Abstract: The invention concerns a method for the continuous production of a flexible tube body from two stapled wires (9, 10) individually bent in bending means (7, 8), three stitches, unsupported by a mandrel, and such that wires (9, 10) remain constantly in contact so as to optimize their resistance to external pressure. Bending means (7, 8) can be arranged with respect to each other without affecting the bending adjustment. The method consists in stapling the two spirals by elastically deforming the turns so that one crosses the other to cause the wires to overlap partially. The invention also concerns an equipment for producing a flexible tube body.

Abstract: A helically wound and helically ribbed plastic tubing incorporating one or plural support beads with at least one of the support beads defining one or plural helical lumens. The support bead is free of joints or bonding lines extending between the lumen(s) and ambient so that the lumen is free of unintended fluid communication between the lumen and ambient, and the lumen is capable of transporting or containing gaseous or fluid materials without leakage. The support bead may encapsulate an electrical conductor, which may be a heating wire for the purpose of providing a heat source to fluid flow in the central passage of the tubing product. Alternatively, the electrical conductor may be an energy or signal conducting element suited for sensing purposes or data transmission along a length of the tubing, for example. A lumen termination fitting may connect to the tubing. Apparatus and methods for making the tubing product are also disclosed.

Abstract: A flexible hose having a sufficient strength while ensuring the air permeability is provided. In a hose formed by winding a soft resin tape helically such that leading tape end brim portions and trailing end brim portions extending in the hose longitudinal direction are overlapped to each other in the hose radial direction, gaps for ventilation for making the inside of the hose and the outside communicate with each other is formed by interposing a gap forming member having a concavo-convex shape between both end brim portions or forming a concavo-convex shape on one of surfaces of the end brim portions which face each other in an opposed manner.

Abstract: This invention relates to a flexible tube that includes a bellows having a plurality of convolutes formed in the wall of said tube and extending above the top surface of the tube, said convolutes being spaced from one another in the axial direction of the tube, wherein at least one of said convolutes comprises two opposing bending sections and two restrained elongation sections positioned between the bending sections, and wherein the height of the bending sections above the top surface of the tube is greater that the height of the restrained elongation sections above the top surface of the tube.

Abstract: A flexible hose which has a hose body made of soft synthetic resin, a reinforcement made of hard synthetic resin wound spirally and joined to the hose body by fusion, and a conductor arranged inside the reinforcement in its longitudinal direction. The conductor does not adhere to the reinforcement and is movable. The hose body is formed by: extruding a tube made of soft resin from a head of an extruder; pressing and flattening the tube to form a strip; and winding the strip spirally with the adjacent side edges joined together.

Abstract: An improved hose is used to install loose fill insulation. The hose includes projections extending from an inner surface which serve to condition the insulation as it proceeds through the hose and is dispensed. In a first exemplary embodiment of the present invention, the projections are formed so as to be perpendicular to a longitudinal axis of the hose. In a second exemplary embodiment of the present invention, the projections are formed so as to be angled, by an angle less then ninety (90) degrees with respect to the longitudinal axis of the hose. In a third exemplary embodiment of the present invention, the projections are formed with a serrated edge. In a fourth exemplary embodiment of the present invention, the projections are formed as part of a cap member which is disposed around the periphery of the hose. In a fifth exemplary embodiment of the present invention, the projections include an additional perpendicular projection member extending therefrom.

Abstract: A method of producing a hose in which a relatively inelastic material, such as ultra-high molecular weight polyethylene, is wrapped around an uncured hose. A rope is then wrapped about this combination with a cure wrap encircling the entire hose. During the curing process, the rope becomes embedded in the inelastic material forcing the underlying hose to be displaced. Once fully cured, the cure wrap and the rope are removed. The valleys where the rope was embedded into the hose provides flexibility which allows a hose with a highly protective outer coating to be flexible enough to reduce susceptibility to kinking during use, has a low coefficient of friction during dragging, is highly resistant to abrasion, and provides significantly improved chemical resistance compared to conventional hose constructions.

Abstract: A tubular member useful as an inner liner for the working channel of a flexible endoscope has a distal portion which is specially treated to make it highly flexible and resistant to kinking or collapsing when it bends with the flexible section of the endoscope. The tubular member is also useful as a catheter device or as a component of a catheter device or catheter system. A multiplicity of external ridges on the distal portion of the tubular member reinforce the tubing wall and prevent kinking or buckling of the wall or collapsing of the inner lumen. The external ridges may be formed by convolutions of the tubing wall or by external threads which are formed on the exterior of the tubing wall within the flexible distal portion. An outer helical reinforcing coil may be added between the external ridges to further reinforce the flexible distal portion of the tubular member from kinking or collapsing.

