Provided are extrusion dies having entrance, orientation, merging (205), and exit (211) sections, which dies may be used to produce fibers having, e.g., oriented reinforcement materials (e.g., PTFE) dispersed within. The dies provide fibers having enhanced mechanical and processing properties. The orientation section comprises orientation channels (203) wherein a ratio of a cross-sectional area having of the channel inlet to a cross-sectional area of the channel outlet is between 2 and 45.

Provided are extrusion dies having entrance, orientation, merging (205), and exit (211) sections, which dies may be used to produce fibers having, e.g., oriented reinforcement materials (e.g., PTFE) dispersed within. The dies provide fibers having enhanced mechanical and processing properties. The orientation section comprises orientation channels (203) wherein a ratio of a cross-sectional area having of the channel inlet to a cross-sectional area of the channel outlet is between 2 and 45.

A staple cartridge assembly for use with a surgical stapling instrument includes a staple cartridge including a plurality of staples and a cartridge deck. The staple cartridge assembly also includes a compressible adjunct positionable against the cartridge deck, wherein the staples are deployable into tissue captured against the compressible adjunct, and wherein the compressible adjunct comprises a first biocompatible layer comprising a first portion, a second biocompatible layer comprising a second portion, and crossed spacer fibers extending between the first portion and the second portion.

A polymer optical fiber is provided which shows improved hydrolytic stability. This fiber comprises a polymeric optical core and cladding layer, surrounded by a polymeric overcladding layer which comprises a miscible blend of one or more hydrolytically stable amorphous polymers. By varying the ratios of the component polymers in the overcladding blend, the glass transition temperature and the coefficient of thermal expansion of the overcladding layer may be tuned to optimize the attenuation and bandwidth of the plastic optical fiber.

A polymer optical fiber is provided which shows improved hydrolytic stability. This fiber comprises a polymeric optical core and cladding layer, surrounded by a polymeric overcladding layer which comprises a miscible blend of one or more hydrolytically stable amorphous polymers. By varying the ratios of the component polymers in the overcladding blend, the glass transition temperature and the coefficient of thermal expansion of the overcladding layer may be tuned to optimize the attenuation and bandwidth of the plastic optical fiber.

A spinneret and system are provided for microfilm blowing of hollow polymer fibers. The spinneret includes a gaseous fluid passageway and a polymer dope passageway wherein the gaseous fluid passageway is inside the polymer dope passageway. Gaseous fluid is expelled from the gaseous fluid passageway within an annulus of polymer dope extruded from an extrusion opening of the spinneret. The extruded polymer dope is blown up and expanded by the gaseous fluid to form a hollow fiber with unique characteristics.

A spinneret and system are provided for microfilm blowing of hollow polymer fibers. The spinneret includes a gaseous fluid passageway and a polymer dope passageway wherein the gaseous fluid passageway is inside the polymer dope passageway. Gaseous fluid is expelled from the gaseous fluid passageway within an annulus of polymer dope extruded from an extrusion opening of the spinneret. The extruded polymer dope is blown up and expanded by the gaseous fluid to form a hollow fiber with unique characteristics.

Cables are constructed with extruded discontinuities in the cable jacket that allow the jacket to be torn to provide access to the cable core. The discontinuities can be longitudinally extending strips of material in the cable jacket.

A filament is fed to an extrusion head. The filament has a semi-crystalline polymeric reinforcement portion and a polymeric matrix portion. The reinforcement and matrix portions run continuously along a length of the filament. The reinforcement portion has a higher melting point and a higher crystallinity than the matrix portion. The temperature of the filament is raised in the extrusion head above the melting point of the matrix portion but below the melting point of the reinforcement portion so that the matrix portion of the filament melts within the extrusion head, thereby forming a partially molten filament within the extrusion head. The partially molten filament is extruded from the extrusion head onto a substrate, the reinforcement portion of the partially molten filament remaining in a semi-crystalline state as it is extruded from the extrusion head. Relative movement is generated between the extrusion head and the substrate as the partially molten filament is extruded onto the substrate in order to form an extruded line on the substrate. The matrix portion of the extruded line solidifies after the extruded line has been formed on the substrate.

A method for producing filaments of polyacrylonitrile and an extrusion head for carrying out said method are provided, wherein the method comprises preparing a polyacrylonitrile polymer solution and passing said solution through an extruder plate that determines the formation of filaments, a central chamber being defined between the extruder plate and a floating plate connected to a vibrating system, said chamber being surrounded by a peripheral chamber into which the polymer solution is introduced under pressure. The polymer solution then passes through to the central chamber via small radial conduits that accelerate the material, and is subjected to vibration in the central chamber before passing through the extruder plate.