CA1109000A - Hollow filament bundle for diffusion device - Google Patents
Hollow filament bundle for diffusion deviceInfo
- Publication number
- CA1109000A CA1109000A CA291,548A CA291548A CA1109000A CA 1109000 A CA1109000 A CA 1109000A CA 291548 A CA291548 A CA 291548A CA 1109000 A CA1109000 A CA 1109000A
- Authority
- CA
- Canada
- Prior art keywords
- filaments
- filament
- bundle
- longitudinal axis
- individual
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000009792 diffusion process Methods 0.000 title claims abstract description 11
- 239000012530 fluid Substances 0.000 claims abstract description 12
- 238000000926 separation method Methods 0.000 claims abstract description 3
- 239000011800 void material Substances 0.000 claims description 8
- 239000008280 blood Substances 0.000 claims description 7
- 210000004369 blood Anatomy 0.000 claims description 7
- 239000004627 regenerated cellulose Substances 0.000 claims description 5
- 230000001747 exhibiting effect Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 4
- 239000000835 fiber Substances 0.000 description 27
- 238000004804 winding Methods 0.000 description 21
- 239000000385 dialysis solution Substances 0.000 description 10
- 239000012510 hollow fiber Substances 0.000 description 10
- 229920002678 cellulose Polymers 0.000 description 8
- 239000001913 cellulose Substances 0.000 description 7
- 238000000502 dialysis Methods 0.000 description 7
- 230000010355 oscillation Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000005520 cutting process Methods 0.000 description 4
- 238000009730 filament winding Methods 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 230000023555 blood coagulation Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 229920002301 cellulose acetate Polymers 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 210000003734 kidney Anatomy 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 229920000298 Cellophane Polymers 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000017531 blood circulation Effects 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 238000004382 potting Methods 0.000 description 1
- 230000037452 priming Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/08—Polysaccharides
- B01D71/10—Cellulose; Modified cellulose
-
- 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
- B01D63/0231—Manufacturing thereof using supporting structures, e.g. filaments for weaving mats
-
- 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
- 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
- B01D63/033—Specific distribution of fibres within one potting or tube-sheet
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/24—Formation of filaments, threads, or the like with a hollow structure; Spinnerette packs therefor
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
- D01F2/02—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from solutions of cellulose in acids, bases or salts
- D01F2/04—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from solutions of cellulose in acids, bases or salts from cuprammonium solutions
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Textile Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- External Artificial Organs (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Character Discrimination (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This application discloses an apparatus and method for preparing an elongated, coreless bundle of homogeneously distributed hollow, generally longitudinally-directed, semi-permeable filaments, free of direct mechanical attachment to each other, for use as a fluid separation element in a dif-fusion device such as a dialyzer. The filaments are positioned in the bundle whereby the majority of the lengths thereof, and the overall directions thereof, define an angle to the longitudinal axes of the said filament bundle. The filaments are positioned in crossing, overlying relation with adjoining filaments, said filaments essentially occupying individual, parallel, flat planes. The filaments define first sets of generally parallel strands defining a first angular relation to said longitudinal axis and second sets of generally parallel strands defining an opposite angular relation to said longitudinal axis, a first filament of a first set being overlaid by a first filament of a second set, which first filament of said second set is, in turn, overlaid by a second filament of said first set, which second filament of said first set is, in turn, overlaid by a second filament of said second set. The said relationship continues throughout the majority of the filaments of the first and second sets to define interleaving releationships, in which the filaments of each set overly the immediately-preceding filaments of the other associated set, and are overlaid by the immediately-following filaments of said other set, the majority of individual filaments thereof extending across 15 to 50 percent of the width of said filament bundle.
This application discloses an apparatus and method for preparing an elongated, coreless bundle of homogeneously distributed hollow, generally longitudinally-directed, semi-permeable filaments, free of direct mechanical attachment to each other, for use as a fluid separation element in a dif-fusion device such as a dialyzer. The filaments are positioned in the bundle whereby the majority of the lengths thereof, and the overall directions thereof, define an angle to the longitudinal axes of the said filament bundle. The filaments are positioned in crossing, overlying relation with adjoining filaments, said filaments essentially occupying individual, parallel, flat planes. The filaments define first sets of generally parallel strands defining a first angular relation to said longitudinal axis and second sets of generally parallel strands defining an opposite angular relation to said longitudinal axis, a first filament of a first set being overlaid by a first filament of a second set, which first filament of said second set is, in turn, overlaid by a second filament of said first set, which second filament of said first set is, in turn, overlaid by a second filament of said second set. The said relationship continues throughout the majority of the filaments of the first and second sets to define interleaving releationships, in which the filaments of each set overly the immediately-preceding filaments of the other associated set, and are overlaid by the immediately-following filaments of said other set, the majority of individual filaments thereof extending across 15 to 50 percent of the width of said filament bundle.
Description
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BACKGROUND OF THE INVENTION
This invention relates to a machine used in the manufacture of hollow fiber dialyzers of the type used in artificial kidney systems, and to the fiber bundles and dialyzers produced thereby.
Artificial kidney systems include dialyzers or membrane diffusion devices through which blood from a patient flows for treatment. One type of dialyzer is known as a hollow-fiber dialyzer.
A hollow-fiber dialyzer includes an elongated, and generally-cylindrically-shaped casing within which ' many very-fine, hollow and semipermeable fibers are ! positioned and secured adjacent their terminal ends to the casing. Blood from the patient flows through the dialyzer inside the fibers. Dialysis solution flows through the dialyzer and surrounds and-contacts the fibers ~, , so as to receive bodily waste products from the blood and remove them from the dialyzer.
The fibers are made from a long hollow filament of Cellophane* or of a cellulose derivative, such as sold under the trade name Cuprophan*. The filament is continuous ' and is supplied on a spool.
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*denotes trade mark
BACKGROUND OF THE INVENTION
This invention relates to a machine used in the manufacture of hollow fiber dialyzers of the type used in artificial kidney systems, and to the fiber bundles and dialyzers produced thereby.
Artificial kidney systems include dialyzers or membrane diffusion devices through which blood from a patient flows for treatment. One type of dialyzer is known as a hollow-fiber dialyzer.
A hollow-fiber dialyzer includes an elongated, and generally-cylindrically-shaped casing within which ' many very-fine, hollow and semipermeable fibers are ! positioned and secured adjacent their terminal ends to the casing. Blood from the patient flows through the dialyzer inside the fibers. Dialysis solution flows through the dialyzer and surrounds and-contacts the fibers ~, , so as to receive bodily waste products from the blood and remove them from the dialyzer.
The fibers are made from a long hollow filament of Cellophane* or of a cellulose derivative, such as sold under the trade name Cuprophan*. The filament is continuous ' and is supplied on a spool.
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*denotes trade mark
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In manufacturing the dialyzer it is impractical to individually cut the filament into individual fibers, group or bunch the fibers, and then assemble the dialyzer.
One suggested process for bunching the fibers is to form the filament into a hank or bundle by winding the filament on a wheel, grasping the wound filaments at two points and removing the hand from the wheel. The hank or bundle is then pulled into a cylindrical casing. In this form the filament is still continuous, and after further preparation the looped ends of the hank are cut so as to form the open-ended fibers. As can be appreciated, only one device can be made from each hank.
In other winding systems the filament is wound on a support, which support ultimately becomes a part of the device. Unfortunately, in the dialyzer the support is an inactive element which occupies space and thereby reduces the efficiency of the device.
Hollow fiber dialyzers of other diffusion devices are made from bundles of fibers which are positioned in gen-erally parallel relation to the longitudinal axis of thefiber bundle. The result of this is to create, during use, relatively inhomogeneous flow spaces about the exterior of the fibers, where shunting of the dialysis or other solution passing around the exterior of the fibers takes place, providing uneven and poor dialysis results. Also, stagnant areas are formed in the dialyzer which can enhance blood clotting.
Some commercial hollow fiber dialyzers of the prior art use fibers made from cellulose acetate, which is then regenerated into cellulose. Those fibers, when wet, are very soft and do not provide a good, generally self-supporting, fiber matrix for providing generally homogenous flow channels through the bundle of fibers.
- As a result, the longitudinally arrayed parallel 5 fiber bundles, particularly when made of cellulose regenerated from a cellulose ester, have exhibited dialysis clearance rates and blood clotting characteristics which-are below optimum.
Furthermore, the soft cellulose filaments gen-10 erally are packed together to provide an undesirably low "void fraction" (which is the fraction of the fiber bundle which is not occupied by fibers, and which constitutes in ` a dialyzer the flow path for dialysis fluid). Since the wet, soft filaments are not very self-supporting, if a void 15 fraction of as much as 0.4 is utilized, the tendency of the soft filaments to permit the formation of fluid shunt paths through the space between the filaments becomes very pro-, nounced.
? Stiffer hollow cellulose filaments can be obtained through the cuprammonium-regenerated cellulose process, which is an old and well-known process. Such filaments are commer-cially available, for example, from Enka Glanzstoff A.G. in Wuppertal, West Germany. However, these fibers have been difficult to assemble on a commercial basis into an effective dialyzer.
