Container House Spray Plastic Process
The spray plastic process for container houses mainly includes steps such as surface pretreatment, electrostatic spraying, heating curing, and standing cooling.
I. Surface Pretreatment
Degreasing: The chemical degreasing method is used. The metal surface of the container house is soaked in an alkaline degreasing agent solution to remove oil stains and prevent them from affecting the coating adhesion.
Derusting: Rust and oxide scale on the metal surface are removed through pickling or mechanical methods (such as sandblasting) to prevent further rusting.
Phosphating Treatment: The workpiece is soaked in a phosphating solution to form a layer of phosphate protective film on the metal surface, enhancing the coating adhesion and corrosion resistance.
II. Electrostatic Spraying
Workpiece Pre-baking: The workpiece that has undergone phosphating treatment is placed in an oven and heated to raise the workpiece temperature and remove residual moisture, facilitating powder adhesion.
Electrostatic Powder Spraying: An electrostatic spraying machine is used to uniformly spray dry, impurity-free high-quality powder coating onto the workpiece surface. The powder is adsorbed onto the grounded workpiece under the action of an electrostatic field.
Powder Selection: The commonly used powder coating is an epoxy resin-based insulating powder, which has good insulating properties, corrosion resistance, and impact resistance.
III. Heating Curing
The workpiece that has been sprayed with powder is sent into a curing oven and heated at a high temperature of 180-200°C to melt, level, and cure the powder, forming a dense coating. The curing time and temperature are adjusted according to the type of powder coating and the requirements of the workpiece.
IV. Standing Cooling
After curing is completed, the oven power is turned off, and the workpiece is allowed to cool naturally inside the oven to avoid coating cracking or loss of luster due to sudden cooling.
V. Quality Inspection
Strict quality inspections are carried out on the coating, including coating thickness, adhesion, corrosion resistance, etc., to ensure that the coating meets relevant standards and requirements.