Abstract: A scuff cover (10) for protecting an elongate inner element (14), such as a hose or a cable, comprises a flexible base tube (30) having an inner surface (34) defining a central passage (38) for movably receiving the inner element. The base tube (30) has an outer surface (36). A rub strip (40) projects from the outer surface (36) of the base tube (30). The rub strip (40) comprises an inner layer of material (42) on the base tube (30) and an outer layer of material (44). The outer layer of material (44) has a lower coefficient of friction than the inner layer of material (42) and forms the radially outermost surface of the scuff cover (10). The outer layer of material (44) is preferably ultrahigh molecular weight polyethylene.

Abstract: The hose of the present invention comprises a soft hose wall (A) and a spiral reinforcement (B) for retaining the configuration of the hose. The hose wall (A) is formed with a composition comprised of: a resin component (A1) containing a diene-series or hydrogenated diene-series rubber component, and an olefinic resin; and a lubricant (A2). The rubber component may be a random or block copolymer of styrene and butadiene. The olefinic resin may be a polypropylene-series resin. The lubricant (A2) may be a higher fatty acid or its derivative (e.g., a higher fatty acid amide), a higher alcohol or its derivative, a hydrocarbon-series wax, an organopolysiloxane, or fluorine-containing resin. The present invention provides a hose which is lighter, free from PVC, and capable of maintaining excellent flexibility even used for a long period of time.

Abstract: A flexible hose having a sufficient strength while ensuring the air permeability is provided. In a hose formed by winding a soft resin tape helically such that leading tape end brim portions and trailing end brim portions extending in the hose longitudinal direction are overlapped to each other in the hose radial direction, gaps for ventilation for making the inside of the hose and the outside communicate with each other is formed by interposing a gap forming member having a concavo-convex shape between both end brim portions or forming a concavo-convex shape on one of surfaces of the end brim portions which face each other in an opposed manner.

Abstract: A multi-layer plastic tube comprises a base tube and a barrier layer surrounding the base tube, the barrier layer being impermeable to oxygen, and a protective layer applied on the barrier layer for protecting the barrier layer from damage, wherein the material of the barrier layer and protective layers may include a lubricant.

Abstract: An improved hose is used to install loose fill insulation. The hose includes projections extending from an inner surface which serve to condition the insulation as it proceeds through the hose and is dispensed. In a first embodiment of the present invention, the projections are formed so as to be perpendicular to a longitudinal axis of the hose. In a second embodiment of the present invention, the projections are formed so as to be angled, by an angle less then ninety (90) degrees with respect to the longitudinal axis of the hose. In a third embodiment of the present invention, the projections are formed with a serrated edge. In a fourth embodiment of the present invention, the projections are formed as part of a cap member which is disposed around the periphery of the hose.

Abstract: A flexible hose 10 having a flexible material 12 and a more rigid material 14. The flexible material 12 and the more rigid material 14 being helically wound and molded together to form a hose 10 with an exterior surface 16 and an interior surface 18. The cross-section of the more rigid material 14 having at least two peninsulas 20, extending in longitudinally opposite directions, at least one radially inwardly extending peninsula 22, and at least one radially outwardly extending peninsula 22. The longitudinally extending peninsulas 20 are embedded in the flexible material 12 and the radially extending peninsulas 22, 24 are at least partially embedded in the flexible material 12. In the preferred embodiment, the longitudinally extending peninsulas 20 are centrally located in the flexible material 12 between the respective surfaces 16, 18 of the hose 10 and the radially outwardly extending peninsula 24 extends beyond the flexible material 12 on the exterior surface 16 of the hose 10.

Abstract: The invention concerns a conduit element made of metal for uncoupling high frequency vibrations in connection with exhaust gas conduits of motor vehicle internal combustion engines. To improve the uncoupling of these high frequency vibrations, the conduit element of the invention basically comprises a screw thread-shaped or annularly undulating short corrugated sheathing hose of high rigidity inserted into the exhaust gas conduit, as well as a knitted jacket placed on the waved corrugated sheathing hose segment in a force-locking or form-locking manner.

Abstract: A flue ducting for atmospheric boilers is disclosed and comprises two coaxial generally tubular ducts 10, 11, and a generally undulating linear spacer 12 between said ducts. Linear features are provided on the mutually facing surfaces of the ducts, the features being shaped to engage the undulating spacer 12. One end of the annular space between the ducts 10, 11 is closed.

