Art-type textured paint has strong aesthetics and good screen printing effect

Preparation and Screen Printing of Fine Art Reticulated Coatings

Reticulated coatings have developed rapidly in recent years as environmentally friendly coatings. With the improvement of living standards and the expansion of the paint market, competition has intensified, and the variety of coatings has also been diversified and beautifully developed. As an aesthetically pleasing paint, fine art textured paint has attracted more and more attention from manufacturers and users because of its strong decorative effect and high product added value. Since the art-type textured paint is different from the ordinary paint, the manufacturer will encounter many problems in the production and painting process. Art-type paint is a new type of paint, and its technology is still incomplete. It is still at a stage of exploration and accumulation. Combining the experience in the production and coating practice in South Hubei, the author briefly talked about the understanding of the art type textured paint. The art type textured paint refers to the coating film formed on the surface of the workpiece after the screen is screen printed or spray baked to form a film with a mesh shape. Its surface is characterized by its clear texture lines, bright surface, concavo-convex texture, and excellent touch and feel. Since the textured paint is different from the general paint, its formulation, production, screen printing or spraying parameters are also different from the general paint.

First, the formulation of the fine-texture type textured net coating is actually a combination of the art-type corrugated additive, the gold-silver powder and the base material through the internal extrusion process, and the corrugated additive, the gold-silver powder, the resin and the filler are integrated together. The effect formed. In addition to the characteristics of general corrugated products, it also has its own characteristics. The formation of the grid texture originates from the Benard vortex effect. After the art-type coating obtained after the internal extrusion process is screen-printed or sprayed, the resin softens during the baking process to form a molten coating film surface, and there is a surface tension gradient under the action of the corrugating aid, which will generate a thrust force. The paint moves from the bottom layer to the top layer. This flow forms an irregular hexagonal mesh (called Benard Vortex) with sides and edges connected. The middle of the grid is the original moving point, which is the part with low surface tension. The edge of the grid is the part with high surface tension. Under the influence of gold and silver powder, uneven grain-like effect will be formed, and the coating film will be fully cured. The surface forms uneven patterns or stripes.

Therefore, the following must be noted when designing an art-type textured paint in formula design.

1. The amount of resin should not be too low, generally requiring the resin to account for more than 70% of the base material. Too low resin content is not conducive to the migration of gold and silver powder in the melt flow after the internal extrusion and the formation of the Benard vortex effect. The textured lines are not clear and the roughness is not obvious.

2. The resin with higher viscosity should be used. Due to the high viscosity, the coating fluidity in the molten state is poor, which is conducive to the formation of Benard's vortex effect, thus making the reticulate three-dimensional effect stronger.

3. Gold and silver powder should use non-floating type, the general usage is 2% to 2.5%. Because the gold and silver powder is mixed with the base material after being extruded in the inner layer, the uneven texture is formed by affecting the flow of the inner layer of the coating film under the baking and melting conditions. Therefore, if the floating type gold and silver powder is selected, it will be due to Under the molten melting conditions, the gold and silver powders are floating, which has little effect, which affects the formation of lines. After the extrusion of gold and silver powder, the color and sheet structure were seriously damaged, generally grayish black. It is better to use silver powder which is cheap and easy to obtain without affecting the texture effect.

4. Consider the effect of corrugation when selecting the packing, such as the three-dimensional effect, size, and the exposed bottom. Under normal circumstances, as much as possible, fine-textured textured paints do not use titanium dioxide, and the amount of pigment fillers is small, otherwise the effect of the texture pattern will be blurred.

5. The size of the texture depends on the amount of the texture aid and gold and silver powder. It is required to properly control the amount of leveling agent and filler used for strong three-dimensionality.

6. Considering the sagging phenomenon caused by the thick coating film or screen printing during spraying and baking, a certain amount of bentonite can be added to the formula design.

Second, product preparation

After the formulation is confirmed, the production process of the product, including the mixing and extrusion process parameters, directly affects the effect of the screen printing film. Because the metal powder in the raw material, the friction is easy to generate static electricity, easy to burn, so the mixing time is generally about 1 min. During the production process, the extruder screw speed and the extrusion zone temperature should be kept consistent in order to ensure the stability of the product's fine arts. Due to the strong shearing effect of the silver powder on the extruder, it appears grayish black. Therefore, if the background color is white or close to the texture color, the apparent effect of the grid will be affected. This should be noted during the color adjustment process. Art-type textured paint generally has a strong hiding power. The thickness of the coating will affect the appearance of the coating. In order to better control the thickness of the coating film during screen printing, the screen mesh number is generally around 140. If the particles are too fine, it will affect the thickness of the screen printing and thus affect the effect of the texture.

Third, the screen printing process

During screen printing or spraying, effective pretreatment of the substrate is required. Otherwise, the adhesion and bending performance of the omentum may be impaired due to grease or dirt remaining on the surface of the workpiece. Because the effect of the reticulate coating is greatly affected by the thickness of the coating film, it is particularly important to control the thickness of the coating film during screen printing. In addition powder contains metal powder, electrostatic voltage can not be too high, otherwise it is easy to produce sparks, and the phenomenon of powder blockage, affect the screen printing effect.

Fourth, the conclusion

Because of its strong aesthetics and good screen printing effect, the art-type textured paint has been applied in batches to home appliances, lighting housing protection and other products. Although art-type reticulate coatings have been in existence for some time now, technology has a certain basis, but different manufacturers will have different problems in the production process due to various reasons, both in the process of groping and accumulating experience. Process technology needs further improvement.

Reprinted from: Chen Yi