With its unique technical characteristics, printing technology gets rid of the limitations of flat printing. It can not only print on a flat surface, but also print on the surface of various shapes, such as: sphere, cylinder, cylinder, Cone, special-shaped surface, etc. Printing is a very popular surface treatment process in the cosmetic tube and cosmetic bottle industries. For example, when the surface of the product requires a complex colorful decoration effect, or a larger area of text or overall pattern decoration effect, the printing process has unparalleled operability and cost-effectiveness compared to other processes.

Silkscreen printing is the main printing commonly used in the cosmetics packaging industry. Special Silkscreen printing, due to the use of ink, has a rich and full printing quality, and a strong three-dimensional impression of printed patterns or fonts. It has a broad application market in the textile, electronics, automotive, anti-counterfeiting, and cosmetic industries.

Silkscreen printing

Silkscreen printing is composed of five main elements, which are Silkscreen printing plate, squeegee, ink, printing table and substrate.

Basic Principles of Silkscreen printing

Use the Silkscreen printing plate to print with the ink through the mesh of the graphic part and the mesh of the non-graphic part not through the ink.

When printing, pour the prepared ink on one end of the Silkscreen printing plate, and use a scraper to move the ink part on the Silkscreen printing plate horizontally toward the other end of the Silkscreen printing plate with a certain pressure (the movement accuracy is determined by the gear spacing) . The ink is squeezed from the mesh of the graphic part to the substrate by the squeegee while it is moving. Because of the viscosity of the ink, the imprint is fixed within a certain range. During the printing process, the squeegee is always in line contact with the Silkscreen printing plate and the substrate, while other parts of the Silkscreen printing plate are separated from the substrate, so that the ink and the screen will break and stay on the surface of the substrate. When the squeegee is scraped across the entire layout, it is lifted, and the Silkscreen printing plate is lifted at the same time, and the ink is scraped back to the initial position, so far is a printing stroke.

Because the Silkscreen printing mesh can choose different meshes, dyes and pigments with different viscosity, particle size, weather resistance or acid and alkali resistance can be directly put into the ink for deployment, and can be processed according to specific application scenarios. Corresponding performance of plastic substrates that account for the main proportion of cosmetic packaging. In addition, printing can also produce a variety of color mixing or specific printing effects, such as adding shiny metal powder to the ink to obtain a dazzling flash effect, with color printing, showing a variety of shiny colors under the light. Another example is the foaming ink, which gives the substrate a unique texture with excellent touch.

Features of Silkscreen printing

Low cost and quick results;

Adapt to irregular substrate surface;

Strong adhesion and good ink adhesion;

Thick ink layer and strong three-dimensional effect;

Strong light resistance, good color forming;

Wide range of materials for printing;

Small print size limit;

The main technical requirements of Silkscreen printing:

The text or patterns of the manuscript should not be too close;

The text or graphic design of the manuscript should not be too fine;

The selection of the number of screens and the preliminary design of the draft need to be considered comprehensively;

The color continuity needs to be combined with the shape of the substrate, and comprehensive consideration should be given to the design of the draft;

Before printing, it is necessary to fully consider the suitability of the surface of the substrate and the ink, select the appropriate ink and the correct pretreatment method;

When choosing the printing method of pad printing, it is necessary to control the evaporation speed of the ink. The ideal situation is that all the ink on the etching plate is transferred to the printed object. In the production process (close to 10 microns or 0.01 mm thick ink will be transferred to the substrate), the plastic head is susceptible to air, temperature, static electricity, etc. If the ink volatilization speed and dissolution speed are controlled in a balanced state during the entire process from the etching plate to the transfer glue head and to the substrate, then it is considered a successful printing. Evaporate too fast, and the ink dries up before being absorbed. Evaporation is too slow, the surface of the ink has not yet formed a gel, and it is difficult for the glue head to adhere to the substrate.

Details that need to be paid attention to during the printing process:

When the screen frame is laid flat, keep the screen surface 3~4mm away from the bottom plate. If the Silkscreen printing area is large and the screen tension is small, the height should be enlarged to about 5mm;

Pour the printed material onto the screen in the frame, and try printing on white paper first. If the problem is found, make symptomatic adjustments, and try printing again until the silk-screened text or graphics are qualified;

The surface of the substrate should be kept clean and reach the standard of non-greasy and smooth;

When Silkscreen printing, place the substrate in a fixed position according to the positioning requirements, put down the screen frame, touch the substrate, and the screen is 1.5~2mm away from the surface. To ensure linear contact, the blade edge of the scraper should be made at right angles.

Details to be noted after printing:

The ink drying method can be divided into various forms such as natural drying, heating drying, ultraviolet drying, electron beam drying, infrared drying, and microwave drying. Whether subsequent drying is required should be determined according to the ink usage instructions;

After the first printing, if the Silkscreen printing plate is to be printed for the second time, the residual ink on the Silkscreen printing plate must be cleaned with screen washing water to ensure that the meshes of the graphic part are not blocked by the ink, and then After being fully dried, store it in a safe place.