A multilayer tube is provided which suppresses the amount of calcium and organic component leaching to a low level and which can be realized as a tube that has mechanical properties at 60° C. This multilayer tube includes a first polyolefin resin layer configuring the innermost layer, and a second polyolefin resin layer arranged outside of the first polyolefin resin layer; the amount of calcium leaching, measured in accordance with SEMI F-57, of the material of the first polyolefin resin layer is less than 30 μg/m2; the ratio of the thickness of the first polyolefin resin layer to the total thickness of the first polyolefin resin layer and the second polyolefin resin layer is 0.011-0.17. By means of this configuration, it is possible to suppress the amount of leaching of calcium and organic substances to a low level, and to realize a pipe having a strength that takes into account a 60° C. use environment.

A long tube formed of an elastic material includes: an upper portion including a printable upper surface; a lower portion facing the upper portion; a first side wall connecting the upper portion and the lower portion; a second side wall connecting the upper portion and the lower portion and facing the first side wall; a first upper joint portion located at a connection portion between the upper portion and the first side wall and configured to bend the first side wall with respect to the upper portion; a first lower joint portion located at a connection portion between the lower portion and the first side wall and configured to bend the first side wall with respect to the lower portion; and a first side wall joint portion configured to bend the first side wall.

A long tube formed of an elastic material includes: an upper portion including a printable upper surface; a lower portion facing the upper portion; a first side wall connecting the upper portion and the lower portion; a second side wall connecting the upper portion and the lower portion and facing the first side wall; a first upper joint portion located at a connection portion between the upper portion and the first side wall and configured to bend the first side wall with respect to the upper portion; a first lower joint portion located at a connection portion between the lower portion and the first side wall and configured to bend the first side wall with respect to the lower portion; and a first side wall joint portion configured to bend the first side wall.

The invention relates to the use of at least one catalyst, at least one copper heat stabiliser and at least one oligo- or poly-carbodiimide with a matrix including at least one polyamide, in order to form a composition that has a good melt viscosity and is stable during transformation, in particular during extrusion.

A polyetheretherketone pipe of length greater than 250 meters and a residual stress of less than 5 MPa may be made using a calibrator device 2 which includes a cone shaped opening 6 arranged to receive a molten extruded pipe shaped polymer. Attached to the front member 4 is a vacuum plate 14a and successive vacuum plates 14b-14h are attached to one another to define an array of vacuum plates, the vacuum plates being arranged to allow a vacuum to be applied to a pipe precursor passing through opening 16. The vacuum plates 14 also include temperature control means for heating or cooling the plates and therefore heating or cooling a pipe precursor passing through the openings. With a vacuum applied to opening 6, 16 and heating/cooling the plates, an extruded hot plastics pipe is inserted into calibrator 2 via opening 6 and conveyed through opening 16 in plates 14, whereupon it is urged by the vacuum against the cylindrical surface defined by plates 14 to maintain its shape and the temperature of each plate is controlled to control the rate of cooling of the pipe precursor passing through. The pipe may be cooled at a relatively slow rate so that a pipe made from a relatively fast crystallising polymer crystalises and the crystallinity of the pipe along its extent and throughout its thickness is substantially constant.

A polyetheretherketone pipe of length greater than 250 meters and a residual stress of less than 5 MPa may be made using a calibrator device 2 which includes a cone shaped opening 6 arranged to receive a molten extruded pipe shaped polymer. Attached to the front member 4 is a vacuum plate 14a and successive vacuum plates 14b-14h are attached to one another to define an array of vacuum plates, the vacuum plates being arranged to allow a vacuum to be applied to a pipe precursor passing through opening 16. The vacuum plates 14 also include temperature control means for heating or cooling the plates and therefore heating or cooling a pipe precursor passing through the openings. With a vacuum applied to opening 6, 16 and heating/cooling the plates, an extruded hot plastics pipe is inserted into calibrator 2 via opening 6 and conveyed through opening 16 in plates 14, whereupon it is urged by the vacuum against the cylindrical surface defined by plates 14 to maintain its shape and the temperature of each plate is controlled to control the rate of cooling of the pipe precursor passing through. The pipe may be cooled at a relatively slow rate so that a pipe made from a relatively fast crystallising polymer crystalises and the crystallinity of the pipe along its extent and throughout its thickness is substantially constant.

A pipe pulling device guides extruded plastic conduit tubing through a building structure. The device has a fastener body including a main shaft supporting a resilient expansion sleeve thereon that can be inserted into an open end of the tubing. A nut is threaded onto the main shaft for axially compressing the expansion sleeve between the nut and a fastener head at the inner end of the main shaft to radially expand the sleeve within the tubing and frictionally grip the fastener body relative to the tubing. The nut is tapered outwardly and supports an elongate, rigid tip body extending longitudinally outward from the tubing to guide insertion of the tubing through cavities in the building structure. Various accessories can be secured to the nut or the tip body to assist insertion of the pipe pulling device through different building structures.

A rubber tube has an inner surface at least partly roughed so that the ratio (Rz/D) of the maximum height Rz of the inner surface to the inner diameter D of the tube is not less than 0.038. The ratio (Rp/D) of the maximum peak height Rp of the inner surface to the inner diameter D of the tube may be not less than 0.019. The ratio (Rv/D) of the maximum valley depth Rv of the inner surface to the inner diameter D of the tube may be not less than 0.019. The ratio (Ra/D) of the arithmetic average roughness Ra of the inner surface to the inner diameter D of the tube may be not less than 0.0036. The ratio (Rq/D) of the root mean square height Rq of the inner surface to the inner diameter D of the tube maybe not less than 0.0046. Thus, the rubber tube has a reduced adhesiveness.

A rubber tube has an inner surface at least partly roughed so that the ratio (Rz/D) of the maximum height Rz of the inner surface to the inner diameter D of the tube is not less than 0.038. The ratio (Rp/D) of the maximum peak height Rp of the inner surface to the inner diameter D of the tube may be not less than 0.019. The ratio (Rv/D) of the maximum valley depth Rv of the inner surface to the inner diameter D of the tube may be not less than 0.019. The ratio (Ra/D) of the arithmetic average roughness Ra of the inner surface to the inner diameter D of the tube may be not less than 0.0036. The ratio (Rq/D) of the root mean square height Rq of the inner surface to the inner diameter D of the tube maybe not less than 0.0046. Thus, the rubber tube has a reduced adhesiveness.

A fluoroelastomer composition containing (a) a polyol-crosslinkable fluoroelastomer, (b) a cross-linking agent for polyol crosslinking, (c) a crosslinking accelerator; and (d) at least one acid acceptor selected from basic magnesium carbonate and magnesium phosphate, wherein the content of a divalent metal oxide is lower than 1 part by mass with respect to 100 parts by mass of the fluoroelastomer (a). Also disclosed is a molded article obtained by crosslinking the fluoroelastomer composition.