Review of lithographic printability (7)

VII. Suitability of materials

(1) Selection of printing plates: There are many kinds of printing plates, which can be: 1. Plates are divided into aluminum, zinc, stone, resin, nylon, cardboard and glass. 2. The structure is divided into single layer, double layer and multiple layers. 3. The plate making method is divided into manual, transfer, optics, and electronics. 4. Plates are divided into plano-convex, plane, and plano-concave. 5. Grinding methods are divided into ball mill, brush mill, chemical mill, electronic chemical mill, blasting mill. 6. Layout treatment consists of chemical and anode. 7. Film coating methods are self-coated, machine-coated and pre-coated. 8. The film coating surface is divided into single-sided and double-sided. 9. Shaiban tablets are divided into positive and negative types. 10. Film processing methods are divided into film type and film type. 11. There are 11 types of printers, including proofers, express machines, pagers, rotary machines, and business printers. Seen from the above, there are quite a few types. In fact, at present, many printing plates used by Taiwan's lithographic printing plants are pre-coated and positive ones, and are generally referred to as the PS version. The quality of printing using this type of printing plate is quite high, and the plate making procedure is simple, as long as it is automatically processed in the plate processor, it can be completed in a few minutes. However, there are still a few home-style printing plants that use zinc or aluminum plates to make plates that are specially designed for small amounts of book printing.

(b) the choice of paper: there are three types of choices, quality and weight. In terms of species, there are 1. Printing Paper: Bond Paper, Book Paper, Magazine Paper, Newsprint Paper, Mould Paper, Coated Paper, Bible Paper, Dowling Paper, etc. 2. Writing paper: book paper, letter paper, miscellaneous paper, typing paper, card paper, drawing paper. 3. Drawing Paper: watercolor paper, special paper, ordinary paper, charcoal paper, sea drawings. 4. Packaging paper: kraft paper, sulfite paper, match paper, anti-rust paper, cigarette paper, fruit paper, sulfuric acid paper, cellophane paper, wax paper. 4. Filter paper: chemical analysis paper, insulating paper. 5. Absorption paper: blotting paper, carbon paper, napkins, toilet paper. 6. Special processing paper: back carbon paper, photosensitive paper, fiber paper. 7. Cardboard categories: yellow cardboard, white paperboard, coreboard, corrugated cardboard, ticket paperboard, construction cardboard and other seven categories.

Seeing that there are so many types above, it's not hard to know how to make a choice for a time. It is not difficult to do so, because the most commonly used are the first type of wood forest paper, molded paper and coated paper. In terms of quality choice, Daolin Paper has all-wood forests, ivory road forests, Baidao forests, and color road forest paper. Mold paper has white mold, beige mold and color mold papermaking. Coated paper has a mirror copper plate, super light double copper, super double copper, double-sided copper plate, single-sided copper plate, snow plate copper plate and coated copper plate paper and so on. There are also the choices of printing paper, magazine paper, scheduling paper, and advanced scheduling paper. In fact, there are only a few of them.

(C) the weight of paper: There are two commonly used methods of weighing - ─ 1. Basis weight, is more common in the world, is a one-meter square of paper, weight on the electronic balance, in grams , which is gsm, or "mipping amount." 2. Weighing, weighing a pound of 500 sheets of paper, which is pounds/order. Both are used at home and abroad, but for the sake of convenience, it is easier to use the basis weight to avoid the same thickness of the paper in the 31x43 "pounds and 25x35" pounds, often easy to mess. The basis weight of most papers is from 60 to 100 gsm, that of coated papers is from 80 to 190 gsm, and that of molded papers is as low as 45 gsm. The use, purpose, function, and characteristics of the paper must be known before use. It is not difficult.

(4) The relationship between paper and humidity: First of all, we must know that paper is a pulp consisting of 99% moisture, 0.5 to 1% cellulose, fillers and gums, referred to as pulp, and then sent the pulp. On the paper making machine, the pulp cloth is filtered on the moving wire mesh to remove most of the water through a long sliver funnel, and then the hot water is squeezed out by the hot-pressing wheel to dry off the excess water to make a paper. After the above brief description, we can know that the paper has "mesh and non-mesh" points, with a thick mesh surface and a non-mesh surface. At the same time, there will be a "silk flow", that is, the arrangement of fibers in the direction of the strip. This directly affects the paper and causes the phenomenon of bending after being damped. This has a lot to do with bookbinding. If the flow of paper follows the long edge, the edge of the book is straight, otherwise it is very easy to bend.

(5) Selection of inks: Lithographic printing inks are mostly transparent four-color inks, and there are not many choices for color printing. At most, gold and silver are added. On the other hand, there are many choices in color printing, and in special printing, there will be various choices due to certain special requirements, such as fluorescent ink, pearl ink, desensitizing ink, magnetic ink, and ultraviolet ink. There is also a distinction between transparent and opaque ink. Nowadays, many large printing plants use four-primary transparent ink in large barrels. The automatic transfer pipe for high pressure pumping is used to send the ink directly to the printing press. The staff will not be too troublesome and do not need to transfer ink. This work has become very It's easy.