What are the best types of packaging for shipping?

Shipping goods across global supply chains involves various environmental challenges, especially managing moisture. Changes in temperature and humidity can cause moisture to accumulate in shipping containers, posing severe risks to the integrity of products.

Moisture can lead to the growth of mould and mildew, cause packaging to weaken or disintegrate, and even result in the corrosion of metal items. Container desiccants play a role in safeguarding cargo during transit.

These materials are designed to absorb excess moisture within the container, thus maintaining a dry environment. Their use helps to ensure that products arrive at their destinations in the same condition as they were shipped, without damage from humidity or condensation.

Understanding Container Desiccants

Desiccants work through a process known as adsorption (not to be confused with absorption). Adsorption involves the adhesion of water vapor molecules to the surface of the desiccant material. The effectiveness of a desiccant depends on its pore structure and surface area; the greater the surface area, the more moisture it can adsorb.

Understanding the specific properties and behaviors of different types of desiccants allows for strategic placement and usage in shipping containers tailored to the sensitivity and requirements of the transported cargo. This ensures optimal protection against moisture throughout the shipping process.

Types of Desiccants Used in Containers

• Silica Gel: Silica gel has a high moisture absorption rate and non-reactive nature. It’s often found in small packets or canisters and is particularly effective in maintaining a dry environment for a variety of goods, from electronics to food products.
• Calcium Chloride: Known for its extremely high moisture absorption capacity, calcium chloride is effective at low and high humidity levels. It is commonly used in bags that can hold a considerable amount of absorbed water, making it ideal for long transit times.
• Clay: A more cost-effective option, clay desiccants are effective within a moderate humidity range and are often used for less sensitive cargo. While not as efficient as silica gel or calcium chloride in extreme conditions, they are suitable for general shipping needs.
• Molecular Sieves: These synthetic desiccants are used for specialized applications where very low humidity levels are required. Molecular sieves are highly effective in adsorbing water molecules at a microscopic level, making them suitable for sensitive and high-value products.

Benefits of Container Desiccants

Container desiccants offer several benefits, from preventing mold and mildew to enhancing the overall shelf life of the cargo. Here’s a look at these benefits:

Prevention of Mold and Mildew: Mold and mildew thrive in moist environments and can significantly damage organic materials such as wood, paper, and textiles. They not only compromise the physical integrity of these materials but can also cause health problems and unpleasant odors.

By effectively controlling the humidity levels inside shipping containers, desiccants prevent the growth of these fungi. This is crucial for shipments that spend extended periods in transit, particularly through varying climatic conditions.

Protection Against Cargo Spoilage: Many products, including food items, pharmaceuticals, and electronics, are highly sensitive to moisture. Moisture can lead to the deterioration of perishable goods, degradation of pharmaceutical effectiveness, and irreversible damage to electronic circuits.

Container desiccants absorb unwanted moisture, maintaining the quality and functionality of these sensitive products throughout their journey. This moisture management is particularly vital in intermodal transport, where changes in temperature and humidity are frequent and can otherwise lead to condensation.

Efficacy of Desiccants: Container desiccants are designed to last for the duration of the shipping process. They are engineered to have a high moisture absorption capacity relative to their mass, so they do not become saturated quickly and continue to perform effectively over long periods.

This makes them a cost-effective solution for moisture control in shipping. Desiccants’ shelf life is also enhanced by their ability to maintain their structural integrity and absorption efficiency under a wide range of temperatures and humidity levels, ensuring that they remain effective from the point of departure to the final destination.

Selection Criteria for Desiccants

Selecting a suitable desiccant requires understanding the shipping conditions, the nature of the cargo, and the specific risks associated with moisture damage.

By weighing these factors and choosing a desiccant that aligns with the needs of the cargo and shipping route, businesses can ensure that their products arrive in optimal condition. Here’s a breakdown of the key selection criteria and comparing different desiccant materials.