Abstract: An improved hose is used to install loose fill insulation. The hose includes projections extending from an inner surface which serve to condition the insulation as it proceeds through the hose and is dispensed. In a first embodiment of the present invention, the projections are formed so as to be perpendicular to a longitudinal axis of the hose. In a second embodiment of the present invention, the projections are formed so as to be angled, by an angle less then ninety (90) degrees with respect to the longitudinal axis of the hose. In a third embodiment of the present invention, the projections are formed with a serrated edge. In a fourth embodiment of the present invention, the projections are formed as part of a cap member which is disposed around the periphery of the hose.

Abstract: A hose comprises a hose wall comprising a soft synthetic resin and a hard spiral reinforcement fused with or bonded to the hose wall for retaining the hose configuration. The hose wall comprises at least one layer of a chlorine-free thermoplastic elastomer such as a polystyrenic thermoplastic elastomer, a polyolefinic thermoplastic elastomer and a polyurethane-series thermoplastic elastomer. The reinforcement comprises a hard wire and a covering resin layer formed on the hard wire. The hose wall and the covering resin layer are formed with the same series elastomer. This hose is lighter and free from PVC resins, and has the same flexibility as that of the conventional PVC hoses.

Abstract: A double-walled spiral pipe in accordance with the present invention is composed of an outer wall 10 having a cylindrical shape, which is prepared by winding spirally a coated steel plate 11 having corrugations 12; and an inner wall 20 having a cylindrical shape, which is contacted with the wave bottom of corrugations of said outer wall 10, and can contracted or elongated depending upon a change of the pitch of the corrugations of said outer wall 10. The inner wall 20 having a cylindrical configuration is installed to be contacted with the wave bottom of corrugations of the outer wall 10, and functions to drain a sewage, etc. The inner wall 20 has a semi-circular portion which is formed at the point of the wave bottom of the corrugations of the outer wall, and a plane surface is formed between the semi-circular portions.

Abstract: A pipe for carrying gaseous fluid, more particularly in motor vehicles, and particularly for the admission of air for combustion to the engine or for ventilation of the vehicle interior, including an outer layer (1) of a fluid-tight flexible material and a non-woven fibrous inner layer (2) secured to the outer layer (1).

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner tube made of polymeric material, an outer sleeve of reinforcing material disposed in telescoping relation on the inner tube from one end thereof to the other end thereof, rib structure disposed between the sleeve of reinforcing material and the inner tube, the rib structure being disposed on the inner tube so as to define alternating coil structure of rib structure and coil structure of non-rib structure serially along the longitudinal axis of the inner tube in a like repeating pattern thereof, the coil structure of non-rib structure comprise coil structure of void space, and an outer tube of polymeric material disposed between the rib structure and the sleeve of reinforcing material so as to extend in a generally straight-line manner from coil structure of the rib structure to coil structure of the rib structure so as to tend to prevent the sleeve of reinforcing material from entering i

Abstract: A lightweight hose (80) is disclosed which is formed from a heat seamable material and includes a helically-wound reinforcing member (88). The hose (80) can be formed in a short, definite length and a relatively long, indefinite length by a mandrel and a continuous process, respectively. In one aspect of the invention, a lightweight conduit (80) comprises a tubular wall (82) formed of at least one ply of heat seamable material and at least one helical member (88) whereby the at least one ply is bonded to itself and to the at least one reinforcing member (88) without additional adhesive. The invention also relates to lightweight conduits in the form of connectors such as cuffs (140) and T- and Y-connectors (170) and (180), respectively. The invention further relates to a method for forming a lightweight conduit, including but not limited to, the embodiments of a hose described herein.

Abstract: A convoluted flexible protective sleeve comprises a wall made of heat-resistant plastics material and a layer of infra-red radiation-reflecting metal vacuum deposited on the outer surface of said wall. The layer is between 0.05 and 5 micrometers in thickness.

Abstract: A flexible conveying element, in particular for the exhaust systems of automotive combustion engines, having a helically or annularly corrugated metal hose which is installed coaxially in the metal bellows. The outside diameter of the metal hose is smaller than the inside diameter of the bellows and the ends of the hose are situated inside the end fittings of the bellows. The metal hose has an interlocked profile and the bellows and the hose are in an at least indirect contact with each other in at least one additional zone between the two end fittings.

