Gold powder printing process

Gold and silver powder printing gold and silver powder are actually copper-zinc alloy and pure aluminum powder. Gold powder is divided into light golden, medium golden and dark golden by color. Silver powder contains 99.5% pure aluminum. Due to the active nature of aluminum powder, the surface is easy to generate oxidized strands, and the lower explosive density of powder in air is 27 to 50 g/cm3, and water will release hydrogen, affecting the stability of color paste, so it is less practical than gold powder. Printing is common. The following focuses on the process of gold powder printing points.

1 gold powder printing process points.

a. The commonly used fineness of gold powder is 100 to 1200 mesh. The finer the particles, the more reddish the light and the poorer luster. On the contrary, the coarser the particles, the stronger the luster, the stronger the luster, and the better the scrubbing fastness. Therefore, the number of meshes should be selected properly, and the finer the finer the general coating selection, the better. Often controlled between 200-400 mesh.
b. The penetrant contributes to the increase of brightness, and the diffusion agent NNO and penetrant JFC are more commonly used.
c. Antioxidants can retard the oxidation rate of gold powder in the air, prevent the formation of oxide film and dark, commonly used are metol (sulfuric acid methylaminophenol) and benzotriazethasone, this agent is not directly added Adjusted in emulsified paste.
d. Emulsification paste, such as using ordinary pulp, is easy to separate and oxidize, so it should be specially formulated. Its formula is:

Special white oil 700ml
Water Xml
Ping Ping plus O 50ml
Diffusion agent NNO 40ml
Thickener M 20ml
Benzotriazole (alcohol equal amount) 10ml

Note: 1 litre (2000 rpm)

2 gold powder printing process recipes and processes.

a. Formula:

Gold powder (400 mesh) 350g
Adhesive MR-96 400g
Dedicated emulsifying paste 250g

b. Process flow: printing gold powder→baking (160°C, 1.5 minutes)→rolling resin→→baking (temperature, time same as before)→→tentiveness→→calendering→→shrinkage proofing→ inspection.

The purpose of the above calendering is to increase gloss, reduce friction and prevent powder fall. In the case of low demand for golden light but high requirements for fastness, golden powder can be used to replace some of the amount of powdered gold, especially when used in black or dark sauce. It is often called “flying gold”.

3 gold flower tube carving and arrangement.

The most prominent part of the engraving is the depth of 0.02mm, which is usually about 0.12mm, and the flying face is larger, which is conducive to the smooth flow of printing ink.

The use of engraved flower tube for the printing of gold powder is most straightforward and it is usually divided into two times. Usually it is usually placed in the final process. When screen printing is used, the screen printing plate is preferably a hot platen, which is generally printed in single or double numbers. When co-printed with other dyes, specific arrangements should be made depending on the pattern and dye properties. Such as overprinting with vat dyes, first printed with gold powder is appropriate, oxidation is best to use cold water, not using acid and strong oxidants.

Process flow: printing gold powder→baking→rolling resin→baking→stretching→calendering→deflection.

Foam printing method can also be adopted. In the printing paste, foaming agent and thermoplastic resin are added. After high-temperature curing, the foaming agent decomposes, gas is released to expand the printing paste to form a three-dimensional pattern, and the powder coating is fixed by resin. . This is not only a simple process, but also has no harsh feel. The flow is: Cold platen flat screen printing → baking.