Bags and Barrier Material
In military packaging, bags and barrier materials are the first line of defense for a wide range of sensitive equipment. They are designed to create a sealed, controlled environment that protects items from common threats like moisture, dust, grease, and static electricity during long-term storage and challenging transport conditions. These materials are fabricated from multiple layers, often including foil, polyethylene, and other materials, to achieve a high level of protection.
Barrier Materials
Barrier materials are the building blocks for military-grade bags and are engineered to be highly resistant to environmental factors.
- MIL-PRF-131: This is a performance specification for water vapor-proof, grease-proof, flexible, heat-sealable barrier materials. It’s the gold standard for protecting items from moisture vapor and corrosion. The material is typically a laminate with an aluminum foil layer, providing an extremely low water vapor transmission rate (WVTR). This is crucial for protecting metal parts, electronics, and other corrosion-sensitive items.
Military-Spec Bags
These bags are fabricated from the barrier materials and are the actual containers for the items. Their design and construction are also governed by strict specifications.
- MIL-DTL-117: This is the detailed specification for heat-sealable, flat barrier bags. It dictates the construction, dimensions, and performance of the bags themselves. The specification covers various types and classes of bags, each suited for a different purpose:
- Class C: Waterproof and grease-proof bags for general-purpose protection.
- Class E: Water vapor-proof and grease-proof bags, often made from MIL-PRF-131 material, for high-level protection against moisture.
- Class F & H: Bags that offer electrostatic protection and electromagnetic shielding, which are essential for packaging sensitive electronic components.
VCI (Volatile Corrosion Inhibitor) Packaging
To prevent rust and corrosion on metal parts, Volatile Corrosion Inhibitor (VCI) packaging is used. VCI packaging, which can include papers and bags, works by releasing a vapor that creates a protective molecular layer on metal surfaces. This layer prevents corrosive elements like oxygen and water from reacting with the metal. This method eliminates the need for messy grease or oil coatings, allowing items to be ready for use immediately upon unboxing. VCI products are often specified under MIL-PRF-3420.
Fiberboard and Other Containers
Fiberboard is another critical component of military packaging, used to create durable shipping boxes and containers. These containers are designed to be strong enough to withstand the rigors of military logistics. They are specified by military standards such as ASTM D5118 and come in various grades (e.g., V3c, W5c, V11c) to meet different strength and weather resistance requirements. Fiberboard can be used for both single-wall and double-wall corrugated containers, providing structural integrity for packaged goods.