Glass cannot be gilded directly. Usually, the gilding layer is silk-screened on the glass surface, and then gilding is performed. The process is briefly described as follows:
silk screen
The bronzing process itself is not complicated. It uses heat and pressure to transfer the metal layer on the bronzing paper to the surface of the product. There are two conditions that must be met to be qualified: one is that the metal layer can be completely separated from the PET base film. , the other is that the separated part can be tightly covered on the surface of the product. Adhesives that can produce adhesion with paper and plastic are easy to coat on the surface of hot stamping paper, so direct hot stamping is easy to understand. The hot stamping of glass must be done by means of coating technology, and the process of realizing this coating on the surface of glass is screen printing.
In order to form a strong bronzing layer on the surface of the cup, the coating of the silk screen must reach a certain thickness, so the mesh number of the silk screen should not be too high.
glass varnish
Some ink manufacturers tell us that UV glass varnish can be used, but we have not seen this trade company use it, they use solvent-based glass varnish, which needs to be baked at high temperature. The adhesion of solvent-based varnish is very good.
The workers will put the cups on a plate next to the screen printing machine and wait for printing. Their screen printing machine is a common circular printing machine that is easy to see in the market. I looked at the jig they made, it's a jig on four wheels, it's a bit difficult to adjust, but once it's adjusted, it's easy to print. Such a fixture is also very adaptable. Even if the glass cups with different diameters and tapers are replaced, the angle is only adjusted. In addition, the cup itself has a certain tolerance, and the four wheels themselves can also consume some of the diameter tolerance of the cup.
After the workers have finished printing, they put the cups one by one in another tray. The drying process is to ensure that the surface of the varnish is dry, that is, it cannot stick, otherwise, the thickness of the coating will change.
Hot Stamping and Thermal Transfer
Silk screen glass varnish is only for bronzing preparation, whether it can achieve exquisite bronzing effect depends to a large extent on the bronzing process.
With the advancement of automation, the automatic bronzing machine for glass cups also came into being. The automatic glass bronzing machine integrates silk screen printing, UV curing and bronzing technology, which greatly improves the production efficiency. The automatic glass bronzing machine adopts a flat turntable. Structure, with the improvement of users' requirements for precision, more and more production factories design and manufacture servo-controlled automatic hot stamping machines.
Glass bottle is the safest packaging container. It has an advantage in the packaging of food, cosmetics, wine and other products. Usually, glass bottles need to be printed
square glass bottle
A square glass bottle is a bottle that is square in shape. It consists of four planes and requires printing on four sides. The printing of square bottles comes down to plane printing. You can use a plane screen printing machine to print one side at a time, or install an automatic rotating fixture on the plane screen printing machine to complete two or four sides of printing at a time.
Square bottles can also be printed on the automatic screen printing machine, one is to use the four-color automatic flat screen printing machine for silk screen printing, the other is to use the four-color automatic curved screen printing machine to print on the automatic screen printing machine, common Using UV glass ink.
The hot stamping of the square bottle is similar to the hot stamping of the flat glass. First, the glass varnish is screen-printed, and then the hot stamping machine is used for hot stamping. The current glass thermal transfer film is also relatively mature and can be directly used for thermal transfer printing to complete multi-color decoration at one time.
round glass bottle
Round glass bottles are one of the most stocked packaging forms on the market, and they still need silk screen printing, bronzing, heat transfer printing and other decoration methods.
Round glass bottles, like plastic bottles, are most commonly used for silk screen printing. Whether it is a semi-automatic screen printing machine or a fully automatic screen printing machine, it is the machine that users like to choose. Fully automatic screen printing machines often use UV screen printing technology, while semi-automatic screen printing machines use ink UV type and heat curing type are more common.
The heat transfer printing process for round bottles uses a curved surface heat transfer machine and a glass heat transfer film
Round glass bottles also often encounter hot stamping process, similar to flat products, it needs curved screen printing machine to print glass varnish and then use heat transfer machine for hot stamping.
On the fully automatic printing machine, the silk screen printing machine and heat transfer machine are combined on one machine to complete silk screen printing and bronzing at one time. A UV curing or heat curing device will be installed between silk screen printing and bronzing to accelerate the drying of the ink.