Abstract: Pipe-like air duct is formed of hard aluminum foil. Concaves and convexes give flexibility to the air duct. For the air duct, kraft paper is wound on both surfaces of the aluminum foil. This air duct is disposed between an outer panel and an inner panel of vehicle body along the panels, laid to the rear seat of the vehicle, and connected to a blow-off port for the rear seat. In a collision of the vehicle, the air duct is subjected to plastic deformation, by which the shock energy caused by an external force is absorbed.

Abstract: A flexible hose 1 of the present invention is formed by blocking and interrupting a spiral groove 5 inside a hill 2 of a corrugated hose end portion 1a or 1b (inner surface helical concave portion) to form a closed section 4, or by blocking and interrupting a spiral groove 5 formed outside a valley 3 of a corrugated end portion 1a or 1b of a hose (outer surface helical concave portion) to form a blocked section 4. The flexible hose of the present invention can provide an improved air tightness when connected to a joint, requiring no troublesome steps or treatments.

Abstract: Two hard steel wire-made reinforcing wires and two synthetic resin wires which are harder than a soft synthetic resin pipe wall are alternately wound spirally on an inner side of the synthetic resin pipe wall while keeping predetermined intervals.

Abstract: A process for making a length of rubber tubing with axially spaced circumferentially corrugated flexible segments from a sleeve of uncured rubber and the product resulting therefrom. An end length of a sleeve of uncured rubber is placed over an end portion of a forming mandrel and an external form is placed around the sleeve end length. Rudimentary corrugations are then formed in the end length after which the sleeve is moved axially along the forming mandrel so that a new length portion of the sleeve is placed in a forming position. Then using the external form, rudimentary corrugations are formed in the second length portion of the sleeve. These steps are repeated until the desired number of axial length portions in the sleeve are provided with rudimentary corrugations. The resulting product is then cured to form a length of rubber tubing with a plurality of axially spaced circumferentially corrugated flexible segments.

Abstract: A double-walled structure in a ventilation duct system has an inner tube and an outer tube and, arranged therebetween, a sound-absorbing material. The inner tube is a helically-wound lock-seam tube formed from a sheet metal strip having parallel longitudinal areas of expanded metal.

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner tube made of polymeric material, an outer sleeve of reinforcing material disposed in telescoping relation on the inner tube from one end thereof to the other end thereof, rib structure disposed between the sleeve of reinforcing material and the inner tube, the rib structure being disposed on the inner tube so as to define alternating coil structure of rib structure and coil structure of non-rib structure serially along the longitudinal axis of the inner tube in a like repeating pattern thereof, the coil structure of non-rib structure comprise coil structure of void space, and an outer tube of polymeric material disposed between the rib structure and the sleeve of reinforcing material so as to extend in a generally straight-line manner from coil structure of the rib structure to coil structure of the rib structure so as to tend to prevent the sleeve of reinforcing material from entering i

Abstract: A high pressure subsea pipe, particularly for underwater use, has the ability to flex while being transported and installed. The pipe has a friction reinforcement structure made of overlapping layers increasing substantially the capacity of the pipe in longitudinal direction. The reinforcement layer may be a helical wrap, either cylindrical or conical, or conical sleeves nested within one another. An articulated carcass has turns of a helically wrapped main and ancillary wires, offering no axial slack in either tension or compression or in both directions while remaining flexible.

Abstract: The flexible hose comprises a bellows hose wall 1 composed of an inner wall 2 and an outer wall 3 each made of a soft resin and a spiral hard reinforcement 4 interposed therebetween. As the hose contracts, a spiral groove 7 is formed inside of the hose. The inner wall 2 is not partially bonded or fused with the outer wall 3 and the hard spiral reinforcement 4 to form unbonded sites or fragments 8. As the hose contracts, the unbonded fragments 8 are separated from the outer wall 3 and the spiral hard enforcement 4 and move to the inward direction of the hose, and close the spiral groove 7. Therefore, even a fluid flows to any longitudinal direction, the flexible hose reduces a flow resistance.

Abstract: A laminated tape comprising a main layer of a polyester-series thermoplastic polyurethane resin and a covering layer formed of a soft vinyl chloride resin fused with at least one surface of the main layer is spirally wound, and its adjacent side edges are bonded each other to form a hose wall. The shrinkage ratio of the length of the hose in an unloaded condition is 25% or less relative to the original length of the hose as determined by measuring the original length and the length of the hose after the test which comprises subjecting the hose compressed in a longitudinal direction to ten heating/cooling-cycles successively, one cycle comprising a heating step for exposing the compressed hose to an atmosphere of 70.degree. C. for two hours and a cooling step for cooling the heat-treated hose at an atmosphere of -20.degree. C. for two hours, followed by returning the temperature of the hose to an ordinary or room temperature and allowing the hose to stand for one hour.

