Several Kinds of Postpress Printing and Finishing Technology of Paper Products

Post-press processing technology, also known as post-printing technology. Strictly speaking: after the printing technology is not a technology, can only be called a method, but in the anti-counterfeiting packaging, due to the different printing locations, will directly affect the anti-counterfeiting effect. Therefore, the author believes that post-printing (anti-counterfeit) is a technology with special significance, because traditional printing will provide opportunities for counterfeiters due to poor management, and secondly, it cannot suppress the activities of criminals from the economic side, and the printing technology is just right. Solve the above two problems.

After the printing carrier is completed, it is often necessary to design the printing process based on the object such as paper container processing or book binding or surface processing (ie, the finishing process of the finishing technology), and in the finishing technology of the paper container, usually Using composite - film - hot stamping - polishing - molding. The following is a brief explanation of this common process.

1 . Film . Before coating, a strict inspection of the quality of the finished paper print should be carried out - because the surface of the film is flat, clean or not, the hardness, the smoothness of the edge, the speed of drying, the amount of residual solvent, dusting, The accuracy, strength, and laminating speed of the composite board will directly affect the film quality of the paper products (such as air bubbles and wrinkles).

2. Pad printing . Although it is second only to hot stamping, it is favored by the printing industry because of its low material cost and continuous batch production, as well as the ability to complete rotary transfer printing and slitting in one shot, with less waste. Taiwan's gravure pad printing equipment mostly uses acrylic resin as the link material, plus gold, silver powder, etc., and directly adopts rotogravure printing to print the ink on the PET mold first, and then randomly transfer to the printing material again. The emergence of the technology, first, is much lower than the cost of stamping, the second is the ability to mechanical rotation continuous operation, but better than the letterpress transfer printing effect, slightly more than the hot stamping effect.

3. Silk screen printing . The method is mainly to directly print UV ink or transparent ink on gold paper or silver paper (usually used in cigarettes and wine box packaging in recent years). As a part of the decoration, it is often screen-printed with a manual or rotary screen. Because silk screen ink film is thicker than gravure pad printing 1~2 times, some units still use the copper and zinc plate to make the hot stamping technology on the electric aluminum. There are also varnish or ink transfer printing spring couplets, and then put the aluminum surface and flat surface paste, pressure on the flat, such as varnish or varnish oil completely dry and uncovered, it showed almost the same hot stamping with the quality of hot stamping.

4. Hot stamping. This is the production method that has been used for nearly half a century. Hot stamping temperature, pressure, hot stamping speed control determines the quality of hot stamping. After hot stamping usually requires: graphics and text does not change color, no white, no fade, and so on. Although hot stamping is lower in efficiency than wheel transfer printing, it has the advantage that printing and screen printing are not comparable to small pieces of printed materials. In particular, hot stamping on the job (photos) cannot be replaced by other methods.

5 . Polishing . Paper products should be selected according to the use of coating oil (paint slurry). In 2003, Wuhan Jinlong Cigarette Factory imported two high-speed labeling machines (two times the traditional, almost increasing the temperature by nearly 50 degrees). When traditional alcohol-soluble cigarettes and coating oils are used, the results are due to speed or The influence of temperature caused the migration of ink on the trademark and the sticking of the varnish to fail to be properly labeled, and the authenticity rate was less than 70%. After the improvement of ink and coating oil, it was transferred to normal production. At the same time, the UV coating of the cigarette box should be left at the joints on both sides to prevent the glue from sticking out.

6. Security . Laser holograms are printed directly on paper, so-called security paper. Now generally used in securities (such as covering the scratch scratch ink) mostly. There are also technologies such as printing anti-counterfeiting technology and security line anti-counterfeiting for watermark paper carriers that use coins as substrates. There are also miniature letter security thread, fluorescent security thread, business card paper, pearl paper, laser iris paper, aluminum foil and gold foil paper, silver foil paper and reprocessed embossed paper, refraction paper, punch paper, and matting paper. Even in the papermaking process, red, blue fibers or colored flakes (blocks, powders) are incorporated into the pulp, or are scattered on the surface before the paper is unmolded, fluorescent reflections occur under ultraviolet irradiation, and the like. Plano-convex printing and multi-process printing, special gloss printing, special matt printing, and laser holographic iris printing are collectively referred to as anti-counterfeit finishing technology for paper products.

7. Molding. Under proper pressure, the location of the indentation of the packaging paper product should be accurate, and the focus of its technology is the accuracy of the template. There are also paper-based prints made with air-press calendering, matte, iced, etc., which are also popular with consumers.

Paper finishing technology in the final analysis: You are looking at the other side and the financial class by-pass. Because with the development of the times and the passage of time, the situation will undergo new changes, especially the amount of solvent volatilization and total solvent residues in the ink, varnish and adhesive systems after film formation in the process of paper product finishing and The problem of environmental pollution caused by the amount of waste slag, etc., all we have to do is to solve the many problems that have been forced by the advancement of technology. As soon as possible, China's paper product finishing technology is becoming more perfect and perfect as soon as possible.