:
DESCRIPTION OF THE INVENTION
In accordance with the invention there is provided an elongated, coreless bundle of homogeneously distributed hollow, generally longitudinally-directed, semi-permeable filaments, free of direct mechanical attachment to each other, for use as a fluid separation element in a diffusion device. The filaments are positioned in the bundle whereby the majority of the lengthsthereof, and the overall direc-tions thereof, define an angle to the longitudinal axes of said filament bundle. The filaments are positioned in crossing, overlying relation with adjoining filaments, said filaments essentially occupying individual, parallel, flat planes. The filaments define first sets of generally parallel strands defining a first angular relation to said ~- 15 longitudinal axis and second sets of generally parallel strands defining an opposite angular relation to said longitudinal axis, a first filament of a first set being overlaid by a first filament of a second set, which first filament of said second set is, in turn, overlaid by a second filament of said first set, which second filament of said first set is, in turn, overlaid by a second fila-ment of said second set. The said relationship continues throughout the majority of the filaments of the first and second sets to define interleaving relationships, in which the filaments of each set overly the immediately-preceding filaments of the other associated set, and are overlaid by the immediately-following filaments of said other set, the majority of individual filaments thereof ; extending across 15 to 50 percent of the width of said filament bundle.
B
Accordingly, the crossing angular relation of the filaments provides a unique structure, from the viewpoint of longitudinal, unattached filament bundles, providing a substantial improvement in the dialysis solution flow char-,,.~
5 acteristic in the space between the filaments in the bundle.
The filament bundle may be fabricated as described herein and assembled into a dialyzer, or other diffusion de-vice such as an oxygenator, a reverse osmosis device, an ultrafiltrator, or the like. The filament bundle is prefer-10 ably characterized by a void fraction of at least 0.4, and preferably about 0.6 to 0.8, which provides a desirably greater volume for dialysis solution to percolate through ,~ the bundle outside of the filaments, for improved diffusion f characteristics-. Preferably, relatively stiff filaments are 15 used such as cuprammonium-regenerated cellulose filaments, polycarbonate filaments, or other filaments of generally similar stiffness, to provide for a self-supporting characteristic in the filaments of the bundle when wet.
Furthermore, the filamtnt bundles of this invention 20 comprise filaments, the majority of which define an angle (of preferably about one to five degrees) to the longitudinal axis of the bundle, and are in nonwoven crossing relationship with neighbor filaments with the filaments each preferably essen-tially occupying individual, paralle, flat places. The result 25 of this is to create an improved and generally more uniform i. ~
configuration in the flow space exterior of the filaments in the bundle, resulting in a substantial improvement in diffusion and dialysis characteristics.
As a further characteristic of the above structure, 30 the majority and preferably essentially all of the lengths of the filament are disposed at preferably a generally uni-form angle to the longitudinal axis of the bundle, and also .
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at an angle to a plane passing through the longitudinal axis of the bundle, which plane is perpendicular to the planes which contain individual filaments. Preferably, such a _ central plane perpendicular to the planes of the individual filaments will intersect from fifteen to fifty percent of the filaments in the bundle, and generally most preferably from twenty to thirty-five percent, to provide a bundle which exhibits an improved fluid flow path, particularly for dialysis solution, through the bundle outside of the filaments A further characteristic of the preferred fila-ment bundles of this invention is that they have the pro-perty of exhibiting increased resistence to being pulled apart, due to their unique structure, in a direction trans-verse to the longitudinal axis and parallel to the planeswhich contain individual filaments, when compared with the direction transverse the longitudinal axis and perpen-dicular to the planes which contain individual filaments.
Thus, the filament bundles of this invention exhibit an increased independent self-supporting characteristic des-pite the fact that they are nonwoven and free of direct - mechanical attachment to each other. Thus they tend to remain together in a coherent, generally-ordered bundle while it is being assembled into a dialyzer.
Preferably, the void fraction, as defined above, in the bundles of this invention is in excess of 0.4, and . . .
most preferably between about 0.6 and 0.8. As a result of this, there is more room for dialysis solution or other fluid passing through the bundle between the filaments, to provide an improved dialysis solution flow path which, in particular, provides good access of the dialysis solution to the filaments in the central region of the bundle. In the filament bundles of the prior art, the void fraction can be as low as 0.1.
Preferably, the angle of intersection between the filaments and a second plurality of parallel planes which are perpendicular to the plurality of planes which contain individual filaments, is about one to five degrees, and preferably two to three degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of one side of the winding machine used to manufacture the filament bun-! dle of this invention showing the take-up reel, two fila-ment supply spools and the filament guide;
FIGURE 2 is a diagrammatic and perspective view of a drive system for driving-the take-up reel and for moving the filament guide;
FIGURE 3 is a perspective view, partially in section, showing a two-cam system for controlling the :~ movement of the filament guides on each side of the machine;
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FIGURE 3A shows an alternative single cam system for controlling the guides;
FIGURE 4 is an enlarged perspective view showing a filament guide assembly;
FIGURE 5 is a side elevational view showing the take-up reel;
FIGURE 6 is a sectional view taken substantially along line 6-6 of FIGURE 5 and showing a hub-and-locking mechanism for the take-up reel;
FIGURE 7 is a greatly enlarged elevational view showing a portion of the take-up reel;
FIGURE 8 is a view taken substantially along line 8-8 of FIGURE 7 and showing the filament crossover;
FIGURE 9 is a perspective view showing a split sleeve for use in bundling the filament for cutting into the fibers; and FIGURE 10 is an end view of the split sleeve with one side opened;
FIGURE 11 is a schematic view of a filament bundle of this invention showing the typical arrangement of a few of the filaments in the bundle for illustrative purposes;
FIGURE 12 is a sectional view taken along line : 12-12 of FIGURE 11;
FIGURE 13 is a perspective view of a dialyzer utilizing the filament bundle in accordance with this invention.
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DESCRIPTION OF THE PREFERRED EMBODIMENT
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General Referring now to FIGURE 1, winding machine 10 for making the filament bundle of this invention includes a body 12 on each side of which is provided a winding mechanism. The body includes a boxlike main section 14, which is supported by a pair of legs 16 and 18. A control console and supply spool mounting section 20 is supported in a cantilever fashion from the back end of the main body section 14.
Two substantially identical winding mechanisms are provided, one on each side of the body. Thus, two winding operations can be performed simultaneously, if desired.
Each winding mechanism includes upper and lower spool support shafts 22 and 24, which extend laterally from the mounting section 20. Two filament supply spools 26 and 28, each having wound thereon a continuous hollow filament, are mounted on the shafts 22 and 24. The filaments 30 and 32 extend from ~he spools through the filament guide assembly 34 and to the driven take-up reel assembly 36. A protective and transparent case, such as 38, having two access doors 38a and 38_ is carried by the main body section so as to enclose the guide assembly and take-up reel.
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Drive System The rotation of the take-up reel assembly 36 _ and movement of the filament guide assembly 34 are con-trolled by a drive system, which is enclosed with the main body section 14. The system includes an electric motor 40, which drives both the reel assembly and the guide assembly. The motor speed can be caried between 0-2000 rpm.
The Reel Drive. The motor 40 is connected to the take-up reel through a gear and timing belt system as described hereinafter. The motor 40 is connected to a 5:1, worm-gear-type speed reducer 42 having an output gear 44. A geared output drive timing belt 46 is trained ; about the gear 44, as well as the driven gear 48, which is mounted on the cross-shaft 50. A counter, take-off . -- .
gear 52 is mounted on the cross-shaft 50 and is connected to a rpm counter 54 by a counter timing belt 56. The gearing system is arranged such that the counter is synchronized with the take-up reel rpm.
A reel drive gear 58 is also mounted to the shaft 50 and is connected to a reel drive shaft 60 by a gear 62 on the shaft 60 and a timing belt 64. The take-up reel assembly 36 is mounted to an end of the shaft 60. Thus the take-up reel is driven: by the motor 40; through the gear reducer 42; through the gear 44, belt \~ -.
46 and gear 48; through shaft 50; through gear 58, belt 64 and gear 62; and through shaft 60. Through this system the take-up reel can be driven at between 0-400 rpm.
he Guide Drive. The guide assembly 34 is mounted so as to cause the filament to reciprocate or move laterally with respect to the take-up reel assembly 36 at a rate related to the rotation of the take-up reel.
The motor 40 drives the guide assembly. A variable speed control 64 is mounted to the motor 40. The speed control includes a manual spee-' adjuster 65 and an output gear 66.
The speed of the output gear 66 is controllable between 0-400 rpm. A drive timing b~lt 68 is trained about the r ,~ output gear 66 and a smaller drive gear 70. For each revolution of the output gear 66, the driven gear 70 revolves 2.25 times, so as to provide a 2.25:1 gear ratio.
The driven gear 70 is secured to one end of a shaft 72, which enters a gear box 74. A second aligned shaft 76 ;- exits the gear box and a gear 78 is secured to the outer end of the shaft 76~ A rotatable cam drive shaft 80 extends upwardly from the gear box and is driven by the shaft 72. A bevel gear arrangement (not shown) is pro-vided within the gear box for driving the shafts 76 and 80.
Another timing belt 82 is trained about the gear , 78 and a gear 84 for driving a second rotatable cam drive ' ~ 25 shaft 86 and a counter 88, through a gear box arrangement t .
