A modular disk coextrusion die is formed of a plurality of cells stacked together. Each cell includes a symmetrical arrangement of thin annular disks, including a central routing disk and two distribution disks on both sides of the central routing disk. The distribution disks are oriented so that their respective distribution inlet openings oppose each other by about 180 degrees. The symmetrical arrangement permits each cell to process the melt streams in a manner that provides enhanced layer uniformity and bubble stability. By stacking several cells, blown films having up to several hundred layers can be made using twelve, twenty-four or more polymer melt streams. Complex films made from the modular disk coextrusion die are also provided.

A two piece adapter for extrusion of cylindrical core-shell structures using conventional biomedical needles includes first and second adapter pieces. The first adapter piece includes first and second (core and shell) inlet ports. The core inlet port leads directly to a male Luer fitting attachable to a core needle and surrounded by a threaded chamber. The shell inlet port is led, via a side chamber, into the side of the threaded chamber. The second adapter piece attaches to the bottom of the threaded chamber and is configured to attach to a shell needle, so that the shaft of the core needle sits inside the shaft of the shell needle.

A two piece adapter for extrusion of cylindrical core-shell structures using conventional biomedical needles includes first and second adapter pieces. The first adapter piece includes first and second (core and shell) inlet ports. The core inlet port leads directly to a male Luer fitting attachable to a core needle and surrounded by a threaded chamber. The shell inlet port is led, via a side chamber, into the side of the threaded chamber. The second adapter piece attaches to the bottom of the threaded chamber and is configured to attach to a shell needle, so that the shaft of the core needle sits inside the shaft of the shell needle.

In the case of a die head and a process to produce multilayer tubular film made from thermoplastic polymers, the advantages of radial distributors and axial distributors should be combined. This is achieved in that at least one distributor is a plate distributor and at least one distributor is an axial distributor, whereby the plate distributor is located in an annular element of the axial distributor upstream of the melt merge zone to the ring-shaped die.

A modular disk coextrusion die is formed of a plurality of cells stacked together. Each cell includes an arrangement of thin annular disks, including at least a first cap disk, a first distribution disk, a first transition disk and a first spreader disk. The modular disk coextrusion die includes at least one channel disk having at least one inlet opening and at least two outlet openings per inlet opening. The thin annular disks are configured so that a first of the outlet openings of the channel disk is in fluid communication with the first distribution disk in the first cell and a second of the outlet openings in the channel disk is in fluid communication with the first distribution disk in the second cell. The channel disk provides for a more efficient utilization of space at the inlet of the modular disk coextrusion die and enables the feeding of up to twenty melt streams.

A modular disk coextrusion die is formed of a plurality of cells stacked together. Each cell includes an arrangement of thin annular disks, including at least a first cap disk, a first distribution disk, a first transition disk and a first spreader disk. The modular disk coextrusion die includes at least one channel disk having at least one inlet opening and at least two outlet openings per inlet opening. The thin annular disks are configured so that a first of the outlet openings of the channel disk is in fluid communication with the first distribution disk in the first cell and a second of the outlet openings in the channel disk is in fluid communication with the first distribution disk in the second cell. The channel disk provides for a more efficient utilization of space at the inlet of the modular disk coextrusion die and enables the feeding of up to twenty melt streams.

A melt distributor (1) having a plurality of bifurcated melt passages melt passages (5.1, 5.2, 5.3) for redirecting and distributing melt flows from a thermoplastic plastic. The melt distributor can be connected to a multiple extrusion head for producing multi-layer preforms. The branched junction (8) is configured as a rounded y-shaped conduit branch, and at least the branched junction (8) between a supply passage part (6) and the discharging passage parts (7.1, 7.2) of the bifurcated melt passage follows a continuously bent curve, the curvature of which is not equal to zero. The rounded and continuously bent configuration of the branched junction (8) contributes to shorter flow paths and avoids the formation of dead zones.

A melt distributor (1) having a plurality of bifurcated melt passages melt passages (5.1, 5.2, 5.3) for redirecting and distributing melt flows from a thermoplastic plastic. The melt distributor can be connected to a multiple extrusion head for producing multi-layer preforms. The branched junction (8) is configured as a rounded y-shaped conduit branch, and at least the branched junction (8) between a supply passage part (6) and the discharging passage parts (7.1, 7.2) of the bifurcated melt passage follows a continuously bent curve, the curvature of which is not equal to zero. The rounded and continuously bent configuration of the branched junction (8) contributes to shorter flow paths and avoids the formation of dead zones.

A blown film coextrusion line includes a support frame, a plurality of extruders each mounted to the support frame and extending upward at an angle, and a downward facing blown film coextrusion die connected to distal ends of each of the plurality of extruders and receiving individual polymer streams from them. The blown film coextrusion line is compact and sturdy and eliminates much of the floor space and towered mounting structure that was required for conventional blown film coextrusion lines. A corresponding method of making a multilayer coextruded blown film is also provided.

A method of producing a microtube is provided. The method comprising co-electrospinning two polymeric solutions through co-axial capillaries to thereby produce the microtube, wherein a first polymeric solution of the two polymeric solutions is for forming a shell of the microtube and a second polymeric solution of the two polymeric solutions is for forming a coat over an internal surface of the shell, the first polymeric solution is selected solidifying faster than the second polymeric solution and a solvent of the second polymeric solution is selected incapable of dissolving the first polymeric solution. Also provided are electrospun microtubes.