Application Of 3D Printing Technology In Textile Stereoscopic Printing

Application of 3D printing technology in textile stereoscopic printing

　　 3D printing It is a popular special printing in recent years. Stereoscopic printing is simulating the distance between two eyes, shooting from different angles, recording the left and right pixels on the photosensitive material. When watching, the left eye can see the principle of the left pixel and the right eye to see the right pixels. It can reproduce objects vividly and has a strong sense of three dimensions. The product has clear image, rich level, vivid image and profound artistic conception. The gloss of printed matter is good, the color is bright, and it is not easy to fade. Because the printed product surface is covered with a concave convex column mirror grating plate, it can directly view the three-dimensional effect of panoramic picture. In addition, 3D printing is also widely used in manufacturing printing industry, such as 3DP printing technology, which can be used to manufacture ceramic shell and core for casting. With the continuous development of screen printing technology and the increasing demand for novelty of fabric printing, special printing has played an important role in fabric printing. Textile printing has opened up a new direction for development.

Printing printed text on textiles has always been following the traditional print process. Printing technicians can print anything imaginable, but designers can only design flat objects, except for foamed ink. Although foamed ink can produce three-dimensional effects, it is difficult to control the degree of foaming. Even the best printing workers can hardly reproduce the fine level of images accurately when printing with foamed ink.

The characteristics of three-dimensional image printing are not merely the use of a different kind of ink or emulsion. The successful three-dimensional printing needs to master different operating procedures with ordinary printing. Compared with the standard printing process, although it is not very difficult, but there is a great difference, and must be combined with many comprehensive systems, three-dimensional printing can produce new huge impact.

Screen printing is the most commonly used printing method for textile printing. On the screen, 3D printing is made of 24 wire /cm screen and stretched on a reusable net frame with tension of at least 30N/cm.. There are currently 5 kinds of wire diameters in the wire mesh, with a range of 120~145 m. Practice has proved that the finest wire mesh is better, because the wire mesh with fine diameter can make up as much ink as possible in the same opening. In addition, it is better to use dyed screen, because the emulsion used in the three-dimensional printing process needs a longer exposure time, while the dyed screen can reduce the light scattering performance. On the stencil, screen printing technicians know that the thickness of the template is the main factor affecting the ink film thickness. In 3D printing, the thickness of the template is directly related to the thickness of the ink film after curing. Practice has proved that if every operation procedure is ensured, the curing ink film can reach 90% of the thickness of the template. In 3D printing, a template of 200 m is usually used.

At present thick Template There are mainly 3 kinds of production, each of which has its own merits and demerits. Although the emulsions used in each coating method are slightly different, rapid exposure must be used to compensate for the ultra thick emulsion layer. Quick exposure SBQ emulsion or pure photosensitive resin emulsion (liquid or diaphragm) preferably use diazo or double curing type. For screen printing, we need to know not only how thick the printing template is, but also how to make thick template. Let's talk about the selection and use of materials in three-dimensional printing of fabrics.

1. the most basic method of liquid emulsion is to use liquid emulsion repeatedly coated on the screen. It needs to be coated on the screen printing surface for 15~20 times, so that the template reaches the required thickness. First, the first layer of emulsion is applied to the printing surface of the screen and then thoroughly dried. In order to shorten the drying time, the drying chamber should have a dehumidifier to keep the humidity between 40% and 45%. After coating the first layer of emulsion and drying, tape around the image of the same printing surface to increase the thickness of the template quickly. Coat second layers of emulsion and dry with a layer of adhesive tape. Repeat second, third steps until the desired template thickness is achieved. The advantage of this method is that it can be operated with familiar technology. The disadvantage is that it takes a long time (at least a few days) and the thickness of the emulsion layer is not well controlled. The most difficult thing is that because of the irregular coating method, it is very likely that the total number of coated coatings will be missed.

2. capillary sensitive diaphragm is a fast method for making ultra thick template. It is to stick the capillary sensitive diaphragm to the silk screen. The most ideal material is a thick pure photosensitive resin capillary diaphragm. At present, 150 micron m direct chip has been sold in the market, and the 200~250 m diaphragm will soon be available.

When you stick the capillary sensitive diaphragm, you should first prepare a flat plate, smaller than the size of the screen frame, larger than the outer dimension of the image, 1mm thick, and the surface should be absolutely smooth. It is recommended to use glass plates, smooth edges and four corners, and ensure full contact between the wire mesh and the diaphragm. Then put a capillary sensitive diaphragm on the plate, the emulsion face up; then put the screen on the capillary sensitive diaphragm and print it face down. Along the side of the capillary sensitive diaphragm, pour a thin layer of liquid emulsion onto the screen, disperse the liquid emulsion on the entire screen, contact the capillary sensitive diaphragm, paste the mold piece, and finally dry the emulsion layer. However, it is important to note that the liquid emulsion compatible with the capillary sensitive diaphragm must be used, that is to say, the sensitizer used in the liquid emulsion is the same as the capillary sensitive diaphragm and has the same basic chemical properties. Most emulsion manufacturers can provide compatible emulsion and capillary sensitive diaphragm. To increase the thickness of the template, the polyester base can be torn off from the diaphragm after drying the capillary sensitive film / direct emulsion layer, and another layer of capillary sensitive diaphragm should be pasted on it.

