Water resistance requirements for paint film of rural lighting ready board box in Africa

Facing the outdoor working conditions of high temperature and rainy weather, large temperature difference between day and night, and frequent waterlogging during flood season in rural Africa, the water resistance of polyester spray paint film for lighting Ready Board Box shall comply with GB/T 1733 "Determination of Water Resistance of Paint Films", and also match the general coating specifications of SANS and Eskom rural lighting ready boards in South Africa. The test adopts a room temperature distilled water immersion test, with the test water temperature controlled at 23 ℃± 2 ℃. The sample is intact in a box or a test sample of the same process, and the coating dry film thickness is controlled at 60-90 μ m.

Basic admission criteria: The paint film should be continuously immersed in water for 168 hours (7 days), and visually inspected after being taken out and dried. There should be no bubbles, whitening, peeling, wrinkling, or substrate corrosion; According to ASTM D714, the foaming grade is determined to be level 0, and the scratch adhesion maintains level 0-1. For rural areas in Africa that are rainy, low-lying, and prone to short-term water accumulation, it is recommended to upgrade the technical requirements by immersing in water for 240 hours without coating defects.

Process requirements for African lighting ready board: The cold-rolled steel plate of the box must be completely degreased and pre treated with phosphating, using outdoor weather resistant polyester powder, and the use of ordinary epoxy powder is prohibited. After the immersion test is completed, it cannot be judged solely based on surface appearance. It is necessary to simultaneously review the wet adhesion and ensure that the tape does not peel off and the coating does not peel off in patches. If the project is located near the coast and there is a salt spray environment, the water resistance index needs to be linked with the neutral salt spray test. Products that fail the immersion test will be directly judged as anti-corrosion failure. This water resistance index can effectively resist long-term high humidity, box condensation, and short-term rainwater immersion during the rainy season, avoiding paint film bulging and peeling, causing steel plate corrosion and perforation, and ensuring the long-term stable operation of the ready board in the African wilderness.