Xin xiang Ceramic Mug Manufacturer, the process of making ceramic mugs, the clay will become ceramic mugs raw blanks after some series of processes. Ceramic mugs of raw blanks need to be embellished, in the previous article, we introduced the glaze knowledge of ceramic mugs, this article, we talk about ceramic cups of flower paper. In the previous Xinxiang ceramics introduced ceramic flower paper category is suitable for microwave oven, also introduced, water decal process. Today, we systematically and comprehensively introduce the knowledge of ceramic mugs paper.

1. What is flower paper

Ceramic cup flower paper, is a ceramic mug “makeup” means. It is like a kind of tattoo stickers, through the firing process, the customer's customized pattern, fused to the ceramic mug. Let different ceramic mugs have different pictures, suitable for different people and scenes. So, how is the ceramic flower paper made up? It has 3 layers. The lowest layer is the base layer that holds the pattern. The most commonly used materials for the base layer are kraft paper or water-soluble paper. The base layer is discarded after the application and cannot be involved in the firing. The second layer is the pattern layer, which is made up of pigments. The patterns and colors we choose are reflected in this layer. There are three processes for producing this layer: lithography, screen printing and digital printing. The pattern layer is produced through one of these processes. The top layer is the cover oil layer. The function of this layer is to protect the pattern layer in the center.

2. Flower paper classification

According to the material of the flower paper can be divided into 3 categories: acetal film paper, underglaze flower paper and water transfer decal paper. Often seen is the water transfer paper, today mainly to explain this one. The other two, we will talk about later. According to the firing temperature, ceramic mugs can be divided into: high-temperature paper and low-temperature paper. Purchasers are often asked by the ceramic factory is: “this ceramic mug needs high temperature paper or low temperature paper”. According to the temperature distinction between paper, is the most important thing for buyers to understand.

2.1. High-temperature paper firing temperature is 780-850 ℃, high-temperature paper color is light, high solidity. Low temperature floral paper firing temperature is 650-750 ℃, its color is very bright, very bright red and gold are low temperature floral paper. So, what causes them to have different firing temperatures and different vibrant colors after firing? Actually, it's similar to the glazes in our last post. The colors all come from metal oxides. The metal oxides cobalt, manganese, etc. that are used for the colors in the high-temperature flower paper have a high melting point, so they are high-temperature flower paper. On the contrary, low-temperature flower paper with cadmium, selenium and other metal oxides, these oxides are less resistant to high temperatures, but the color is bright, and the firmness of the firing is not as good as high-temperature flower paper.

2.2. High-temperature flower paper and low-temperature flower paper need different adhesives. High-temperature flower paper glue: the glue is natural resin (such as rosin) or high-temperature glue, when fired will be completely burned to ash, leaving no residue. This way the glaze is smooth and will not blister. If the glue is not burned clean, the glaze will have black spots (like burnt rice grains). Glue for low-temperature floral paper: organic resins (such as acrylics) are used, and they burn clean at low temperatures. However, if the temperature is not high enough, the glue residue will stick to the glaze and be sticky to the touch. After firing at low temperature, if you wipe the mug with a wet cloth, the glue residue may whiten (like a tape mark).

3. Flower paper production process

3.1. Lithographic printing (offset printing)
Lithography is the production of patterns on aluminum printing plates, each color corresponds to a plate. When printing, the ink adheres to the raised portion of the printing plate and is transferred to the patterned paper by means of a rubber cylinder. This technique is suitable for mass production and has the lowest cost, which is about $0.1 to $0.3 per sheet of floral paper. If the order quantity exceeds 100,000 pieces, lithography is the most economical choice. However, its disadvantage is that the color is not bright enough, can only print a maximum of 6 colors, and can not show metallic or three-dimensional effect.

3.2. Screen Printing (Screen Printing)
Screen printing needs to make a separate screen plate for each color, through manual color printing layer by layer scraping. For example, when making a gift mug with a gold embossed pattern, workers need to repeatedly scrape 3 to 4 times to increase the thickness of the ink layer. The advantage of this technique is that it can achieve three-dimensional effects (ink layer thickness of up to 0.1 to 0.3 mm) and metallic colors, and is suitable for medium-volume orders (5,000 to 50,000 pieces). However, the color register error is large (about ± 0.5 mm), small characters or fine patterns are easy to blur, and each color needs to be dried, the production cycle is long.

