Sampling of some aluminum profiles without products, sites, production licenses, certificates, their oxide film thickness does not meet the national requirements, and some even have no oxide film.

Aluminum profiles with a large amount of mixed aluminum and waste aluminum can greatly reduce the cost. However, it will lead to unqualified chemical composition of construction aluminum profiles, which seriously endangers the safety of construction projects. The inferior aluminum profile greatly reduces the closing time. The loss of chemical reagents is reduced, and the cost is reduced, but the corrosion resistance of the profiles also greatly reduces the selection of aluminum alloy guardrail products with high reputation.