As temperatures and humidity levels rise during summer, the storage and application of Sodium Carboxymethyl Cellulose (CMC) become more challenging for manufacturers in the paper industry. Sodium carboxymethyl cellulose (CMC) is significantly affected by high temperature and humidity in summer, with key issues focusing on powder moisture absorption and caking, reduced solution viscosity, and mold growth or deterioration of aqueous solutions.

Moisture Control Is Critical During Storage

Sodium carboxymethyl cellulose is highly hygroscopic, meaning it easily absorbs moisture from the surrounding environment. During summer, warehouses should remain cool, dry, and well ventilated, with temperatures controlled below 30°C and relative humidity maintained under 60%. Dehumidifiers and ventilation systems are commonly recommended to improve storage conditions.

To further reduce the risk of moisture absorption, CMC packages should be stored on pallets positioned 10–20 cm above the floor and at least 20 cm away from walls. Direct sunlight exposure must also be avoided. For opened packages, the inner plastic bag should be tightly sealed or heat-sealed immediately after use to prevent caking and loss of product quality.

Proper Dissolution Methods 

In high-temperature conditions, improper dissolution techniques can significantly affect the performance of CMC. Experts emphasize that boiling water should never be used during summer preparation. Excessively hot water causes the outer layer of CMC particles to rapidly form a gel film, trapping dry powder inside and creating undissolved lumps commonly known as “fish eyes.”

To avoid this issue, manufacturers are advised to use cold or room-temperature water during dissolution. The dry mixing method is considered highly effective, where CMC is first blended with other dry materials before being gradually added into vigorously stirred water. Slow and uniform feeding during vortex mixing can also minimize agglomeration and improve dissolution efficiency.

Freshly Prepared Solutions Recommended

Another major concern during summer is microbial growth in CMC aqueous solutions. Without preservatives, prepared solutions can deteriorate quickly under hot and humid conditions. Industry professionals recommend preparing solutions based on immediate production needs and avoiding overnight storage whenever possible.

Using freshly prepared solutions not only helps maintain viscosity stability but also reduces the risk of bacterial contamination, ensuring better product consistency in paper manufacturing applications.

Transportation and Production Adjustments Also Important

In addition to storage and dissolution management, companies are encouraged to optimize transportation and production schedules during extreme summer weather. Protective packaging, humidity-resistant handling, and reduced exposure to high-temperature environments during transit can help preserve product quality before use.
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