Application of conventional powder coating additives

The effects of conventional additives are similar, and the formula is basically the same. For example, the amount of leveling agent absorbed by epoxy resin is 4% to 5%, and the amount of leveling agent absorbed by silica is 0.8% to 1.6%. For the dosage of resin and curing agent, first determine the content of the base material in the formula, and then calculate according to the recommended ratio. Generally, the excess curing agent is 5-10%. Therefore, we will only describe the key products in the texture and functional additives.

Application of sanding agent

There are many ways to make sand grain powder. The method of adding more fillers or fumed silica is difficult to extrude and the powder rate is not high. The sand texture agent we use is modified PTTE, which is similar to the effect of major foreign companies, but its price is only about half of imported products. The amount of such additives is about one thousandth. Physical separation and matting play the role of sand, and the gloss can be reduced to 2 degrees. Compared with the previous filling method, the extrusion efficiency is high, the wear on the equipment is small, the resin content can be more or less, the surface effect is fine and uniform, and the hand feel is good. Adding an appropriate amount of acetobutyl cellulose can make a silky texture effect.

Application of Spot Flower Diffuser

Similar to the patterns of different flower dots pointed out with a watercolor pen, the dot flower diffuser drives the paint to spread when it is melted, and we call it dot pattern powder. The production of dotted powder requires a two-step method, that is, firstly, the dotting agent and the pigment to be diffused are mixed and extruded, crushed, and the powder in the 100-150 mesh is retained, which is called dot powder. The base powder used is similar to the conventional powder, but no flow aid is needed, and a little powder can be made by adding a little powder in the proportion of about 1%. Some powders have several different dots added to them. This kind of powder has certain contamination, and needs to be cleaned up a little after painting.

Application of wrinkle agent

Wrinkles are also called orange lines. Our company’s wrinkle agents include one-step wrinkle agent 805 and two-step flotation agent K-30. Its main components are butyl acetate and polyacrylate, and the corresponding imported grades are CAB-551 and 2874. The formulations of these two additives are generally similar. Among them, 805 is easy to use, and the powder wrinkles produced are relatively uniform, but the three-dimensional effect and anti-interference ability are slightly worse. The wrinkle powder produced by the embossing agent K-30 has strong three-dimensional effect and anti-interference ability, and the texture effect is not affected when the curing temperature changes, but it needs to be mixed and sieved twice. Powder manufacturers can choose according to the actual situation of the factory.

Application of Hammer

There are also two ways to make hammer powder. Hammer pattern agent 856 can be used to prepare powder coatings with dendritic, shallow dish and different three-dimensional hammer pattern effects. Strong and clear texture. Due to the high resin content in the formula, it is necessary to add organic bentonite or dimethyl imidazole to prevent sagging. About 1% floating aluminum powder needs to be added to the formula. The available domestic brands such as Harbin and Zhangqiu, imported PC150, 2081, 80000A and so on. There are also manufacturers who add embossing agents to reduce the shrinkage holes that appear on the bottom of the workpiece.

The application of sponge

Foaming agent is mainly used in the production of cotton wool (also known as water pattern or cloth pattern) and reticulated powder. The surface effect of this kind of powder is more beautiful, and it is used by many security door manufacturers. However, this type of powder has certain toxicity and irritates the eyes, and workers are prone to pink eye disease after exposure to this type of powder. In addition, the powder has strict requirements on the thickness of the coating film and the baking temperature, and a small amount of polyester is added to the formula to adjust the texture and improve the flexibility. At present, there are 3 types of sponges for epoxy resin, polyester resin and polyurethane resin.

Application of anti-yellowing agent

Powder coatings need to be extruded and baked at high temperature during production or use, while some organic polymers undergo oxidative denaturation at high temperatures, resulting in yellowing in color. The function of the powder anti-yellowing agent is to prevent the yellowing of the polymer at high temperature and prevent the yellowing of the coating film from being used for too long at room temperature. In addition to the anti-yellowing group, the anti-yellowing agent also has a grafting group compatible with the powder resin, which also increases the compatibility and appearance of the coating film. The general addition amount is 1%, and it can be maintained for 30 minutes at 220 °C without discoloration.

Application of UV Absorbers

This product is a preventive stabilizing additive, which can strongly absorb ultraviolet light waves of 270-380 nm. Its outstanding features are good heat and light stability, low volatility, and synergistic effect with phenolic antioxidants and hindered amine light stabilizers. , which can absorb the ultraviolet rays before they endanger the polymer molecules, protect the polymers from ultraviolet rays, and thus improve the weather resistance of the coating film to varying degrees.

Application of powder energizer

The powder loading rate is related to the particle size of the powder, the charged amount of the particles, the moisture content of the powder, the spraying air pressure, and the voltage. The charged amount of powder particles can be improved by additives, which we call powder energizers. Its main component is an organic salt of charged group, which is added during powder batching, mixed and extruded, which can effectively increase the charged amount of the powder particles during spraying, thereby increasing the powder loading rate, and at the same time, it can overcome the electrostatic shielding effect and make the edge Corners or inner surfaces are easy to powder. We estimate that when the dosage is 2/1000, the one-time powder application rate can be increased by 26%. There are two types of varieties currently used: EDI of organic ammonium salts, used in varieties with low resin content such as wrinkled sand grains; N308 of organic esters, used in high-gloss powders.

Application of powder defoamer

The problem of powder defoaming is getting more and more attention. When a powder coating is cured, the air entrapped by the workpiece or the coating itself has a longer time to reach the surface, while the paint film has a relatively short time to form, thus forming air bubbles or pinholes. The most widely used defoamer is fine wax powder, the typical representative is BYK961 wax powder; the brand with the best application effect in China is 4430; carbonate treated with ethylene glycol can be used in various powders. Defoamer 4430 can not only eliminate the pores formed by the powder itself due to water, but also eliminate the pores caused by the iron and aluminum parts caused by the plate, improve the fluidity of the powder particles and the leveling of the powder coating, and can also replace the elimination of benzoin. Yellowing phenomenon due to benzoin. However, if the thickness of one spray of powder coating exceeds 200 μm, the disadvantages cannot be eradicated from pinholes.

Application of dry powder flow agent

To achieve thin powder coating, the powder particle size must be small. The powder particle size is too fine, the powder particles are easy to agglomerate, it is easy to block when spraying, and there are scars after curing. The main function of the dry powder flow agent is to reduce the friction between powder particles, thereby reducing the angle of repose, improving the fluidity of the powder during the spraying process, and prolonging the storage period of the powder. The variety we produce has been recognized by manufacturers in Taiwan, Singapore and other places.

Application of anti-sticking and hardening series additives

The surface hardness of the coating film is also highly valued by powder manufacturers. Products with excellent coating film are often scratched due to friction and scratches during packaging and transportation, which greatly reduces the product quality. This kind of inert polyamide material can perfectly solve the above problems and has good anti-pollution performance. There are also manufacturers who add less than 0.5% anti-blocking agent when making thermal transfer powder.