The image quality problem of the printing product of pure cotton direct jet machine
Cotton Direct Injection MachineThere are many problems often encountered in printing processing, and how to solve these problems, here is a brief analysis for everyone to help you effectively avoid or improve in future operations.
1. The image clarity of the digital direct-injection printing product is not good
(1) Phenomenon. The image is blurred and there are broken graphics in the image.
(2) Cause: The height of the jet nozzle is not adjusted properly, or the inkjet resolution does not match the fabric.
(3) Solution: Due to the weaving method of the fabric, the surface cannot be as smooth as paper. Generally, digital direct-injection printing mostly uses 360-720dpi for operations. Very few fabrics will be printed with 1440dpi precision. Because if the surface of the fabric is not smooth, no matter how high the accuracy is, it will not make sense, and it will affect the jetting speed, which will increase the operating difficulty of software, computers and digital direct-injection printing equipment. The resolution should be reasonably selected according to the fineness of the pattern and the finish of the fabric, and the height of the nozzle should be reasonably adjusted for fabrics of different thicknesses. If the print head is too low, it is easy to block and scratch the print head (friction to the fabric is not flattened and easy to wrinkle), which will affect the color of the pattern; The angle of the parabola, the boundary of the printed pattern will be blurred, the accuracy is poor, and the color is not bright enough. So when printing, you need to adjust the nozzle to the proper height.
2,T-shirt printerThe color level in the printed product pattern is not rich enough
(1) Phenomenon: The level transition in the pattern is unnatural, the tone of expression is not strong, and the level is relatively smooth.
(2) Reason: improper selection of ink or not suitable for the fabric.
(3) Solution: Digital direct-injection printing uses the number of sprayed droplets to change the color level. As stippled jet printing, there is no problem in expressing dark colors with high dot density, and sometimes it feels a little bit bad. Or due to the mixing of extra color points, it is easy to produce the phenomenon of gray and dark color and reduced color vividness. In order to solve the problem of light-colored areas, the density can be increased by using both dark and light pigments and dual pigments to produce better results. Another method is to pre-mix the colors. The so-called "spot color" jet printing, but it must be supported by a color measurement and matching system and an automatic slurrying system, and the number of sets will be limited.
3. In the process of digital direct-injection printing, the surface particles of the finished product are relatively coarse or there is ink flow
(1) Cause: It is caused by improper adjustment or damage of the ink jet port.
(2) Solution: the choice of digital direct-injection printing accuracy. Generally, worsted fabrics are mostly printed with high precision 720x720dpi. The printing accuracy is directly related to the printer's resolution. Using 720dpi resolution for fabric printing, the accuracy is already quite high. The general woollen fabric can be printed with 360X360dpi precision. This can increase the printing speed and meet the printing accuracy.
4. Ink bleeding after digital direct-injection printing
(1) Reason: Because the volume of the fabric printing part can absorb less ink, under the action of the capillary effect, the excess ink on the fabric surface diffuses along the capillary between the fibers, causing the digital direct injection printing pattern to bleed. In addition to the composition of the ink itself, the main factors affecting the permeation of the dye ink on the fabric are also very important factors including the type of fiber and the structure and specifications of the fabric.
(2) Solution: Treat the fabric with a suitable thickener to block the gap between the fibers and prevent the ink from spreading along the capillary. For light and loose fabrics, the gaps between the fibers are large and the water holding capacity is poor. In digital direct-injection printing, the ink is easy to flow along the gaps between the fibers, causing bleeding. The structure of the fabric is tight, the space between the fibers is small, and the ink permeation is small. The quality of the thickener and the ratio of use are very important, and it is necessary to use a gradient ruler to compare (sample) in the proofing for experiments.
5.Digital t-shirt printing machineThe color fastness of the printed product is not good
When using pigmented inks, when the pigments reach nano-level dispersion, the only disadvantage is the decrease in solarization. The order of light fastness is as follows: acrylic resin> polycyanamide resin> body dye> rosin ester. We know that cationic dyes have poor light fastness, and when dyed on acrylic fibers, they have good light fastness. When acrylic emulsion is used as pigment printing adhesive, the printed fabric generally does not have the problem of unqualified light fastness. The hard monomers in acrylic emulsions generally use acrylonitrile or methyl methacrylate to improve its stability under the conditions of direct sunlight and heat treatment. When it is used as a paint binder, it can also significantly improve the light fastness of the pigment. Pay special attention to the constituent elements of dye ink when choosing dye ink.