1.Why is moisture protection for the core so important?
Structural Characteristics: The tightly wound internal structure of the coil makes it extremely difficult for moisture to dissipate, creating a stuffy, damp environment.
Condensation Risk: Under conditions of large temperature differences between day and night or between the inside and outside of the warehouse, condensation easily forms on the metal surface inside the coil core, a major cause of corrosion.
Capillary Action: If the ends of the coil are not sealed, moisture from the ground or air can be sucked deep into the coil through tiny gaps between the steel layers, like a wick.
Severe Consequences: Rust on the coil core can cause the steel layers to stick together, resulting in "surface tearing" or "delamination" during unwinding, rendering the product unusable. Furthermore, corrosion spreads from the inside out, affecting overall quality.
2.What are the core requirements for standard moisture-proofing of roll cores?
Materials: Use specialized, high-strength, good-adhesion rust-proof corner protectors or thickened waterproof plastic end caps, tightly fitted onto both ends of the roll material.
Function: Physically prevents air and moisture from directly entering the roll core from the end faces, while protecting the roll material from damage during hoisting and transportation. This is the most basic and indispensable step.
Built-in desiccant (core moisture-proof method)
Materials: Place a bag of "vapor phase rust inhibitor desiccant" or "silica gel desiccant" inside the core hole before bundling.
Function: Actively absorbs residual or slowly seeping trace amounts of moisture within the sealed space of the core, keeping the internal air dry. Vapor phase rust inhibitors also release corrosion-inhibiting components, forming a protective film on the metal surface.
Outer Moisture-Proof Packaging (Enhanced Protection)
Materials: Wrap the entire steel coil with a moisture-proof film (such as PE film) or moisture-proof paper, then secure it with steel straps or packing straps.
Function: Provides an additional moisture and dust barrier for the entire coil, especially the sides. This is particularly important for products shipped by sea or stored in humid environments.
3.What are the storage and transportation requirements?
Storage: Store in a clean, dry, and well-ventilated indoor warehouse. Open-air storage is strictly prohibited. If short-term outdoor storage is unavoidable, cover tightly with a tarpaulin and elevate the container to prevent ground moisture from rising.
Elevation: The roll material must be elevated using materials such as wooden blocks to maintain a distance from the ground and prevent ground moisture from penetrating.
Transportation: During transportation, especially for sea freight containers, ensure the containers are dry and undamaged. Some high-end customers may request container desiccants to be placed inside the containers.
4.What suggestions do you have for the purchasing party?
The procurement contract should explicitly require that "moisture-proof treatment of the core" be written into the packaging clause. For example: "Waterproof and rust-proof corner protectors must be added to both ends, sufficient vapor phase rust-preventing desiccant must be placed inside the core, and a moisture-proof film must be covered on the outside."
5.What suggestions do you have for users?
Key checks upon arrival: Upon receiving the goods, be sure to check whether the end corner protectors are intact and not detached, and whether the desiccant bag is in place. If any damage to the packaging or lack of moisture-proof measures is found, take photos immediately, record the information, and promptly report it to the supplier.