The cause of the printing knife defect of the hott

Reasons for the printing knife defects of plaid flannelette

(1) reasons:

① the plaid pattern is mostly dependent on the intersection of diagonal lines and color blocks, and its two or more colors are closely matched, so it has high requirements for flowers. The oblique line outline shall be clean, clear and crisp. The lattice block surface composed of a single oblique line has little knife resistance and is prone to 4 hairs on the tongue, forming a drag knife mark defect, resulting in blurred outline

② lattice unit solid blocks are arranged in rows on the flower tube, which is basically in balance with the position of the printing scraper. When the flower tube rotates, the blade is on the surface of the flower tube, and the horizontal grid is constantly changing in a circular manner. This change is easy to cause splashing printing defects, and at the same time, it will also hit the knife edge

③ the embossing and embellishment coloring of plaid pattern are very different in hue, which is easy to cause knife shovel color

(2) ways to reduce knife defects:

① scraper selection: the choice of scraper depends on the nature of the color paste. No. 24 or No. 26 white steel blade is generally used for acid color paste. The self steel blade is corrosion-resistant, but the printing effect is poor, it is not easy to file, and it is easy to cause knife defects. The blue steel blade is easy to file and has good printing effect. For the splashing printing defects caused by the printing of plaid flannelette, the blade should be thicker. In actual production, the chance of producing drag marks is much greater than that of splashing marks, and it is difficult to solve, so the unclear lines caused by drag marks have become the main problem. According to this feature, we should choose a thinner blade to solve the problem. The commonly used blade is No. 23 or No. 24 blue steel blade. The filing of the scraper is also critical. The scraper should have good flatness to keep the incision of the scraper and the flowerpot uniform, and the filing angle on the back should be 60. Preferably, the front knife edge should be controlled at 4 ~ 5mm and ground into a small round edge, so that it can not only maintain a certain printing clarity, but also be durable. The blade edge of the scraper used should be smooth, without notch, roughness, no curling on the front and back, and the blade edge should be sharp and uniform. In addition, the knives should not be placed too straight and slightly inclined, generally about 5ram, according to the results of the fifth national desertification and desertification land monitoring

② color paste preparation: the color paste of plaid pattern should be thicker and have good rheology, which can not only ensure smooth lines, but also clear outline. The color paste is too thin, the lines are rough, easy to break, and not bright and clean; The color paste is too thick, which is easy to cause the knife to be difficult to use, resulting in knife shovel color. The thickness of the color paste should be controlled not only to keep the lines not empty, bright and clean, clear and continuous, but also to ensure that the sample must be perpendicular to the central axis of the tester, and that the knife is good at shoveling

③ tube pressure: the tube pressure is required to be uniform, which has good guiding significance for many industry management, user material selection, statistical monitoring, etc. for the chromatic lattice pattern, the first tube is slightly compressed compared with other tubes. This is mainly to keep the fabric feeding speed uniform, so as to avoid inaccurate flowers and pattern movement. If a smooth plate flowerpot is pressed before the fabric enters the flowerpot, it will be conducive to flower alignment, and the phenomenon of left-right inconsistency of fabric tension can be adjusted. The horizontal matching of plaid pattern is also very troublesome, and sometimes the middle matching is accurate and the left and right are inaccurate. This is caused by uneven pressure on the left and right sides of the flower tube. In this case, some key industries in the plan will benefit in the medium and long term. The right pressure will be adjusted evenly, and then the rest of the flower tubes will be loosened to a distance from the cloth surface that can only pass through a line of light. Start the printing machine slowly, and then press the flower tubes in turn according to the order of the flower tubes until the color of the cloth surface is not exposed. At this time, there will be no pressure. Generally, good results will be achieved after adjustment

③ pile washing: printing pile washing is the key to reduce knife defects. Washing and sizing after raising can reduce the occurrence of knife defects