Flexible tubing or hose is formed from continuously extruded thermoplastic material helically circumferentially wound at a wrapping station around an array of bearing-supported rods that are concurrently but individually turned and are canted relative to an imaginary central axis. The tubing or hose is formed to have a continuous reinforcing rib helically wound therearound and continuously integrally connected thereto. The positions of the rods are progressively altered during formation of at least a contiguous portion of the tubing or hose, causing the resulting contiguous portion to exhibit a progressive continuous change in diameter. The resulting tubing or hose may be transversely severed at intervals along its length, and may be flattened to form cuffs near where severed. A selected portion of the tubing or hose, which may or may not at least partially coincide with the contiguous portion, may be axially compressed and annealed to relieve stress therein.

A system and method for forming a strut. A strut comprises a laminated composite tube having a substantially hollow interior and a pair of longitudinal stiffeners attached to opposite sides of the laminated composite tube.

A tubular membrane comprises a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on said inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.

A method of producing a wind turbine rotor blade. The wind turbine rotor blade has at least an inner blade portion and an outer blade portion, as well as a connecting element. The inner blade portion is wound on a winding form having a first and a second winding portion. The first and second winding portions are releasably fixed to each other by way of a screw connection. The second winding portion is of a conical configuration so that after winding of the inner blade portion a sleeve is produced at an end of the inner blade portion.

There is provided a flexible, helically wound conduit for a breathing circuit. The conduit includes an inlet, an outlet, and an enclosing wall defining a flow passage between the inlet and the outlet, wherein at least a region of the enclosing wall is permeable to water vapor and one or more of O.sub.2 and CO.sub.2. The axial tensile strength of the enclosing wall is greater than 40N. Further provided are limbs comprising the conduit, a method of manufacturing the conduit and the use of the conduit to remove water vapor and/or CO.sub.2 from gas exhaled by a patient.

A system and method for forming a strut. A strut comprises a laminated composite tube having a substantially hollow interior and a pair of longitudinal stiffeners attached to opposite sides of the laminated composite tube.

A tubular membrane includes a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on the inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.

Helically reinforced, flexible tubing or hose is formed from continuously extruded thermoplastic material helically circumferentially wound at a wrapping station around an array of bearing-supported rods that are concurrently but individually turned and are adjustably canted relative to an imaginary center axis. The tubing or hose being formed has a continuous reinforcing rib helically wound therearound and continuously integrally connected thereto. The resulting tubing or hose may be transversely severed at intervals along its length to provide discrete lengths of hose that are annealed while axially compressed to relieve stress.

In one embodiment, a breathing circuit component is provided and comprises: an inlet; an outlet; and an enclosing wall defining a gases passageway between the inlet and the outlet, at least a region of the wall comprising a membrane that allows the passage of water vapour without substantially allowing the passage of liquid water or respiratory gases, wherein, said membrane has a thickness of about 35 to 45 micrometers.

An expiratory limb for a breathing circuit includes an enclosing wall defining a flexible singular expiratory flow passage between an inlet and an outlet and bounding the flexible singular expiratory flow passage and ambient air. The expiratory limb includes one or more regions of the enclosing wall that made from a material that allows passage of water vapor without allowing passage of liquid water, thereby forming a water vapor flow path from the flexible singular expiratory flow passage to the ambient air through the material. The expiratory limb is configured to allow diffusion of water vapor along the flexible singular expiratory flow passage and dry the flow of expiratory gases between the inlet and the outlet.