A common inventory of the eight major special printing methods
The range of special printing is very wide. Here we only choose a few printing methods commonly used in book printing for a brief introduction.
1. Woodblock watermark
Woodblock watermark is a traditional printing method created and invented by the working people in China. The woodblock watermark was developed by inheriting the traditional printing technology of the motherland and has a history of more than 1,000 years. It can use rice paper and silk to print various fine reproductions, and the Chinese painting reproductions made by woodblock watermarking method can almost reach the real situation, so it is famous all over the world.
The characteristic of woodblock watermark is that it can perfectly reproduce the unique style of Chinese ink painting and color ink painting, which is difficult to achieve by modern printing. It is difficult to find the traces of printing on the replica of the woodblock watermark. It can maintain the tone and charm of the original painting, and can achieve an artistic effect similar to the authentic traces of the same painter.
The making and printing of woodblock watermarks are completely done by hand. It mainly includes three processes: sketching, engraving and watermarking.
1. Sketch. First analyze the manuscript. The number of printing plates and sub-versions is determined according to the color levels of the manuscript, light and shade, the painter's style and artistic characteristics, and the size of the screen. The size of the printing plate and the number of printing colors depend on the complexity of the colors. Generally from a few sets to dozens of sets. After dividing the version, I started to sketch, first covered the screen with translucent swallow paper, and used a brush to sketch meticulously, piece by piece. As many printing plates as you want, you have to outline how many pieces of swallow paper.
2. Engraved. Paste the manuscript paper sketches on the wooden board, and engrave them after drying. Pear wood or jujube wood is mostly used for the wooden board, and the surface should be smooth and smooth. The engravers engraved the sketches of the sketches into wood blocks of different colors. When sculpting, they should pay attention to the strokes and strokes of the original painting, and fully understand the characteristics and style of the original painting, so that the spirit of the original painting can be fully expressed. When engraving, the printing plates of the same color tone should be put in one place.
3. print. Use the engraved wood plate to print in sequence. The colors used in printing are not inks, but water-based pigments used in Chinese painting. The tool for applying paint is a brown brush. When printing on top of the color, the shade and the size of the moisture should be the same as the original. After printing, some of them also need to be processed with a paintbrush. Finally mounted as a finished product.
2. Colo Printing
Colo printing, also known as glass printing. This is the earliest printing method using photo-engraving technology. Judging from the relative position of the graphic and blank parts of the printing plate on the printing plate, the Kellogg version is not concave or convex, and belongs to the lithographic version.
Coro printing is to apply a layer of bone photosensitive resin and dichromate-coated photosensitive film on frosted glass, and then apply negative film on the film to expose it. The back side should also be exposed briefly, washed with water, and dried. , Part of the light is hardened to form an image. The depth of the image is not expressed by dots of different sizes (because the Corot version does not use a screen), but by the density of the fine wrinkles of the film. The greater the amount of light felt by the film, the wrinkles
The more lines there are, the darker the hue. Conversely, the brighter the hue, when the film image is brushed with ink, contacted with the paper, and imprinted, the positive image of the positive picture is printed.
The Coro edition has the advantages of exquisite printing, precision, and good reproduction effect. It is suitable for copying some delicate paintings with rich shades and delicate manuscripts. In addition to copying monochrome originals, this technique can also be used to copy color originals. When printing color pictures, as with woodcut watermarking techniques, several plates must be made separately according to the original and overprinted several times in order to print a colorful and realistic reproduction of layers and tones.
Because the base of the Colo version is a glass plate, and it is printed by contacting the paper with a weak film, the life of the printing plate is short, and it cannot be used for mass reproduction. .
3. Electrophotographic offset printing
Using an electrophotographic plate-making machine to directly make an offset plate from the original document is called an electrophotographic plate-making method.
The zinc oxide paper-based printing plate made by electrostatic photographic plate-making method can be directly mounted on an offset printing machine for printing. This is used to replace photographic plate making and zinc offset printing in a certain range, and has achieved obvious results in shortening the book publishing cycle, reducing printing costs, and saving valuable materials.
