Traffic barriers can be divided into: highway guardrails, railway guardrails, airport guardrails, port guardrails and urban road guardrails;
According to the painting method, it can be divided into: plastic fence and plastic fence;
According to the powder coating, it can be divided into: thermosetting powder barrier and thermoplastic powder barrier.
Spraying process guardrail spraying equipment includes preheating furnace, dust chamber and recovery unit, curing furnace, suspension conveyor and automatic control system. The preheating furnace is used to dry the residual moisture of the guardrail and bring the workpiece to a certain temperature, increasing the amount of powder and the thickness of the coating.
There are several automatic spray guns on each side of the powder chamber and a large cyclone powder recovery unit on the side of the powder chamber.
The length of the curing oven is determined according to the production efficiency. Since the length of the guardrail is 4.32 meters, the curing oven also adopts a single row straight-through type. An air curtain device is provided at the inlet and outlet of the curing oven to prevent hot air from escaping inside the furnace. Regardless of the energy source used, heat is circulated through the hot air.
The suspension conveying device comprises a guide rail, a catenary line, a driving device, a tensioning device and a suspension device, etc., and constitutes a conveying system, ensuring that the guardrail plate is convenient for unloading, preheating, dusting, solidifying and cooling at a certain speed. Spray suspension suspension transport is much slower than impregnation because the cure time is longer than the plasticization time.
The spraying process of the guardrail during the spraying process is: pretreatment→suspension→dust removal→cure→cooling→checking→packaging. Spraying has strict requirements on the surface of the workpiece, so the guardrail must be pretreated. The pretreatment of the guardrail can be carried out by a chemical solvent method, that is, degreasing or silane, to obtain a clean surface. When the guardrail is suspended, the horizontal suspension is adopted, and each group is vertically suspended 3~4 rows.
When spraying, the distance between the spray gun and the guardrail is generally 200mm. Adjust the electrostatic voltage to 60~80kV, and the compressed air should be free of oil, water and dust. A filter recovery unit is used to ensure that the powder does not overflow and is properly recycled. The curing temperature is generally 180~200 °C, and the conveying speed is adjusted, so that the guardrail board is continuously baked at this temperature for 20~25 minutes. For columns, the baking time should be longer due to the thicker wall thickness.
In recent years, China’s powder coatings have done a lot of effective work in raw material selection, additive preparation, mixing, extrusion and pulverization, which has significantly improved the weather resistance of powder coatings. However, the quality of powder production in China is currently uneven. A few manufacturers are only pursuing interests, adding recycled materials, lacking inspection methods, low-quality products, short-term color changes and cracking after powder coating, and good powder coating traffic barriers. Outdoor use. Aging tests typically use artificial accelerated aging tests and natural weather exposure tests. The artificial aging test is to simulate the atmospheric conditions and then compare the samples, and only reasonable calculation of the aging time equivalent to outdoor.
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