3.3 Digital printing (inkjet printing)
Digital printing eliminates the need for plate making and directly prints the pattern onto the floral paper with ceramic ink, which is cured by ultraviolet light. Digital printing can be done quickly and in rich colors, supporting photo-quality gradient effects. It has the highest flexibility, with orders starting at 50 sheets, but it also has the highest cost ($5 to $8 per sheet) and special colors such as gold need to be filled in later by hand.

3.4. Core differences between the three technologies:
Cost: lithographic < screen < digital (suitable for orders from large to small).
Color effect: digital ＞ screen ＞ lithographic (from gradient to metallic).
Production speed: lithographic suitable for long-term large quantities, digital suitable for urgent small quantities.

4. Decal operation steps

4.1 The first step: pretreatment
Clean the mug: use non-woven cloth dipped in 95% alcohol to wipe the glaze surface to ensure that there is no dust, oil or water marks. If you use paper towels may be residual fluff, wipe with water will lead to poor decal.
Preheat the mugs: leave them in the preheating zone at 40-50°C for 3-5 minutes, especially in winter, to avoid condensation when appliquéing cold mugs which may cause the pattern to shift.

4.2. Step 2: Applique operation
4.2.1. Soaking method (flat mugs):
a. Soak the decal paper in 25℃ water for 8-12 seconds to separate the backing paper from the pattern layer.
b. Slide the pattern onto the surface of the mug, fix the center first, and then use the rubber scraper to scrape from the center to the edge at an angle of 45° to discharge the air bubbles. If the scraping force is too strong, the pattern may be torn, and the residual air bubbles will produce pinholes after firing.
4.2.2. Transfer film method (curved mugs)
a. Cover the pattern paper with transfer film and compact it to make sure there are no air bubbles.
b. Slowly tear off the backing paper and stick the film with pattern to the mug surface, use 60℃ hot air gun to locally heat to assist bonding.
c. Tear off the transfer film evenly, too fast may result in pattern residue.

4.3. Step 3: Drying and Quality Inspection
4.3.1. drying: dry at 55-60 ℃ for 15-20 minutes, touch no wet feeling can be. Too high temperature will lead to glue failure.
4.3.2. QC:
Alignment accuracy: check the pattern splicing at the mug handle, mug mouth, etc., the error needs to be less than 1mm.
Edge checking: use strong light to observe whether the edge is warped or not, and the decal glue needs to be reapplied after discovery.
Bubble treatment: use the tip of a needle to poke bubbles and make up the glue, otherwise it will burst when firing.

4.4 Step 4: treatment before entering the kiln
a. Dust removal: blow the surface of the mugs with an ionic air gun, especially at the inner edge of the mouth of the mugs where dust is likely to accumulate.
b. Stacking protection: invert the mugs on the silicone shelf to avoid handling the pattern.

5. Precautions for the decal process

a. Environmental control: decal workshop needs to be maintained at about 25 ℃, humidity 60%, to avoid deformation of the paper or glue failure.
b. Flower paper preservation: avoid light and flat, expired flower paper (more than 1 year) glue will fail, easy to fall off after sticking.
c. Burning risk: low-temperature flower paper (such as gold) need to strictly control the temperature, more than 750 ℃ may lead to metallic color blackening. The heating stage (300-600℃) needs to be slow (3℃ per minute) to prevent the pattern from cracking.
d. Pattern haloing: Applique when the glaze is not thoroughly dry, need to ensure that the glaze is dry for more than 24 hours after application.
e. Lack of color after firing: check the ink thickness (screen printing needs to be ≥ 20 microns) or kiln temperature is too high.
f. Blackening of the gold edge: the gold-containing flower paper should be fired in the oxidizing flame to avoid contact with smoke.
g. Decals off: Decals need to be put into the kiln within 8 hours, otherwise the glue fails.

Different images of ceramic coffee mugs are derived from ceramic flower paper. The cost and difficulty of making ceramic flower paper is determined by the number of colors, whether there are gradient colors, and special colors such as red, gold and silver. The raw ceramic is the foundation of the mug, and the quality of the glaze and the paper is a direct factor in the aesthetics of the mug. The above information is based on the quality of ceramic flower paper hardware guarantee, ceramic mug flower paper is beautiful, but also by virtue of the ceramic mug factory technical workers operating practices and quality control guarantee. Both hard and soft to ensure that we get our hands on a beautiful ceramic coffee mug.