What measures should be taken to prevent fumigation-free wooden pallets from becoming moldy during long-term storage?
Release Time : 2026-01-15
Fumigation-free wooden pallets, with their advantages of requiring no chemical fumigation and meeting international quarantine standards, are widely used in logistics and warehousing. However, during long-term storage, improper environmental control can still lead to mold growth, resulting in surface mildew and reduced strength. To ensure stable performance, comprehensive measures are needed, including environmental management, material pretreatment, and the application of moisture-proof and mildew-proof technologies.
The core conditions for mold growth are humidity, temperature, and nutrients. Although fumigation-free wooden pallets undergo high-temperature and high-pressure treatment, if the storage environment humidity consistently exceeds 20%, components such as cellulose and starch in the wood can still become a source of nutrients for mold. Especially during humid seasons or in enclosed warehouses, poor air circulation accelerates moisture condensation, providing a breeding ground for mold. Therefore, controlling environmental humidity is the primary task in preventing mold growth. It is recommended to install hygrometers in the warehouse to monitor environmental humidity in real time and maintain humidity within a reasonable range using dehumidifiers, air conditioners, and other equipment. For example, during the rainy season or in humid coastal areas, dehumidifiers can be used to reduce air moisture content. If the warehouse lacks specialized equipment, desiccants such as quicklime and calcium chloride can be placed to absorb excess moisture, but they need to be replaced regularly to maintain their effectiveness.
The moisture content of wood is a key factor affecting mold growth. Although fumigation-free wooden pallets undergo drying during production, they may still reabsorb moisture due to fluctuations in ambient humidity during long-term storage. If the moisture content exceeds 20%, mold spores easily germinate on the wood surface, forming black, green, or yellow mold spots. Therefore, it is essential to ensure the pallet's moisture content meets standards before storage. For newly produced pallets, natural air drying or low-temperature drying can be used to further reduce moisture content; for used pallets, if long-term storage is required, they should be thoroughly dried after cleaning before being stored. Furthermore, avoid stacking pallets directly on damp ground during storage; use moisture-proof mats or pallet racks to reduce the contact area with the ground and prevent moisture penetration.
The application of anti-mold agents is an effective means of inhibiting mold growth. Currently, wood anti-mold agents on the market are mainly divided into three categories: water-based, oil-based, and powder. They can be applied by spraying, soaking, or brushing. For example, after diluting the anti-mold agent according to a certain ratio, it can be sprayed evenly on the surface of the pallet using a sprayer, or the pallet can be directly soaked in the anti-mold solution, allowing the agent to penetrate into the wood and form a protective layer. The active ingredients in the anti-mold agent can destroy the cell structure of mold and inhibit its reproduction, thereby extending the pallet's storage period. However, it is important to note that the choice of anti-mold agent should meet environmental protection requirements to avoid harm to the health of operators or the environment; at the same time, the treated pallets must be thoroughly dried to prevent residual agents from corroding goods or packaging materials.
The ventilation conditions of the storage environment directly affect the rate of mold growth. In a closed warehouse, air circulation is slow, and moisture easily accumulates, leading to increased local humidity; while a well-ventilated warehouse can accelerate air exchange and reduce mold concentration. Therefore, when storing fumigation-free wooden pallets for a long time, a warehouse with good ventilation should be chosen first, or air circulation should be enhanced by installing exhaust fans and opening windows. If the warehouse is a closed structure, doors and windows can be opened periodically for short periods of ventilation, but this should be avoided on rainy days or during periods of high humidity to prevent external moisture from entering. In addition, sufficient gaps should be left when stacking pallets to avoid obstructing airflow; a distance of 10-15 cm between pallets is generally recommended.
The pallet stacking method is closely related to the storage period. For long-term storage, if pallets are stacked too high or haphazardly, the bottom pallets may be deformed under pressure, while also obstructing airflow and increasing the risk of mold. Therefore, a "well" or "triangle" stacking method is recommended to create passageways between pallets, facilitating airflow and inspection. At the same time, the stacking height should be controlled, generally not exceeding 1.5 meters, to prevent structural damage to the bottom pallets due to prolonged pressure. Furthermore, a moisture-proof film or plastic sheet can be placed around the pallet stack to form an isolation layer, reducing the intrusion of ground moisture and external water vapor.
Regular inspection and maintenance are crucial for ensuring the long-term storage quality of pallets. It is recommended to conduct a comprehensive inspection of the pallets monthly, focusing on whether there are mold spots, discoloration, or deformation on the surface. If slight mold is found, the moldy areas can be sanded down and then treated with an anti-mold agent. If the mold is severe, the contaminated pallets should be isolated to prevent cross-contamination, and the supplier should be contacted immediately for replacement. At the same time, check whether the warehouse environment meets the standards, such as humidity and ventilation, and adjust storage strategies accordingly.