Abstract: The invention relates to a corrugated pipe of thermoplastic polymer material for use as fluid line with at least one polymer layer, comprising closed geometric outer contours which are spaced at an interval from each other in the axial direction of the pipe and which define a corrugation on the pipe jacket in at least one radial angular sector in axial, longitudinal direction one behind the other. The closed geometric outer contours are designed in such a manner that two jacket lines of the pipe jacket surface, which lines are approximately opposite one another, are free of corrugations and that these jacket lines extend in the longitudinal direction of the pipe (FIGS. 1b-1d).

Abstract: A metal pipe and method of forming the same with an integrally formed liner for use in corrosive and abrasive environment utilizes a liner formed of a comparatively thick polymer which is thermally bonded to the metal pipe. An intermediate polymer/adhesive layer is applied to the metal pipe to facilitate thermal/chemical bonding. The intermediate layer is preferably applied to the sheet metal in a pre-treatment process prior to roll forming ribs into the sheet metal. The polyethylene liner is applied after the pipe has been formed, to provide a smooth, hydraulically efficient surface which is resistent to the corrosive action of sulfuric acid and the like encountered in sanitary applications, as well as abrasion caused by the flow of water-born debris such as dirt and gravel as is encountered in culvert applications.

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner tube made of polymeric material, an outer sleeve of reinforcing material disposed in telescoping relation on the inner tube from one end thereof to the other end thereof, rib structure disposed between the sleeve of reinforcing material and the inner tube, the rib structure being disposed on the inner tube so as to define alternating coil structure of rib structure and coil structure of non-rib structure serially along the longitudinal axis of the inner tube in a like repeating pattern thereof, the coil structure of non-rib structure comprise coil structure of void space, and an outer tube of polymeric material disposed between the rib structure and the sleeve of reinforcing material so as to extend in a generally straight-line manner from coil structure of the rib structure to coil structure of the rib structure so as to tend to prevent the sleeve of reinforcing material from entering i

Abstract: The present invention is directed to a new and improved flexible hose assembly for transmitting pressurized air, gases and/or fluids between two spaced apart components. The hose assembly includes an inner liner surrounded by a helix formed of thermoplastic material having a substantially flat surface portion for bonding with the inner liner, eliminating the need for a outer cord to prevent the helix from floating relative to the liner. A self-adjusting retainer ring serves to compress the flexible hose onto the beaded end portion of a component with increasing pressure as the pressure increases within the hose assembly. Preferably the retainer ring is formed from a single piece of thermoplastic material.

Abstract: A flexible tube includes an inner tube and an outer tube structure mounted around the inner tube. The outer tube structure includes an outer protective tube wound around the inner tube and including a helical channel defined therein. An elastomeric tubular member is securely mounted in and extended along the helical channel. A rigid strip member is securely received in and extended along a length of the elastomeric tubular member. A number of elastomeric strings received in and extended along the length of the elastomeric tubular member.

Abstract: A sheath is provided with necessary conditions where inner and outer surfaces thereof are both formed in an uneven helical shape, where the outer surface of a trough is almost flat, where a width W of the trough between inflection points of a curve along the inner surface of the trough and a width w of a top between inflection points of a curve along the top satisfy the relation of W>w, where a thickness T of the trough and a thickness t of the top satisfy the relation of T>t, where a projection of the inner surface of the trough is formed in a gentle arc compared to a recess of the inner surface of the top, and where an inner perimeter of the recess of the inner surface projects circumferentially outward more than an outer-perimeter of the outer surface of the trough. The sheath is entirely formed of polyolefin resin material.

Abstract: A flexible hose which is formed by attaching a resin reinforcing coil member to a cylindrical body, the cylindrical body being composed of a nonwoven fabric layer which is formed by winding a nonwoven fabric tape spirally and connecting adjacent side end portions and an air-cut layer which forms on at least one side of the nonwoven layer. The nonwoven fabric tape and the reinforcing coil member are formed of heat-fusible resin materials, and the reinforcing coil member is fused with the nonwoven fabric layer in a body.

Abstract: A synthetic resin hose includes a corrugated tube wall and an electrically conductive wire disposed substantially straight along the axial direction of the tube wall and configured so that the whole length of the electrically conductive wire on the inner circumferential surface side thereof is covered with the tube wall and the outer circumferential side thereof is enclosedly covered with only top portions of the tube wall.

