Various improved designs for expansion tool heads are disclosed herein that are structured (1) to provide improved and more-evenly distributed strain in the pipe during the expansion strokes of the tool head which can include more gradually inducing the strain in the pipe and/or (2) to avoid the induction of plastic deformation of the pipe in regions of seal formation between the radial-inwardly facing surface of the pipe and the radially-outward facing surface of the fittings (i.e., the ribs of the fitting) especially in instances in which the tool head is not rotated between separate expansion steps. This may be achieved, for example, by the use of convexly curved outer profiles that limit initial insertion depth of the tool in the pipe prior to expansions and/or by the use of a hybrid toothed profile.

Aspects of the disclosure relate to manufacturing a balloon envelope for use in a stratospheric balloon system. For instance, a stream of polyethylene mixture is extruded through an extruder in order to orient molecules of polymer chains of polyethylene and to provide an oriented film. The oriented film is passed through an electron beam and thereby crosslinking the polymer chains to provide a cross-linked film. The cross-linked film is heat sealed to form the balloon envelope.

Aspects of the disclosure relate to manufacturing a balloon envelope for use in a stratospheric balloon system. For instance, a stream of polyethylene mixture is extruded through an extruder in order to orient molecules of polymer chains of polyethylene and to provide an oriented film. The oriented film is passed through an electron beam and thereby crosslinking the polymer chains to provide a cross-linked film. The cross-linked film is heat sealed to form the balloon envelope.

The invention is related to a polyethylene composition characterized in that it comprises a base resin and an inorganic mineral filler which is present in the composition in an amount of 1 to 50 wt % in respect to the weight of composition, wherein said base resin comprises: a) a first crosslinked polyethylene (PEX) having a gel content (measured according to ASTM D 2765:2006) in the range of 5% to 80% in respect to the weight of crosslinked polyethylene (PEX), said crosslinked polyethylene (PEX) being obtained from recycled wastes and b) a second polyethylene (PE) selected from virgin polyethylene and recycled polyethylene, or mixtures thereof. The invention is further related to a process for production of said polyethylene composition, and use of the polyethylene composition.

An expanding tool comprising: an actuator comprising a cylindrical housing that defines an actuator housing cavity; a primary ram disposed within the actuator housing cavity, the primary ram defining an internal primary ram cavity; a secondary ram disposed within the internal primary ram cavity; a cam roller carrier coupled to a distal end of the secondary ram; a drive collar positioned within a distal end of the actuator housing cavity; a roller clutch disposed within an internal cavity defined by an inner surface of the drive collar; a shuttle cam positioned between the roller clutch and a distal end of the primary ram; an expander cone coupled to the primary ram; and an expander head operably coupled to the drive collar. When triggered, the actuator first rotates the expander head and then the actuator expands the expander head.

A foam twin-sheet formed air filled gasket is provided. The foam sheets need not be covered with one or more layers of air impermeable materials before, during or after the twin-sheet forming process. Methods for manufacturing the air filled gaskets are also disclosed.

An expanding tool comprising: an actuator comprising a cylindrical housing that defines an actuator housing cavity; a primary ram disposed within the actuator housing cavity, the primary ram defining an internal primary ram cavity; a secondary ram disposed within the internal primary ram cavity; a cam roller carrier coupled to a distal end of the secondary ram; a drive collar positioned within a distal end of the actuator housing cavity; a roller clutch disposed within an internal cavity defined by an inner surface of the drive collar; a shuttle cam positioned between the roller clutch and a distal end of the primary ram; an expander cone coupled to the primary ram; and an expander head operably coupled to the drive collar. When triggered, the actuator first rotates the expander head and then the actuator expands the expander head.

Highly crosslinked polymer particulate and methods of manufacturing highly crosslinked polymer particulate. The highly crosslinked polymer particulate includes a plurality of crosslinked polymer granules. Each crosslinked polymer granule includes a highly crosslinked polymeric material and a property-modifying filler. The highly crosslinked polymeric material includes a plurality of polyethylene polymer chains and a plurality of chemical crosslinks. The the plurality of chemical crosslinks includes chemical crosslinks that covalently bond a given polyethylene polymer chain of the plurality of polyethylene polymer chains to another polyethylene polymer chain of the plurality of polyethylene polymer chains. The property-modifying filler is configured to modify at least one property of the plurality of crosslinked polymer granules. A characteristic dimension of each crosslinked polymer granule of the plurality of crosslinked polymer granules is at least 10 micrometers and at most 5 millimeters.

Aspects of the disclosure relate to manufacturing a balloon envelope for use in a stratospheric balloon system. For instance, a stream of polyethylene mixture us extruded through an extruder in order to orient molecules of polymer chains of polyethylene and to provide an oriented film. The oriented film is passed through an electron beam and thereby crosslinking the polymer chains to provide a cross-linked film. The cross-linked film is heat sealed to form the balloon envelope

Aspects of the disclosure relate to manufacturing a balloon envelope for use in a stratospheric balloon system. For instance, a stream of polyethylene mixture us extruded through an extruder in order to orient molecules of polymer chains of polyethylene and to provide an oriented film. The oriented film is passed through an electron beam and thereby crosslinking the polymer chains to provide a cross-linked film. The cross-linked film is heat sealed to form the balloon envelope