Silk screen technology and surface printing

Talking about the technology of silk screen printing, silk screen printing is generally used for the surface with a relatively flat surface. If the surface arc is too large, it is necessary to use pad printing.

The application of silk screen printing is very extensive. Many of our logos are mostly screen printed, and the principles are similar, but the process is not quite the same, but I think the main concern here is the screen printing of structural parts. Before the screen printing, the structural parts will be sprayed with oil first. After the oil injection, the paint will be needed. After the paint is applied, it can be silk screened. Silk screen printing and printing are all capable of printing monochrome. If there are multiple colors, then there are several colors, we must print a few times, do several net frames, if there are three colors, we must print three times and make three frames. (The network frame is not necessarily down, but sometimes it can be shared, but this is not recommended, especially if it is of a different color, it will have a great impact on the silkscreen results.) When you leave the film, you must also produce three copies. In fact, how the body is printed is not very important. Just look at it, because that is not our job, and we need to understand how to do it. This will have a great influence on the silkscreen in the future.

When a silkscreen film for a product is to be produced, first of all, you should consider it as a few colors. There are a few colors. When you make a document, you should first build several layers and then build a hierarchical relationship. Now that the last printing of that kind of color is on the top, after you do this, you can start working. First, find the corresponding view of the structure diagram of the product you want to do and export it to the corresponding film making software. It is recommended to use the .wmf format. At this time, the imported file is not 1:1. You need to scale up to 1:1 accordingly. It is important to do this step to ensure the accuracy of the film. Then place this layer on the background layer and lock it to avoid accidental shifts. Now you can officially do a film. Please follow the following guidelines when you make a document:

1. Establish benchmarks so that they will not run in the silk screen.
2. Put the same color on the same layer;
3, text size, please refer to the appropriate safety standards, because this is a requirement, not how much you want to be small;
4, the line should not be too thin, when the screen printing oil will not go.
5, after the completion of the production of the corresponding text into a curve, and all the things on each layer into a separate layer, and together with the benchmark output together into another file, or divided into several pages can go out of the film .

Surface decoration technology curved printing

Introduction As a method of printing a character or a pattern on the surface of a plastic molded product, a curved printing method is often used. Curved printing refers to using a piece of flexible rubber to print the text or pattern to be printed on the surface of a resin molded article containing a curved surface or a slightly convex surface.

The principle of surface printing: Surface printing is the first place in the ink engraved with text or pattern gravure, and then copy the text or pattern onto the surface, and then use the surface to transfer the text or pattern to the surface of the molding, and finally through heat treatment or UV The ink is cured by light irradiation or the like.

Surface printing process:

Degreasing of molded products
2. Surface treatment of molded articles (if necessary)
3. Printing
4. Ink curing
5. Excessive coating, post-treatment (if necessary)
Printing process
1. Put the ink in the gravure
2. Scraping excess ink
3. Extrude the surface to obtain the ink
4. Transfer the surface ink to the surface of the molded article
5. Clean the surface and layout (if necessary)

Pre-treatment process: In order to obtain beautiful, durable prints, it is necessary to pre-treat molded products. The pre-treatment includes cleaning of grease and garbage on the surface of the molded product, and surface treatment for improving the wettability and adhesiveness of the ink.

Pre-cleaning (degreasing): Using organic solvents to clean the surface of the molded product from oil stains. Because the surface of the molded product is easily contaminated by mold rust inhibitors, mold release agents, human grease, and resin additives, the ink cracks and the adhesion between the ink and the molded product is reduced. Especially when there is a problem of uneven printing, it indicates that the surface of the molded product is highly likely to be contaminated.

Surface treatment: The adhesiveness of most synthetic resins and inks is inferior to metal and paper. For this reason, it is necessary to perform appropriate processing on the surface of the molded product.

In particular, “winning steel” must be preceded by a corona discharge treatment method to treat the surface.
Ink Curing Process: In most cases, the ink is cured using certain methods. In particular, for engineering plastics, good printing effects cannot be obtained by simply drying in order to prevent contamination by oil or solvents. For this reason, the use of a reactive ink can improve the adhesion of the resin to the ink.

Hardening methods include thermal hardening and UV hardening. Whatever method is used, the chemical reactivity of the ink is used. Please be sure to select the appropriate ink.

Thermal curing treatment: The printed product is placed in a thermostatic chamber so that the printed matter is irradiated with far-infrared rays or hot air, and the ink is cured due to thermal reaction. Usually the temperature is controlled at about 60 to 100°C, and sometimes the temperature is about 150°C. In general, a high curing temperature results in a good printing effect. However, when the substrate is a plastic molded product, if the substrate is treated with high temperature, the molded product will shrink or deform.

In addition, if the drying after printing is not sufficient, heating causes foaming of the solvent.

UV curing treatment: A method in which a printed article is cured by a photochemical reaction under ultraviolet (UV) irradiation at a specific wavelength.

Post-treatment process: In order to improve the durability of prints, post-treatments such as surface coating are sometimes performed.

The surface coating method is generally the most common application of a heat-curable or UV-curable clear coating solution.