Encyclopedia of printing: a common inventory of eight special printing methods (4)

Seventh, decal printing

Decal printing is a printing method in which a plain or special ink is printed on a coated paper surface. The commonly used adhesive layer is made of gum, which not only allows the ink to penetrate the paper, but also allows the image on the adhesive layer paper to be easily transferred to other objects. In order to obtain an image on an adhesive sheet, any of the embossing, lithographic or gravure printing methods may be used, and the lithographic offset printing method is generally used for printing.

Decal printing is divided into two categories: trademark decals and porcelain decals. Trademark decals are printed with ordinary inks or iron inks. Their purpose is to attach to the surface of wood or metal utensils. The porcelain decal printing is to print the porcelain decal paper first, and then attach the patterned one side to the surface of porcelain and enamel ware, and then go down the kiln, according to the requirements of different materials, after satin burning at an appropriate temperature, so that the printed material appears the required figure. Patterns and colors.

The process of decal printing is divided into three parts: crepe paper, plate making, and printing.

1. The crucible paper is the first procedure of the decal printing operation process, which is easy to print and easy to peel off.

The main raw materials required for crepe paper are wood paper, copy paper, yellow powder, starch, and labe gum. The tools include a wooden platform and a row of pens.

The crepe paper can be divided into manual crepe paper and mechanical crepe paper.

a. Hand-held paper. First spread the copy paper on the platform board, use the row of pen yellow powder glue, evenly coated on the copy paper, and then cover the paper on the paper, brush repeatedly with a row of pen or towel, so that two paper No air bubbles. Then remove it from the flat plate and let it dry for about half a day. Then use a line brush to brush the starch paste and try to make it even when it is sizing. A layer of gum arabic was evenly coated on the starch-dried surface (ie, one side of the copy paper) and allowed to print after drying.

b. Mechanical paper. Copy paper webs and wood paper webs were respectively placed on the paper loading shaft of the paper crepe machine. There was a glue roll in the middle, and the alginic acid binder was applied to the paper and wood paper through the rotation of the loading shaft and the coating roller. In the middle, the two layers of paper are adhered by a flattening roller, dried by a drying mechanism, conveyed to a delivery section, and then sent to a calender for gluing, and then dried for printing.

2. The plate making process of decals printing is the same as that of the ordinary lithographic plate making. Only the graphic on the plate is positive. When printed on the tape, it is in the reverse direction. When the image is transferred to the surface of the desired object, the graphic becomes positive again.

3, printing good paper is generally lithographic offset printing method. Trademark decal printing As decal paper uses and uses different methods than ordinary offset printing products, when printing multicolor graphics, the order of the color registration is the opposite of that of ordinary lithographic offset printing, that is, the color ink with good transparency is first printed, and the ink is printed afterwards. Strong color hiding ink, so that the finished product is attached to the article, the color and general offset printing the same effect. In order to transfer the picture and text to the surface of other objects, the color layer of the picture and text will not be affected by the color of the object itself, and the white ink with low transparency should be printed on the last layer of ink layer once or twice. As a background color.

When printing on porcelain decals, special inks made of high-temperature pigments must be used to withstand high-temperature calcination. The high-temperature pigments are mostly metal oxides, the particles are coarse, the melting point is not the same, and the ink is denser. Therefore, they are mostly used for color registration and are not suitable for overprinting.

4, the transfer trademark printing decals paper transfer method is relatively simple. First apply a layer of varnish to the surface of the object to be transferred. After a little drying, apply a decaling paper moistened with water and other solutions to the surface and apply a certain pressure. Carefully remove the backing paper. Leave it on the surface of the object and then apply a layer of varnish to protect the graphic.

The porcelain decal paper transfer method: First, a layer of gelatin solution is coated on the surface of the porcelain, and then one side of the decal paper is pasted on the porcelain, and the surface of the decal paper is closely contacted with the porcelain surface. After the gelatin solution is dried, the porcelain is immersed in water. The gum arabic coated on the copy paper is first expanded and then dissolved, so that one side of the decal paper graphic is fixed on the porcelain surface and the other side is separated from the copy paper. Due to gelatin

The water-soluble property is smaller than that of the resin, so that the image containing the metal oxide leaves the copy paper and adheres to the surface of the porcelain. The paper is peeled off and the residual glue on the porcelain surface is washed away. After drying, the ink can be put. Into the kiln calcined to become beautiful and beautiful porcelain patterns.

Decal printing was originally used to decorate porcelain. Nowadays, decal printing has been widely used both in industry and in daily life.

8. Braille printing

Blind people can't read pictures and prints with their eyes, but their sense of touch is more sensitive, and they can use their fingers to figure out various high and low ideas. Braille readings rely on the protruding 2 children to form the pinyin word code. Therefore, the printing of Braille books, documents, etc. is different from the method of printing ordinary books.

Braille printing, first use a special typewriter to press out the concave point on the double sheet iron, make the concave and convex model, then insert a special thick paper between the two layers of iron sheet. After being heated and pressed, various uplifting dots are pressed on the surface of the thick paper without any ink color.

Braille readings should be proofread after making a printing plate. If there is an error in the composition of the braille, you can use a small hammer to level the printed point and correct it. Finally bound into a book.

Braille printing can also be used to print simple line drawings, and screen printing can also be used to print braille readings.