Abstract: A tubular section member for use as a fluid flow hose or as an admission or exhaust silencer, characterized in that it includes internal partitions or ribs (12) which are corrugated in shape in cross-section, which are interconnected by an axial core (16) along the axis of the section member, and which are wound helically along said axial core (16).

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner corrugated hose made of polymeric material and having a plurality of outwardly convex projections with recesses therebetween and extending from one end thereof to the other end thereof, an outer sleeve of reinforcing material disposed in telescoping relation on the inner hose, and a tube of polymeric material disposed between the sleeve of reinforcing material and the inner hose and extending in a generally straight-line manner from projection to projection of the inner hose so as to tend to prevent the sleeve of reinforcing material from entering into the recesses of the inner hose an amount that would tend to substantially reduce the flexibility characteristics of the inner hose.

Abstract: An abrasion resistant composite hose comprises (a) an outer layer composing a spiral tape of a soft synthetic resin, where adjacent side edges of the spiral tape join each other to form the outer layer, (b) a spiral reinforcement of a hard synthetic resin for retaining and reinforcing the outer layer, and (c) an inner layer comprising a spiral strip formed by a rubber, where adjacent side edges of the spiral strip join each other to form the inner layer, and the outer layer and inner layer join each other. In such a composite hose having this structure, at least a periphery of the strip except an exposed surface to an inner surface of the hose is covered with a covering element comprising a rubber adhesive to the soft synthetic resin constituting the outer layer, and the rubber strip is formed by a rubber having higher abrasion resistance than the covering element to obtain a composite hose having enhanced abrasion resistance.

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner corrugated hose made of polymeric material and having a plurality of outwardly convex projections with recesses therebetween and extending from one end thereof to the other end thereof, an outer sleeve of reinforcing material disposed in telescoping relation on the inner hose, and a tube of polymeric material disposed between the sleeve of reinforcing material and the inner hose and extending in a generally straight-line manner from projection to projection of the inner hose so as to tend to prevent the sleeve of reinforcing material from entering into the recesses of the inner hose an amount that would tend to substantially reduce the flexibility characteristics of the inner hose.

Abstract: A synthetic resin tube comprises an internal layer which is made of non-rigid synthetic resin and has a substantially smooth inner circumferential surface, and an external layer which is formed by winding a strip made of rigid synthetic resin around an outer circumferential surface of the internal layer overlapping winds of the strip and connecting the external layer with the internal layer, a cross section of the strip being S-shaped. When the external layer is formed, adjacent winds of the strip are connected temporarily and capable of being disconnected. After the external layer is formed, flexibility can be given to an optional length of the tube by removing the temporary connection among the winds of the strip.

Abstract: The external shape of a pipe wall is formed of sectionally rectangular wall portions and sectionally circular wall portions which are disposed alternately in an axial direction of the pipe, and the internal shape of the pipe wall is formed into a substantially linear circular-cylindrical surface. The whole of the pipe wall is formed of a material of synthetic resin or rubber.

Abstract: An article of manufacture which has a high resistance to chemicals, solvents, and heat formed from a blend of (A) a polyamide, such as polycaprolactam; (B) a functionalized polyethylene, such as low density polyethylene; and (C) an unfunctionalized low density polyethylene. The blend has a melt viscosity suitable for extrusion into convoluted tubing, nonconvoluted tubing, sheets, films, and the like.

Abstract: A synthetic resin corrugated pipe includes a pipe wall having an annularly- or helically-shaped convex-concave surface. The convex-concave surface has a plurality of convex portions having a quadrangular cross-sectional shape and a plurality of concave portions having a circular cross-sectional shape.

Abstract: A heat insulating noise reducing duct includes: an internal layer formed by helically winding a flat fibrous band and integrally bonding outer circumferential faces of adjacent joint parts of the band by resin reinforcing bands to thereby form a substantially smooth cylindrical shape; one or more resin linear bodies helically wound between these adjoining resin reinforcing bands and bonded to the fibrous band; an open-cell foam layer formed by helically winding an open-cell foam resin band onto an outer circumferential face of the inner layer while making its paired side edges abut each other; an intermediate sheet layer formed by helically winding a thin resin sheet-like band onto an outer circumferential face of the open-cell foam band while partially overlapping the resin sheet-like band, and by integrally bonding the overlapped parts; a closed-cell foam layer formed by helically winding a closed-cell foam resin band onto an outer circumferential face of the sheet layer while making its paired side edges a