Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H81/00—Methods, apparatus, or devices for covering or wrapping cores by winding webs, tapes, or filamentary material, not otherwise provided for
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/02—Hollow fibre modules
  • B01D63/021—Manufacturing thereof
  • B01D63/0233—Manufacturing thereof forming the bundle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
  • B29C53/80—Component parts, details or accessories; Auxiliary operations
  • B29C53/8008—Component parts, details or accessories; Auxiliary operations specially adapted for winding and joining
  • B29C53/8016—Storing, feeding or applying winding materials, e.g. reels, thread guides, tensioners

Definitions

• the present invention concerns a novel process for making a fiber bundle.
• the illustrative embodiment concerns a novel process for making a hollow fiber mass transfer device bundle and also concerns a novel mass transfer device bundle.
• the device of that patent is assembled by winding a length of the hollow tubular conduit of semipermeable membrane about a core in a plane which defines an acute angle to the longitudinal axis and intersects both ends of the core.
• the core is rotated about its longitudinal axis, or the plane of winding is correspondingly rotated to the same effect, to laterally displace on the core each winding of conduit from its immediately preceding wind ⁇ ing.
• the resulting wound structure allows a low cost construction of a high performance mass transfer de- vice.
• the flow pattern is around the circumference of the cylindrical element formed by the winding process. However, as the flow goes around the circumference, it will encounter flow paths of different length.
• the void fraction of the resulting structure increases radially outwardly of the bundle.
• the void fraction near the outside of the bundle will be greater than the void fraction on the inside of the bundle.
• the term "void fraction" connotes the ratio of space to space and fiber, whereby a greater void fraction means more space.
• the mass transfer device is an oxygenator, for example, having a void fraction on the outside that is substan ⁇ tially larger than the void fraction on the inside results in a much larger blood flow rate on the outside because there is more resistance on the inside. As the void fraction on the outside becomes smaller, there is less flow rate on the outside. However, since the flow path on the outside is inherently longer than the flow path on the inside, if the void fraction were equal throughout the bundle, the flow rate on the outside would not ' be equal to the flow rate on the inside but the blood flow would be unequal because of the longer flow path on the outside.
• an optimum hollow fiber oxygenator comprises a bundle in which the flow rate is substantially constant throughout the bundle, the blood outlet saturation is substantially constant throughout the bundle, and the void fraction increases slightly in the radial outward direction of the bundle.
• the pres- ent invention provides a novel process for obtaining this optimum device and also concerns a novel device having these optimum properties.
• the present invention may be applicable to other devices using other fibers.
• the present invention could be used with non-permeable tubing such as em ⁇ ployed in a heat exchanger; Further, the present invention could be used with an absorption filter, us ⁇ ing an absorbant filter material such as polyesters or natural fibers. Other impregnated fibers could be em ⁇ ployed in connection with the present invention.
• a proc- ess for making a fiber bundle.
• the process comprises the steps of providing a core having a longi ⁇ tudinal axis, winding a length of the fiber around the core from an arm in a plane that is at an acute angle with respect to the longitudinal axis of the core and is between opposite ends of the core, providing rela ⁇ tive rotation between the longitudinal axis of the core and the position of the winding arm, and, during wind ⁇ ing of the fiber around the core, changing the ratio of (a) the angular velocity of the wind and (b) the rela- tive rotational velocity between the longitudinal axis of the core and the position of the winding arm.
• the ratio-changing step comprises* the step of increasing the ratio during winding whereby the void fraction of radially-outward annuli of the wound bundle is less than the void frac ⁇ tion would be if the ratio remained constant.
• the outer 10 per ⁇ cent annulus of the bundle is wound at a ratio that is at least 5 percent greater than the ratio at which the inner 10 percent annulus is wound.
• the process is used for making a hollow fiber mass transfer device.
• the mass transfer device comprises a core with a hollow fiber bundle overlying the core and in symmetrical re- lationship to the longitudinal axis of the core.
• Figure 1 is a perspective view of a mass transfer device bundle, prior to its being enclosed within a housing, constructed in accordance with the principles of the present invention.
• Figure 2 is a diagrammatic cross-sectional view of a wound bundle.
