Container House Painting Process Diagram

The painting process for container houses can refer to the following key steps and the integration of general painting procedures, as detailed below:

I. Coating Specification Formulation Formulate a detailed coating specification sheet based on the material of the container house (such as panels and profiles), usage environment (such as corrosion resistance level and climatic conditions), and the requirements of the container owner. Specify technical parameters including coating type (such as epoxy zinc-rich paint, polyurethane paint, etc.), dry/wet film thickness (typically, the dry film thickness ranges from 50-120μm), dilution ratio (such as 3% deionized water dilution), paint viscosity (to be measured with a viscometer), drying conditions (such as high-temperature baking at 120-140℃ for 30 minutes, followed by air-drying at room temperature for 10 minutes for shaping), nozzle size (selected based on coating thickness), and pump pressure (affecting spray uniformity). Parameters may vary for different container types (such as standard containers and special containers) and require targeted adjustments.

II. Substrate Preparation

1. Panel Preparation: Select Grade A panels that comply with the ISO8501 standard. Remove oil, dust, and corrosion products using solvents (such as acetone and alcohol). After cleaning, wipe or blow-dry the panels to prevent moisture residue from affecting coating adhesion.
2. Profile Preparation: Treat profiles using an 8-nozzle sandblasting machine with an abrasive mix ratio of S280:G25:steel wire segments = 5:3:2 and a line speed controlled at 3m/min. Ensure that the sandblasting grade, roughness (typically Ra ≥ 6.3μm), sandblasting density, and cleanliness meet Grade A standards, consistent with panel preparation requirements.
3. Secondary Sandblasting: After container assembly, perform secondary sandblasting on welds, cut edges, and other areas to remove welding oxides, splatter, and impurities generated by stress relief, ensuring strong bonding between the coating and the substrate.

III. Coating Application and Stirring Take epoxy zinc-rich paint as an example. Its two-component nature and high zinc powder content can easily lead to uneven coating. Before application, mix the base agent and curing agent in proportion and dilute with 3% deionized water to the specified viscosity. Key Point: Continuously stir the coating throughout the spraying process to prevent zinc powder sedimentation. The stirring container, stirrer type (such as an electric stirrer), and stirring time (typically 5-10 minutes) must strictly adhere to process requirements to ensure uniform zinc powder content in the coating.

IV. Drying and Inspection

1. Drying: After spraying, bake the coating at 120-140℃ for 30 minutes to fully cure it, followed by air-drying at room temperature for 10 minutes for shaping, reducing the risk of stress cracking.
2. Inspection: After placing the coating under standard conditions for 24 hours, use a pencil hardness tester to measure the coating hardness (which must reach 3H or above) and an adhesion scratch tester to measure adhesion (with a cross-cut rating of ≤ Grade 1 considered qualified), ensuring that the coating performance meets requirements.

V. Process Integration Recommendations The painting process for container houses can integrate general painting procedures (substrate pretreatment → spraying/brushing → drying → inspection) with container-specific requirements (such as secondary sandblasting and strict stirring) to form a closed-loop control system. Detailed process documents must be formulated from coating specifications to final inspection to ensure traceable quality.