Bone China Decal Paper Production Process

1. Introduction

• Have you ever wondered how the beautiful patterns on the bone china(also called bone porcelain) plates and bone china mugs were realized? To be specific, Bone China Decal Paper Production realized? 
• Have you ever questioned why it is just a simple sample, why do bone china manufacturers charge you a relatively huge sample fee?
• Have you ever wondered why there is a MOQ in the development of bone china products?

Bone china products with decal

The article mainly includes the below subjects.

1. What is the decal paper?
2. What’re the main steps of making the decal paper.
3. Factors that affect the price of decal paper price
4. Conclusion.

1. What is the decal paper?

Want to understand these issues, let me take a look at the production process of ceramic decal paper. The flow chart below briefly summarizes the production process of ceramic decal paper.

Fine bone china decal production process

1.1 What’s decal paper?

Decal paper, also known as water transfer decal paper, is a decorative process that first prints the pattern on a special paper pre-coated with water-soluble glue, and then wets it by water to transfer it to the surface of the object(like ceramics). Decal paper is mainly used for the decoration of irregular surfaces of ceramics, glass, sports equipment (helmets, rackets, etc.), metal, wood and other objects.

Bone china bowls with decal

1.2 What’s decal paper composed of? 

The ceramic decal paper is composed of the bottom paper (also called paper base), a sol middle layer, and oil surface cover.

In this article, we mainly discuss the related content of bone china decal paper. Bone china is a kind of ceramic, and its production process is the same as the ceramic decal paper.

2. Bone china decal paper production process

The bone china decal paper production process is mainly divided into 3 steps, which are pre-print preparation, printing control, and post-print inspection.

Bone porcelain paper is a kind of high-temperature decal paper. After the decal is dried, it should be fired for four hours at the temperature of more than 600 degrees. For high-temperature decal paper, the pre-print part is extremely important, including design, color separation, layout making and material selection.

High-quality small-film decal paper, the pattern is clear and delicate, the color is saturated and accurate, there is no picture defects or grain, it has better ductility and is not easy to break when applying, and the firing effect is ideal. The ability to meet these quality requirements depends to a large extent on the pre-print processes.

2.1 pre-print preparation

(1) Design and color separation

As the color separation of bone china decal paper is limited by the nature of the pigment, it is not as simple as ordinary three primary colors. The ceramic pigments must be fused with the surface of the enamel through a medium-high temperature firing to present different colors. Different ceramic pigments contain different chemical components, and these elements cannot be mixed with each other, plus, individual pigments have higher requirements for printing.

Understanding the properties of bone china pigments, and color in the pre-print separation process will help greatly when making judgments and dealing with some practical problems.

How to accurately review and color separation? How many colors does a pattern have? Whether each color can be overprinted, which greatly tests the technical level of the professional.

(2) Screen manufacturing

The bone china decal screen has a relatively high requirement for the thickness of the color layer, so the quality of the printed ceramic paper cannot be judged by the fineness degree when the number of screen lines for the pattern is high, it is necessary to use a high mesh screen.

The use of high mesh screen has three disadvantages:

• High cost;
• Color layer is thin, it is difficult to express the hue of ceramic color;
• Easy to block the net. The standard screen is a 300T polyester mesh.

The screen-printed color layer is easy to access to ceramic pigments, and the screen and pigment costs are low, and the printability is optimal.

After selecting the number of screen lines and the type of screen, the more difficult process is to make a screen (commonly known as screen exposure). The following points of printing screen exposure should be strictly noted:

• Choose the net.
• Use capillary film or good photosensitive glue to ensure good image reproduction.
• Whether the tension value of the screen is suitable will directly affect whether the printing color is accurate.

 (3) Color adjustment

Screen printing ink is prepared by mixing a coloring pigment(ceramic pigment) and varnish in a certain ratio (confirming the mixing ratio according to the specific gravity of the pigment), and the viscosity is suitable for screen printing.
Screen printing ink, like ordinary color printing ink, has three basic elements, which are color, brightness and saturation. There are also bright, dark, thick, and light points.

