Abstract: The invention relates to an apparatus and method for coating a pipe or a section of a pipe with a polymer layer. The apparatus comprises an applicator for applying polymer melt on the surface of a pipe or pipe section, a roller for pressing the polymer applied by the applicator towards the pipe or pipe section, and means for circumferentially moving the applicator and the roller around the periphery of the pipe or pipe section. According to the invention the apparatus further comprises a drive for rotating the roller as the roller is moving around the periphery of a pipe or pipe section. By means of the invention, higher quality coatings can be applied to field joints of steel pipes, for example.

Abstract: Abrasion resistant polymer pipe and a process for the production thereof. The pipe comprises a first, abrasion resistant inner layer (1) and a second, structural layer (2), which is placed on the outer side of the inner layer. The first and the second layers comprise extrudable polymer materials and they are preferably separated by an alarm layer which indicates wear or depletion of the inner layer. The pipe is suitable for use in the mining industry and generally for conducting liquid and gaseous fluids containing abrasive particles.

Abstract: A hollow profile used in the manufacture of a spirally wound double-walled thermo-plastic pipe, having essentially a rectangular cross section, two side walls and an outer wall and an inner wall limiting a cavity within. In the hollow profile the inner wall of the pipe is thicker than the wall of the hollow profile intended to form the outer wall of the pipe. The inner rounding radius of the edges adjacent to the thicker wall of the hollow profile is considerably larger than the rounding radius of the two other edges of the cavity and the inside surface of the thicker wall comprises a rib extending in the hollow cavity of the profile, on the side of the profile forming the inner side of the pipe, in the longitudinal direction of the profile at least essentially along the whole length of the profile.

Abstract: The invention concerns a method for manufacturing pipes coated with a peelable protection layer, wherein the core pipe (1) is produced by extruding and calibrating, after which the surface of core pipe (1) is heated before a protecting coating layer (7a) is applied onto the core pipe (1) on passing through a coating die (7), followed by cooling the applied coating layer (7a) before the readily coated pipe (9) is drawn out of the process. The method is characterized in that the degree of adhesion between core pipe (1) and coating layer (7a) is controlled by rapid and effective heating of the surface of the core pipe (1) to a predetermined temperature and by controlling welding time and stretching of the coating layer being applied onto the core pipe (1) by maintaining a controlled vacuum level inside the coating die (7) forcing the coating layer to hit the surface of the core pipe at an angle as steep as possibly, preferably between 45 and 90 degrees, most preferably between 60 and 80 degrees.

Abstract: Method and apparatus for coating a pipe or a pipe section with a layer of at least one polymer. The method includes providing the pipe or the pipe section having an outer surface defining the periphery of the pipe or the pipe section; applying on the outer surface of the pipe or pipe section a layer of at least one polymer material in melt stage using a nozzle, which is mounted on a carriage capable of travelling along the periphery of the pipe or the pipe section; and moving the carriage along at least a part of the periphery during the application of the polymer material to form a layer on the surface of the pipe or the pipe section that is particularly useful for coating field joints in pipelines.

Abstract: Method and apparatus for coating a pipe or a pipe section with a layer of at least one polymer. The method includes providing the pipe or the pipe section having an outer surface defining the periphery of the pipe or the pipe section; applying on the outer surface of the pipe or pipe section a layer of at least one polymer material in melt stage using a nozzle, which is mounted on a carriage capable of travelling along the periphery of the pipe or the pipe section; and moving the carriage along at least a part of the periphery during the application of the polymer material to form a layer on the surface of the pipe or the pipe section that is particularly useful for coating field joints in pipelines.

Abstract: A hollow profile used in the manufacture of a spirally wound double-walled thermo- plastic pipe, having essentially a rectangular cross section, two side walls and an outer wall and an inner wall limiting a cavity within. In the hollow profile the inner wall of the pipe is thicker than the wall of the hollow profile intended to form the outer wall of the pipe. The inner rounding radius of the edges adjacent to the thicker wall of the hollow profile is considerably larger than the rounding radius of the two other edges of the cavity and the inside surface of the thicker wall comprises a rib extending in the hollow cavity of the profile, on the side of the profile forming the inner side of the pipe, in the longitudinal direction of the profile at least essentially along the whole length of the profile.

Abstract: The invention relates to an apparatus and method for coating a pipe or a section of a pipe with a polymer layer. The apparatus comprises an applicator for applying polymer melt on the surface of a pipe or pipe section, a roller for pressing the polymer applied by the applicator towards the pipe or pipe section, and means for circumferentially moving the applicator and the roller around the periphery of the pipe or pipe section. According to the invention the apparatus further comprises a drive for rotating the roller as the roller is moving around the periphery of a pipe or pipe section. By means of the invention, higher quality coatings can be applied to field joints of steel pipes, for example.

Abstract: The present publication discloses a method for coating pipes. The method comprises applying curable first polymer (e.g. epoxy) onto the surface of the pipe and partially curing the first polymer or leaving the first polymer uncured to in order to form a reactive first polymer layer. Thereafter, the pipe with the reactive first polymer layer is heated and a second polymer (e.g. polyolefin) is applied directly onto the heated reactive first polymer layer, whereby the two polymers react and form a protective coating on the pipe or pipe section. In particular, the heating can be carried out in two steps such that the first polymer stays reactive until the application of the second polymer.

Abstract: The invention relates to a method and a device for cooling an extruded thermoplastics pipe (1) by directing a gaseous cooling medium tangentially towards the inner surface of the thermoplastics pipe (1) along its whole periphery, whereby the interior of the thermoplastics pipe (1) is divided by means of a protecting pipe (8) into an outer ring-shaped flow channel (9) for the cooling medium along the inner surface of the thermoplastics pipe (1), and a central return channel (10) through which a part of the cooling medium is intended to be sucked back influenced by the flow of cooling medium in the outer ring-shaped flow channel (9), and to be redirected towards the inner surface of the thermoplastics pipe (1).