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89, which is similar to that previously described in connection with the gear box 74. The counter 88 is syn-chronized with the rotation of the shafts 80 and 86, which in turn, is related to the rate of reciprocation of the guide arm, so that the counter indicates the rate of guide arm reciprocation or oscillation.
Referring now to FIGURE 3, each of the shafts 80 and 86 carry at their upper end a cam, such as 90 and 92, which controls the reciprocation of the guide assem-bly 34 and the filaments. A reciprocating control rod 94 extends from within the body 14 through a sidewall 14a and connects at its outer end to the guide assembly 34.
At the inner end, the rod 94 includes a cam follower 96, which is biased against the cam 90 by a coiled compression 15 spring 98 that bears against a bearing plate 100 and the cam follower 96. Rotation of the cam 90 causes the rod 94 to reciprocate. It will be appreciated that the guide arm on the other side of the machine (not shown) is controlled in a similar manner.
With this arrangement the rate of reciprocation of the guide arm can be controlled between 0-900 oscilla-ions per minute.
In the alternative cam construction shown in FIGURE 3_, there is a single grooved cam 102. Here there is only one drive shaft 80a which drives the single cam, ' which, in turn, controls the two control rods 93a and 94a.
It will be appreciated that the speed of the cam drive shaft 80 relative to the take-up reel drive shaft 60 can be controlled and adjusted with the speed control adjuster 65. If no adjustment is made, the ratio of guide arm reciprocation to take-up reel rotation remains constant regardless of the speed of the take-up reel. However, use of the adjuster 65 permits adjustment and control of the ratio of guide arm reciprocation to take-up reel rotation.
Guide Arm Assembly The guide arm assembly 34 is mounted to the outside of sidewall 14a by a vertically adjustable mounting plate 101, a pivotally adjustable side plate 102 and a forwardly and rearwardly adjustable lateral support plate 104. An upper filament sensing switch 106 is mounted to the top side of the plate 104 and a lower filament sensing switch 108 is supported by and is positioned below the plate 104. Each switch includes leaf-life member, such as 110, which is biased toward the filament and which engages and senses the presence of the filament, such as 30. In the event the filament breaks during wlnding, the member 110 moves upwardly and actuates means (not shown) for disabling the drive system and for applying a controlled braking action to the supply spool shafts and the take-up reel to minimize breakage of filaments on other reels.
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An elongated and swingable guide arm 112 is pivotally mounted at its back end to the support plate 104, forwardly of the switch 106, by a pin 114. The con-trol rod 94 is connected to the arm at a point intermediate the ends of the arm by a universal-type joint 116. The head 112a at the forward end of the guide arm carries upper and lower spring-like filament guides such as 118, which cooperates with the spring-like filament guides, such - as 119, associated with the switches. As the control rod reciprocates, the head 112a swings back and forth in a manner controlled by the cam 90.
The Take-Up Reel Assembly ' The take-up reel assembly 36, as shown in FIGURES
5 and 6, includes a filament winding plate 120 and a hub-and-locking system 122 for removably securing the plate to the machine.
` The Winding Plate. The plate 120 has a large, .. j.
circular and centrally positioned opening which defines the inner edge 124, and has six support edge carrying sections 126, 128, 130, 132, 134 and 135. Each of the - sections are positioned radially outwardly from the center of the plate and equally about the periphery.
A V-shaped filament support assembly, such as 136, is mounted on the plate at each of the support sec-tions, such as 126. Each of the support assemblies, such ,, ~ , .
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as 136, includes a pair of outwardly extending U-shaped filament supports 138 and 140, each of which terminates in a lower beveled edge, such as 138a and 140a. Each of the supports, such as 138 and 140, is bolted to the plate through bolt-receiving apertures in the plate 120. As can be seen in FIGURE 5, the filament support assemblies can be movably positioned in one of three different radial ; positions. Thus the supports 138 and 140 can be moved from the inner position as shown to an intermediate position at 142 and 144, or to an outer position at 146 and 148.
It will be appreciated that such changes in position can increase or decrease the length of the fila-.:
ments bundles between the sets of supports. For example,by moving the supports radially outwardly, the length of the bundles between the adjacent supports is lengthened.
This permits the manufacture of hollow fiber dialyzers of different lengths.
The Hub-and-Locking System. The system 122 for securing the plate 120 to the machine is shown in both FIGURES 5 and 6. That system includes a hub as-sembly 150, which is secured to an end of the winding shaft 60 by a set screw 151. The hub assembly includes a flanged, boss-like member 152 to which~a wheel-like support plate 154 is secured. The support plate includes ~-~ 25 three radial spokes 156, 158 and 160, each of which has ; j -16-,',~.
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an elongated guide slot, such as 162. The outer periphery of the plate is L-shaped in section and defines an axial or laterally-extending shoulder 164 and a circumferential - shoulder 166.
The take-up reel winding plate 120 is constructed such that the inner edge 124 can be fitted onto the shoulder 164 with the plate against the circumferential shoulder 166. This fit prevents radial movement of the reel plate 120 relative to the hub 150. The plate 120 is removably secured in driving relation to the hub assembly by six studs, such as 167a, which extend outwardly from the shoulder 166 and which engage six stud-receiving apertures, such as 167_, in the winding plate.
- Three generally radially-extending locking arms 168, 170 and 172 are provided to secure the winding plate ,~,, 120 to the support plate 154 by preventing axial movement of the winding plate with respect to the support plate ' shoulder 166. The arms are secured at their inner ends to the hub 150 by a pin, such as 174, and a pivotable collar-like member 176. Each arm carries a guide block, ~- such as 178, which moves radially within the slot 162 in the arm. The guide block 178 is secured to the arm and in the slot by a pin 180. Each of the locking arms is of a length such that when the arms are in the extended, radial and locking position, the outer end of the arm is positioned radially outwardly over the shoulder 164 and in overlying ~ .
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relationship to the plate 120 With this construction the arm can lock and hold the take-up plate on the winding machine in fixed relation to the shaft 60.
The collar 176 is pivotable with respect to the shaft 60 and to the support arms, such as 160. As can be seen in FIGURE 5, a stop pin 182 defines the limits of movement for the collar 176~ The collar is held in the `~ locked position by a spring-loaded detent assembly (not shown). In the position shown in FIGURE 5, in full line, the arms are positioned to lock the plate in position, Pivoting of the collar 176 causes the arms to retract and the guide members, such as 178, slide within the slots 162, until the outer ends of the arms move within the inner edge of the shoulder 164. With the locking arms retracted, the take-up plate 120 can be removed from the : machine by pulling it axially outwardly.
Operation of the Winding Machine As can be seen from the drawings, the two -~ spools of hollow-fiber filaments are mounted on the shafts 22 and 24 and each filament is guided through the guide assembly 34 and started on the take-up reel 36. The machine is actuated so that the motor rotates the take-up reel assembly 36. As this occurs, the take-up reel draws filament from the supply reel through the guide assembly. The action of the cams, such as 90, causes the guide arm 112 to oscillate or move laterally, ~ 7 inwardly and outwardly as the take-up reel rotates. The cam is designed in a manner such as to provide an even distribution of the filament on the guides. The shape of the cam cooperates in preventing build-up of filament at the edges of the guide by increasing the arm speed at.
each end of the oscillation. Also, the cam can be shaped to lay down a filament which exhibits a generally constant ': angle to the axis of the bundle. Furthermore, the cam pre-vents close-packing of the filament windings and causes the filament which is being wound to crossover the pre-vious winding of the filament. This crossover is dia-grammatically shown in FIGURE 8 where it can be seen that an upper filament winding 190 crosses over a lower fila-ment winding 192.
15It has also been found that the use of the two reels is beneficial from the point of view that a suf-: ficient quantity of filament is supplied so as to contin-- uously feed the take-up reel and thereby avoid the need to stop the winding operation and start a second spool.
. 20 This stopping has been found to be detrimental to the ef-ficiency of the dialyzer since undesirably large flow channels may be formed where one spool ended and the other began. It is believed that the channel may be formed as a . result of differences in filament tension at the end of the . 25 first spool and at the beginning of the second spool.
During winding it has been found to be often .~;
desirable to rotate the take-up reel at a speed greater than the speed at which the guide arm oscillates. This, at the maximum,can provide, after cutting of ten percent of the length of the bundle during removal from the reel, individual filaments which occupy about thirty percent of the width of the bundle. In one particular operation the take-up reel is driven at 200 rpm and the guide arm is oscillated at 160 or 180 oscillations per minute. Overall, it is generally preferred for there to be from about 0.45 to 1.7 back and forth oscillations per rotation of the take-up reel, especially in a reel of the design shown where six bundles are simultaneously manufactured. The above ratio may correspondingly vary for take-up reels which ~, make different numbers of lengths of filament bundles.
Thus it will be appreciated that as the geo-metry of the take-up reel, for example the size and dia-meter of the take-up reel, changes, the oscillations of the guide arm must also change in order to effectuate ~ .
; proper crossover.
Once the filaments are wound on the take-up reel and the bundles are of a sufficient size for use in hollow fiber dialyzers, the winding operation is stopped.
Preparation of Fiber Bundles An elongated split case 200 as shown in FIGURE
7 25 9 is used in forming the fiber bundles from the filaments ~ and for removing the bundles from the take-up reel. The ,, .
