Cardboard boxes and paper materials are widely used for packaging various types of products. High relative humidity can compromise the strength and durability of cardboard boxes, causing them to soften due to the interaction of moisture with the cellulose fibers in the cardboard. The strength of cardboard comes from the tightly bound cellulose fibers, which are held together by hydrogen bonds and Van der Waals forces. During storage, these hygroscopic cellulose fibers absorb moisture from the surrounding air, leading to a deterioration in the overall rigidity of the product. In cold or cool packaging rooms, high relative humidity causes cellulose fibers to swell by absorbing moisture from the air. When cellulose fibers absorb moisture, the hydrogen bonds between the fibers can be broken or weakened by water molecules. This leads to the fibers separating and the cardboard structure deteriorating, resulting in the loss of the original form of the cardboard. Warping, shrinkage, and surface deformations weaken the strength of the cardboard. Cardboard boxes or paper materials that are systematically exposed to high relative humidity without dehumidifiers are at a higher risk of tearing and breaking compared to dry-stored cardboard boxes. Using deformed and structurally weakened boxes for transportation and storage increases the risk of damage.
During the summer, cardboard boxes stored in underground or shaded areas often suffer surface depressions due to high relative humidity. Stacking boxes is the most efficient way to maximize storage space in warehouses. However, boxes stored in high-humidity areas, especially those at the bottom of the stacks, tend to collapse.
To preserve the integrity of cardboard boxes and paper rolls that need to be stored in high-humidity areas, silica gel adsorption dehumidifiers or mechanical condensation dehumidifiers should be used. Maintaining the relative humidity in the storage area at 60% or lower ensures the stability of the cardboard’s mechanical strength. The choice of dehumidifier system depends on the seasonal or annual temperature patterns in the storage area. In low-temperature storage areas, silica gel adsorption dehumidifiers offer a more energy-efficient solution, while mechanical condensation dehumidifiers are recommended for storage conditions that do not have low temperatures but are below ground level.
An alternative method for small storage areas is to stabilize relative humidity by heating the indoor air. Heating the air does not change the absolute humidity but reduces the relative humidity. However, using a heating device in areas without highly insulated panels can be costly. Insulating the ceiling and addressing condensation on surfaces like windows are important considerations for capacity calculations in processes integrating dehumidifiers.
Using dehumidifiers in storage areas keeps products dry, allowing for higher stacking of palletized cardboard boxes and reducing the costs associated with replacing damaged products. This also saves labor and eliminates the risk of toppling stacks due to softened bottom boxes, thereby preventing potential workplace accidents. The use of silica gel adsorption industrial dehumidifiers, which can utilize alternative energy sources for the regeneration heater, further lowers operating costs while maintaining the overall rigidity of the products.
We as NKT – Humidity Control Technologies, our expert engineering team provides the best industrial dehumidifier solutions for storing cardboard boxes and paper rolls, offering energy-efficient, high-performance solutions.
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