Screen printing methods and requirements for special products (1)

First, Lottery silk screen

In the past 10 years, the need for masking inks has increased year by year. In the offset text, numbers, symbols and then use screen ink thick screen printing film, so that it is completely covered, and then made of cards is a lottery ticket. Lottery tickets come in many forms, such as sports lotteries, social welfare fund-raising lottery tickets and so on. This type of lottery ticket can be seen by using coins or nails to scrape off the masked ink, and the printed text, numbers, etc. can be seen below. In addition, by masking images, words and numbers can be combined into a variety of interesting entertainment, which is very popular.

1. Lottery ticket composition, because most of the lottery ticket is a one-time, so paper printing, generally 150 ~ 200g/m2 of coated paper. First of all, with offset printing of text, numbers, images, etc., the printing surface of the offset printing is flat, which is advantageous for the final screen printing. The offset-printed printing surface must be coated with a good transparency, and its function is not only to make the masking ink strippable, but also to make the offset printing image stable. The final screen printing is then performed on the coating using masking ink, typically only partially masked thick film printing is performed on the letter and the digits.

2. Lottery performance requirements. 1 After the masking ink with stability is printed on the lottery ticket, it should be easier to peel off with nails or coins. The ink lottery ticket printed as a commodity is stable for at least one year of circulation. 2 After removing the masking ink, the exposed characters, numbers, etc. cannot be contaminated by the ink. 3 Masking ink should have sufficient shielding. (4) The ink film that covers the ink should have certain toughness, that is, the surface of the ink film must not be damaged by some external force during operations such as drying or cutting of the lottery ticket, and the same requirements must be met in the circulation of the product.

From the above points of view, 3 and 4 are almost determined by the performance of the masking ink, so it is very important to select the appropriate ink. The 1 and 2 are determined by the degree of adhesion of the coated paper and the masking ink. The faults that existed in previous experiments are mainly 1 and 2, so this is a key issue.

Second, the silk screen of electrical decoration advertising board

The electric advertisement board generally projects light from the inside of the advertising board to make the surface more beautiful. The main materials used are acrylic plates and glass plates. In addition to printing, the board is also decorated with cutout text and lines. The main processes of screen printing electrical decoration advertising board are surface printing, inside printing, full shading printing and so on.

The most commonly used electric advertisement boards printed inside are electric screens printed on the inside of an acrylic board, and finally printed in solid white, and the surface of the board can be formed into a glossy decorative pattern. If the light inside disappears, light from other directions will reflect on the surface and various colors will appear.

In the case of surface printing, milky white translucent plates are generally used. Since all-white printing is not required, uneven quality rarely occurs, but scratches are easily generated on the surface.

When shading, it can be printed in two ways. If the surface is intended to be shaded with full red, the same plate may be used for shading purposes before the full red color is printed, silver or gray is printed, and then full red is printed on top. When the electric decoration is performed, only the text or the pattern part is highlighted, which is very clear and beautiful, so it is often used for the printing of road signs or guide plates.

In the case of acrylic printing, the material itself is highly charged due to its electrically charged nature and it is easy to adhere to dust.

Since dust adheres to the electrical panel very clearly, in order to eliminate dust and prevent static electricity, alcohol is used to wipe the substrate once before printing. Because the light is emitted from the inside, the printed scratch marks are also very noticeable. For this reason, great attention is paid to the grinding of the squeegee, the printing pressure, the printing speed, etc., and uneven printing should be minimized. Due to the use of a good light-transmitting ink, after printing and electro-decoration, the tinge of a person's tone seems to have changed completely. When combined with other colors, it is possible to make products that differ from the customer's requirements if light transmission is not observed. In the case of four-color printing, if the color is adjusted without light transmission, a very light and blurred image may be formed.

Third, the metal advertising board silk screen

Metal advertising boards refer to guide plates and billboards whose materials are metal plates. Their predecessors were billboards and melamine billboards. Metal materials are mainly made of aluminum and stainless steel. The surface of stainless steel has the advantage of no rust. After screen printing, hardener can be applied to the surface for processing. Aluminum can use its plasticity, embossed by the pressure method, so that its surface has a concave and convex pattern, enhance three-dimensional and improve visual effects.

The earliest metal billboards were enamel billboards. They were made of galvanized iron plates and used enamels to prevent rust. They were mostly used for billboards, place name plates, etc. Although this brand is adaptable to the climate, the process is time consuming and coloring is not easy. With the development of spraying technology, melamine billboards began to appear, which improved the rust-proof performance. It can be colored by digging-cut screen printing. Since the billboard began using hard plastic as the main material, the melamine advertising board gave people a sense of being out of date. Iron plate billboards are old and obsolete. Due to their own weight, processing is affected and it is difficult to circulate products.

The main material of the metal advertising board has been transformed into aluminum sheet or thin zinc sheet. These materials are light weight, have good processability, and are easy to handle even if they are large in size. In order to increase the strength of the metal sheet, a part of it may be raised as a rib, and the amount of material used is approximately the same as that of the flat plate.