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Four steps of coating aluminum roll forming
Release time:2019-8-27 15:11:58      Hit count:241

Coating aluminum coil is not just a coil of equipment can be produced, generally a coating aluminum coil production line needs to have pre-treatment, coating coating, heating, exhaust gas recovery these four steps, the next to tell you about the coating aluminum coil molding four steps.

I. pre-treatment of rolled aluminum:

Substrate pretreatment technology is produced with the production of coating technology, which serves for coating technology and lays the foundation for the preparation of fine coating. Precoated roll aluminum all the substrate surface in the production process will remain some grease and lubricant, of course, in the process of transportation may adhere to other substances, if not removed, will affect the coating and use of roll aluminum. In addition, the clean substrate surface needs to undergo chemical treatment to generate a stable conversion film, thereby improving the corrosion resistance of the substrate and coating adhesion.

Because of the high speed of the precoating line, these process conditions require that all pretreatment nights be efficient to ensure that the substrate is clean and the conversion film covers all substrate surfaces.

The pretreatment section mainly includes hot - alkali degreasing, hot - water cleaning, chemical treatment and passivation treatment.

Ii. Coating method:

Coating is the core of the production line, the main equipment including roller coating machine and baking. Generally use the front or reverse coating process, according to the different direction of the coating roller and the transmission roller, can be divided into two kinds of process: forward coating and reverse coating.

Coating equipment roller coating machine is the use of roller coating coating on aluminum on a kind of equipment Shanghai scrap, the application of the most kdwa6td is two rollers and three rollers. The two-roll machine is mainly composed of paint groove, feed roller, coating roller and transmission roller. Work, the prior adjustment of the paint by the work pump into the paint groove, the roller is responsible for the paint in the paint groove up and transfer to the coating roll, coating roll coating in the transmission of aluminum, the transmission roller is mainly responsible for the transmission of metal coil. In the actual operation process, there is a certain ratio between the relative rotation speed of the feed roller, the coating roller and the transmission roller.

Compared with the two-roller machine, the three-roller machine has one more control roller. The control roller is used to adjust the amount of coating transferred from the material extraction roller to the coating roller, which has a certain effect on the accurate control of the amount of coating. If three rollers between the rotation speed ratio is not reasonable, coating out of the material will produce horizontal stripes and vertical stripes and other surface problems. In general, the linear velocity of the barrel surface of the three rollers:

Coating roller speed > driving roller speed > lifting roller speed reasonable control of the three roller rotation speed and the ratio between each other is one of the key factors to have a good appearance of coating film, three roller machine is mainly used in the surface requirements of high occasions.

The painting process generally pre-coating roll aluminum coating process by coating layer number can be divided into three coating process, two coating process and single coating process. According to the direction of rotation of the coating roller and transmission roller can be divided into two kinds of process: forward coating and reverse coating. Coating roller rotation direction and substrate direction of the same coating mode for smooth coating. Reverse coating. Generally, the smooth coating process can only apply a lower wet film thickness, and the surface appearance of this process is not ideal, solid this process is not used. Reverse coating process is currently the most widely used coating process. By adjusting the rotation ratio between rollers and the speed of the substrate, the desired thickness and appearance of the coating film can be recovered. Coating is the core part of the whole production line, the main parts of this section:

1, the relative rotation between the roller speed than 2, the thickness of the substrate and the balance of speed and substrate surface temperature parameter 3, the clearance between the viscosity and the roller coating 4, the dry film thickness of the coating and the coating and the relationship between the roll gap 5, curing time, drying tunnel length, base plate speed, the relationship between substrate thickness and temperature.

The post treatment stage is used to further process the aluminum coil produced, giving it better protection and decorative effect. The main film, printing, embossing and pressure. In this simple description: the film is the spalling of polydilute hydrocarbons film pressed on top of the paint. Printing is the printing of various patterns and patterns on the metal roll after finishing the coat. Embossing is the hot embossing of a design on a film surface. Pressing is a three-dimensional pattern made by matching the Yin and Yang patterns on the steel roller.

Gas heating gas heating is currently the most widely used method, mainly using natural gas, gas and other fuels. This method is mainly economic, another point is the production process in the exhaust can be recycled.

Iv. Exhaust gas recovery:

Most of the coatings used at present contain a certain amount of organic solvents, so Shanghai scrap metal recycling experts said in the production process will inevitably produce exhaust, which contains a large number of organic solvents and carbon dioxide gas, will cause a certain degree of harm to people's health and the environment. Burned at present, the commonly used method to deal with exhaust, specific methods: introducing production line produced by the exhaust gas preheating device of oxidation purification and heat treatment, resulting in a solvent, hot air, introducing the solvent with hot air and fuel gas burning chamber combustion, after combustion, exhaust gas into water and carbon dioxide containing organic solvent, the heat generated by heat exchange device is recycling, makes the final concentration of harmful gas emissions into the air exhaust is reduced greatly. The main components of the unit are preheating oxidation unit, incineration chamber and heat exchange bed. It is possible that the initial investment in the production line is large, but it is worthwhile and necessary from the perspective of environmental protection and energy.

Read these, I believe that you have a further understanding of the four steps of coating aluminum roll molding, I hope our introduction to you helpful.

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