Wrinkle is a variety with a relatively large amount of texture powder and a wide distribution. It was mainly used in the instruments and meters of power distribution cabinets in the early days. Its uneven surface scatters light to avoid reflections that stimulate and fatigue the human eye. Also began to use wrinkle painting.
The requirements for wrinkles are strong three-dimensional effect, uniform distribution of wrinkles, and no bottom showing. Different customers have different requirements for the size of wrinkles. It is not easy to spray large wrinkles (thin spraying is easy to show the bottom, thick spraying will make the lines flat), and small and medium wrinkles are good. spray.
Large wrinkle method: less filler, choose embossing agent with coarse particle size, the thickness of the embossing agent should be reasonable, the coarse one can make the grains bulge, and the thin one can eliminate the exposed bottom holes, or use special embossing agent.
Small wrinkle method: There are two methods, one is to add more fillers, up to 50% or more, and more light calcium carbonate can be added, adding more fillers can reduce costs, which is also the method used by most manufacturers. One is to add less filler. At this time, if you want to make the wrinkles smaller, you can add an accelerator, and mix the embossing agent with a fine particle size and increase the amount. This way the spraying area will be larger, or the mechanical properties such as bending will be better. , For example, the pre-coated board is sprayed first and then stamped to form, which requires good bending.
External mixing and internal extrusion: wrinkles have external mixing method (also called post-mixing, post-addition, using embossing agent) and internal extrusion method (wrinkle agent is mixed and extruded with other raw materials). External mixing with embossing agent can adjust the texture as you like, and the three-dimensional effect of wrinkles is stronger. It is the main method used in CHINA. The disadvantage is that the texture of recycled powder changes, and internal extrusion overcomes this shortcoming. In addition to the three-dimensional effect, internal extrusion is not as good as external mixing. In terms of practice, it is also more difficult than squeezing in.
Accelerators, organic bentonite, light calcium carbonate, etc. in the formula can sometimes play a greater role in the wrinkle powder formula.
Other factors: using epoxy or polyester with a high softening point is good for graining; using a screw with poor extrusion effect to extrude the texture is better, especially the internal extrusion method, some manufacturers are equipped with a special screw for texture powder; The output temperature can be 10 degrees lower than that of flat flour; the powder can be properly ground to a coarser point, and the auxiliary grinding speed is reduced to pass 140 mesh.
illustrate:
(1) 0.05% 2-methylimidazole can be added to the formula, and the accelerator can increase the three-dimensional effect and help the cold furnace pattern.
(2) Adding more embossing agents to the formula of the large-grain base powder can make fine wrinkles, that is, the large-grain base powder can be adjusted smaller, and the small-grain base powder is difficult to increase.
(3) 104B special effect embossing agent can be used for thick workpiece castings, etc. 104B special effect floating agent can also be used for dull wrinkles that are more difficult to produce.
Figure 1 Enlarged view of wrinkles (convex places are taller, concave places are deeper)