• Absorption Capacity: The ability of a desiccant to absorb moisture relative to its weight is crucial. A higher absorption capacity means the desiccant can handle more moisture over a longer period, which is particularly important for long shipments or humid conditions.
• Temperature Range: Desiccants must perform effectively within the specific temperatures they encounter during transit. Some desiccants, like calcium chloride, can absorb moisture across various temperatures, while others might be more effective in cold or warm conditions.
• Reactivity and Safety: Certain desiccants can react chemically with the cargo or emit harmful gases. Therefore, it is essential to choose non-reactive, non-toxic desiccants for food, pharmaceuticals, and other sensitive products.
• Physical Form: Desiccants come in various forms, such as beads, crystals, and powders. The choice of form can affect the ease of handling and the efficacy of moisture absorption in the specific shipping environment.
• Cost-Effectiveness: The cost of desiccants can vary significantly based on their type and required quantities. Evaluating the cost relative to their protection is important for maintaining budgetary constraints without compromising cargo safety.

Best Practices in Application

Effective use of desiccants in shipping containers requires strategic placement and accurate calculation of the necessary quantities. These practices ensure that moisture is controlled uniformly throughout the container, safeguarding the cargo against potential damage. Below are guidelines on optimizing the application of desiccants for maximum effectiveness.

Placement Strategies for Maximum Effectiveness

• Even Distribution: Desiccants should be evenly distributed throughout the container to prevent localized moisture pockets. This can involve placing desiccant packs between layers of goods, within the packaging of the products themselves, or in hanging devices that can be placed around the walls of the container.
• Proximity to Moisture Sources: Position desiccants close to where moisture is most likely to accumulate. For instance, placing them near the doors and on the container’s ceiling can be effective because these areas are prone to “container rain” or condensation droplets forming due to temperature fluctuations.
• Accessibility and Airflow: Ensure sufficient airflow around the desiccant materials. This can be facilitated by not overcrowding the container and allowing space around the boxes or pallets for air to circulate freely, enhancing the desiccant’s ability to capture moisture.
• Avoid Direct Contact with Cargo: While proximity is essential, direct contact between desiccants and sensitive products should be avoided to prevent damage from the desiccant material, especially if the desiccant becomes fully saturated.

Calculating Required Desiccant Quantities

1. Assess the Cargo and Container Size: The type and volume of the cargo, as well as the size of the container, are the primary factors to consider. More absorbent materials, like textiles or wooden products, might require more desiccant compared to less absorbent materials like plastic or metal.
2. Consider the Shipping Duration and Conditions: Longer transit times and routes through varied or extreme climatic conditions necessitate more desiccants. The expected differences in temperature and humidity during the journey should be considered.
3. Use Standard Calculations or Guidelines: Many desiccant manufacturers provide guidelines based on the type of desiccant, the volume of the container, and the nature of the goods being shipped. As a rule of thumb, a typical 20-foot container might use between 4 to 8 kilograms of silica gel or 2 to 4 kilograms of calcium chloride.
4. Customize Based on Experience and Past Issues: Adjust quantities based on past experiences with similar shipments. If previous shipments have encountered moisture-related issues despite following standard guidelines, consider increasing the amount of desiccant.

Conclusion

Proper moisture management in shipping is essential for protecting the cargo from physical and chemical damage and ensuring the safety and usability of the shipped products upon arrival. Effective use of desiccants helps prevent mold, mildew, and corrosion, which can compromise the structural integrity and functionality of various products.

Using container desiccants also plays a significant role in promoting sustainability within the shipping industry. By extending the life of products and reducing the incidence of spoilage, desiccants decrease waste and the need for replacement shipments, reducing the overall carbon footprint associated with transporting goods.

At Stream Peak International, we are a global supplier of high-quality desiccants committed to enhancing shipping efficiency and sustainability. We manufacture our container desiccants under stringent quality control standards, boasting ISO 9001 and 14001 certifications. With a dedicated in-house quality assurance lab, we ensure that each product meets the rigorous demands of moisture control in shipping.