Which packaging category requires a minimum thickness of 0.1 mm and weld seams and closures that are sift-proof?

• A. Metal
• B. Plastic Bags
• C. Paper Bags
• D. Fiber cans or boxes

Answer: (B)

The key idea is that certain packaging categories for solids used in air transport must have both enough wall strength and a closure that prevents dust from escaping. A minimum wall thickness of 0.1 mm gives the packaging enough rigidity to resist tearing and puncture during handling, while a sift-proof closure ensures nothing can escape through seams or openings.

Plastic bags are designed to meet these needs by using a material thick enough to provide durability and a heat-sealed or otherwise fused closure that forms a dust-tight seal. When sealed properly, the seam acts as a sift-proof barrier, preventing powders or small particles from leaking out.

Other packaging types typically rely on different construction methods and may not specify this exact combination of minimum thickness and sift-proof closures for solids.