1. Production of electrostatic photographic version
The method of making plates with an electrostatic plate-making camera is:
(1) Place the original on the original frame and position it after focusing.
(2) Put the zinc oxide photosensitive paper in the position of the photosensitive plate in the camera dark box.
(3) Electricity. Make the light guide layer of zinc oxide photosensitive paper evenly charged. The charging device is also in the camera's dark box.
(4) Exposure. The light irradiates the photoconductive layer of the charged zinc oxide photosensitive paper, so that the charge in the light-seeking part disappears, and the non-light-seeking part forms an electrostatic latent image.
(5) Development. The developer powder with the opposite charge to the surface of the zinc oxide paper base is adsorbed on the charge latent image by the attraction of the opposite charges, and becomes a visible image. This development process is carried out in the camera dark box.
(6) Remove the developed paper plate, use a vacuum pump to suck up the excess developing powder, put it in the fixing box to heat and fix it, and then wipe a thin layer of protective agent on the surface of the paper plate.
The above steps total about 5 to 6 minutes.
2. Printing of electrostatic photographic plates
The zinc oxide paper plate made can be printed directly on the plate cylinder of the offset printing machine.
Since the electrophotographic printing plate is a paper-based printing plate, usually only about 2,000 sheets can be printed per plate, and even after processing, there is also a phenomenon of expansion and contraction, so it is more suitable for monochromatic text printing with fewer prints. [next]
Fourth, filtered printing
Filter printing is commonly known as stencil printing.
The graphic part on the filtered version is composed of holes with different sizes (or stroke thickness). When printing, the ink is pressed from the hole to the surface of the substrate to complete the printing.
Filter printing includes spray printing and screen printing.
1. Spray printing. First make a perforated plate by hand, and then place the printing plate on the substrate, and spray or brush to transfer the ink to the surface of the substrate.
2. screen printing. This is the most widely used printing method in filtered plate printing. You can print book covers, copy color oil paintings, decorative patterns of product packaging, instrument dials, marks on machines, and radio circuit boards.
The screen-printed printing plate base was originally made of cotton or silk thread, and later used nylon, polyester, polyethylene, stainless steel, copper and other metal wire woven nets, which were stretched on the net frame.
The plate-making method of filtered plates can be divided into manual plate-making, photo plate-making and electronic plate-making.
For photo-engraving, first apply the photoresist on the silk screen, copy the negative picture obtained from the photo or electronic separation into a positive picture, adhere to the screen coated with the photoresist for printing, then rinse and develop, dry and to make. The part of the printing plate where the photoresist is washed away is the graphic part.
Screen printing used to be manual printing, and later gradually used screen printing machinery to print. There are two types of screen printing machines: flat screen printing machine and rotary screen printing machine. According to the automatic Chengzhi, it can be divided into semi-automatic and automatic screen printing machines.
5. Embossing
The concave and convex embossing does not use ink, but uses pressure to press out various concave and convex patterns and patterns on the printed matter, white paper or cardboard, which is known as "rolling concave and convex".
We often see many raised patterns and graphics on printed products such as bottle labels, trademarks, cartons, envelopes, etc. These products are made by the embossing method. The replicas are vivid and beautiful, and have a strong three-dimensional sense.
The concave and convex embossing can be divided into two types, one is embossing, the other is pressing steel wire.
1. Embossed. The embossed gravure is made by etching or engraving method, and the plate material is copper plate or steel plate.
Stick the engraved copper (steel) gravure on the metal bottom plate of the flat press, level the printing plate, and paste the yellow cardboard on the flat plate to correct the pressure; then use glue, gypsum powder and water to mix into gypsum Paste, quickly spread a layer of gypsum paste on the flat board with yellow cardboard, slightly flattened, cover the gypsum paste with a piece of tissue paper, and then cover with a thin layer of plastic film to prevent gypsum powder from embedding into the plate pattern in. After that, you can manually turn the machine and gradually increase the pressure. The front and back are embossed twice, the first time the pressure is small, the second time is properly pressed, and the gypsum paste is completely dried. Letterpress.