• Figure 3 is a perspective view of a core and wind ⁇ ing mechanism.
• Figure 4 is a perspective view of a core for the purpose of showing a winding layout.
• Figure 1 shows bundle 12 in a condition after the hollow fiber has been wound around the core 10, sealant bands 14 have been applied around the bun ⁇ dle, and the bundle has been cut transversely to form ends 16 and 18, as is disclosed in United States Patent No. 3,794,468.
• bundle 12 is " formed of a hollow* fiber of semipermeable membrane that is wound about a core 10 to form a multi-layer winding of the fiber in which individual adjacent windings in the same layer are generally parallel to each other, but indi ⁇ vidual adjacent windings of the fiber in adjacent layers define an angle to each other.
• the ends of the core transverse to the fiber windings are then potted with a curable sealant.
• FIG. 1 is a diagrammatic view of a cross-section of the bundle of Figure 1, with seven different annuli of the bundle being designated with the numbers 1 to 7.
• Annulus 1 is the innermost annulus of the bundle while number 7 is the outermost annulus of the bundle.
• the bundle of Figure 1 has been wound with a constant winding ratio.
• winding ratio connotes the ratio of (a) the angular velocity of the wind and (b) the rela- tive rotational velocity between the longitudinal axis of the core and the position of the winding arm.
• the void fraction increases radially outwardly in the bundle.
• annulus 2 will have a greater average void fraction than annulus 1
• annulus 3 has a greater void fraction than annulus 2
• annulus 4 has a greater void fraction than annulus 3, etc.
• a c _on- stant winding ratio the flow rate increases radially outwardly in the bundle.
• the blood saturation percent ⁇ age decreases outwardly in the bundle and the pressure drop remains substantially constant throughout the bun ⁇ dle.
• the following chart shows the void fraction, flow rate, blood saturation percentage, and pressure drop with respect to the numbered annuli in Figure 2, with a constant winding ratio of 360:1.
• the appara ⁇ tus comprises a winding arm 20 that is driven by pulley 22 coupled through belt drives 24 and 26 which are con ⁇ nected to pulley 28 that is keyed to the shaft 30 of motor 32.
• Arm 20 is hollow and a hollow fiber 34 from a suitable source (not shown) extends through arm 20 and out its distal end 36.
• a core 38 having hollow end extensions 40, 42 is positioned on a spindle 44 with the end extensions 40, 42 being coaxial with the spindle 44 and the axis of the cylindrical core 38.
• Spindle 44 is driven by a suitable driving means, including a variable speed mo ⁇ tor 42.
• the spindle and -hence the core axis are at an acute angle with respect to the plane of the wind of winding arm 20, preferably 2.5 .
• winding arm 20 moves in the direction of the arrow 46 about the axis of portion 48 of winding arm 20.
• the core rotates in the direction of arrow 50 about the axis of spindle 44 which, as stated above, is at an acute angle with respect to the - - -
• extensions 40, 42 have a .65 inch diameter and the core has a 1.975 inch outer diameter with a 9.95 inch length, as indicated in Figure 3. The winding continues until the bundle has an outer diameter of 2.626 inches, as indicated in Figure 2.
• the rotational ve ⁇ locity of spindle 44 decreases during the winding of the bundle, while the angular velocity of arm 20 re ⁇ mains constant and the position of the winding arm drive mechanism remains constant.
• the winding arm drive may move, in a planetary manner, about the core, with " a decreasing planetary motion during winding. This will increase the ratio of (a) the angular velocity of the wind and (b) the relative rotational velocity between the longitudinal axis of the core and the position of the winding arm.
• the rotational velocity of the core may be maintained constant while the position of the winding arm drive is maintained constant while the angular ve ⁇ locity of the wind is increased during the winding of the bundle. It can be seen that there are many varia ⁇ tions available for changing the ratio of (a) the angular velocity of the wind and (b) the relative rota- tional velocity between the longitudinal axis of the core and the position of the winding arm.
• the flow rate is in cubic centimeters per second and the pressure drop is in millimeters of mercury.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• External Artificial Organs (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (7)

Family Cites Families (4)

• 1984
  • 1984-03-23 US US06/592,835 patent/US4572446A/en not_active Expired - Fee Related
• 1985
  • 1985-02-08 EP EP85901199A patent/EP0177510B1/en not_active Expired
  • 1985-02-08 WO PCT/US1985/000199 patent/WO1985004339A1/en active IP Right Grant
  • 1985-02-08 JP JP60501043A patent/JPS61501497A/ja active Granted
  • 1985-02-08 DE DE8585901199T patent/DE3573887D1/de not_active Expired
  • 1985-03-22 CA CA000477274A patent/CA1242175A/en not_active Expired
  • 1985-03-22 IT IT20017/85A patent/IT1184179B/it active

Patent Citations (7)

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