Abstract: Method and apparatus for coating a pipe (2) or a pipe section with a layer of at least one polymer. The method comprises providing a pipe (2) or a pipe section having an outer surface defining the periphery of the pipe or pipe section; applying on the outer surface of the pipe or pipe section a layer of at least one polymer material in melt stage using a nozzle (3), which is mounted on a carriage capable of travelling along the periphery of the pipe (2) or pipe section; and moving the carriage along at least a part of the periphery during the application of the polymer material to form a layer on the surface of the pipe (2) or pipe section. The outer surface of the pipe or pipe section is being locally heated by induction heating before the application of the polymer material onto said surface. The present invention is particularly useful for coating field joints in pipelines.

Abstract: Container for dry powders, granules, pellets, gas and other ignitable substances and method of producing the same. The container comprises a wall (11-13) formed by a spirally wound profile having an open cross-section, wherein adjacent windings of the profile are attached to each other. According to the invention, the profile comprises a first thermoplastic layer forming the inner surface (11) of the profile and a second thermoplastic layer (12) placed about the first thermoplastic layer and forming the outer surface of the profile, said second layer being antistatic. The present containers have good mechanical strength properties and accumulation of electric charges inside the container can be efficiently avoided. The container can be used, e.g., as a drier for material/powder/pellets.

Abstract: The invention concerns a method and device for joining thermoplastics pipes manufactured by spiral winding of a hollow profile. The method according to the invention is characterized in that a welding mirror (5) adaptable to the prepared end surfaces of the pipes and provided with heating means, is inserted in the slot between the pipes (1), the pipe ends are pressed against the heated welding mirror to heat the thermoplastics material at the end of the pipe ends to a welding temperature to render the plastics material on the joint surface plastic, the welding mirror (5) is removed from between the pipes, the heated pipe ends are pressed against each other so that the thermoplastics materials melt together to form a welded joint, and the welded joint is allowed to cool. The welding mirror (5, 5?) according to the invention is characterized in that the welding mirror is adaptable to the shape of the end surface of the pipe cut along a radial side wall (6) of the hollow profile.

Abstract: This invention relates to a hollow profile (1) used for the manufacture of a spirally wound double-walled thermoplastic pipe, which hollow profile has essentially a rectangular cross section and the wall (2) of the hollow profile intended to form the inner wall of the pipe is thicker than the wall (4) intended to form the outer wall (4) of the pipe. The invention is characterized in that the inner rounding radius (7a) of the edges adjacent to the thicker wall (2) of the hollow profile is considerably larger than the rounding radius (7) of the two other edges of the cavity (6).

Abstract: Abrasion resistant polymer pipe and a process for the production thereof. The pipe comprises a first, abrasion resistant inner layer (1) and a second, structural layer (2), which is placed on the outer side of the inner layer. The first and the second layers comprise extrudable polymer materials and they are preferably separated by an alarm layer which indicates wear or depletion of the inner layer. The pipe is suitable for use in the mining industry and generally for conducting liquid and gaseous fluids containing abrasive particles.

Abstract: The invention relates to a method and a device for cooling an extruded thermoplastics pipe (1) by directing a gaseous cooling medium tangentially towards the inner surface of the thermoplastics pipe (1) along its whole periphery, whereby the interior of the thermoplastics pipe (1) is divided by means of a protecting pipe (8) into an outer ring-shaped flow channel (9) for the cooling medium along the inner surface of the thermoplastics pipe (1), and a central return channel (10) through which a part of the cooling medium is intended to be sucked back influenced by the flow of cooling medium in the outer ring-shaped flow channel (9), and to be redirected towards the inner surface of the thermoplastics pipe (1).

Abstract: The invention concerns a method for manufacturing pipes coated with a peelable protection layer, wherein the core pipe (1) is produced by extruding and calibrating, after which the surface of core pipe (1) is heated before a protecting coating layer (7a) is applied onto the core pipe (1) on passing through a coating die (7), followed by cooling the applied coating layer (7a) before the readily coated pipe (9) is drawn out of the process.

Abstract: A method for producing a lightweight end wall of a containers characterized by the following stages: manufacturing a large size lightweight thermoplastics tube by spirally winding and joining together a hollow profile of thermoplastics, cutting a piece from such a tube to form a pre-form of an end wall, heating the pre-form into a mouldable state, pressing the pre-form into a dome shaped piece between a male and a female mould-half, cooling the dome shaped piece while pressed between the mould-halves, maching-tooling the edges of the cooled piece to match the cross-sectional surface of the tube mantle, and joining the mantle and the end wall together by welding.

Abstract: This invention relates to a hollow profile (1) used for the manufacture of a spirally wound double-walled thermoplastic pipe, which hollow profile has essentially a rectangular cross section and the wall (2) of the hollow profile intended to form the inner wall of the pipe is thicker than the wall (4) intended to form the outer wall (4) of the pipe. The invention is characterized in that the inner rounding radius (7a) of the edges adjacent to the thicker wall (2) of the hollow profile is considerably larger than the rounding radius (7) of the two other edges of the cavity (6).

Abstract: This invention concerns a method and an apparatus for making a spirally-wound tube from a hollow thermoplastic profile (1) having a substantially rectangular cross-section, which method comprises the steps of: winding the thermoplastic profile (1) around a drum (2) and joining adjacent loops together by welding, and smoothing the outer weld joint (13) by means of extra heat and a smoothing body resting against the weld joint (13).