Xinxiang Ceramic Mug Manufacturer, many ceramic mug buyers get ordered mugs, its body is not smooth, (exceptions for special needs such as frosted mug, matte mug, etc.). Ceramic mugs like this, in fact, belong to the unqualified products. Xinxiang ceramics factory stands in the producer's point of view, for ceramic mug surface appears similar to the unevenness of the orange peel phenomenon (commonly known as “orange peel glaze”), to explain the reasons for its formation. The main reasons include: glaze formula, firing process and billet quality.

1. what does orange peel glaze look like?
Imagine the skin of a fresh orange: covered with tiny bumps, uneven to the touch. Ceramic mug if the appearance of orange peel glaze, looks like the orange peel “printed” on the cup. Specific performance: surface roughness: the original should be smooth surface of the mug appeared wavy undulation; dull luster: like a layer of mist, reflective effect is poor; feel bad: finger scratching can obviously feel the grain. This defect not only affects the beauty of the ceramic mug, but also reduces the grade of the cup, and even lead to serious glaze flaking.

2. Why does orange peel glaze?
Ceramic mugs appear orange peel glaze phenomenon, very similar to our failure to do the cake. When making a cake, if the quality of the cream, flour problems, or baking temperature is not controlled, it is easy to make a failed cake. The orange peel glaze of ceramic mugs is also due to the glaze and firing process.

2.1. glaze viscosity
In the previous article about ceramic mug glaze (Instructions for making glazes in ceramic mugs), we introduced. Before a glaze is put into the kiln and fired, it is a paste-like liquid. When a mug is coated with glaze and fired in a kiln, it becomes a smooth “glass layer” on the surface of the mug. The role of kaolin in the glaze, play the role of the binder. The glaze paste adjusts the viscosity of the glaze by adjusting the content of kaolin and water. If the proportion of kaolin exceeds 15%, then its viscosity is too strong, and the phenomenon of orange peel glaze will easily appear. If the glaze is not finely ground enough, the diameter of the particles inside is too large. Then, such a ceramic mug will be covered with fine bumps, feel uneven, and have a poor luster.

2.2. Glaze too thick
Ceramic mug glazing process, we have talked about it before. It is mainly divided into: dip glaze, spray glaze and brush glaze. In the glazing process, whether the glaze is uniform, can lead to ceramic mug flow glaze. Similarly, whether the glaze thickness meets the requirements also determines whether the mug will appear orange peel glaze phenomenon. If the glaze is applied too thinly, especially with darker colors, you will notice that the mug will have a vaguely ceramic undertone. If the glaze is applied too thickly, exceeding the safe thickness of 0.25 mm, the ceramic mug will be prone to orange peel glaze.

2.3. Firing
The firing process is what transforms a mug from “clay” to “ceramic”. In the previous article, we introduced the firing process of various equipment, temperature and humidity control (In-depth analysis of the firing process of ceramic mugs) . So, how does the firing process lead to the orange peel glaze on ceramic mugs? Mainly because: in the heating stage, the heating speed is too fast or missing insulation stage, resulting in the glaze is not uniformly melted on the beginning of solidification; another reason is that the kiln does not reach the high temperature of the glaze melting (for example: the kiln is no longer warmed at 1250 ℃, resulting in the glaze is not completely melted); the last reason is that the kiln is too fast to cool down, high-temperature heat preservation time is not enough, resulting in the glaze suddenly shrinkage caused by the orange peel glaze phenomenon.

2.4 Failure of Raw Billet
In addition to the above 3 reasons, leading to the phenomenon of orange peel glaze, there is another kind of ceramic mug raw billet reason. Glaze, glaze, firing, these three processes are acting on the ceramic mug billet. Ceramic mug raw material if the iron content is higher than 1%, iron and glaze will produce exclusion reaction, the phenomenon of orange peel glaze. If there is dust on the surface of the ceramic mug raw billet, resulting in reduced glaze adhesion during the glazing process, will also produce the phenomenon of orange peel glaze.

3. How to solve the orange peel glaze
According to the practical experience of Xinxiang ceramic factory, the following measures can reduce the incidence of orange peel glaze from 20% to 3%:

3.1 Improve the glaze formula
Add “lubricant” to the glaze - borax and lithium faience, used to stabilize the viscosity of the glaze. In the powdering stage of the glaze material, the precision and grinding time of the ball mill should be ensured, and in the sieving stage, the fineness of the glaze material should be ensured. In addition, the use of stable quality raw materials, pay special attention to the content of iron and sulfur.

3.2 Control glaze application
At present, Xinxiang ceramic factory adopts automatic glazing assembly line to make the glazing process and quality inspection more rigorous. Through the automated assembly line, the glazing process is guaranteed to be uniform, and the glaze thickness error is within 0.01mm. Through this, the glazing process of ceramic mugs is guaranteed to be problem-free.

3.3. Kiln automation
China's previous kilns were mostly based on traditional kilns, and the firing process was mainly dependent on the experience of the technicians. Nowadays, kilns use automation from fuel to temperature control. The heating up time, firing temperature, holding time and cooling down process are precisely controlled by computer.

3.4. Clean Raw Billets
The ceramic factory itself is with the concentration of clay and ceramics, so the production plant is relatively dusty. Ceramic mugs need to be dehumidified and dried after the production of raw blanks (Drying and trimming process of ceramic mug clay blanks). Raw billet in the drying stage, it is inevitable to fall on the dust, in the later part of the glaze link will be prone to problems. Ceramic factory for this problem using measures are mainly, control the environment of the drying plant; glaze before the use of air guns to clean the billet.

4. Frequently Asked Questions
Q1：Home to buy a mug with orange peel glaze, can I still use it?
A: Mild orange peel glaze does not affect the use, but heavy may lead to glaze off, it is recommended to replace.
Q2：How to judge the orange peel glaze with naked eyes?
A：Rotate the mug to the light, the smooth glaze will reflect evenly, and the orange peel glaze will have bright and dark ripples.
Q3：Why do some handmade mugs intentionally do orange peel effect?
A: The deliberately created texture is different from the defects, which are usually evenly distributed and treated with anti-peeling.

By understanding the glaze characteristics and controlling the production process, orange peel glaze can be completely avoided. This is not only a technical problem, but also a test of craftsmanship - Xinxiang Ceramics Factory strives for excellence in every link in order to guarantee that every mug is smooth as a mirror and warm to the heart.