Place the printed product between the steel (copper) intaglio plate and the gypsum relief plate, and the concave and convex embossing can be performed with a large pressure. The operation method during imprinting is basically the same as the general three-color plate printing method, but the pressure requirement is greater.
If the printing paper used is thicker and harder, you can use the hot pressing method, which is to use electric heating to generate heat and emboss the metal gravure at the same time, thereby obtaining a higher quality product.
2. Pressed steel wire. Also called die cutting process. The edges of some color prints, such as certain trademarks, bottle labels, and other exquisite prints, are made into arc-shaped edges according to design needs, and are generally not cut with ordinary paper cutters. Instead, it is pressed with a steel wire method.
6. Plastic printing
Plastic printing is the process of printing text or images on plastic products such as polyethylene, polyvinyl chloride, polypropylene and other vinyl films.
The surface of the plastic is relatively smooth, and the performance of absorbing ink is extremely poor. The ink attached to the surface of the plastic after printing is completely dried by the oxidized conjunctiva, unlike the general paper that is also accompanied by absorbent drying at the same time. A few days after printing, the imprint is still very easy to wipe off. This is one of the biggest features and problems in plastic printing. For this reason, the ink for plastic printing should have the characteristics of high viscosity and strong adhesion, which can make the ink molecules firmly adhere to the plastic surface and easily oxidize the conjunctiva and dry.
Before printing on plastic films such as polyethylene and polyvinyl chloride, surface activation treatment must be performed. To enhance the adhesion of the ink. Commonly used methods include chlorine gas treatment, oxidation treatment, corona discharge treatment, etc.
The operation of plastic printing plate mounting, pad printing and printing process is the same as that of ordinary relief plate printing. However, due to the characteristics of plastics, the printing pressure is slightly higher than that of ordinary letterpress printing, the imprinting is solid, and the ink brushing requirements are good to help the ink adhere to the surface of the plastic and make the imprint solid and beautiful.
7. Decal printing
Decal printing is a printing method that prints pictures and text with ordinary ink or special ink on the paper surface coated with glue. The commonly used glue layer is made of gum, which can not only prevent the ink from penetrating into the paper, but also make the image on the glue layer paper easily transferred to other objects. In order to obtain the image on the offset paper, any one of embossing, offset printing or gravure printing method can be used, usually by offset printing method.
Decal printing is divided into two categories: trademark decals and porcelain decals. The trademark decal printing is to use ordinary ink or iron ink for printing. Its purpose is to stick on the surface of wood or metal utensils. Porcelain decal printing is to first print the porcelain decal paper, and then paste the patterned side on the surface of porcelain and enamelware, and then go down to the kiln. Grain and color.
The process of decal printing is divided into three parts: mounting paper, plate making, printing.
1. Mounting paper Mounting paper is the first process of the decal printing operation process, the function is to facilitate printing and easy to peel off.
The main raw materials required for mounting paper are wood paper, copy paper, yellow powder, starch, rubber gum, tools such as wooden platform, row of pens, etc.
The mounting paper can be divided into manual mounting paper and mechanical mounting paper.
a. Hand-mounted paper. First spread the copy paper on the platform board, dip the yellow pen powder glue with the row pen, and evenly coat it on the copy paper, then cover the paper with wooden paper, and brush it flatly with the row pen or towel to make the two papers No air bubbles. Remove it from the tablet and let it dry for about half a day, then dip the starch paste with a row pen, and try to make it even when sizing. A layer of gum arabic is evenly coated on the dried starch surface (that is, the side of the copy paper), which can be printed after drying.
b. Mechanical mounting paper. Copy roll paper and wooden roll paper are respectively placed on the paper loading shaft of the laminating machine, and there is a glue roller in the middle. Through the rotation of the paper loading shaft and the glue roller, the alginic acid adhesive is applied to the copy paper and wood paper In the middle, the two layers of paper are bonded by a flattening roller, dried by a drying mechanism, and transported to the paper receiving part, and then sent to the calender to be glued and dried for printing.
