A hollow fiber membrane is formed by embedding a braid having a spiral open weave of monofilaments only, to avoid a whiskering problem. The open weave is characterized by contiguous, circumferential, rhomboid-shaped areas of polymer film separated by monofilament. When the braid is supported on a plasticized PVA cable having a scalloped periphery, the braid can be infiltrated with membrane polymer which, when coagulated, embeds the braid positioning it around the lumen. The embedded spiral weave, free of any circumferentially constricting monofilament, allows the membrane to be biaxially distensible. The membrane has give not only in the axial or longitudinal direction but also in the radial direction. Give in the radial direction permits soiled membranes to be backwashed under higher pressure than in a comparable braid which is not radially distensible.

Formulations usable as support material in additive manufacturing such as 3D inkjet printing and which feature a viscosity of no more than 50 cPs at 35 C., are provided. The formulations are composed of at least one hydrophilic curable material which provides, when hardened, a material that is dissolvable or swellable in an aqueous solution; and at least one non-curable material that is capable of being swelled by said hardened material formed of said at least one curable material. Additive manufacturing processes utilizing these formulations and objects obtained thereby are also provided.

A hollow fiber membrane is formed by embedding a braid having a spiral open weave of monofilaments only, to avoid a whiskering problem common in prior art multifilament braid-supported tubular membranes. The open weave is characterized by contiguous, circumferential, rhomboid-shaped areas of polymer film separated by monofilaments. When the braid is supported on a plasticized PVA cable it can be infiltrated with membrane polymer which, when coagulated embeds the braid positioning it around the lumen. The spiral weave, free of any circumferentially constricting monofilament, when embedded in film, allows the membrane to be biaxially distensible. In other words, the membrane has give not only in the axial or longitudinal direction but also in the radial direction. Give in the radial direction permits soiled membranes to be backwashed under higher pressure than in a comparable braid which is not radially distensible.

A repair method is provided during which a thermoplastic patch is arranged on a thermoplastic aerospace component. An ultrasonic horn is arranged on the thermoplastic patch. The thermoplastic patch is vertically between the thermoplastic aerospace component and the ultrasonic horn. The thermoplastic patch contacts the ultrasonic horn. The thermoplastic patch is continuous ultrasonic welded to the thermoplastic aerospace component using the ultrasonic horn.

A repair method is provided during which a thermoplastic patch is arranged on a thermoplastic aerospace component. An ultrasonic horn is arranged on the thermoplastic patch. The thermoplastic patch is vertically between the thermoplastic aerospace component and the ultrasonic horn. The thermoplastic patch contacts the ultrasonic horn. The thermoplastic patch is continuous ultrasonic welded to the thermoplastic aerospace component using the ultrasonic horn.