Secure goods during shipment with Dunnage Bag

As goods move across diverse climates and handling conditions, they are exposed to various risks that can compromise their integrity, appearance, and usability. Two critical challenges in shipping protection are controlling moisture and ensuring cargo stability.

Moisture control is vital to shipping logistics, particularly as excess humidity can severely affect various products. Equally important is cargo stability, which ensures that goods remain secure and undamaged, regardless of the rigors of transport.

Combining the moisture-absorbing capabilities of container desiccants with the stabilizing force of dunnage bags provides a comprehensive protection strategy. This integrative approach addresses both climatic and mechanical threats to cargo, making it an effective method for various shipments, from sensitive electronics to bulk agricultural products.

Understanding Container Desiccants

Container desiccants are materials specifically formulated to absorb moisture from the air within enclosed environments, such as shipping containers.

They maintain a low-humidity atmosphere during transit, which helps to prevent the formation of condensation and protects sensitive goods from moisture-related damage. The most commonly used types of desiccants in shipping include:

• Calcium Chloride: Highly effective at absorbing moisture at various temperatures, it can hold up to several times its weight in water, making it suitable for high moisture conditions.
• Clay: A more economical option, clay desiccants offer moderate moisture absorption suitable for shorter shipping durations or less sensitive cargo.

How Desiccants Work

Desiccants work through a process known as adsorption, where moisture vapor in the air is drawn onto the surface of the desiccant material. The physical and chemical properties of the desiccant dictate the rate and capacity of moisture adsorption. Desiccant’s physical and chemical properties dictate the moisture adsorption rate and capacity

For example, silica gel features a vast network of microscopic pores that capture water molecules. In contrast, calcium chloride undergoes an exothermic reaction, converting absorbed moisture into a liquid brine, trapping it and preventing it from re-entering the container environment. This absorption capability prevents cargo degradation, especially for products susceptible to moisture, such as electronics, pharmaceuticals, and food items.

Benefits of Using Dunnage Bags

Dunnage bags, also known as airbags or inflatable bags, secure and stabilize cargo during transportation. They are placed in the void spaces between cargo items or between cargo and the container walls to prevent movement and shifting that could cause damage.

Dunnage bags are typically made from polypropylene or vinyl and can be inflated with air to the required pressure. There are several types of dunnage bags, categorized mainly by the material and the level of load they are certified to bear:

• Polywoven Dunnage Bags: Made from woven polypropylene and suitable for heavy-duty applications, offering high strength and durability.
• Paper Dungeon Bags: These bags consist of multiple layers of kraft paper, ideal for lighter, less demanding loads.

Role of Dunnage Bags

Dunnage bags are critical in stabilizing cargo by filling the void spaces within shipping containers, trucks, or railcars. These bags exert pressure against the cargo when inflated, holding items firmly in place.

This stabilization is essential in preventing cargo from shifting, tilting, or falling during transport, particularly during the handling and transportation phases where movement is frequent and potentially abrupt. The bags offer several advantages over other cargo stabilization methods, such as strapping, blocking, and bracing:

• Versatility: Dunnage bags can be used in various cargo configurations and types, adapting to spaces.
• Cost-Effectiveness: They are generally less expensive and require less installation labour than more rigid stabilization methods like wood blocking.
• Efficiency: Inflating and placing dunnage bags quickly and easily reduces packing time and effort.
• Reusability: Many dunnage bags are designed for multiple uses, making them an eco-friendly option.
• Damage Prevention: Unlike hard stabilizers, dunnage bags create a cushion of air that reduces the risk of damaging the cargo, providing gentle yet effective stabilization.

Selection Criteria

By considering these selection criteria for desiccants and dunnage bags, shippers can optimize their cargo protection strategy, ensuring that goods arrive at their destination in good condition, regardless of the shipping challenges they face.

How to Choose the Right Desiccant

Selecting the appropriate desiccant for shipping requires understanding the specific needs of the cargo, the environmental conditions expected during transit, and the physical characteristics of the desiccants available. Here are key factors to consider:

1. Absorption Capacity: Choose a desiccant that can absorb sufficient moisture relative to its weight and volume, considering the length of the transit and expected humidity levels. For instance, calcium chloride is suitable for very humid conditions due to its high absorption capacity.
2. Compatibility with Cargo: Ensure the desiccant does not chemically react with the cargo. For example, silica gel is inert and safe for use with electronics and foods, while other desiccants might be more reactive.
3. Desiccant Packaging: The packaging material should be robust enough to withstand the transit conditions without rupturing. Non-woven fabrics bags are common for allowing moisture ingress but keeping the desiccant material contained.
4. Regulatory Compliance: Some desiccants may be subject to regulatory restrictions, especially in food and pharmaceutical shipping. Always verify that the desiccant complies with relevant local and international regulations.
5. Cost-Effectiveness: Consider the cost per absorption unit and the total cost impact on shipping. While more efficient desiccants might be more expensive upfront, they could offer savings through better protection and reduced damage.

