Offset printing suitability (middle)

Sixth, the suitability of post-press processing

(A) Post-processing: After printing, the surface is processed with: water-based PVA. This is an early method. It has good transparency, good moisture resistance and good water resistance, but solvent-resistant inks must be used, and it is rarely used. At present, there are more commonly used UV coating and PP, OPP plastic film, etc., film scalability, good stiffness, do not have to use high heat and high pressure, single-sided and double-sided blemishes can be, do not have to pay too much attention to the ink drying The problem is therefore the most popular one at this stage. It is divided into smooth and matte, each with its own different feelings and effects. In general, advanced book covers, book clothing, and Chinese paintings use matte surfaces. For glossy books and magazines that highlight color effects, bright surfaces are often used. Only when the humidity changes, thin paper can cause curling as its disadvantage. Another bronzing process must be carefully considered before or after polishing. After the first bronzing, the glazing is protected and the gold foil is not easy to wear, but the gloss is poor. If the gilding after the first glazing is sometimes difficult after UV glazing, this must be considered in advance.

(2) Stapling: Although there are various kinds of binding, there are hardcover, paperback, saddle-wear, threading, and binding. All kinds of bindings have different characteristics. In the binding process, it is necessary to pay attention in advance to the requirements of processing machinery. , to do all the preparations, can only be carried out smoothly, otherwise it will produce a lot of unnecessary post-order issues, such as: folding alignment, folding sequence, binding time extension, homework and so on. Another hardcover, pay attention to paper and paste materials, and whether it will be after the paste due to poor absorption of the material off, but also pay attention to whether the weather is affected by changes in its quality and after the paste to be fully dry and other factors. Binding books must pay attention to the quality of the hot melt glue, and the internal pages and the cover must not come off due to brittleness.

VII. Suitability of finished products

(a) posters: mostly single prints. The requirements for the use of paper should be not easy to stretch, and the ink used should not fade easily. Because it is often hung in the hall and exposed to the wind, it is best to protect it with a layer of PP or OPP film after the printing is completed. This will not only enhance the color brightness, but also make the surface less susceptible to color. Loss also has the potential to stop UV radiation and reduce fading.

(B) Catalogue: Its main function in the performance of product features and advantages, so the production of beautiful and attractive is the most important condition. This kind of print must use high-quality paper, beautiful color pictures, exquisite design, careful processing and binding, so that readers like to achieve the effect of publicity.

(C) magazine: This is a book for the public to publish, and sometimes there are certain objects, the use of paper mostly for printing paper, printing methods are mostly lithographic, binding more riding nails, thick books are used for binding. Production also has time and quality requirements.

(D) books: divided into stringed paperback and hardcover books, threading paperbacks for schools, general novels and other books. Hardcover focuses on advanced books and dictionaries. In the production, in order to adapt to its long-term preservation characteristics, it must be long straight for the direction of the trade flow to be more straight.

(E) Form: often multi-joint type, the current use of non-carbon paper is more, can use carbon paper as its main advantage, but the non-carbon paper has the upper paper, medium paper, the next paper, the upper paper for upper use, The middle paper is for the middle layer, and the lower paper is the lower layer. When using, please pay attention to the layer of the paper. When the following paper is placed on the upper layer, there is no replication function.

VIII. Suitability of materials

(1) Selection of printing plates: There are many kinds of printing plates, which can be:

1. Plate is divided into aluminum, zinc, stone, resin, nylon, cardboard, 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. Plates 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 many types. In fact, at present, many printing plates used in Taiwan's lithographic printing plants are pre-coated and positive-type ones, or simply PS plates. The quality of printing using this type of printing plate is very high, and the plate making procedure is simple. It can be completed within minutes by simply placing it in the plate processor. There are still a few family-owned printing houses that use zinc or aluminum plates to make a small version of a protein plate.

(b) the choice of paper: there are three types of choices, quality and weight. Total in terms of categories:

1. Printing Paper: Bond paper, printing paper, magazine paper, newsprint paper, model papermaking, edition paper, bible paper, doline 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, thallium paper, cellophane, wax paper.

