pressure sensitive adhesive, then peel off the metal foil, then metal The portion of the foil that needs to be transferred is transferred to the surface of the print to achieve cold stamping. The cold stamping process has low cost, energy saving, high production efficiency, and can utilize existing equipment components without adding additional devices. It is a promising new process.
2. First hot stamping and post hot stamping
The hot stamping of the self-adhesive is also divided into the first hot stamping and the hot stamping. The first hot stamping refers to first stamping on the labeling machine and then printing; then the hot stamping refers to printing first, and finally bronzing. The key to hot stamping and post-hot stamping is the drying problem of the ink. There are two situations in the relationship between bronzing patterns and printed patterns: juxtaposition and overprinting. Due to the different inks used, the label printing must be carried out by two processes: first hot stamping and post hot stamping.
1 first hot stamping process
When the labeling machine with the intermittent paper feeding unit is used to print the label with ordinary ink, the first hot stamping process is adopted. Since the ink used is an oxidative polymerization drying type, it takes a certain time for the printed ink layer to dry completely, so bronzing The pattern must avoid the ink. The best way to avoid ink is to pre-warm the roll material and then print it.
The use of the first hot stamping process requires that the printed pattern and the bronzing pattern be separated (parallel) because the surface of the electrochemical aluminum is smooth, not inked, and cannot be printed. The first hot stamping prevents the ink from smearing and ensures the quality of the label printing.
2 post bronzing process
The post-hot stamping process is applied to the labeling machine where the hot stamping parts are mounted on the back door, and UV ink is used for printing. The web material is first printed and the ink is dried instantaneously by a UV drying device and then bronted on the surface of the material after drying or on the surface of the ink. Since the ink is dry, the bronzing pattern and the printed pattern can be juxtaposed or overprinted without ink smearing.
In the two hot stamping methods, the hot stamping is an ideal method, which also brings convenience to the label pattern design and expands the application range of the bronzing pattern. However, due to the limitations of the device function, the label printing cost is relatively high. The first hot stamping process is suitable for small label processing of simple patterns, low cost and wide application range, and is a commonly used method for small and medium-sized printing plants.