As a safe and economical method in cargo transportation, container shipping is the preferred choice for most exporters. However, sea transport can lead to dampness issues. Not every sea shipment results in significant losses. Some shipments might be fine for the first few times, but severe losses due to dampness may occur around the sixth or seventh shipment. Many people wonder how their goods can get damp even when packed in tightly sealed containers. Where does this water come from? The root cause lies in the lack of systematic moisture-proof protection measures for containers.
Firstly, containers are not actually airtight. All containers will have some moisture from the loading process and the goods themselves; no container is completely airtight. The structural design of containers means gaps exist, especially around the doors. Implementing systematic protective measures can effectively prevent significant damage and economic losses to goods due to dampness. When using containers for export goods, please systematically inspect the container first. Check the container doors, walls, floor, and top for any obvious holes, gaps, or damage. Ensure the container is dry and clean.
Secondly, where does the moisture inside the container come from?
The moisture inside the container mainly comes from the moisture in the air itself, the goods themselves, packaging materials (cardboard boxes, wooden boxes, etc.), pallets, the wooden floor of the container, container leaks, etc. The International Container Lessors Association states that the moisture content of container wooden floors should not exceed 14%. In reality, the average moisture content of containers still in use at many ports is 18%, with some even exceeding 25%. The main component of the container floor is cork, which has a high moisture content. Heavy goods often require wooden crates. The goods themselves, such as cotton and linen products, palm products, etc., also have a high moisture content. Never use a recently washed, hot container; use a dry container. All pallets and other wooden products used inside the container must be dry, with a relative humidity preferably not exceeding 12%. A humidity detector can be used to check the moisture content of the packaging materials. Pay special attention to the storage of containers, pallets, and corner protectors.
In fact, in an ocean environment, the inside of a container is like a large steamer. Once sealed, the temperature inside the container will be more than 10 degrees higher than the outside temperature, with the temperature and humidity changing drastically due to the daily variations in ocean temperature and humidity. When goods are transported from a low-temperature area to a high-temperature area, or when the storage environment of the goods suddenly changes from cold to hot, the moisture inside the pallets, wooden boxes, etc., will also evaporate. The water vapor in the air will condense into water on the surface of the goods or their packaging when it cools, and the goods themselves will also release water. When the container moves from a high-temperature area to a low-temperature area, the internal temperature changes from high to low, reaching the dew point temperature, and the water vapor will condense into water droplets, condensing on the top and surrounding inner walls of the container, eventually dripping onto the goods. This is why the goods get wet.
Hengyuan friendly reminder: Please use container desiccants and take moisture-proof protection measures in advance. The purpose is to absorb moisture from the air to reduce the total amount of moisture entering the container. The amount of container desiccant used depends on the type of goods, the length of the voyage, and the acceptable level of damage. Generally, it is recommended to use more than 6 1 kg container desiccants, such as Hengyuan's HDTW-1000 model, for a 20-foot container. Hang the container desiccant on the hanging rings on the inner wall of the container. If the packaging materials in the container have a high moisture content, such as wooden boxes and pallets, the amount of container desiccant should be increased. More valuable goods should be better protected, and the amount should be increased. You can also additionally spread some FB-3000 container desiccants on the cardboard boxes.
In short, the cost of using desiccants is very low, far less than the value of the goods themselves. Protecting goods at such a low cost is a very effective solution.
