Abstract: A semi-rigid, flexible duct including a pair of coaxial sleeves, namely an inner sleeve and an outer sleeve disposed parallel to and about the inner sleeve and a resilient wound element disposed between the sleeves. Each of the inner sleeve and the outer sleeve constitutes an aluminum foil ribbon. The wound element imparts corrugations to the two sleeves, such that the duct is extendible between a compacted configuration suitable for storage and for shipping and an extended configuration suitable for installation in a gas transport arrangement. Both the inner sleeve and the outer sleeve are of a predetermined thickness rendering the duct substantially rigid when in an extended configuration and enabling the duct to maintain its substantial rigidity upon extension from a compacted configuration. Optionally, at least one of the sleeves further includes a second, plastic layer bonded to the aluminum foil ribbon layer.

Abstract: A semi-rigid, flexible duct including a pair of coaxial sleeves, namely an inner sleeve and an outer sleeve disposed parallel to and about the inner sleeve and a resilient wound element disposed between the sleeves. Each of the inner sleeve and the outer sleeve constitutes an aluminum foil ribbon. The wound element imparts corrugations to the two sleeves, such that the duct is extendible between a compacted configuration suitable for storage and for shipping and an extended configuration suitable for installation in a gas transport arrangement. Both the inner sleeve and the outer sleeve are of a predetermined thickness rendering the duct substantially rigid when in an extended configuration and enabling the duct to maintain its substantial rigidity upon extension from a compacted configuration. Optionally, at least one of the sleeves further includes a second, plastic layer bonded to the aluminum foil ribbon layer.

Abstract: A durable, semi-rigid, flexible duct including a pair of coaxial sleeves, namely an inner sleeve and an outer sleeve disposed parallel to and about the inner sleeve and a resilient wound element disposed between the sleeves. Each of the inner sleeve and the outer sleeve constitutes an aluminum foil ribbon. The wound element imparts corrugations to the two sleeves, such that the duct is extendible between a compacted configuration suitable for storage and for shipping and an extended configuration suitable for installation in a gas transport arrangement. Closely and evenly-spaced ridges that are situated in between the corrugations, add rigidity and durability to the duct. Both the inner sleeve and the outer sleeve are of a predetermined thickness rendering the duct substantially rigid when in an extended configuration and enabling the duct to maintain its substantial rigidity upon extension from a compacted configuration.

Abstract: A semi-rigid, flexible duct including a pair of coaxial sleeves, namely an inner sleeve and an outer sleeve disposed parallel to and about the inner sleeve and a resilient wound element disposed between the sleeves. Each of the inner sleeve and the outer sleeve includes a first layer having metallic properties and at least one of them further includes a second, plastic layer bonded to the first layer. The wound element imparts corrugations to the two sleeves, such that the duct is extendible between a compacted configuration suitable for storage and for shipping and an extended configuration suitable for installation in a gas transport arrangement. All of the layers of both the inner sleeve and the outer sleeve are of a thickness predetermined to together render the duct substantially rigid when in an extended configuration and predetermined to together enable the duct to maintain its substantial rigidity upon extension from a compacted configuration.

Abstract: A semi-rigid, flexible, duct for gas transport and for clothes dryer exhaust transition, and a method for manufacture thereof, including a pair of coaxial sleeves, an inner sleeve and an outer sleeve disposed parallel to and about the inner sleeve, and a resilient helical element disposed between them; wherein each of the inner sleeve and the outer sleeve includes a first aluminum layer and a second polyester layer, wherein the helical element imparts helical corrugations to the sleeves such that the duct is axially extendible between a compacted configuration suitable for storage and shipping and an extended configuration suitable for installation in a gas transport arrangement, and wherein all the layers of the sleeves are of a thickness predetermined to together render the duct substantially rigid when in the extended configuration and to together enable the duct to maintain its substantial rigidity upon extension from the compacted configuration.