Laminated glass (usually referring to glass with films such as PVB, SGP, and EVA sandwiching in the middle) gets moldy during long-distance transportation. The key is to prevent the "paper print mold" on the glass surface (especially in a humid environment) and the interlayer material from getting damp. This is a common but completely preventable problem.
I. Prevention at the Source of Production and Storage (The most crucial Step
Ensure the glass itself is dry: Before leaving the factory, the glass must be thoroughly cooled and dried, and its surface temperature should be close to the ambient temperature to prevent condensation water from forming inside after packaging.
Use anti-mold isolation materials
Anti-mold powder/anti-mold paper: Between glass sheets, special anti-mold spacer paper containing anti-mold agent (VCI) must be used instead of ordinary paper or inferior paper. This kind of paper can continuously release anti-mold gas and form a protective layer on the surface of the glass.
Desiccant (moisture absorber) : Place an adequate amount of high-efficiency desiccant (such as silica gel desiccant) in the packaging box to absorb the moisture that may invade during transportation. Calculate the quantity accurately (usually based on the packaging volume and the estimated transportation time).
Strict cleaning: Before packaging, the glass surface must be thoroughly cleaned to remove contaminants such as fingerprints and dust that may breed mold.
Second, scientific and rigorous packaging methods
Sealed moisture-proof packaging
Use high-strength waterproof corrugated cardboard boxes or wooden crates as outer packaging.
After the glass is separated with anti-mold paper, it is tightly wrapped with high-quality plastic film (such as PE film) as a whole to form the first moisture-proof barrier. The seal should be tight and it is best to use heat shrink film.
For sea transportation or extremely humid environments, it is recommended to use moisture-proof bags made of aluminum foil composite materials for wrapping, as their moisture-proof effect is far superior to that of ordinary plastic films.
Corner protection and filling
The four corners and edges of the glass should be protected with anti-collision corner guards to prevent damage to the packaging.
All the voids inside the packaging box are filled with dry fillers (such as foam or bubble wrap) to prevent the glass from moving inside the box and also to help prevent moisture.
Clear identification
Prominently mark the outside of the packaging box with labels such as "Fragile Glass", "Handle with care", "Keep dry", "Do not expose to rain" and "This side up".
A prompt label saying "Please check the condition of the desiccant after opening the box" can be affixed.
Iii. Process Control of Long-distance Transportation
Container/Vehicle selection
Dry, clean and well-sealed containers or trucks must be used. Check if there are any holes or signs of rain leakage in the carriage.
For sea transportation, if conditions permit, refrigerated containers (Reefer containers) can be used for temperature-controlled and moisture-controlled transportation. This is the safest but more costly method.
Avoid extreme temperature differences
Container "rain" phenomenon: This is a common problem in sea transportation. When containers are transported from cold regions to hot ones, the air inside condenses into water droplets on the cold walls. The solutions include:
Use moisture-absorbing materials: Hang moisture-absorbing bags inside the box or place a large amount of desiccants.
Use dehumidification systems: such as container-specific dehumidifiers (suitable for high-value goods).
Avoid "under deck" positions: When booking space, try to request that the goods be placed in containers on the deck, where ventilation and temperature are relatively better.
Transportation route and time:
Try to choose direct transportation methods to reduce the time for intermediate transfer and open-air stacking.
Avoid long-distance transportation during the rainy season. If it is unavoidable, all moisture-proof measures must be strengthened.
Iv. Handling upon Arrival
Open the box in time for inspection
After the goods arrive, the boxes should be opened as soon as possible in a dry environment.
Immediately check whether the desiccant is saturated, whether the anti-mold paper is intact, and whether there is any moisture or mold spots on the glass surface.
Correct storage
If not installed immediately, the glass should be stored vertically in a dry and well-ventilated indoor warehouse, avoiding being placed flat or close to walls or the ground.
Keep the temperature and humidity of the storage environment stable.