Selecting the Appropriate Dunnage Bag

Choosing the right dunnage bag involves understanding the physical demands of the cargo and the characteristics of various dunnage bag materials. Consider these factors:

1. Cargo Weight: Heavier items require dunnage bags with higher burst strength. Polywoven and vinyl dunnage bags are typically used for heavy loads due to their robustness and durability.
2. Void Space Size: The size of the dunnage bag should be appropriate for the void space it needs to fill. If it is too small, it won’t adequately stabilize the cargo, and if it is too large, it may not fit or could damage the cargo or container.
3. Material Suitability: The choice of material depends on the specific requirements for moisture resistance and durability. For example, vinyl is preferable for moisture-prone environments, whereas polywoven bags might be chosen for their superior strength and puncture resistance.
4. Ease of Use: Consider how easy the dunnage bags are to inflate and position. Some bags come with rapid inflation tools and valves that save time and labor during packing.
5. Reusability and Environmental Impact: Eco-conscious companies might prefer reusable dunnage bags. Although more costly initially, they can be deflated, stored, and reused, offering long-term savings and environmental benefits.

Installation Techniques

Proper installation of desiccants and dunnage bags is crucial for maximizing their effectiveness in protecting cargo during transit. Here are some best practices:

Placing Desiccants in Containers

• Strategic Placement: Distribute desiccants evenly throughout the container to ensure uniform moisture absorption. Place them near the ceiling and walls where condensation will likely form and close to moisture-sensitive products.
• Avoid Direct Contact: Keep desiccants away from direct contact with cargo, especially food and pharmaceuticals, to prevent contamination. Use breathable desiccant bags that allow moisture ingress but prevent any contact with the goods.
• Proper Sizing: Calculate the appropriate amount of desiccant based on the volume of the container, the type and quantity of cargo, and the expected shipping conditions. Overloading a container with too much desiccant can be wasteful, while too little may not adequately protect against moisture.
• Secure Placement: Ensure that desiccant bags are securely placed so they do not shift during transit. They can be hung from container desiccants with hooks, placed in pouches on container walls, or securely nestled within cargo stacks where they won’t fall over.
• Check for Airflow: Position desiccants in areas where air circulates to enhance their efficiency. Good airflow helps desiccants absorb moisture more effectively throughout the container.

Effective Dunnage Bag Placement

• Assess Void Spaces: Before loading the container, identify all the void spaces between cargo items and along the walls of the container. These are the areas where dunnage bags will most effectively stabilise the load.
• Choose the Right Size: Select dunnage bags that appropriately fill the void without overinflation. Overinflated bags can damage goods or burst, while underinflated bags may not adequately secure the cargo.
• Proper Inflation: Inflate dunnage bags to the manufacturer’s recommended pressure, often indicated on the bag. This ensures they are firm enough to stabilize the cargo without exerting excessive pressure that could cause damage.
• Layer Placement: Dunnage bags should be placed in horizontal layers between stacks of goods and vertical layers between the cargo and container walls. This helps distribute the load evenly and prevents shifting in multiple directions.
• Accessibility and Safety: Ensure that dunnage bags are accessible and easily inflated and deflated. Avoid placing sharp objects near the bags to prevent punctures. Regularly inspect bags throughout loading to ensure they are intact and properly positioned.

Conclusion

Shippers can significantly enhance the safety and integrity of goods in transit by implementing solutions such as desiccants and dunnage bags. The process involves strategically placing desiccants within the cargo space to control humidity levels, thus preventing condensation and moisture-related damage.

Concurrently, dunnage bags are positioned to fill voids and secure cargo, mitigating the risk of movement and physical damage. This dual approach not only enhances the protective environment within the container but also optimizes the use of space and materials for cost-effective shipping solutions.

Stream Peak International is a global supplier of container desiccants, renowned for our commitment to quality. Our manufacturing plant is certified to ISO 9001 and 14001 standards, ensuring environmental and quality management. We also operate a dedicated in-house QA lab, meticulously overseeing every aspect of our product quality to reduce goods damage and enhance sustainability.