1.What is the conflict between environment and materials?
Material Characteristics: Cold-rolled coils have an exposed, smooth steel substrate without any protective coating, making them chemically reactive and highly susceptible to corrosion.
Maritime Environment:
High Salinity: Marine air is rich in salt spray, and salt is a strong catalyst for steel corrosion.
High Humidity: Humidity at sea often exceeds 85%, providing continuous conditions for electrochemical corrosion.
Diurnal Temperature Variation: This leads to frequent condensation on cargo surfaces.
Long Duration: Maritime shipping cycles typically last several weeks, providing ample time for corrosion.
2.What are the basic protective packaging requirements?
Apply rust-preventive oil to form a film that isolates air and moisture. This is the most economical and effective method.
3.What are some options for inner packaging and protective packaging?
Wrapped with VCI vapor phase corrosion inhibitor paper/film
It continuously releases rust-preventive gases, forming a protective layer in a confined space, especially protecting the inner ring and interlayer of the roll material.
4.What are the key operational and contractual points?
Packaging Integrity: Ensure the packaging is completely sealed, especially the ends and inner openings of the roll material.
Clear Labeling: The outer packaging should be clearly marked with "Keep Dry," "Handle with Handle," and "This Side Up," and it is recommended to indicate the rust-preventive expiration date.
Definitive Contractual Liability: This is the most important step! The specific standards for rust-preventive packaging must be clearly and explicitly specified in the sales contract and letter of credit (e.g., "Using XXX standard, sprayed with rust-preventive oil, wrapped with VCI paper inside, and covered with waterproof PE film outside"). This clearly separates the risk of rust during transportation from production quality liability.
Insurance Issues: If cargo damage is caused by failure to take reasonable rust-prevention measures, marine insurance may refuse to pay.
5.What are some summaries and suggestions?
Minimum Requirements: Rust-preventive oil must be applied and an outer waterproof membrane must be used.
Strong Recommendation: Adopt the above "standard solution," as this is common industry practice and an effective guarantee.
Action Guidelines: Based on the length of the voyage, season (rainy/dry season), transportation area (such as passing through equatorial high-humidity areas), and specific customer requirements, select or negotiate to determine the rust-preventive packaging level, and write it in black and white in the contract.