On May 1st, the debugging of the Zoomlion Agricultural Machinery project entered its final phase, marking a significant milestone in the project's progress!

Huicong Surface Treatment Network: 1. Ambient Temperature Requirements: The optimal temperature range for spray foaming is 15–35°C. If the temperature is too low, the foam plastic is prone to peeling off the surface of the object, its density will significantly increase, and material consumption will rise markedly. Conversely, when the ambient temperature is too high, the foaming agent will be excessively consumed. 2. Moisture: Isocyanates readily react with water to form brittle urea-containing substances. The surface to be coated must be free of dew or frost. When the air humidity is too high, dehumidification is necessary; otherwise, the adhesion between the foam plastic and the object will be affected, making it easy to detach. 3. Wind: When spraying outdoors, at a wind speed of 5 m/s, heat...

Huicong Surface Treatment Network: The coating process for automotive painting lines can generally be divided into two major parts: first, the surface treatment of metals prior to coating, also known as pretreatment technology; and second, the actual coating application process. Surface treatment primarily involves removing oil stains, dust, rust, and old paint layers during repair work from the workpiece surface, thereby improving the surface condition of the workpiece. This includes mechanical and chemical treatments applied to the workpiece surface according to specific conditions, such as phosphating, oxidation, and passivation treatments. Automotive Painting Lines—The anti-rust coating process for construction machinery typically consists of two stages: the surface treatment process prior to coating and the application of an anti-rust primer. Surface treatment is one of the critical steps in anti-rust coating. The quality of anti-rust coating for construction machinery largely depends on the effectiveness of the surface treatment method used. According to Imperial Chemical Industries in the UK, the lifespan of a coating is influenced by three main factors: surface treatment accounts for 60%; coating application accounts for 25%; and the quality of the coating material itself accounts for 15%. In the construction machinery industry, different components require different surface treatment methods. Mechanical cleaning can effectively remove rust, weld spatter, and oxide scale from workpieces, relieve welding stresses, and enhance the adhesion between the anti-rust coating and the metal substrate, thereby significantly improving the anti-rust performance of construction machinery components. The standard for mechanical cleaning requires reaching Sa2.5 grade. The surface roughness should reach one-third of the thickness of the anti-rust coating. The steel shot used in blasting and shot peening must meet the requirements of GB6484. For thin-sheet stamped parts, chemical surface treatment is commonly employed. Automotive Painting Lines—The typical process flow is as follows: pre-degreasing → degreasing → hot water wash → cold water wash → acid pickling → cold water wash → neutralization → cold water wash → surface conditioning → phosphating → cold water wash → hot water wash → pure water wash → drying. This process can be adjusted appropriately based on the oil and rust conditions of thin-sheet stamped parts—for example, the acid pickling step may be omitted, or the pre-degreasing step may be skipped. Degreasing and phosphating are key steps in the chemical treatment process, directly affecting both the quality of the chemical treatment and the quality of the anti-rust coating. Relevant process parameters and associated auxiliary equipment are also important factors that cannot be overlooked when it comes to surface treatment quality. Due to the wide range of construction machinery, diverse specifications, heavy overall weight, and large component sizes, spray coating is generally adopted for the coating process. Automotive Painting Lines—Spray coating tools include air spray guns, high-pressure airless spray guns, air-assisted spray guns, and portable electrostatic spray guns. Air spray guns have low spraying efficiency (around 30%), while high-pressure airless spray guns waste coating material. Both types share the common drawback of causing significant environmental pollution, so they have been—and continue to be—gradually replaced by air-assisted spray guns and portable electrostatic spray guns. For instance, the well-known construction machinery company Caterpillar Inc. in the U.S. uses air-assisted spray guns for coating, while portable electrostatic spray guns are employed for thin-sheet coverings such as engine hoods. Coating equipment for construction machinery generally utilizes relatively modern water-spray booths. Small and medium-sized components can also use water curtain booths or pump-less spray booths; the former offer advanced performance, while the latter are cost-effective and convenient. Given the heavy weight and large thermal capacity of construction machinery units and components, the drying of anti-rust coatings typically employs uniform hot-air convection drying. The heat source can be selected based on local conditions, including steam, electricity, light diesel oil, natural gas, and liquefied petroleum gas.

Huicong Surface Treatment Network: Coating processes are extensively used in automotive surface treatment, and wastewater is generated in virtually every stage of the production process [1]. As a result, the treatment of automotive coating wastewater has become a major challenge in today’s wastewater treatment projects, urgently requiring solutions. Through years of exploration and engineering practice, it has been found that adopting physicochemical plus biochemical treatment for automotive coating wastewater is both economically viable and effective. However, in practical applications, certain issues still arise, necessitating optimization and improvement of this process to make automotive coating wastewater treatment more stable and efficient. 1. Sources and Characteristics of Automotive Coating Wastewater The wastewater generated during the coating process mainly comes from pre-degreasing and acid...

Huicong Surface Treatment Network: Fillers: Fillers, also known as extenders or bulk pigments, include materials such as chalk (light calcium carbonate), talc, white carbon black, and barium sulfate. These are nearly all white powders with high tinting strength and opacity. In coatings, they enhance the weather resistance of the coating film and are less prone to chalking. They are also commonly used in putty formulations. Pigments: Pigments, also called colorants, can be categorized into inorganic and organic pigments. Inorganic pigments boast high opacity, high density, and excellent light- and heat-resistance; examples include titanium dioxide, lithopone, iron oxide red, iron oxide yellow, and ultramarine blue. Organic pigments, on the other hand, offer vivid colors, high tinting strength, and superior chemical resistance; examples include fast-yellow, phthalocyanine pigments, toluidine red, and Lithol Red.