![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
[China Aluminum Industry Network] 1 Foreword
Aluminum coating organic coating surface treatment process will inevitably appear unqualified coating quality products, such as electrophoretic coating defects often appear low film, yellowing, particles, bubbles and other defects, powder electrostatic spray often appear pinholes, bubbles Defects such as granules, strands, and cross-colors, if they are scrapped, will inevitably affect the yield and timeliness of delivery, resulting in unnecessary losses. Therefore, more and more aluminum companies are concerned about how to remove unqualified coatings on aluminum and recycle substrates for rework. In addition, in order to ensure the electrical conductivity of the workpiece during the electrostatic spraying process, the spray coating tool is also subjected to a peeling treatment of the organic coating.
Aluminum stripping organic coating methods can be roughly divided into three categories: chemical methods, pyrolysis methods and mechanical methods. The chemical release method uses an etchant, a solvent or a combination of the two; the pyrolysis method utilizes a high temperature furnace, an open flame, a hot fluidized bed, a molten salt bath, and a laser to perform the release treatment; a mechanical release method uses a high pressure water, an abrasive medium , Brushes, Mills, Scrapers, Cutting Machines, Low Temperature Processing, etc.
2 Chemical stripping
The working principle of the chemical release agent is to soften or dissolve the coating film, to break the connection between the coating film and the substrate, and then the loose coating film is mechanically removed. Chemical release agents can be classified according to operating temperature (hot or cold) and can be classified according to their composition, such as corrosives (acidic or basic), solvents or corrosive/solvent combinations. The corrosive agent stripper generally uses a heating process, and the stripping temperature reaches 80 to 100°C.
Solvent-based chemical release agents use a cold process and operate at or near room temperature. Solvent-based chemical release agents are usually liquids obtained by mixing solvents such as chlorinated hydrocarbons, ketones, esters, alcohols, and benzenes. The use of a solvent to osmotically swell the overcoat layer can effectively remove various aluminum surface-treated coatings, and it is easy to directly peel the coating film or peel off the coating film. The release of the release agent is achieved through a series of physical and chemical processes such as dissolution, infiltration, swelling, exfoliation, and reaction.
There are many chemical release agents that are currently commercially available. The advantages of chemical stripping agents are the variety of formulations and the ability to remove highly durable coatings such as acrylics, epoxies, polyesters, and polyurethanes with minimal impact on the aluminum substrate. The disadvantages are potential health and environmental hazards related to the use of corrosive materials, chlorine-containing solvents, and flammable solvents.
Corrosive release agents are usually acidic and are strippers composed of strong acids such as concentrated sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid. Concentrated hydrochloric acid and nitric acid are easily volatile to produce acid mist and corrode the aluminum base material. Concentrated phosphoric acid stripping takes a long time and has a corrosive effect on the substrate. Therefore, the above three acids are used less frequently. Concentrated sulfuric acid and aluminum, iron and other metals passivation reaction, the corrosion of aluminum is very small, while the organic matter has a strong dehydration, carbonization and sulfonation to make it soluble in water, so concentrated sulfuric acid is often used as acid stripper .
Because solvent-based mold release agents are cold, ie, operate at or near room temperature, they are slower than hot, corrosive release agents and take longer to coat. Therefore, a combination of release agent came into being. The combined release agent formulation uses corrosive materials and solvents that combine the advantages of both. They can remove the more durable and chemical resistant coatings. They can operate at or near room temperature, operate at a temperature below the boiling point of the solvent, and have a speed of action between the corrosive release agent and the solvent-based release agent. Domestic products have been listed, the use of good results.
The utility model discloses a Kitchen Shower head that is convenient to switch the water outlet mode, has a compact structure, and is easy to use and a kitchen faucet using the kitchen shower head. The shower head includes a shower body and a shower head provided with a spray water outlet and a V-shaped water outlet. , The shower head is provided with a water separator, and the water separator is provided with an annular flow channel and an inner flow channel respectively connected to the spray water outlet body and the V-shaped water outlet body, and the lower end of the outer wall of the water separator is upwardly circular A plurality of water inlet holes connected to the annular flow channel are provided, and a first sealing ring is provided on the lower side of the water inlet hole; the water outlet end of the shower body is connected with a converter, and the converter is provided with a communicating In the water diversion cavity at the water outlet end of the shower body, the lower end of the water diversion device is installed in the water diversion cavity and can move up and down, and the upper end of the inner wall of the water diversion cavity is provided with a matching first sealing ring
Kitchen Pull Shower,Kitchen Pull Shower Head,Stainless Steel Shower Head,Rotating Wash Basin Shower
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.kitchen-sinkfaucet.com