How does the material composition of dunnage affect its suitability for different types of cargo?

The material composition of dunnage, which is packing material used to protect and support cargo during transit, greatly affects its suitability for different cargo types due to variations in strength, moisture absorption, chemical reactivity, and potential for contamination. Wood, a common dunnage material, provides good support and shock absorption but can absorb moisture, leading to mold growth or corrosion if used with moisture-sensitive cargoes like steel or paper. Softwood is preferable to hardwood due to its lower density and reduced risk of damaging sensitive cargo. Plastic dunnage is water-resistant and chemically inert, making it suitable for cargoes that are susceptible to moisture damage or chemical reactions. However, plastic may not provide the same level of support as wood for heavy items. Cardboard dunnage is lightweight and inexpensive but offers limited strength and is easily damaged by moisture, making it suitable only for light, dry cargoes. Rubber dunnage provides excellent shock absorption and is resistant to slippage, making it ideal for securing delicate or irregularly shaped items. Metal dunnage, such as steel shims, offers high strength and durability but can cause damage to sensitive surfaces and is prone to corrosion. Therefore, selecting the appropriate dunnage material requires careful consideration of the cargo's properties, the potential environmental conditions, and the desired level of protection to prevent damage, contamination, or instability during transport.