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split case includes an upper semi-cylindrical member 202 and a lower semi-cylindrical member 204, which are joined by a pair of flexible hinges 206 and 208. As can be seen in FIGURE 10, the sections can be opened and positioned and clamped about the wound bundles of the filament.
Referring now to FIGURE 7, once the members are in position, they tightly grasp the bundles of fila-ment therebetween and the filament may then be cut at either end of the case so as to form open-ended fibers and permit removal of the bundles from the reel. The cutting converts the continuous filament to the individual hollow fibers used in the dialyzer. After cutting and removal, the individual -~ bundles are then treated and formed into the hollow fiber dialyzers.
Referring to Figure 11, a schematic view of a filament bundle 210 made in accordance with this invention is shown, with the great majority of the filaments being omitted for a clearer disclosure of the filament relation-ships. Basically, most of the filaments shown in the bundle 210 fit the overall relationships of the filaments in the bundle as schematically illustrated in Figure 8, resulting from the winding techni~ue utilized as described in this invention. The winding tension is preferably from about 0.5 to 5 gm. per filament being wound, preferably less than one gram per filament.
It should also be added that when two or more fila-ments are wound onto the reel at once, as specifically disclosed herein, the pair of filaments lie side by side in a relationship ~, ' ,~ i r r~
in which each filament as shown in Figures 8 and 11 can represent separate multiple, parallel filament members, located adjacent to one another in the filament bundle. The term "filament" as utilized herein is intended to include this plural structure.
Filament bundle 210 may, in one embodiment, be at least five thousand generally longitudinally directed, semi-permeable individual filaments, free of mechanical attach-; ment to each other, made of cellulose for dialysis, or any other appropriate material for other diffusion functions. Preferably,the dialysis filaments are made of cuprammonium regenerated cellulose, the individual filaments having a sufficient wet tensile strength (e.g. at least about 100 grams) and are still enough to retain, in the main, the crossing overlying structure into which they are formed, as illustrated in Figures 8 and 11.
"Softer" fibers, such as cellulose acetate derived filaments, when wet, may sag at random throughout the bundle, to form uneven flow paths outside of the filaments.
Preferably, the individual cellulose filaments used herein define an outer diameter of 100 to 400 microns, there being preferably at least about nine thousand separate filaments which exhibit an aggregate surface area of at least 0 5 square meter and preferably one to two square meters. The wall thick-ness of the individual filaments is preferably from 10 to 30 - 25 microns fon example, 16 microns.
As shown in Figure 8, the array of filaments 190, 192 are in angular relation to each other and to longitudinal axis 212 of the filament bundle (Figure 11). In the manufacture of the filament bundle of this invention, filaments 190 are laid down as guide arm 112 is swinging transversely of the longitudinal axis 212 in one direction. Filaments 192 are laid down while ;~ ' ~'~ .
the guide arm 112 is swinging in the opposite transverse direction.
As shown in the detail of FIGURE 8, filament l90a is laid down by a first swing of the guide arm 112 in a first transverse direction as the reel assembly 36 rotates.
- Filament 192_ is then laid down on top of filament 190_ by the further rotation of reel assembly 36, as arm 112 swings back in the opposite transverse direction, so that filament 192a overlies filament l90a. Then, on the next rotation of reel 36 as guide arm 112 swings back in the first transverse direction again, filament 190_ is laid down, over-lying filament 192a. Thereafter, as guide arm 112 is swung back again in the opposite transverse direction, and reel 36 rotates, filament 192_ is laid down, to overlie filament l90b, and so on through the entire assembly operation, to form the resulting filament-bundled loop, which is cut into six filament bundles 210 in the specific embodiment shown.
Filament bundle 210, in its completed form, may be about 15 to 25 cm., specifically, 20.5 cm., in length prior to assembly into a dialyzer housing, and may comprise about 11,500 individual filaments having an outer diameter of 247 microns and an inner diameter of 215 microns, to provide a dialyzer unit having the useful surface area of about 1.5 s~uare meters. Each filament may traverse about 27 percent of the width of the bundle, except for angled filaments 216.
It should be noted that the crossing points 214 of the respective filaments as shown in Figure 8 are in ~r~h~ ~
roughly linear arrangement with each other. This does not necessarily have to be the case. The arrangement of the various crossing points is dependent upon the revolutions per minute of the reel, compared with the number of oscillations per minute of arm 112. It is, in fact, generally preferable for the crossing points to lie in different positions with each rotation of the reel member, to avoid uneven Fiber buildup or "resonance".
Filaments 216 should also be noted (Figure 11) as a category of filament which is likely to be found in most filament bundles 210. As can be seen, these filaments are laid down on the reel during the time that guide arm 112 reaches a lateral limit of its swing, and begins to swing back again in the opposite direction, causing the resulting filament to first travel in one angular direction with respect to axis 212, and then to turn and be oriented in the opposite, similar angular direction to axis 212, defining a lateral apex 218 at the edge of the bundle. In fact, in the actual bundles of this invention, it is noted that some of these and other fibers can straighten out and form other wavy bends to some degree, and thus do not assume the ideal configuration which is as shown in Figure 11. Nevertheless, the bundle as a whole exhibits the essential structure, characteristics, and advan-tages described herein.
Most preferably, the ideal angles of filaments 190, 192 and 216 to axis 212 are constant, at preferably 2 to 3 for example, 2.15 or 2.59.
- -In the particular filament bundle which is specifically described herein, the void fraction may be about 0.64, resulting in a very substantial increase in dialysis clearance when placed in a dialyzer housing. Also, the dialyzer using the bundle structure of this invention, made of cuprammonium regenerated cellulose filaments can exhibit low blood clotting.
The filament bundle of this invention exhibits the remarkable characteristic in that it resists being laterally pulled apart in direction 218 (Figure 12) to a degree which is perceptibly and significantly greater than its resistance to being laterally pulled apart ln direction 220. The resistance of being pulled apart at direction 220 is essentially equal to the similar resistance of conventional filament bundles, which is indeed very low. Accordingly, while the filament bundle of this invention requires some outside retention to hold together, it exhibits a better tendency to retain its structure while being assembled into a dialyzer than the conventional filament bundles.
Referring to FIGURE 13, a dialyzer for blood lS
shown incorporating filament bundle 210 of this invention.
; Basically, the dialyzer may, if desired, be of conventional structure as currently used with filament bundles.
Bundle 210 is encased in a tubular housing 222, .
~- 25 which encloses the squarish bundle 210 as wound (as in Figure 12), and holds it in a cylindrical configuration for optimum flow characteristics.~ The filament ends of bundle 210 pass through .
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cured potting compound members 224, which are specifically each in the shape of a disc, and sealingly positioned inside enlarged chamber ends 226 of housing 222, so that the filaments of bundle 210 pass through the disc-shaped structures 224 to permit flow through the Eilaments.
Caps 228 are placed on the ends of tubular housing 222 in sealing manner, and each carry a port 230.
Potted discs 224 are slightly spaced from the inner ends of caps 228, to provide a manifold chamber, for providing a fluid flow path between the ports 230 through the hollow filaments of bundle 210 in a sealed flow path.
A second flow path is provided to the dialyzer by means of second ports 232, which may be laterally posi-tioned adjacent the ends of housing 222 on opposite sides thereof as shown. Enlarged portions 226 of the housing serve as a second manifold means to uniformly distribute fluid around the exterior of bundle 210 in the annular chamber defined between the bundle and the inner wall of the housing in that area. In the central, constricted portion of housing 222, bundle 210 fits snugly within the housing wall, without any outside space as there is in enlarged chamber portions 226.
Accordingly, a second fluid flow path passes from one port 232, about an enlarged chamber 226, and then in a ` 25 percolating flow path through the crossing filament of -' .
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bundle 210 to the opposite enlarged chamber 226, and the other port 232.
_ The flow path between ports 230 is typically used for blood, while the flow path between ports 232 is for dialysis solution.
The two flow paths are sealed from each other so that there is no mixing of the fluids passing through them, except by means of diffusion through the walls of the filaments of bundle 210.
Preferably, a countercurrent flow pattern is utilized, in which blood flows in one direction through the dialyzer, and dialysis solution flows in the opposite direction.
Dialyzers made as specifically described herein, ~; 15 having about 11,500 thin-walled capillaries of about 16 microns thickness, and defining an active surface area of about 1.5 square meters, have been shown to provide supe-rior clearance characteristics in the small and middle molecule ranges, coupled with wide range, managable ultra-filtration capabilites. The priming volume of such a dialyser, made in accordance with this invention, may be 125 ml. in the blood compartment, with a volume change which is relatively insensitive to pressure variations.
The dialyzer of this invention, utilizinq , ; 25 Cupraammonium derived cellulose fibers, may be packed dry, '.
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climinating the formaldahyde flushing procedure used insome prior art dialyzers.
It will be appreciated that numerous changes and modifications can be made in the embodiments disclosed herein without departing from the spirit and scope of this invention.
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In manufacturing the dialyzer it is impractical to individually cut the filament into individual fibers, group or bunch the fibers, and then assemble the dialyzer.