2. The plate-making of plate-making decal printing is the same as that of general photolithography. It's just that the pictures and text on the printing plate are positive. When printed on the offset paper, it is reversed, and when transferred to the surface of the desired utensil, the pictures and text become positive.
3. The printed and mounted paper is generally printed by offset printing. Trademark decal printing is different from ordinary offset printing products because of the application and usage of decal paper, so when printing multi-color graphics, the color registration sequence is opposite to that of general lithographic offset printing, that is, the color ink with good transparency is printed first, and then printed. Color ink with strong hiding power, so that after the finished product is pasted on the article, its color and luster are the same as those of general offset printing. In order to make the image transfer to the surface of other objects, so that the color gradation of the image is not affected by the color of the object itself, the white ink with low transparency must be printed once or twice on the last ink layer. As a background color.
When printing on porcelain decals, special inks made of high temperature resistant pigments must be used to withstand high temperature calcination. Most high-temperature pigments are metal oxides, with coarser particles, different melting points, and thicker ink colors, so they are mostly used for color registration and are not suitable for overprinting.
4. The transfer method of transfer label printing decal paper is relatively simple. First coat the surface of the object to be transferred with a layer of ink, after a little drying, apply decals dipped in water and other solutions to the top and apply a certain pressure, then carefully peel off the backing paper and ink layer Just stay on the surface of the object, and then apply a layer of varnish to protect the graphic.
Porcelain decal transfer method: first apply a layer of gelatin solution to the surface of the porcelain, then stick the decal side of the decal to the porcelain and press the plain clothes to make the surface of the decal printed with the pattern closely contact with the surface of the porcelain. After the gelatin solution dries, the porcelain is immersed in water. The gum arabic coated on the copy paper swells first and then dissolves, so that one side of the decal paper is fixed to the surface of the porcelain and the other side is separated from the copy paper. Due to gelatin
The water solubility is lower than that of resin, so that the graphics containing metal oxides leave the copy paper and attach to the surface of the porcelain, remove the copy paper, and wash off the residual gum on the surface of the porcelain. It is calcined in the kiln and becomes a beautiful and beautiful porcelain pattern.
Decal printing was originally used to decorate porcelain. Now decal printing is widely used in industry and daily life.
8. Braille printing
Blind people cannot read printed images of pictures and texts with their eyes, but their touch feels more sensitive, and they can use their fingers to draw out various high and low ideas. Braille readers rely on the protruding two sub-words to form a Pinyin code. Therefore, printing Braille books, documents, etc. is different from the printing method of general reading materials.
For braille printing, first use a special typewriter to press out the recessed ideas on the double-layer iron sheet to make a concave-convex model, and then insert a special thick paper between the two layers of iron sheet. After heating and pressing, various raised dots are pressed on the surface of the thick paper without any ink color.
Braille readings should be proofread after they are made into a printing plate. If the braille composed by the ideas is wrong, you can use a small hammer to knock the printed ideas flat and correct them to make new ideas. Finally bound into a book.
Braille printing can also print simple line drawings, and can also use screen printing methods to print Braille readings.
hot air brush was created to replace both blow dryers and wooden hair brushes. Now, instead of holding the devices in both hands, a woman can use a lightweight device that dries and curls (or straightens) hair simultaneously.
interesting option is a hot air brush with styling attachments. Combo kits may feature several round brushes, attachments for pin-point styling, and concentrators.
Hot Air Brush,Hot Hair Brush,Ceramic Hair Brush,Electric Hair Brush
Ningbo Meirou Electric Appliance Co.,Ltd. , https://www.mrhairdryer.com