Aspects of the disclosure relate to envelopes for aerial vehicle. The aerial vehicle may include an envelope including a plurality of gores. The aerial vehicle may also include a seal arranged between a pair of the plurality of gores, the seal including six layers of envelope material heat-sealed together.

A non-compliant fiber-reinforced medical balloon comprises a first fiber layer and a second fiber layer embedded in a continuous matrix of thermally-weldable polymer material defining a barrel wall, cone walls and neck walls. The fibers of the first fiber layer have a pattern of different lengths and are divisible into a first group and a second group based on length. The length of the fibers of the second group varies progressively in accordance to their proximity to the fibers of the first group; the fibers of the second group closest to the fibers of the first group being longer than the fibers of the second group further from the fibers of the first group. The fiber of the second fiber layer winds circumferentially around the longitudinal axis of the balloon substantially over the entire length of the balloon.

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 provide a fill port apparatus for filling high altitude balloons, such as those used in communications networks, with lighter than air lift gasses. For instance, the fill port apparatus includes a tubular body portion having a passageway extending between a first end and a second end of the tubular body portion. The fill port apparatus also includes an attachment structure arranged at the first end of the tubular body portion. This structure is configured to attach to a top plate of a balloon envelope. The fill port apparatus also includes a plurality of energy directing structures arranged on an interior surface of the tubular body portion. These energy directing structures extend into the passageway from the interior surface and are each configured to contact at least one other of the plurality of energy directing structures when the tubular body portion is welded to itself.

Co-extruded and extruded high-altitude balloons and apparatus and methods for manufacture. A high-altitude balloon has a plurality of layers of coextruded balloon panel extrudate, a first one of the layers extrusion-bonded to a second one of the layers along a first edge, the second one of the layers extrusion-bonded to a third one of the layers along a strip spaced apart from the first edge, extrusion-bonding of successive layers alternating between the first edge and the strip, the first one of the layers and the last one of the layers extrusion-bonded together along a second edge.

Aspects of the disclosure relate to systems and techniques for inspecting seals for high altitude balloons. In one example, a system may include a reflective surface, a translucent material on the reflective surface, and a movable light source configured to move along the reflective surface and provide light to the reflective surface. The light is provided such that it is reflected from the reflective surface and through the translucent material in order to backlight a balloon envelope seal for inspection. A method for inspecting a balloon envelope seal may include placing balloon envelope material on a table, forming a seal between portions of the material, moving a light over the seal, shining light onto a reflective portion of the table below the seal to backlight the seal, and inspecting the seal using the backlighting of the seal.

A high altitude balloon, including a method and machine for manufacture, uses a perimeter border strip to couple two circular balloon panels with a lap or butt seal. Simultaneous sealing of two perimeter seals, one between the border strip and each of two balloon panels, is provided by supporting stacked balloon panels on a rotatable support and sealing around the full perimeter of the two interposed balloon panels and the border strip. The method and machine for manufacture allow for the mass production of high altitude balloons and minimize necessary material handling. The perimeter border strip can be dispensed and guided relative to the perimeter of the balloon panels for positioning before sealing together, as a bonding device is rotated relative to the balloon envelope.

A system for manufacturing a balloon envelope includes a table component and a sealing component. The sealing component includes a first level and a second lower level. The first level further includes first and second platforms. The first platform can provide a work area for sealing respective first and second sheets of material together to form a sealed edge and the second platform may provide a work area for sealing the second sheet of material and a third sheet of material together. The first, second, and third sheets of material respectively form first, second, and third gores of the balloon envelope. The sealing component may be configured to move along length of the first platform and to apply a heat seal to bond the first sheet of material to the second sheet material and form a sealed edge.

Aspects of the disclosure relate to techniques for manufacturing a balloon envelope. In one example, a first sheet of material for a first gore of the balloon envelope is provided. Lap seal material is arranged at least partially on the first sheet of material. A first heat seal is created between the lap seal material and the first sheet of material. A second sheet of material for a second gore of the balloon envelope is arranged over the first heat seal. A second heat seal is created between the lap seal material and the second sheet of material such that the lap seal material is configured to provide additional structural support to the balloon envelope.

A lighter-than-air holographic envelope such as a balloon decorated with a holographic pattern and having long float life (one week or longer) comprises a metal layer, an embossable layer, and a polymeric gas barrier of polyvinyl alcohol/polyvinyl amine copolymer crosslinked with citric acid and an optional additional crosslinking agent such as epichlorohydrin and a heat-seal layer.