Discussion on the Characteristics and Process of Color Screen Printing Screen Printing Flower Pulp

Screen printing fabric special printing for textiles to increase the added value of goods and beautify the role of life. Because of the wide application of special printing, it also promoted the development of screen printing technology.

Color photographs, pictures, oil paintings, and gouache paintings are used to represent objects and spaces with color changes. The principle of using screen printing methods to reproduce colored originals on fabrics is based on visual theory. According to the principle of color separation, an electronic color separation machine is used to decompose color originals with complex color tones into single-color halftone dot positives for yellow, magenta, and cyan, and a color separation positive image is made with a photosensitive platemaking method. After that, the yellow, magenta, and blue primary colors are used to print the monochrome images together, and the color originals are reproduced on the printed fabric.

Positioning means

The error of the color halftone printing printing is allowed to be within 1mm. To make the overlay accurate, the cooperation of the positioning device is crucial. The color image of the screen printed on the paper is positioned by a crosshair. In the halftone color printing of the fabric, one positioning method is to position the various screen plates by the positioner of the plate and the ink pad, and the other method is manual. When printing small area images, use the eye position method. Positioner overprinting is used for mechanical and manual printing, and the production efficiency is high. The fitting clearance of the positioning nail in the positioning hole must not exceed 0.1 mm.

Textile screen printing stations are equipped with different forms of positioners to ensure accurate positioning. There are two types of screen printing in textiles: one is the fixed moving cloth, which is mostly used for manual printing; the other is that the moving version is not used, and it is mostly used for printing on flat screen machines. There is no fixed pattern depending on the specific situation. At present, the position of the printing platen is generally inserted.

Printing essentials

During the printing process, there are many factors that need to be adjusted or controlled, whether it is a mechanical or manual press. Especially for manual operations, various factors must be adjusted by people. The essentials for screen printing on fabrics are: ideological focus, squeegee pushing force should be uniform, angle should be consistent, belt should be balanced, and pulp should be clean. In the operation process, it is necessary to perform side operations, side inspections, and mutual inspections so as to achieve accurate overprinting, uniform thickness, and consistent depth and depth. The principle of printing plate arrangement order is first deep and shallow, first thin and thick.

The hardness of the squeegee and the table top has a great influence on the screen printing. The dot printing requires extremely high definition, the non-textile surface is smooth, the texture is crisp, it is not easy to be deformed, and the dot resolution is guaranteed. The textile has both hygroscopicity, the surface is not smooth, and there are fabric holes. How to print clear prints and how good the squeegee is is very important.

The effect of color quantity on mesh color printing is various. In textile color screen printing, the amount of color only affects the shade of the printed color, and the effect on the color printing of the dot is much greater, because the color of the dot printing pattern is achieved by overlapping and juxtaposition of dots, if a If the color layer is slightly in and out, it will immediately be reflected in the tone, so it is necessary to closely control and grasp the consistency of the amount of color (supply).

The distance between the printing plate and the substrate has little effect on the quality of the finished product in textile screen printing, but it is very important in the dot color printing. This should cause the operator's attention.

Mesh printing pulp features

Mesh color printing printing paste printing paste yellow, crystal red, blue three-color, in the actual printing also need to add a black, so the mesh color printing is also known as the four-color printing. This printing paste is water-soluble, and various fluorescent printing pastes are newly developed. In addition to the correct hue, the requirements for the coating printing paste for mesh color printing should also have a certain degree of transparency, viscosity, drying speed and fastness.

(1) Transparency

Mesh color screen printing is through the dot overlap and parallel reproduction of the original color and tone, which requires a certain degree of transparency of the printing paste. The transparency of the paste can be observed experimentally. The experiment is to print each color paste on a paper with a dark blue pattern, and after drying, observe the clarity of the original pattern, and the degree of transparency of the paste can be known.

(2) Viscosity

In order to allow the dots on the printing plate to be clearly and smoothly reproduced on the fabric, there is a certain requirement for the viscosity and thixotropy of the printing paste.

(3) Drying speed

The drying speed of the printing paste is directly related to the overprinting property of the printing paste, and also determines the printing interval between colors.

(4) Color mixing of printing paste

The color distribution of printing paste is a link that can not be ignored in the printing production process. The basic principle of deployment can not be separated from the color light addition method and color subtractive method.

In order to obtain the ideal color of the slurry, it is necessary to: understand the various specifications and properties of the printing paste, so that the printing paste with the production needs; master the basic knowledge of color, in the use of color palette; the color of the printing and Process technology for analysis, to identify the color of the color sequence, so as not to wrong color sequence, two-color miscibility, color changes; color care should also pay attention to the deployment of primary colors, or easy to make the color out of the "grey."

Mesh color printing product quality

How to evaluate the quality of fabric color mesh printing products is a very complicated issue. For example, the printing industry pays great attention to the pattern of the turtle, and the textile industry holds different views. The current evaluation of fabric color mesh print quality focuses on the degree of copying of the original. It should include three things, namely: whether the tone reduction is complete; whether the color reproduction is accurate; and whether the sharpness meets the requirements.

The appearance artistic effect of fabric printing products is of great importance to the market value of the product. The first product must be clean and tidy, and the second must reflect the characteristics of the fabric. The overall artistic effect must be beautiful and coordinated. In addition, we must pay attention to the packaging and decoration of products.

5. The main defects and preventive measures of mesh color printing

The common defects in fabric screen printing are mostly generated during the printing process and post-processing. In actual operation, analyzing the causes of flaws according to specific conditions and taking corresponding measures is a good way to prevent fabric printing defects.

Source: Screen Printing