Learn about the silkscreen process for your glass bottles
1. The concept of silk screen printing
Glass screen printing is the use of screen printing plates, the use of glass glaze, decorative printing on glass products. Glass glaze is also called glass ink and glass printing material. It is a paste printing material which is mixed and stirred by coloring material and connecting material.
Because of the ink, the effect after printing has obvious concave and convex feeling. The regular bottle (cylindrical type) of silk screen printing can be printed at one time, and the other irregular one is a one-time cost, and the color is also a one-time cost, and it is divided into two types: self-drying ink and UV ink. If the alcohol is wiped off, the UV ink has obvious bumps and it is difficult to wipe off.
2. Types of inks commonly used in screen printing
Due to the different printing materials and printing processes, the requirements for the ink used in screen glass printing are also different.
First of all, the most important thing in glass printing is to strengthen the bonding force between the ink and the glass surface, so that the ink does not fall off or dissolve during the use of glass products.
Secondly, screen glass printing is dried at high temperature, so the ink used is high temperature resistant ink. The inks used for glass screen printing mainly include the following:
1）Glass glaze
According to the firing temperature, the colored glaze can be divided into three types: high temperature, medium temperature and low temperature. Among them, the low temperature (550℃) colored glaze is mainly used for the decoration of thinner glass bottles; the medium temperature (580℃) colored glaze is widely used in cosmetic bottles and glass bottles. The printing of glass products such as cups; the high temperature (600 ℃) color glaze is mainly used for the printing of beverage bottles. Because the color glaze contains heavy metal lead, we must pay attention to the selection of high-quality color glaze, especially food packaging.
2）UV glass ink
The emergence of UV glass ink has solved the drying problem of glass screen printing to a large extent, but it should be noted that excessive curing will cause the embrittlement of the ink film and reduce the adhesion of the ink layer.
3）Two-liquid reactive glass ink
This kind of ink is mainly used for the printing of some small glass containers such as cosmetic bottles, etc. It is prepared on-site when used, and the storage time should not be too long, so as to avoid waste caused by the hardening of the conjunctiva of the ink.
4）Special glass ink for thermosetting
This kind of ink belongs to volatilization drying ink, which can be dried after being placed at room temperature for 10 to 15 minutes. In addition, in order to improve the strength of the ink film and its adhesion, it needs to be baked at a temperature of 180°C for 10 minutes.
5）Glass Pigment Inks
Glass pigments contain low-melting glass powder, and use binders (synthetic resins and organic solvents) to adjust the printability of the ink, but this ink has no intermediate color. After this ink is printed, it is sintered in a heating furnace, so that the binder in the ink is evaporated, and the glass powder is softened and fixed on the glass surface after burning.
The binder of the ink is mainly synthetic resin and organic solvent. The basic requirement for the binder is that it can complete the evaporation, sublimation and combustion process at low temperature, and avoid the residue of the binder when the glass powder is melted. Otherwise, the printing surface will be damaged. Foams and loses smoothness.
6）Gold Liquid, Silver Liquid and Gold Paste
Glass ink composed of various metal organic compounds as the main component added to the binder of the ink. The metal organic compounds used are mainly metal-sulfide turpentine, metal-mercaptan, etc. Liquid silver also contains the same organic compounds. In the gold paste, because the content of gold and silver is very small, it is still feasible to use as printing ink.
We can make the design as per client’s request,matched caps production and also printing,coloring ,bronzing ,screen printing and frosting as per your request in a very short time.
