Ceramic Mug Group, Ceramic mugs come in beautiful prints, photos, or solid colors. Do you know how these images or colors are made? How does it integrate with the ceramic coffee mug? Are they harmful in the microwave? If you want to know this, you have to understand the decal classification and decal technology of ceramic coffee mugs.
Types of decals
Decal paper is a craft paper with patterns printed on the surface of the backing paper, which has a large market. According to the nature of the paper, it can be divided into three categories: butyral film paper, rough underglaze decal paper, and water transfer decal paper.
According to the nature of paper (backing paper), it can be divided into three categories:
1) Butyral film paper; 2) Underglaze decal paper; 3) Water transfer decal paper.
Butyral film flower paper
Butyral film decal paper is also called "alcohol decal paper". It uses butyral and alcohol as raw materials to make a film as a backing paper, and print patterns on the surface of the backing paper. This process still has a large market because of its low cost. , only 1/3 of the price of water-shifting decals, and the craftsmanship and effect can basically meet the decoration requirements. Its disadvantages lie in three aspects: first, the backing paper of the butyral film is thick, and the edge is not neat after use, and it is difficult to register the pattern when printing; on the other hand, due to the nature of the film, it cannot print precious metal preparations; On the one hand, its ductility is limited, and it cannot be moved and pasted on an irregular plane. However, because the large-film decal paper has the most competitive advantage of low price, it will continue to be used as a decorative material for
Chinese ceramics.
Underglaze flower paper
Underglaze flower paper is developed from the most primitive lithographic (lead printing) flower paper. It uses simple water-absorbing, soft paper as the backing paper, screen-prints the water-based glazed reverse-printed pattern on the surface, and then pastes it on the embryonic glaze of the ceramic. The feature of this process is that it is easy to fire (one-time firing), saves cost, is bright, has good wear resistance, and meets international hygienic standards. It also occupies a certain place in the decoration of tableware porcelain. However, its disadvantages are that the pattern is thick, the decals are difficult, and the packaging is difficult.
Water transfer decals
Water transfer decal paper (commonly known as small film decal paper) is more popular in domestic ceramic decoration. The printing form of water transfer decal paper can be flat printing, screen printing and steel plate transfer printing, and the most commonly used of the three is screen printing.
The most basic material of water transfer decal paper is small film bottom paper, which is a kind of paper with strong water absorption and covered with water-soluble adhesive film on the surface. After the printed decal paper is soaked in water, after the paper absorbs water, Dissolving the water sol on the surface can make the pattern of the oil agent slide and separate from the paper surface. The separated pattern still has a little water sol, and it can be pasted on the porcelain. As the name suggests, it is called water transfer decal.
The backing paper of the water-shifting decal paper should have good water absorption, but it also brings contradictions, that is, during the printing process, if the backing paper absorbs too much water, it will become heavy and soft, and the paper will be difficult to organize and handle. Moreover, the paper is bound to swell, resulting in inaccurate color registration during the printing process. This inaccurate feature makes the expansion irregular, which is a difficult problem to solve. If it encounters dry weather, the paper will shrink and become smaller, which will also cause inaccurate color registration. When this happens, the four corners of the paper may be warped, which is not easy to organize and not easy to print. Therefore, when choosing the bottom paper, its stability should be emphasized. Secondly, the environment of the printing workshop should be kept at constant temperature and humidity, with the temperature controlled at 22°C and the humidity around 55%. Another key point of paper is the surface performance of hydrosol, which requires smoothness and is not easy to harden, shrink, and crack. To identify the quality of the paper and whether it is suitable for your production, it is necessary to test it by simulating production. The four corners or one side of the flower paper are warped, most of which are caused by the hardening and shrinkage of the hydrosol surface. If it is difficult to dehydrate and paste the printed flower paper, it is because the hydrosol surface on the surface of the paper cracks when the printed pattern is drying. After the cover glue is applied, the cover glue sticks to the paper due to cracks. The phenomenon can be observed with a X10 magnifying glass. The backing paper with this phenomenon is not suitable for drying, and can only be printed with few colors, and can only be dried naturally, and cannot be put into an oven.
Melamine flower paper (melamine tableware)
It is also called melamine flower paper or imitation porcelain flower paper. The material is 37g to 60g long-fiber paper. The finished product is printed by offset printing or silk screen. In the oven at 70-100 degrees
The linking agent in the ink is baked and volatilized. Then brush the melamine formaldehyde resin on the flower paper. The concentration of the resin is prepared according to the standard of 95 degrees water temperature to completely dissolve the resin. Then dry. Pass through the molding machine for 20-35 seconds and melamine tableware Complete fusion. Melamine tableware in fast food restaurants has been produced. A 37-gram melamine flower paper has been developed for melamine cups. Developed a 60g masking paper. Titanium dioxide was added when making pulp. It solved the problem of color penetration of ordinary melamine flower paper.
Melamine flower paper is divided into long-fiber paper and short-fiber paper in terms of material. The strength of short-fiber paper is slightly weaker. It is easier to break when dealing with flower paper. And the uneven distribution of fibers is easy to produce white stains.
Technical characteristics of flower paper color removal
The color removal of flower paper refers to the color separation of the original paper of flower paper, which is to decompose the original paper into single colors suitable for printing according to the needs of different printing methods.
Four colors are divided into four colors of magenta/cyan/yellow/black for overprinting.
Spot color is to distinguish the different hues of the original, and to distinguish the different saturation and lightness of the unified hue for overprinting. For example, divide a group of pictures of red flowers and green leaves into light green, medium green, dark green, light red, dark red, medium red and brown.
The commonly used software for color removal is: Photoshop, CorelDRAW
Ceramic decal craft
Ceramic decals, also known as "moving flowers", are the most widely used decorative techniques in modern ceramics.
Move flowers
Migrating flowers is to use the paste method to move the colored patterns on the flower paper to the ceramic body or glaze. Sub-glaze decals and under-glaze decals. On-glaze decals include film decals, clear water decals and glue decals. For underglaze decals, only the outline of the pattern is printed on the decal paper, and then manually filled in after pad printing; there are also lines and colors that are pasted at one time, which are called decals with water. There are two kinds of decals: paper and plastic film. Paper decals need to go through the processes of peeling and washing. Later, film decals were invented, which eliminates the need for decals and facilitates mechanized and continuous operations.
Screen printing ceramic decal paper use range and characteristics
1) Ceramic decal paper is mainly used for the decoration of patterns and colors of ceramic vessels, replacing the hand-painted and spray-painted techniques that have been used in the past.
2) The resolution of silk screen ceramic decal paper can reach 40-50 lines/cm.
3) After the screen printing ink pattern on the ceramic decal paper is pasted on the ceramic vessel, it needs to be fired at 700-800°C or 1100-1350°C to adhere firmly, and the color depends on the type of coloring agent in the ceramic.
4) Ceramic decal paper is the carrier of ceramic ink, which can be divided into ceramic overglaze decal paper and ceramic underglaze decal paper. The types of decal paper are different due to their composition.
5) Due to the strong hiding power and poor transparency of ceramic ink, it is not yet possible to use the principle of three primary colors for printing. The dot printing method adopts non-superimposed side-by-side special color ink dot printing.
6) The ink printed on overglaze decal paper is high-temperature solvent-based ink; the ink printed on underglaze decal paper is high-temperature water-based ink.
