T-shirt Printing Prepress Technology (4)

Fourth, screen production

1. Screen making materials, tools

The screen is composed of a frame, a screen, and a photosensitive adhesive. The materials used include nail nails, adhesive meshes, and sealing tapes. The tools for making screens include: stretchers, stretch clamps, and nail guns. , glue machine, glue scraper, dryer, printing machine, water spray gun and so on.

T-shirt printing generally saves a certain number of pattern screens and has a long shelf life. From the economical point of view, the screen frame is generally used. The material of the wooden net frame is preferably fir, and the wood nail gun with a too hard texture is difficult to nail the net nail, and the wood with a too loose texture is easily deformed and loosened.

The use of nail guns is faster and more convenient than sticky nets, but it has poor screen stability. If you can combine the best of the two.

Since T-shirt printing mostly uses water-based paints, polyester mesh should be used because nylon mesh easily expands and relaxes when exposed to water.

2. Stretching the net

T-shirt screens have the same technical requirements as normal screens. However, it should be noted that the screens selected for the different printing materials should be suitable. For example, in a screen set, there are water slurry printing materials and foam printing materials, gold and silver paste printing materials, then the water slurry should adopt 120 mesh screens, and the foamed pulp and gold and silver pastes should adopt 80 to 100 mesh screens. The screen version of the screen is recommended to use a 140-mesh screen. Printing with chemical fiber or purified fabrics, such as the use of water-based printing should be used 140 to 160 mesh screen, the use of ink should be used more than 240 mesh screen.

3. Photographic plate making

Water-based printing materials using water-based photosensitive adhesive, thermosetting ink and solvent photosensitive adhesives are available, with solvent-based photosensitive adhesive is preferred because it is easier to remove the film.

In the screen plate coated photosensitive adhesive should pay attention to the adhesive layer, the general printing surface adhesive layer thicker than the squeegee surface layer. The thickness of the photosensitive film varies greatly depending on the printed material, fabric, and graphics.

(1) The screen mask for screen printing should be printed. If the film is thick, there will be more missed material, making it easier to make the dots paste.
(2) Chemical fiber fabrics Whether ink or water-based paste, heat-curing ink, screen printing film should be book, to prevent paste version, and secondly, printing products will also feel more soft due to printing materials. However, if it is printed thicker Oxford cloth (more than 400 dens for school bags, etc.), the film can be thicker.
(3) The thickness of the screen printing paste and foam printing screen layer must be thick. Especially when printing paste on dark fabrics and rough fabrics, the screen adhesive layer should be about 3 times the thickness of the screen printing adhesive layer (0.3mm or more), so that the printed paste will have strong hiding power. The printed surface is bright and clean.

The production of T-shirt printing screens and their technological requirements are basically the same as those for conventional screen printing. However, since the printing of the glue is about 80 mesh screens and thick film, it is important to take care of the exposure time to avoid exposure during printing. The edges of the image appear jagged.

The prepress process not only determines the quality of the T-shirt production, but also determines its success or failure. In the business, a beautifully designed T-shirt is not very delicately printed, but it can still be sold, because consumers know how to print technology is rarely; but if a T-shirt design is not good , if you print more fine, no matter how good the fabric quality, it will be no one to buy. Because buying a T-shirt is buying culture. The value of a T-shirt pattern is more than the value of a T-shirt blank. Therefore, the design of the T-shirt pattern plays an important role in the composition of the T-shirt value. Of course, this does not mean that print quality is not important. With T-shirts with high printing quality, even consumers who do not understand printing technology can distinguish the level of their acceptance by feeling. We sum up a word in practice: whether the pattern decides whether to sell or not; whether the printing decision is sold well (price).

In addition, in the printing exposure, our company's usual exposure time requirements are not very accurate, but if you use the print test table for testing, you will find that the control of the printing time may not have a big effect on the thick lines, but for Fine lines and screen dots have a great influence. To produce a high-quality screen printing version, you must carefully determine the exposure time. Is the same set of four-color screening film, due to the different dot density of different colors, exposure time should also be different, low-profile screen exposure time should be slightly shorter, high-profile screen exposure time should be slightly longer to avoid loss of high-light outlets .

In addition to computer production, prepress technology can be said to be not difficult to master. The important thing is that it is serious and strives for excellence.




Author: Lu Yunlu