Q:How to choose packaging materials?
A:Moisture-proof packaging materials:
(PE) film: low cost, good flexibility, but high air permeability, suitable for short-term storage or dry environment.
Polypropylene (PP) film: better temperature resistance than PE, slightly better moisture resistance, can be used in medium humidity environment.
Aluminum foil composite material: high barrier (moisture-proof, oxygen-proof, light-proof), extremely strong sealing, suitable for long-term storage or high humidity environment (such as sea transportation), but high cost.
Vapor phase rust inhibitor (VCI) packaging materials: containing vapor phase rust inhibitor, which forms a protective film on the metal surface after volatilization to inhibit corrosion, especially suitable for packaging of complex shapes or precision parts.
Hygroscopic materials (auxiliary protection):
Desiccant: Place silica gel desiccant, montmorillonite desiccant, etc. in the package to absorb residual moisture and control the humidity in the package below 60% (ideal value ≤40%).
Absorbent paper / mildew-proof paper: laid between the boards to absorb surface condensation water and reduce the hidden danger of local moisture.
Q:What packaging methods can prevent white rust?
A:Fully sealed packaging: Use heat shrink packaging or high-frequency welding to seal, ensure that the packaging is not damaged or opened, and prevent external moisture from invading.
Vacuum packaging: Extract the air in the package to form a negative pressure environment, further reduce the oxygen and moisture content, suitable for long-term storage or export transportation of high-end automotive plates (such as galvanized high-strength steel).
Note: Before sealing, ensure that the surface of the plate is dry and clean (no oil, fingerprints, water stains), and avoid residual moisture or pollutants in the package.
Q:What are the differences in the effects of different packaging methods?
A:VCI film + silica gel desiccant: Anti-rust molecules are continuously released, the cost is moderate, but the sealing needs to be checked regularly.
Aluminum-plastic composite film vacuum packaging: Absolutely moisture-proof, suitable for long-term storage, but the cost is high and cannot be reused after unpacking.
Ordinary PE film + wooden pad: Low cost and easy to condense, but the wooden pad absorbs moisture and causes white rust.
Anti-rust paper + corner protector Environmental protection: Suitable for single sheet protection, weak moisture-proof ability.
Q:What is the synergy between packaging and storage?
A:Even with high-quality packaging, the following storage measures are still required:
Warehouse humidity ≤ 50%, temperature 10~30℃;
The board is 15cm above the ground to avoid contact with the concrete floor;
It is forbidden to mix with copper, rubber and other materials.
Q:Are there any special packaging requirements for the automotive industry?
A:High-standard packaging for the automotive industry:
Double-layer packaging with VCI film + aluminum-plastic composite film, with double desiccant inside.
Spray epoxy zinc-based repair paint on the cut edge and seal with anti-rust tape.