One suggested process for bunching the fibers is to form the filament into a hank or bundle by winding the filament on a wheel, grasping the wound filaments at two points and removing the hand from the wheel. The hank or bundle is then pulled into a cylindrical casing. In this form the filament is still continuous, and after further preparation the looped ends of the hank are cut so as to form the open-ended fibers. As can be appreciated, only one device can be made from each hank.
In other winding systems the filament is wound on a support, which support ultimately becomes a part of the device. Unfortunately, in the dialyzer the support is an inactive element which occupies space and thereby reduces the efficiency of the device.
Hollow fiber dialyzers of other diffusion devices are made from bundles of fibers which are positioned in gen-erally parallel relation to the longitudinal axis of thefiber bundle. The result of this is to create, during use, relatively inhomogeneous flow spaces about the exterior of the fibers, where shunting of the dialysis or other solution passing around the exterior of the fibers takes place, providing uneven and poor dialysis results. Also, stagnant areas are formed in the dialyzer which can enhance blood clotting.
Some commercial hollow fiber dialyzers of the prior art use fibers made from cellulose acetate, which is then regenerated into cellulose. Those fibers, when wet, are very soft and do not provide a good, generally self-supporting, fiber matrix for providing generally homogenous flow channels through the bundle of fibers.
- As a result, the longitudinally arrayed parallel 5 fiber bundles, particularly when made of cellulose regenerated from a cellulose ester, have exhibited dialysis clearance rates and blood clotting characteristics which-are below optimum.
Furthermore, the soft cellulose filaments gen-10 erally are packed together to provide an undesirably low "void fraction" (which is the fraction of the fiber bundle which is not occupied by fibers, and which constitutes in ` a dialyzer the flow path for dialysis fluid). Since the wet, soft filaments are not very self-supporting, if a void 15 fraction of as much as 0.4 is utilized, the tendency of the soft filaments to permit the formation of fluid shunt paths through the space between the filaments becomes very pro-, nounced.
? Stiffer hollow cellulose filaments can be obtained through the cuprammonium-regenerated cellulose process, which is an old and well-known process. Such filaments are commer-cially available, for example, from Enka Glanzstoff A.G. in Wuppertal, West Germany. However, these fibers have been difficult to assemble on a commercial basis into an effective dialyzer.
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DESCRIPTION OF THE INVENTION
In accordance with the invention there is provided an elongated, coreless bundle of homogeneously distributed hollow, generally longitudinally-directed, semi-permeable filaments, free of direct mechanical attachment to each other, for use as a fluid separation element in a diffusion device. The filaments are positioned in the bundle whereby the majority of the lengthsthereof, and the overall direc-tions thereof, define an angle to the longitudinal axes of said filament bundle. The filaments are positioned in crossing, overlying relation with adjoining filaments, said filaments essentially occupying individual, parallel, flat planes. The filaments define first sets of generally parallel strands defining a first angular relation to said ~- 15 longitudinal axis and second sets of generally parallel strands defining an opposite angular relation to said longitudinal axis, a first filament of a first set being overlaid by a first filament of a second set, which first filament of said second set is, in turn, overlaid by a second filament of said first set, which second filament of said first set is, in turn, overlaid by a second fila-ment of said second set. The said relationship continues throughout the majority of the filaments of the first and second sets to define interleaving relationships, in which the filaments of each set overly the immediately-preceding filaments of the other associated set, and are overlaid by the immediately-following filaments of said other set, the majority of individual filaments thereof ; extending across 15 to 50 percent of the width of said filament bundle.
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Accordingly, the crossing angular relation of the filaments provides a unique structure, from the viewpoint of longitudinal, unattached filament bundles, providing a substantial improvement in the dialysis solution flow char-,,.~
5 acteristic in the space between the filaments in the bundle.
The filament bundle may be fabricated as described herein and assembled into a dialyzer, or other diffusion de-vice such as an oxygenator, a reverse osmosis device, an ultrafiltrator, or the like. The filament bundle is prefer-10 ably characterized by a void fraction of at least 0.4, and preferably about 0.6 to 0.8, which provides a desirably greater volume for dialysis solution to percolate through ,~ the bundle outside of the filaments, for improved diffusion f characteristics-. Preferably, relatively stiff filaments are 15 used such as cuprammonium-regenerated cellulose filaments, polycarbonate filaments, or other filaments of generally similar stiffness, to provide for a self-supporting characteristic in the filaments of the bundle when wet.
Furthermore, the filamtnt bundles of this invention 20 comprise filaments, the majority of which define an angle (of preferably about one to five degrees) to the longitudinal axis of the bundle, and are in nonwoven crossing relationship with neighbor filaments with the filaments each preferably essen-tially occupying individual, paralle, flat places. The result 25 of this is to create an improved and generally more uniform i. ~
configuration in the flow space exterior of the filaments in the bundle, resulting in a substantial improvement in diffusion and dialysis characteristics.
As a further characteristic of the above structure, 30 the majority and preferably essentially all of the lengths of the filament are disposed at preferably a generally uni-form angle to the longitudinal axis of the bundle, and also .
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at an angle to a plane passing through the longitudinal axis of the bundle, which plane is perpendicular to the planes which contain individual filaments. Preferably, such a _ central plane perpendicular to the planes of the individual filaments will intersect from fifteen to fifty percent of the filaments in the bundle, and generally most preferably from twenty to thirty-five percent, to provide a bundle which exhibits an improved fluid flow path, particularly for dialysis solution, through the bundle outside of the filaments A further characteristic of the preferred fila-ment bundles of this invention is that they have the pro-perty of exhibiting increased resistence to being pulled apart, due to their unique structure, in a direction trans-verse to the longitudinal axis and parallel to the planeswhich contain individual filaments, when compared with the direction transverse the longitudinal axis and perpen-dicular to the planes which contain individual filaments.
Thus, the filament bundles of this invention exhibit an increased independent self-supporting characteristic des-pite the fact that they are nonwoven and free of direct - mechanical attachment to each other. Thus they tend to remain together in a coherent, generally-ordered bundle while it is being assembled into a dialyzer.
Preferably, the void fraction, as defined above, in the bundles of this invention is in excess of 0.4, and . . .
most preferably between about 0.6 and 0.8. As a result of this, there is more room for dialysis solution or other fluid passing through the bundle between the filaments, to provide an improved dialysis solution flow path which, in particular, provides good access of the dialysis solution to the filaments in the central region of the bundle. In the filament bundles of the prior art, the void fraction can be as low as 0.1.
Preferably, the angle of intersection between the filaments and a second plurality of parallel planes which are perpendicular to the plurality of planes which contain individual filaments, is about one to five degrees, and preferably two to three degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of one side of the winding machine used to manufacture the filament bun-! dle of this invention showing the take-up reel, two fila-ment supply spools and the filament guide;
FIGURE 2 is a diagrammatic and perspective view of a drive system for driving-the take-up reel and for moving the filament guide;
FIGURE 3 is a perspective view, partially in section, showing a two-cam system for controlling the :~ movement of the filament guides on each side of the machine;
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FIGURE 3A shows an alternative single cam system for controlling the guides;
FIGURE 4 is an enlarged perspective view showing a filament guide assembly;
FIGURE 5 is a side elevational view showing the take-up reel;
FIGURE 6 is a sectional view taken substantially along line 6-6 of FIGURE 5 and showing a hub-and-locking mechanism for the take-up reel;
FIGURE 7 is a greatly enlarged elevational view showing a portion of the take-up reel;
FIGURE 8 is a view taken substantially along line 8-8 of FIGURE 7 and showing the filament crossover;
FIGURE 9 is a perspective view showing a split sleeve for use in bundling the filament for cutting into the fibers; and FIGURE 10 is an end view of the split sleeve with one side opened;
FIGURE 11 is a schematic view of a filament bundle of this invention showing the typical arrangement of a few of the filaments in the bundle for illustrative purposes;
FIGURE 12 is a sectional view taken along line : 12-12 of FIGURE 11;
FIGURE 13 is a perspective view of a dialyzer utilizing the filament bundle in accordance with this invention.
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DESCRIPTION OF THE PREFERRED EMBODIMENT
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General Referring now to FIGURE 1, winding machine 10 for making the filament bundle of this invention includes a body 12 on each side of which is provided a winding mechanism. The body includes a boxlike main section 14, which is supported by a pair of legs 16 and 18. A control console and supply spool mounting section 20 is supported in a cantilever fashion from the back end of the main body section 14.
Two substantially identical winding mechanisms are provided, one on each side of the body. Thus, two winding operations can be performed simultaneously, if desired.
Each winding mechanism includes upper and lower spool support shafts 22 and 24, which extend laterally from the mounting section 20. Two filament supply spools 26 and 28, each having wound thereon a continuous hollow filament, are mounted on the shafts 22 and 24. The filaments 30 and 32 extend from ~he spools through the filament guide assembly 34 and to the driven take-up reel assembly 36. A protective and transparent case, such as 38, having two access doors 38a and 38_ is carried by the main body section so as to enclose the guide assembly and take-up reel.
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Drive System The rotation of the take-up reel assembly 36 _ and movement of the filament guide assembly 34 are con-trolled by a drive system, which is enclosed with the main body section 14. The system includes an electric motor 40, which drives both the reel assembly and the guide assembly. The motor speed can be caried between 0-2000 rpm.