However, the intermixing property of screen printing ink is far less than that of ordinary color printing inks. It is often caused by improper mixing and chemical reaction between each other during the firing process, which presents undesirable colors and even causes color burst and gold missing.
The coloring agent particles of the screen printing porcelain ink are coarser than the ordinary color printing ink pigment, and the specific gravity is also large, which has a great influence on improving the quality of the decal paper on the screen printing ceramic glaze.

In order to improve the quality of printed products, the requirement for screen printing ceramic ink is that the finer the particles, the better.

2.2 In-print control

The ceramic decal paper is produced by the screen printing process, and the process focuses on ensuring accurate color matching, thick and lustrous color layers, and clear color tone of the pattern.

1. Accurate color matching

There are 3 factors that affect the accuracy of the color registration:
1 Whether the printing machine paper feeding system is adjusted correctly, and the position of the paper is ensured when it is transported from the paper feeding table to the printing positioning device;
2 Whether the tension of each screen is consistent;
3 Whether the paper is inflated by the temperature and humidity of the workshop during multiple printing.

 2. The control of the thickness of the layer

Whether the quality of ceramic decals is excellent is greatly determined by an important criterion, which is whether it can accurately reproduce the original color. There are a few colors that require a very thick print and need to reach 20μm. The embossed pattern even requires a thickness of 200μm. Thickness control needs to master 3 points: mesh number, photosensitive adhesive coating thickness, printing parameters.

3. The effect of the design

The reprinting power of screen printing decals is difficult to compare with modern offset printing. Therefore, the multi-color printing of screen printing decals should be used to compensate for the lack of layering. In the screen printing process, the definition of the tone level can be improved when the thickness of the color layer is ensured and the printing speed is accelerated. The quality of the printing ink also directly affects the reduction of the color tone level.

2.3 Post-print inspection

Because the decal paper is a semi-finished product, it must be fired after the paper is proofed. After firing the decals, you can see the pattern and compare it to the original. Only qualified as before can become a qualified product.

Hope this article can help you have a better understanding of how Bone China Decal Paper Production like.  Once the sample is confirmed, it can be mass produced later. After the production is finished, dried and laminated, and then it can be cut by the staff and applied by the decal applying workers.

bone china products finished decal applying

3. Factors that affect the price of decal paper price

3.1 Why there is a sample fee charged?

It is precisely because of the realization of each pattern that requires these complicated processes, Therefore, in the process of achieving the new products of bone china, a certain sample fee is charged. And this sample fee is generally not refundable. It is these complex processes that result in a high price of paper and paper for a single bone china item if the quantity is small, which ultimately leads to a high cost of bone china products.

3.2 Factors that affect the bone china decal paper cost

The cost of the paper is not only related to the number of printing but also the complexity of printing, that is, the processing of the grade, the type of color, etc., also affect the cost of the paper. The more colors you have, the more difficult it is to make, and the higher the price of ceramic paper.
Another factor that affects the cost of bone china paper is whether it contains gold. Gold can add brilliance to bone china products and make the products look more luxurious. But the cost of gold is much higher than the cost of color.

Therefore, in general, the price of gold-containing ceramic decal paper is higher than the price of color decal paper. Gold is also divided into different varieties and qualities, there are platinum, gold, microwave gold, etc., customers can choose products that suit their own market according to their own needs.
The quality of the pigments is also uneven, some raw materials are easy to fade, and some raw materials contain lead separation, which is harmful to human health. These differences cannot be identified by new buyers of bone china.

Bone china mugs after firing

4. Conclusion

At Longway, you don’t have to worry about the effects you need to achieve, because we work with the most professional bone china decal paper production factories, they have a wealth of experience, and have very high-quality requirements. All you have to do is to prepare your design and tell us the details about your requirements, then leave all the work to us, we will give you satisfactory results in the shortest time.

If you have a new bone china project, if you are looking for a reliable bone china manufacturer, if you are not satisfied with the current bone china product suppliers, as there are various problems in their cooperation with them. You know how to contact us.