The present technology provides a non-cylindrical structure for transporting media, including gases, liquids, solids, or energy comprising a layer of thermal pyrolytic graphite (TPG) surrounded by an outer layer and an inner layer comprising a metal, a ceramic, a glass, or a plastic. In particular, the present technology relates to a non-cylindrical tube or a pipe having an inner layer, an outer layer, and a layer of TPG between the inner layer and the outer layer wherein the TPG layer is configured to manage the direction of heat conduction.

A method and apparatus in the manufacture of a spirally wound and welded tube is disclosed. A thermoplastic profile is slid along a path on a slider arranged in an axial direction of the tube and defining a cylindrically shaped winding surface with a diameter corresponding to the inner diameter of the tube to be manufactured. The profile is directed along a spiral path towards a previous turn of said profile by means of radial rollers spaced along said spiral path by adjusting the position of the rollers: Opposite edges of said profile turns are welded together by providing an extruded welding mass between said profile turns. The welded tube is fed from the welding station by means the rollers by sliding it onto a rotating support.

A method and apparatus in the manufacture of a spirally wound and welded tube is disclosed. A thermoplastic profile is slid along a path on a slider arranged in an axial direction of the tube and defining a cylindrically shaped winding surface with a diameter corresponding to the inner diameter of the tube to be manufactured. The profile is directed along a spiral path towards a previous turn of said profile by means of radial rollers spaced along said spiral path by adjusting the position of the rollers: Opposite edges of said profile turns are welded together by providing an extruded welding mass between said profile turns. The welded tube is fed from the welding station by means the rollers by sliding it onto a rotating support.

The present invention relates to a polyethylene composition comprising—a base resin comprising (A) a first ethylene homo- or copolymer component having a melt flow rate MFR2 (2.16 kg, 190° C.) of equal to or more than 150 g/10 min to equal to or less than 300 g/10 min, determined according to ISO 1133, and (B) a second ethylene homo- or copolymer component, —optional carbon black, —optional further polymer component(s) different to the first ethylene homo- or copolymer components (A) and (B), and —optional additive(s); wherein the first ethylene homo- or copolymer component (A) has a lower weight average molecular weight as the second ethylene homo- or copolymer component (B), and the weight ratio of the first ethylene homo- or copolymer component (A) to the second ethylene homo- or copolymer component (B) is from 40:60 to 47:53; the polyethylene composition has a melt flow rate MFR5 (5 kg, 190° C.) of equal to or more than 0.35 g/10 min to equal to or less than 0.60 g/10 min, determined according to ISO 1133. The invention further relates to a process for the production of such a polyethylene composition, an article, such as a pipe or pipe fitting comprising such a polyethylene composition and the use of such a polyethylene composition for the production of such an article.

A pipe including polyethylene produced in the presence of a solid catalyst and a co-catalyst, wherein the solid catalyst is prepared by the steps of: (a) contacting a dehydrated support having hydroxyl groups with a compound of formula MgR.sup.1R.sup.2; (b) contacting the product of step (a) with modifying compounds (A), (B) and (C), wherein: (A) is carboxylic acid, carboxylic acid ester, ketone, acyl halide, aldehyde or alcohol; (B) is of formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h wherein f, g and h 0 to 4 and the sum of f, g and h=4 provided that when h=4 then compound (A) is not an alcohol; (C) is a compound of formula (R.sup.13O).sub.4M, wherein M is a titanium atom, a zirconium atom or a vanadium atom; and (c) contacting the product of step (b) with a titanium halide TiX.sub.4, whereby the polyethylene has a molecular weight of 720,000 to less than 2,500,000 g/mol.

The present invention relates to a pipe comprising an ethylene-based polymer, wherein the ethylene-based polymer: ⋅ comprises ≥0.10 mol % of units derived from 1-hexene, with regard to the total molar quantity of polymeric units of the ethylene-based polymer; ⋅ has an M.sub.w/M.sub.n as determined in accordance with ASTM D6474 (2012) of ≥2.5 and ≤4.0, preferably of ≥2.5 and ≤3.4; ⋅ has a density as determined in accordance with ASTM D792 (2008) of ≥925 and ≤945 kg/m.sup.3; and ⋅ in the molecular weight range of log(M.sub.w) between 4.0 and 5.5, has a comonomer branch content of between 2 and 15 comonomer-derived branches per 1000 carbon atoms in the polymer, as determined via .sup.13C NMR. Such pipe provides a desirably high long-term strength, as demonstrated by its high strain hardening modulus, as well as desirably high impact strength, as demonstrated by its high Charpy impact strength. Further, such pipe may be compliant with the PE-RT requirements of ISO 22391-1 (2009). For example, such pipe may be used for containing water at temperatures in the range of 40° C. to 80°.

The present invention relates to a pipe comprising an ethylene-based polymer, wherein the ethylene-based polymer: ⋅ comprises ≥0.10 mol % of units derived from 1-hexene, with regard to the total molar quantity of polymeric units of the ethylene-based polymer; ⋅ has an M.sub.w/M.sub.n as determined in accordance with ASTM D6474 (2012) of ≥2.5 and ≤4.0, preferably of ≥2.5 and ≤3.4; ⋅ has a density as determined in accordance with ASTM D792 (2008) of ≥925 and ≤945 kg/m.sup.3; and ⋅ in the molecular weight range of log(M.sub.w) between 4.0 and 5.5, has a comonomer branch content of between 2 and 15 comonomer-derived branches per 1000 carbon atoms in the polymer, as determined via .sup.13C NMR. Such pipe provides a desirably high long-term strength, as demonstrated by its high strain hardening modulus, as well as desirably high impact strength, as demonstrated by its high Charpy impact strength. Further, such pipe may be compliant with the PE-RT requirements of ISO 22391-1 (2009). For example, such pipe may be used for containing water at temperatures in the range of 40° C. to 80°.

This disclosure relates generally to corrugated pipe, and more particularly to corrugated pipe with an outer wrap. In one embodiment, a pipe includes an axially extended bore defined by a corrugated outer wall having axially adjacent, outwardly-extending corrugation crests, separated by corrugation valleys. The pipe also includes an outer wrap applied to the outer wall. The outer wrap may include fibers and plastic. The outer wrap may span the corrugation crests producing a smooth outer surface.

An ethylene-vinyl alcohol copolymer composition contains: (A) an ethylene-vinyl alcohol copolymer; (B) an antioxidant; and (C) a sorbic acid ester; wherein the sorbic acid ester (C) is present in an amount of 0.00001 to 10 ppm based on the weight of the ethylene-vinyl alcohol copolymer composition; wherein the weight ratio (B)/(C) of the antioxidant (B) to the sorbic acid ester (C) is 500 to 1,000,000. The resulting ethylene-vinyl alcohol copolymer composition is less susceptible to coloration.

A polymer composition and a process for the production of this composition comprising a base resin is disclosed herein. The base resin includes a very high molecular weight component, a low molecular weight component, and a high molecular weight component having a weight average molecular weight higher than the weight average molecular weight of the low molecular weight component but lower than the weight average molecular weight of the very high molecular weight component. An amount of the very high molecular weight component in the base resin is 0.5 to 8 wt %. The very high molecular weight component has a viscosity average molecular weight of greater than 1100 kg/mol. The composition has FRR.sub.21/5 of equal to or greater than 38, a melt flow rate MFR.sub.21 of equal to or greater than 6.5 g/10 min and a viscosity at a shear stress of 747 Pa (eta747) of 450 to 3000 kPas.