The Reel Drive. The motor 40 is connected to the take-up reel through a gear and timing belt system as described hereinafter. The motor 40 is connected to a 5:1, worm-gear-type speed reducer 42 having an output gear 44. A geared output drive timing belt 46 is trained ; about the gear 44, as well as the driven gear 48, which is mounted on the cross-shaft 50. A counter, take-off . -- .
gear 52 is mounted on the cross-shaft 50 and is connected to a rpm counter 54 by a counter timing belt 56. The gearing system is arranged such that the counter is synchronized with the take-up reel rpm.
A reel drive gear 58 is also mounted to the shaft 50 and is connected to a reel drive shaft 60 by a gear 62 on the shaft 60 and a timing belt 64. The take-up reel assembly 36 is mounted to an end of the shaft 60. Thus the take-up reel is driven: by the motor 40; through the gear reducer 42; through the gear 44, belt \~ -.
46 and gear 48; through shaft 50; through gear 58, belt 64 and gear 62; and through shaft 60. Through this system the take-up reel can be driven at between 0-400 rpm.
he Guide Drive. The guide assembly 34 is mounted so as to cause the filament to reciprocate or move laterally with respect to the take-up reel assembly 36 at a rate related to the rotation of the take-up reel.
The motor 40 drives the guide assembly. A variable speed control 64 is mounted to the motor 40. The speed control includes a manual spee-' adjuster 65 and an output gear 66.
The speed of the output gear 66 is controllable between 0-400 rpm. A drive timing b~lt 68 is trained about the r ,~ output gear 66 and a smaller drive gear 70. For each revolution of the output gear 66, the driven gear 70 revolves 2.25 times, so as to provide a 2.25:1 gear ratio.
The driven gear 70 is secured to one end of a shaft 72, which enters a gear box 74. A second aligned shaft 76 ;- exits the gear box and a gear 78 is secured to the outer end of the shaft 76~ A rotatable cam drive shaft 80 extends upwardly from the gear box and is driven by the shaft 72. A bevel gear arrangement (not shown) is pro-vided within the gear box for driving the shafts 76 and 80.
Another timing belt 82 is trained about the gear , 78 and a gear 84 for driving a second rotatable cam drive ' ~ 25 shaft 86 and a counter 88, through a gear box arrangement t .
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89, which is similar to that previously described in connection with the gear box 74. The counter 88 is syn-chronized with the rotation of the shafts 80 and 86, which in turn, is related to the rate of reciprocation of the guide arm, so that the counter indicates the rate of guide arm reciprocation or oscillation.
Referring now to FIGURE 3, each of the shafts 80 and 86 carry at their upper end a cam, such as 90 and 92, which controls the reciprocation of the guide assem-bly 34 and the filaments. A reciprocating control rod 94 extends from within the body 14 through a sidewall 14a and connects at its outer end to the guide assembly 34.
At the inner end, the rod 94 includes a cam follower 96, which is biased against the cam 90 by a coiled compression 15 spring 98 that bears against a bearing plate 100 and the cam follower 96. Rotation of the cam 90 causes the rod 94 to reciprocate. It will be appreciated that the guide arm on the other side of the machine (not shown) is controlled in a similar manner.
With this arrangement the rate of reciprocation of the guide arm can be controlled between 0-900 oscilla-ions per minute.
In the alternative cam construction shown in FIGURE 3_, there is a single grooved cam 102. Here there is only one drive shaft 80a which drives the single cam, ' which, in turn, controls the two control rods 93a and 94a.
It will be appreciated that the speed of the cam drive shaft 80 relative to the take-up reel drive shaft 60 can be controlled and adjusted with the speed control adjuster 65. If no adjustment is made, the ratio of guide arm reciprocation to take-up reel rotation remains constant regardless of the speed of the take-up reel. However, use of the adjuster 65 permits adjustment and control of the ratio of guide arm reciprocation to take-up reel rotation.
Guide Arm Assembly The guide arm assembly 34 is mounted to the outside of sidewall 14a by a vertically adjustable mounting plate 101, a pivotally adjustable side plate 102 and a forwardly and rearwardly adjustable lateral support plate 104. An upper filament sensing switch 106 is mounted to the top side of the plate 104 and a lower filament sensing switch 108 is supported by and is positioned below the plate 104. Each switch includes leaf-life member, such as 110, which is biased toward the filament and which engages and senses the presence of the filament, such as 30. In the event the filament breaks during wlnding, the member 110 moves upwardly and actuates means (not shown) for disabling the drive system and for applying a controlled braking action to the supply spool shafts and the take-up reel to minimize breakage of filaments on other reels.
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An elongated and swingable guide arm 112 is pivotally mounted at its back end to the support plate 104, forwardly of the switch 106, by a pin 114. The con-trol rod 94 is connected to the arm at a point intermediate the ends of the arm by a universal-type joint 116. The head 112a at the forward end of the guide arm carries upper and lower spring-like filament guides such as 118, which cooperates with the spring-like filament guides, such - as 119, associated with the switches. As the control rod reciprocates, the head 112a swings back and forth in a manner controlled by the cam 90.
The Take-Up Reel Assembly ' The take-up reel assembly 36, as shown in FIGURES
5 and 6, includes a filament winding plate 120 and a hub-and-locking system 122 for removably securing the plate to the machine.
` The Winding Plate. The plate 120 has a large, .. j.
circular and centrally positioned opening which defines the inner edge 124, and has six support edge carrying sections 126, 128, 130, 132, 134 and 135. Each of the - sections are positioned radially outwardly from the center of the plate and equally about the periphery.
A V-shaped filament support assembly, such as 136, is mounted on the plate at each of the support sec-tions, such as 126. Each of the support assemblies, such ,, ~ , .
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as 136, includes a pair of outwardly extending U-shaped filament supports 138 and 140, each of which terminates in a lower beveled edge, such as 138a and 140a. Each of the supports, such as 138 and 140, is bolted to the plate through bolt-receiving apertures in the plate 120. As can be seen in FIGURE 5, the filament support assemblies can be movably positioned in one of three different radial ; positions. Thus the supports 138 and 140 can be moved from the inner position as shown to an intermediate position at 142 and 144, or to an outer position at 146 and 148.
It will be appreciated that such changes in position can increase or decrease the length of the fila-.:
ments bundles between the sets of supports. For example,by moving the supports radially outwardly, the length of the bundles between the adjacent supports is lengthened.
This permits the manufacture of hollow fiber dialyzers of different lengths.
The Hub-and-Locking System. The system 122 for securing the plate 120 to the machine is shown in both FIGURES 5 and 6. That system includes a hub as-sembly 150, which is secured to an end of the winding shaft 60 by a set screw 151. The hub assembly includes a flanged, boss-like member 152 to which~a wheel-like support plate 154 is secured. The support plate includes ~-~ 25 three radial spokes 156, 158 and 160, each of which has ; j -16-,',~.
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an elongated guide slot, such as 162. The outer periphery of the plate is L-shaped in section and defines an axial or laterally-extending shoulder 164 and a circumferential - shoulder 166.
The take-up reel winding plate 120 is constructed such that the inner edge 124 can be fitted onto the shoulder 164 with the plate against the circumferential shoulder 166. This fit prevents radial movement of the reel plate 120 relative to the hub 150. The plate 120 is removably secured in driving relation to the hub assembly by six studs, such as 167a, which extend outwardly from the shoulder 166 and which engage six stud-receiving apertures, such as 167_, in the winding plate.
- Three generally radially-extending locking arms 168, 170 and 172 are provided to secure the winding plate ,~,, 120 to the support plate 154 by preventing axial movement of the winding plate with respect to the support plate ' shoulder 166. The arms are secured at their inner ends to the hub 150 by a pin, such as 174, and a pivotable collar-like member 176. Each arm carries a guide block, ~- such as 178, which moves radially within the slot 162 in the arm. The guide block 178 is secured to the arm and in the slot by a pin 180. Each of the locking arms is of a length such that when the arms are in the extended, radial and locking position, the outer end of the arm is positioned radially outwardly over the shoulder 164 and in overlying ~ .
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relationship to the plate 120 With this construction the arm can lock and hold the take-up plate on the winding machine in fixed relation to the shaft 60.
The collar 176 is pivotable with respect to the shaft 60 and to the support arms, such as 160. As can be seen in FIGURE 5, a stop pin 182 defines the limits of movement for the collar 176~ The collar is held in the `~ locked position by a spring-loaded detent assembly (not shown). In the position shown in FIGURE 5, in full line, the arms are positioned to lock the plate in position, Pivoting of the collar 176 causes the arms to retract and the guide members, such as 178, slide within the slots 162, until the outer ends of the arms move within the inner edge of the shoulder 164. With the locking arms retracted, the take-up plate 120 can be removed from the : machine by pulling it axially outwardly.