The operation is as follows: first, the proportion of 1 liquid emulsion and 15 parts of water should be dispensed with the coating solution, and the tape should be affixed to the opening part of the screen printing. Then the screen is vertical to the edge of the cleaning pool, and coated with a coating solution to coat the thin sensitive diaphragm that has been pasted on the screen. Another layer of capillary sensitive film is pasted on the diaphragm that has just been wetted with liquid emulsion, and emulsion is laminated with emulsion layer. Dry the diaphragm and tear the polyester bottom film. If you want to increase the emulsion layer, you can repeatedly screen the vertical side of the cleaning pool and use the coating solution to coat the thin sensitive diaphragm that has been pasted on the screen. Repeat operation until the desired emulsion thickness is achieved. The advantage of this method is that the thickness of the template can be increased as required, the surface of the template is smooth, and the emulsion layer is well controlled. The drawback is that the operation procedures are slow, and certainly not as slow as liquid emulsion coating.

3. the fastest way to make thick emulsion layer by thick film is to use the thickest diaphragm. Its thickness range is 100~700 micron M., they are not capillary sensitive diaphragm, and need a special technology. First, choose a membrane with the required thickness. The size of the cutting is 6 to 10mm. larger than the image size on the template. The plastic protective film is torn off from one side of the diaphragm, and the emulsion is placed upwards on the surface of a flat plate (the plate is the same as the plate used for the capillary sensitive diaphragm mentioned above). The printing face of the screen is facing down and placed on the upper side of the diaphragm. Then dilute the liquid emulsion and mix it in 2 portions of emulsion and l of water. Drizzle the thinner liquid from the side of the diaphragm. Scrape the emulsion on the surface of the diaphragm and cover it evenly. Brush off the excess emulsion and dry the same version. When the screen is completely dried, the scraper surface of the screen will be coated with a bucket applicator filled with undiluted liquid emulsion. Dry the screen again, remove second layers of plastic protective film from the diaphragm and prepare for exposure. This method is the fastest way to produce 3D printing templates, but the supply of this template material is limited.

4. exposure of screen printing and screen printing, because emulsion type, thickness, coating technology and exposure equipment will affect the exposure time. No matter which coating method is used, the exposure time is very difficult to master. It is easy to have insufficient exposure and overexposure. Therefore, an exposure calibration device can be equipped with conditions. Generally speaking, exposure can be mastered in this way: for example, the exposure light source is 500kW metal halogen lamp, the distance from the template 16cm, the coating thickness is 700 m, and the exposure time should be 7.5 to 8min.

The way to clean the screen is to soak the two sides of the screen after exposure. Let the emulsion soak for a few minutes before rinsing. The cleaning process should not be urgent, soak and rinse until all images appear. If the Yang pictures used are very clear and the density is high, the level of development will be very clear. Because screen printing time is longer than that of ordinary screen, there must be great patience.

Five printing ink At present, some ink manufacturers can provide ink and additives for stereoscopic printing, and some manufacturers have developed a new type of ink production line. However, it is important to note that the stereoscopic printing ink is not a foaming ink. In fact, any visible foaming will affect the clarity and the three-dimensional effect. The curing temperature of 3D printing ink is within the curing range of standard plastic ink (usually 149~171 degrees Celsius), but it must be raised to the curing temperature suitable for ultra thick ink layer. If the ink layer is completely solidified, three-dimensional ink will have the same elasticity as standard plastic ink.

Although three-dimensional printing ink is not common, this ink is quite different from the common thick plastic ink layer. If done correctly, the three-dimensional printing image will have a distinct fine level and a clear edge. The printing edge will be raised vertically from the fabric surface and the ink wall will be smooth. Because the ink used in three-dimensional printing is thicker, printing speed is better than usual. In order to achieve better results, the printing stroke should be as clean and smooth as possible. Scraping two times of ink will make the printed matter dirty. Although the ink is thick and the template is very thick, three-dimensional printing can still print good three-dimensional printed images. If you want to increase the thickness of ink film, the best way is to increase the thickness of the emulsion layer on the screen, and not to increase the thickness of the ink layer by scraping two times of ink on a screen. Because after the first ink layer drying, there will be clogging and no more than second scraps. Another way to increase the thickness of ink layer is to make two thick screen plates, continuously print two pieces of screen, and second stencils are printed on the first block printed image. The ink layer between the two screen printing can be dried in an instant, and the second layer of ink is covered on the first layer of ink film. As a result of printing, the thickness of ink layer is basically two times that of a block printing.

6. printing and printing on automatic screen printing machine is easy to debug. It is easy to debug the printing machine because it can control the net distance well, and the net spacing is the key factor in printing. The operation instructions of the automatic screen printing machine should pay attention to the following points: (1) adjust the screen to the printer and minimize the net distance; second, the ink coating speed is slower than the ordinary one, and adopt constant pressure of the ink board. If the angle of the ink board is adjustable, the angle between the ink board and the screen plate can be minimized, and then the ink is covered on the screen plate. Thirdly, the scraper with 75~80 degree medium hardness is used to adjust the scraper pressure, so that the ink on the same plate can be spanferred to the fabric well. Scraper speed is slower than ordinary, and the scraper angle is adjusted. 4. When printing, the three-dimensional part of the image should be printed at last and dried immediately after printing. If you print the three-dimensional ink first, and then print other color ink after drying, there will be a distortion near the part of the printing ink.