A method of fabricating a high-altitude balloon. The method includes coextruding at least two adjacent continuous layers of extrudate, extrusion-bonding the layers of extrudate to one another along an edge of the sheets of extrudate to form a seam, and cooling the extrudate.

A method for forming an object made of a polymeric material, wherein the polymeric material has a melting temperature (Tf), comprising the following steps: melting the polymeric material; cooling the polymeric material below the melting temperature (Tf); extruding the polymeric material into a tubular shaped body (H); inserting the tubular body (H) into a mould (60) having an internal cavity; closing off the tubular body (H) at a first end thereof; blowing air into the tubular body (H) through a second end, in order that the tubular body (H) adheres to the internal cavity of the mould (60).

There is provided a two-direction heating system which comprises one or more heat-absorber modules. Each heat-absorber module comprises a heat-absorber barrel, a heat-absorber screw attached to an internal region of the barrel, and one or more heating units each attached to an external region of the barrel. Heat generated by the heating unit and delivered to first heat-absorber receptors provided on an inner surface of the barrel and second heat-absorber receptors provided on an outer surface of the screw, circulates from the barrel to the screw and from the screw to the barrel, and is thereby transferred to a material placed in the interior region of the heat-absorber barrel.

Apparatus and methods for food production including a food preconditioner (228) operable to heat and partially pre-cook food ingredients, and a twin screw extruder (20) operable to further cook the preconditioned ingredients to create final food products. The extruder (20) includes a pair of hollow core extrusion screws (50, 52, 124, 126, 190) having elongated hollow core shafts (54, 128, 130, 192) equipped with helical fighting (56, 132, 134, 194) along the lengths thereof. The fighting (132, 134, 194) is also of hollow construction which communicates with the hollow core shafts (54, 128, 130, 192). The fighting (56, 132, 134, 194) also includes forward, reverse pitch sections (64, 162, 216). The extrusion screws (50, 52, 124, 126, 190) are designed to impart high levels of thermal energy into materials being processed in the extruders (20), without adding additional moisture.