Classification and process characteristics of aluminum paste for coatings

2024-10-23

Aluminum paste is an indispensable metal pigment. Its main components are flake-shaped aluminum particles and petroleum solvents, which are in paste form. Its characteristics are that the surface of the aluminum flakes is smooth and flat, the particle size distribution is concentrated, the shape is regular, it has excellent light reflection ability and metallic luster, and when mixed with transparent color pigments, the paint film has obvious "angle-dependent color effect", and the decorative effect is very gorgeous and beautiful.

Aluminum paste is mainly used for automotive coatings, weak-current plastic coatings, metal industrial coatings, ship coatings, heat-resistant coatings, coil coatings, etc.

In recent years, China's aluminum paste products have also begun to develop in the direction of using fine spherical aluminum powder as raw materials, and have made major breakthroughs in technology, but its product performance indicators, coating effects, etc. are still somewhat different from similar foreign products.

Aluminum paste is a pigment that undergoes special processing technology and surface treatment to make the surface of the aluminum flakes smooth and flat, the edges are neat, the shape is regular, the particle size distribution is concentrated, and it has excellent matching with the coating system.

Aluminum paste can be divided into two categories: floating type and non-leafing type. During the grinding process, one fatty acid is replaced by another, giving the aluminum paste completely different properties and appearances, with aluminum flakes shaped like snowflakes, fish scales, and silver dollars.

In leafing aluminum pastes, the aluminum flakes are oriented near the paint surface to form an opaque silver film, and this opacity is the main factor that makes leafing aluminum paste an important functional raw material. Leafing aluminum pastes are generally used in roof coatings, maintenance and commercial application coatings that require high protection. The appearance of leafing aluminum pastes can vary depending on the coarseness of the particles, and can range from a rough, white appearance to a gray, highly reflective or mirror-like effect. Coarse-grained leafing aluminum pastes have the lowest hiding power and a rougher structure, but can produce the whitest and brightest coatings. In contrast, fine-grained leafing aluminum pastes have the greatest hiding power, the smoothest structure, and a highly reflective coating.

Non-leafing aluminum paste is evenly distributed in parallel throughout the paint film. The appearance of the film formed is different from that of leafing aluminum paste. Since it can be mixed with various pigments and is suitable for various systems, it has a unique effect on industrial coatings. However, any pigment or dye used with non-leafing aluminum paste must be transparent. Only in this way can the realistic metal surface effect be achieved. There are many types of non-leafing aluminum pastes, ranging from low to high tinting power, coarse to fine particle size, and appearance from white and shiny to gray and delicate. There are also acid-resistant series products to reduce the impact of other adverse environments such as industrial smoke and acid rain on coatings.

Aluminum paste is not easy to ignite and explode. Hiding power, shine, trigger performance, metallic properties, and smoothness are the technical requirements for identifying aluminum paste. The aluminum paste model is classified according to the size of the particle size. Uses: Widely used in plastic paint, hardware and home appliance paint, motorcycle paint, bicycle paint, etc. According to the list of hazardous chemicals, aluminum paste belongs to Class 33646: Paints, auxiliary materials and coatings containing secondary flammable solvents. However, due to the international and domestic requirements for environmental protection and safety of chemical products in recent years, domestic manufacturers have changed their processes and no longer use secondary flammable solvents as carriers, but use safe and environmentally friendly solvents with higher flash points. The aluminum silver paste produced now is no longer a dangerous product in terms of actual chemical properties.