5. Filter paper: chemical analysis paper, insulation paper.

6. Absorption paper: blotting paper, carbon paper, napkins, toilet paper.

7. Special processing paper: back carbon paper, photosensitive paper, fiber paper.

8. Cardboard: yellow cardboard, white cardboard, coreboard, corrugated cardboard, ticket cardboard, construction cardboard. Seeing that there are so many types above, I really don't know how to make a choice for a while. It's not difficult, because the most commonly used are the first class of woodland paper, molded paper, and offset paper. In terms of quality choice, Daolin Paper has all-wood forests, ivory road forests, Bai Daolin, and color road forest paper. Mold paper has white mold, beige mold and color mold papermaking. There are a variety of mirror paper version, super light double, super double, double-sided version, single-sided version, snow version and cloth pattern paper and many other. 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. In addition, the weight of paper, there are two commonly used methods of weight: one for the basis weight, more common in the international market, is a one-meter square of paper, weight on the electronic balance, in grams, That is, gsm, or "mipping amount." One is heavy, and a pound weighing a 500-sheet scale is a pound. Both are used at home and abroad, but for the sake of convenience, it is easier to use the basis weight to save trouble, so that the paper with the same thickness is different from the pound number of 31x43" pounds and 25x35". The basis weight of most papers is from 60 to 100 gsm, the size of the paper is from 80 to 190 gsm, and that of molded paper is as low as 45 gsm. Before use, it is best to understand the purpose, purpose, function, and characteristics before use. The choice is not difficult either. In addition, paper and humidity are closely related. 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. The pulp is then fed to a papermaking machine. The funnel removes most of the water from the pulp screen on the moving screen, and then presses the hot rollers to squeeze out the excess moisture and dry it to make the 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.

(C) the choice of ink: lithographic printing inks are mostly transparent four-color ink, color printing, there is not much choice, up to plus gold, two colors. In contrast, there are more choices in color printing, and in special printing, there will be a variety of choices for certain special requirements, such as: fluorescent ink, pearl ink, black desensitization, 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.

Nine, the suitability of the equipment

(1) Prepress equipment: At present, the prepress area is almost completely computerized, and there are many types of equipment used, and the production areas are also different. There are Japan, Germany, the United Kingdom, Denmark, Israel and other countries of production. However, there are those that are easy to operate and more complex. Many of the simple tasks are submitted to the computer for automatic calculation and the quality may not be poor. There are many complex manual operations and there are many changes in quality that can lead to more complex requirements.

(2) Printing equipment: At present, more than one machine has been used for automatic loading of plates, computerized inks, and registering remote control devices. Therefore, as long as the work is performed on the console, most of the work can be completed and the quality of printed products will be more beautiful.

(3) Postpress and processing equipment: Most of them are electronic and micro-computerized. The adjustment work of the staff is also getting less and less. Many of them are calculated automatically by computers. Therefore, high efficiency and good quality are the advantages of modern equipment.

X. The suitability of the environment

(I) Lighting conditions:

1. Illumination standard - 204.4 +/- 43.6 candles.

2. The color temperature of the light source - 5,000 degrees K for use in viewing a document, and 7,500 degrees K for color comparison in printing.

3. The color appearance index is ─ 90-100.

4. Illumination geometry - The reflection of light from surrounding walls should be minimized.

5. The transmission standard indicates 409+/-88 candles.

(B) wall color: should be light gray, dark blue or green and other cold colors as the principle, should not use red, orange, yellow and other warm color series. Because the latter tends to make the staff feel irritable and uncomfortable, it is also easy to feel disgusted with the work.

(C) Temperature Control: The temperature in the flat-plate workplace must be controlled between 23-25 ​​degrees Celsius so that personnel can work and operate various machines and equipment in a comfortable and ideal environment, and the life of the machine is also relatively prolonged.

(4) Humidity control: The humidity in the plate-type workplace must be kept between RH 55-60%. Excessively high humidity in the air will lead to unstable product quality, easy electronic devices, easy-to-stretch paper, and distortion of processing and binding. Photosensitive materials and photographic lenses have become moldy. These problems will affect the effect and increase the production cost.

(5) Air quality: The air quality in the working environment does not mean that air conditioners are installed. It means that in addition to the air temperature and humidity being controlled, it is more important to introduce fresh air into the room, and to replace the indoor interior with a modest freshness. air. Nowadays, many separated air conditioners merely cool the indoor air and have no ventilation function. This will easily lead to indoor air pollution, resulting in uncomfortable staff, dizziness, and infection of upper respiratory tract.

(6) Wastewater treatment: Some chemicals will be used in the lithographic workshop. Therefore, some waste water will be generated. These will have to be properly treated to avoid environmental problems.

(7) Noise control: The noise a person can endure is about 80 decibels. In the printing workplace, the places where noise is easy to generate are mostly printing rooms. Therefore, the personnel working in this environment must pay attention to the maximum amount of noise. It is better to be below 75 decibels. In some printing fields, the use of commercial products has a good storage environment and can also be damaged. Therefore, the most important principle is to pay attention to the validity period, especially for various chemicals.