Operation of the Winding Machine As can be seen from the drawings, the two -~ spools of hollow-fiber filaments are mounted on the shafts 22 and 24 and each filament is guided through the guide assembly 34 and started on the take-up reel 36. The machine is actuated so that the motor rotates the take-up reel assembly 36. As this occurs, the take-up reel draws filament from the supply reel through the guide assembly. The action of the cams, such as 90, causes the guide arm 112 to oscillate or move laterally, ~ 7 inwardly and outwardly as the take-up reel rotates. The cam is designed in a manner such as to provide an even distribution of the filament on the guides. The shape of the cam cooperates in preventing build-up of filament at the edges of the guide by increasing the arm speed at.
each end of the oscillation. Also, the cam can be shaped to lay down a filament which exhibits a generally constant ': angle to the axis of the bundle. Furthermore, the cam pre-vents close-packing of the filament windings and causes the filament which is being wound to crossover the pre-vious winding of the filament. This crossover is dia-grammatically shown in FIGURE 8 where it can be seen that an upper filament winding 190 crosses over a lower fila-ment winding 192.
15It has also been found that the use of the two reels is beneficial from the point of view that a suf-: ficient quantity of filament is supplied so as to contin-- uously feed the take-up reel and thereby avoid the need to stop the winding operation and start a second spool.
. 20 This stopping has been found to be detrimental to the ef-ficiency of the dialyzer since undesirably large flow channels may be formed where one spool ended and the other began. It is believed that the channel may be formed as a . result of differences in filament tension at the end of the . 25 first spool and at the beginning of the second spool.
During winding it has been found to be often .~;
desirable to rotate the take-up reel at a speed greater than the speed at which the guide arm oscillates. This, at the maximum,can provide, after cutting of ten percent of the length of the bundle during removal from the reel, individual filaments which occupy about thirty percent of the width of the bundle. In one particular operation the take-up reel is driven at 200 rpm and the guide arm is oscillated at 160 or 180 oscillations per minute. Overall, it is generally preferred for there to be from about 0.45 to 1.7 back and forth oscillations per rotation of the take-up reel, especially in a reel of the design shown where six bundles are simultaneously manufactured. The above ratio may correspondingly vary for take-up reels which ~, make different numbers of lengths of filament bundles.
Thus it will be appreciated that as the geo-metry of the take-up reel, for example the size and dia-meter of the take-up reel, changes, the oscillations of the guide arm must also change in order to effectuate ~ .
; proper crossover.
Once the filaments are wound on the take-up reel and the bundles are of a sufficient size for use in hollow fiber dialyzers, the winding operation is stopped.
Preparation of Fiber Bundles An elongated split case 200 as shown in FIGURE
7 25 9 is used in forming the fiber bundles from the filaments ~ and for removing the bundles from the take-up reel. The ,, .
!,' - 20-r ~!
~$~
split case includes an upper semi-cylindrical member 202 and a lower semi-cylindrical member 204, which are joined by a pair of flexible hinges 206 and 208. As can be seen in FIGURE 10, the sections can be opened and positioned and clamped about the wound bundles of the filament.
Referring now to FIGURE 7, once the members are in position, they tightly grasp the bundles of fila-ment therebetween and the filament may then be cut at either end of the case so as to form open-ended fibers and permit removal of the bundles from the reel. The cutting converts the continuous filament to the individual hollow fibers used in the dialyzer. After cutting and removal, the individual -~ bundles are then treated and formed into the hollow fiber dialyzers.
Referring to Figure 11, a schematic view of a filament bundle 210 made in accordance with this invention is shown, with the great majority of the filaments being omitted for a clearer disclosure of the filament relation-ships. Basically, most of the filaments shown in the bundle 210 fit the overall relationships of the filaments in the bundle as schematically illustrated in Figure 8, resulting from the winding techni~ue utilized as described in this invention. The winding tension is preferably from about 0.5 to 5 gm. per filament being wound, preferably less than one gram per filament.
It should also be added that when two or more fila-ments are wound onto the reel at once, as specifically disclosed herein, the pair of filaments lie side by side in a relationship ~, ' ,~ i r r~
in which each filament as shown in Figures 8 and 11 can represent separate multiple, parallel filament members, located adjacent to one another in the filament bundle. The term "filament" as utilized herein is intended to include this plural structure.
Filament bundle 210 may, in one embodiment, be at least five thousand generally longitudinally directed, semi-permeable individual filaments, free of mechanical attach-; ment to each other, made of cellulose for dialysis, or any other appropriate material for other diffusion functions. Preferably,the dialysis filaments are made of cuprammonium regenerated cellulose, the individual filaments having a sufficient wet tensile strength (e.g. at least about 100 grams) and are still enough to retain, in the main, the crossing overlying structure into which they are formed, as illustrated in Figures 8 and 11.
"Softer" fibers, such as cellulose acetate derived filaments, when wet, may sag at random throughout the bundle, to form uneven flow paths outside of the filaments.
Preferably, the individual cellulose filaments used herein define an outer diameter of 100 to 400 microns, there being preferably at least about nine thousand separate filaments which exhibit an aggregate surface area of at least 0 5 square meter and preferably one to two square meters. The wall thick-ness of the individual filaments is preferably from 10 to 30 - 25 microns fon example, 16 microns.
As shown in Figure 8, the array of filaments 190, 192 are in angular relation to each other and to longitudinal axis 212 of the filament bundle (Figure 11). In the manufacture of the filament bundle of this invention, filaments 190 are laid down as guide arm 112 is swinging transversely of the longitudinal axis 212 in one direction. Filaments 192 are laid down while ;~ ' ~'~ .
the guide arm 112 is swinging in the opposite transverse direction.
As shown in the detail of FIGURE 8, filament l90a is laid down by a first swing of the guide arm 112 in a first transverse direction as the reel assembly 36 rotates.
- Filament 192_ is then laid down on top of filament 190_ by the further rotation of reel assembly 36, as arm 112 swings back in the opposite transverse direction, so that filament 192a overlies filament l90a. Then, on the next rotation of reel 36 as guide arm 112 swings back in the first transverse direction again, filament 190_ is laid down, over-lying filament 192a. Thereafter, as guide arm 112 is swung back again in the opposite transverse direction, and reel 36 rotates, filament 192_ is laid down, to overlie filament l90b, and so on through the entire assembly operation, to form the resulting filament-bundled loop, which is cut into six filament bundles 210 in the specific embodiment shown.
Filament bundle 210, in its completed form, may be about 15 to 25 cm., specifically, 20.5 cm., in length prior to assembly into a dialyzer housing, and may comprise about 11,500 individual filaments having an outer diameter of 247 microns and an inner diameter of 215 microns, to provide a dialyzer unit having the useful surface area of about 1.5 s~uare meters. Each filament may traverse about 27 percent of the width of the bundle, except for angled filaments 216.
It should be noted that the crossing points 214 of the respective filaments as shown in Figure 8 are in ~r~h~ ~
roughly linear arrangement with each other. This does not necessarily have to be the case. The arrangement of the various crossing points is dependent upon the revolutions per minute of the reel, compared with the number of oscillations per minute of arm 112. It is, in fact, generally preferable for the crossing points to lie in different positions with each rotation of the reel member, to avoid uneven Fiber buildup or "resonance".
Filaments 216 should also be noted (Figure 11) as a category of filament which is likely to be found in most filament bundles 210. As can be seen, these filaments are laid down on the reel during the time that guide arm 112 reaches a lateral limit of its swing, and begins to swing back again in the opposite direction, causing the resulting filament to first travel in one angular direction with respect to axis 212, and then to turn and be oriented in the opposite, similar angular direction to axis 212, defining a lateral apex 218 at the edge of the bundle. In fact, in the actual bundles of this invention, it is noted that some of these and other fibers can straighten out and form other wavy bends to some degree, and thus do not assume the ideal configuration which is as shown in Figure 11. Nevertheless, the bundle as a whole exhibits the essential structure, characteristics, and advan-tages described herein.
Most preferably, the ideal angles of filaments 190, 192 and 216 to axis 212 are constant, at preferably 2 to 3 for example, 2.15 or 2.59.
- -In the particular filament bundle which is specifically described herein, the void fraction may be about 0.64, resulting in a very substantial increase in dialysis clearance when placed in a dialyzer housing. Also, the dialyzer using the bundle structure of this invention, made of cuprammonium regenerated cellulose filaments can exhibit low blood clotting.
The filament bundle of this invention exhibits the remarkable characteristic in that it resists being laterally pulled apart in direction 218 (Figure 12) to a degree which is perceptibly and significantly greater than its resistance to being laterally pulled apart ln direction 220. The resistance of being pulled apart at direction 220 is essentially equal to the similar resistance of conventional filament bundles, which is indeed very low. Accordingly, while the filament bundle of this invention requires some outside retention to hold together, it exhibits a better tendency to retain its structure while being assembled into a dialyzer than the conventional filament bundles.
Referring to FIGURE 13, a dialyzer for blood lS
shown incorporating filament bundle 210 of this invention.
; Basically, the dialyzer may, if desired, be of conventional structure as currently used with filament bundles.
Bundle 210 is encased in a tubular housing 222, .
~- 25 which encloses the squarish bundle 210 as wound (as in Figure 12), and holds it in a cylindrical configuration for optimum flow characteristics.~ The filament ends of bundle 210 pass through .
r ~ . ., '~
~ .
cured potting compound members 224, which are specifically each in the shape of a disc, and sealingly positioned inside enlarged chamber ends 226 of housing 222, so that the filaments of bundle 210 pass through the disc-shaped structures 224 to permit flow through the Eilaments.
Caps 228 are placed on the ends of tubular housing 222 in sealing manner, and each carry a port 230.
