Thermosetting ink screen printing 3D pattern making process and method

The thermosetting ink screen printing 3D pattern is now widely used in clothing, especially in many sports brand clothing logo, have used thick screen printing process to replace the traditional computer embroidery process, so that brand clothing on a grade.

The screen printing fine 3D pattern has strict requirements on all aspects of film production, ink use, printing method, printing method and thermosetting treatment. The criteria for a high-quality 3D print are: clear prints and strong three-dimensional impressions. There are two concepts involved here: clear imprinting. From the screen printing point of view, the edge of the printed product must be flush, the angle of the right-angled type must be sharp, the edges and the surface must be 90°, the surface is smooth, the rounded corners must be rounded, and the surface Bright; followed by a strong sense of three-dimensional, three-dimensional impression is that the print reaches a certain level of ink, the higher the height, the stronger the sense of three-dimensional. The above quality standards are relatively easy to print large patterns, but if it is a very small pattern, it will increase a lot of technical difficulties. We use cylindrical dots with a diameter of 1mm and a height of 1.5mm as an example to explain various production steps and technical issues.

Making film: Prepare two films, one is a front view and the other is a mirror image.

Screen: Prepare two editions, one for the 100-mesh screen to make the thick version, the other for the 180-mesh screen to make the overlay, and the tension between the two sheets is to reach 20N/cm.

Thick sensitized adhesive coating: The squeegee of the screen is coated twice with a large round sizing sizing machine, and then coated on the screen printing surface (contact surface with the substrate) 4 to 5 times, and after drying, it is continued to be applied on the printing surface. glue. Finally, the thickness of the printing surface is 0.2mm to 0.3mm.

Two-sided printing method: first two-sided film with two-sided adhesive on the two sides of the screen, and good "10" word positioning line, exposure time is one-third of the normal one-sided exposure, such as the total exposure required After 3 minutes, the ink surface was first exposed and then exposed for 2 minutes. Why use two films for exposure on both sides? We can see the difference between a thick version of one-sided exposure and two-sided exposure. Single-side exposure, in the light irradiation process, due to a certain thickness of the photoresist, the light is irradiated upwards through different angles, so that the actual topmost part of the photoresist is smaller than the actual size of the film, and the dried out template is conical. The dots printed with this thick plate must also be conical. The upper and lower exposures, the film made out of a cylindrical shape. Ink use: There are two methods. One is to use transparent thermoset ink and then to overprint with colored ink. The other method is to use thicker printed transparent ink. When the desired height is reached, use thin printing ink to cover the colored surface. . Mix the ink thoroughly before use.

Squeegee: hardness 70 ~ 75, sharp edges, knife-type right angle.

Network distance: According to the printing result, the network distance should be determined. For example, if the screen cannot be popped up quickly after printing, the network distance is too small. For example, there are many pinhole phenomena on the surface of the imprinting and the viscosity of the ink is not large, indicating that the network distance is too large. The ink of the hole is screened and retained in the mesh by cutting without fully adhering to the substrate.

Printing and bulk baking: printing is divided into two forms, one is mechanical printing, a large area of ​​3D pattern is suitable for fully automatic garment printing machine operation, small area of ​​fine 3D pattern is suitable for manual platen printing, because the height of 3D printing is through the screen The thickness and number of prints to complete, the thicker the version will reduce the number of printing, but a small area of ​​3D version can not be done too thick, so the number of printing more will inevitably increase the cost and ergonomics is not high.

Before printing, the surface of the substrate must be leveled. In particular, all cotton knitted fabrics have no light on the surface of the yarn. After weaving the fabric, there is a layer of wool fibers. Since the ink has a small coloring area, if it adheres to the suspended hair, There is no fastness on the fiber. Usually the leveling method is to use a piece of screen plate to glue the paper on the printing site, scrape it with a scraper, and make the back of the screen squeeze the substrate. This method is not very effective. The author designed a crimping device that can be used on both a fully automatic machine and a manual one (another article is introduced), and the effect is better.

The key link for printing 3D is the first time it is printed. The first time it is printed well, the quality is guaranteed and the number of prints will be reduced. The first pass fills the screen with ink. The height of the print is the thickness of the screen plus the photoresist. If the empty part of the screen is filled in the first pass, the number of printings can be reduced effectively and the quality of the back stacking can be ensured, because the height of the back stacking is also the thickness of the screen.

If it is manual printing, when printing the first pass, the force to start scraping the ink should be large, so that the ink is fully in contact with the printed matter to improve the attachment fastness. When the mesh is filled, the ink should be lightly collected to make the ink layer as high as possible. a little. After each printing, it is necessary to carry out bulk baking. There are two methods for bulk baking. One is a bulk oven, and the other is used to blow a gun. Bulk drying temperature and speed should be controlled on the ink surface is just sticky ink is appropriate, thermosetting ink surface curing temperature of about 100 °C, the bulk of the baking temperature is too high will thin the ink layer, thereby increasing the number of printing. After heat curing, the curing temperature of the thermosetting ink is about 160°C, and the baking time can be appropriately extended so that the ink is completely cured and firmly adhered to the substrate. The method of checking the fastness is to stick the substrate with tape paper and then pull it hard. No deinking phenomenon means good fastness.