Single-Layer Flexible Duct Structure for Rigidity and Smooth Airflow

The patent combines a resilient wire helix with a corrugated plastic tubing to create a composite duct structure. The wire helix provides flexibility and structural support, while the corrugated plastic tubing adds rigidity and prevents sagging. This composite construction resolves the contradiction by integrating materials with complementary properties - the metal wire provides tensile strength and flexibility, while the corrugated plastic provides compressive strength and structural integrity.

The patent uses corrugated plastic tubing instead of traditional corrugated aluminum tubing. The plastic tubing is formed with external corrugations that provide rigidity and structural support, while the internal surface remains relatively smooth. This resolves the contradiction by providing the necessary rigidity through external corrugation geometry rather than internal ridges, thereby reducing air flow resistance and preventing lint accumulation.

The patent employs a flexible corrugated plastic tubing shell that provides structural integrity without the weight of solid metal. The corrugated structure of the plastic tubing gives it rigidity and resistance to deformation, while the material itself remains lightweight and flexible. This allows the duct to maintain its shape and structural integrity during installation and use, while being easy to handle, cut, and install compared to heavy metal ducts.

The patent creates a fire-safe composite structure by combining a resilient wire helix (metal) with corrugated plastic tubing. The metal wire helix provides flame resistance and structural support, while the plastic tubing provides flexibility and weather resistance. This composite construction resolves the contradiction by integrating a flame-resistant material (metal wire) with a flexible material (plastic tubing), achieving both flexibility and fire safety.