Potted discs 224 are slightly spaced from the inner ends of caps 228, to provide a manifold chamber, for providing a fluid flow path between the ports 230 through the hollow filaments of bundle 210 in a sealed flow path.
A second flow path is provided to the dialyzer by means of second ports 232, which may be laterally posi-tioned adjacent the ends of housing 222 on opposite sides thereof as shown. Enlarged portions 226 of the housing serve as a second manifold means to uniformly distribute fluid around the exterior of bundle 210 in the annular chamber defined between the bundle and the inner wall of the housing in that area. In the central, constricted portion of housing 222, bundle 210 fits snugly within the housing wall, without any outside space as there is in enlarged chamber portions 226.
Accordingly, a second fluid flow path passes from one port 232, about an enlarged chamber 226, and then in a ` 25 percolating flow path through the crossing filament of -' .
-- ' ~
,.
.
'.
bundle 210 to the opposite enlarged chamber 226, and the other port 232.
_ The flow path between ports 230 is typically used for blood, while the flow path between ports 232 is for dialysis solution.
The two flow paths are sealed from each other so that there is no mixing of the fluids passing through them, except by means of diffusion through the walls of the filaments of bundle 210.
Preferably, a countercurrent flow pattern is utilized, in which blood flows in one direction through the dialyzer, and dialysis solution flows in the opposite direction.
Dialyzers made as specifically described herein, ~; 15 having about 11,500 thin-walled capillaries of about 16 microns thickness, and defining an active surface area of about 1.5 square meters, have been shown to provide supe-rior clearance characteristics in the small and middle molecule ranges, coupled with wide range, managable ultra-filtration capabilites. The priming volume of such a dialyser, made in accordance with this invention, may be 125 ml. in the blood compartment, with a volume change which is relatively insensitive to pressure variations.
The dialyzer of this invention, utilizinq , ; 25 Cupraammonium derived cellulose fibers, may be packed dry, '.
~. -Q~
climinating the formaldahyde flushing procedure used insome prior art dialyzers.
It will be appreciated that numerous changes and modifications can be made in the embodiments disclosed herein without departing from the spirit and scope of this invention.
:
Claims (15)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an elongated, coreless bundle of homogeneously distributed hollow, generally longitudinally-directed, semi-permeable filaments, free of direct mechanical attach-ment to each other, for use as a fluid separation element in a diffusion device, said filaments being positioned in said bundle whereby the majority of the lengths thereof, and the overall directions thereof, define an angle to the longitudinal axis of said filament bundle, said filaments being positioned in crossing, overlying relation with adjoining filaments, said filaments essentially occupying individual, parallel, flat planes, said filaments defining first sets of generally parallel strands defining a first angular relation to said longitudinal axis and second sets of generally parallel strands defining an opposite angular relation to said longitudinal axis, a first filament of a first set being overlaid by a first filament of a second set, which first filament of said second set is, in turn, overlaid by a second filament of said first set, which second filament of said first set is, in turn, overlaid by a second filament of said second set, said relationship continuing throughout the majority of the filaments of the first and second sets to define interleaving rela-tionships, in which the filaments of each set overlie the immediately-preceding filaments of the other associated set, and are overlaid by the immediately-following fila-ments of said other set, the majority of individual filaments thereof extending across fifteen to fifty per-cent of the width of said filament bundle.
2. The filament bundle of claim 1 which is made of cuprammonium-regenerated cellulose said filaments de-fining a wet tensile strength of at least one hundred grams.
3. The filamant bundle of claim 2 in which said hollow filaments define an outer diameter of 100 to 400 microns, there being at least five thousand filaments present in said bundle to provide a filament surface area of at least 0.5 square meter, said filaments each essentially occupying individual, parallel, flat planes.
4. The fialment bundle of claim 3 in which said filaments define a wall thickness of 10 to 30 microns.
5. The filament bundle of claim 4 which comprises at least nine thousand separate filaments which exhibit an aggregate surface area of one to two square meters.
6. The filament bundle of claim 5 in which the individual filaments extend across no more than about thirty percent of the width of said bundle.
7. A dialyzer for blood incorporating a tubular casing which sealingly encloses the filament bundle of claim 1, and manifold means for providing a fluid flow path through said dialyzer via the interior of said hol-low filaments, and second manifold means for conveying fluid through said bundle about the exterior of said filaments.
8. The dialyzer of claim 7 in which the majority of said individual filaments extend across 20 to 35 percent of the width of said bundle.
9. The dialyzer of claim 8 in which the angle of said filaments to a plane parallel to the longitudinal axis of said bundle and perpendicular to the individual planes of said filaments is from two to three degrees.
10. The bundle of claim 1 in which each filament comprises a group of separate, parallel filament members located adjacent one another.
11. The elongated coreless bundle of claim 1 which is enclosed within a hollow housing which is cylindrical along most of its length.
12. The filament bundle of claim 1, wherein said filaments are positioned in said bundle whereby the majority of the lengths thereof, and the overall direc-tions thereof, define an angle of two to three degrees to the longitudinal axis of said filament bundle.
13. The filament bundle of claim 1 further charac-terized by the property of exhibiting increased resistence to being pulled apart in a direction transverse to said longitudinal axis and parallel to the planes which con-tain individual filaments, when compared with the direction transverse to said longitudinal axis and perpendicular to said planes which contain individual filaments.
14. The filament bundle of claim 1, in which the void fraction of said filament bundle is in excess of 0.4.
15. The filament bundle of claim 14, in which said void fraction is from 0.6 to 0.8.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US76771177A | 1977-02-11 | 1977-02-11 | |
| US767,711 | 1977-02-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1109000A true CA1109000A (en) | 1981-09-15 |
Family
ID=25080314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA291,548A Expired CA1109000A (en) | 1977-02-11 | 1977-11-23 | Hollow filament bundle for diffusion device |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS5830057B2 (en) |
| AU (1) | AU3300778A (en) |
| CA (1) | CA1109000A (en) |
| CH (1) | CH619374A5 (en) |
| DK (1) | DK60478A (en) |
| ES (1) | ES466865A1 (en) |
| GB (1) | GB1583015A (en) |
| IE (1) | IE46551B1 (en) |
| IT (1) | IT1088704B (en) |
| NL (1) | NL7711855A (en) |
| NO (1) | NO780441L (en) |
| SE (1) | SE7801567L (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GR68187B (en) * | 1979-05-04 | 1981-11-09 | Univ Minnesota | |
| US4361481A (en) * | 1979-05-21 | 1982-11-30 | Baxter Travenol Laboratories, Inc. | Capillary fiber bundles |
| JPS61204045U (en) * | 1985-05-14 | 1986-12-22 | ||
| SE463479B (en) * | 1986-10-27 | 1990-11-26 | Skf Nova Ab | DRIVE WHEEL WITH BRAKE DISC |
| SE463432B (en) * | 1986-10-27 | 1990-11-19 | Skf Nova Ab | GEARS AND PROCEDURES FOR PREPARING THE SAME |
| US4952312A (en) * | 1988-11-24 | 1990-08-28 | Sorin Biomedica S.P.A. | Method for winding the fibres of exchange devices, such as blood oxygenators and the like, and an exchange device produced by this method |
| CN104803232B (en) * | 2015-04-29 | 2017-04-12 | 四川华西德顿塑料管道有限公司 | Winding mechanism for winding finished PE (Polyethylene) pipeline |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS545796B2 (en) * | 1973-08-14 | 1979-03-20 | ||
| JPS5238836B2 (en) * | 1973-09-13 | 1977-10-01 |
-
1977
- 1977-10-28 NL NL7711855A patent/NL7711855A/en not_active Application Discontinuation
- 1977-11-23 CA CA291,548A patent/CA1109000A/en not_active Expired
- 1977-11-29 IT IT30210/77A patent/IT1088704B/en active
- 1977-12-20 JP JP52154281A patent/JPS5830057B2/en not_active Expired
- 1977-12-20 CH CH1568277A patent/CH619374A5/en not_active IP Right Cessation
- 1977-12-28 GB GB53982/77A patent/GB1583015A/en not_active Expired
-
1978
- 1978-02-03 AU AU33007/78A patent/AU3300778A/en active Pending
- 1978-02-09 NO NO780441A patent/NO780441L/en unknown
- 1978-02-10 DK DK60478A patent/DK60478A/en not_active Application Discontinuation
- 1978-02-10 IE IE302/78A patent/IE46551B1/en unknown
- 1978-02-10 ES ES466865A patent/ES466865A1/en not_active Expired
- 1978-02-10 SE SE7801567A patent/SE7801567L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| IE780302L (en) | 1978-08-11 |
| AU3300778A (en) | 1979-08-09 |
| ES466865A1 (en) | 1979-01-01 |
| IE46551B1 (en) | 1983-07-13 |
| GB1583015A (en) | 1981-01-21 |
| IT1088704B (en) | 1985-06-10 |
| SE7801567L (en) | 1978-08-12 |
| DK60478A (en) | 1978-08-12 |
| JPS53100697A (en) | 1978-09-02 |
| NO780441L (en) | 1978-08-14 |
| JPS5830057B2 (en) | 1983-06-27 |
| NL7711855A (en) | 1978-08-15 |
| CH619374A5 (en) | 1980-09-30 |
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