Fibrous web for processing a fluid

• US 5,652,050 A
• Filed: 03/01/1996
• Issued: 07/29/1997
• Est. Priority Date: 07/28/1994
• Status: Expired due to Term

• Current Assignee: Pall Corporation (Danaher Corporation)
• Original Assignee: Pall Corporation (Danaher Corporation)
• Inventors: Pall, David B., Manteuffel, Richard L.
• Primary Examiner(s): Bell, James J.
• Application Number:
  US08/609,787
• Time in Patent Office: 515 Days
• Field of Search: 428/284, 428/286, 428/297, 428/315.5, 428/315.9, 428/318.4, 428/321.1, 428/903
• US Class Current: 442/394
• CPC Class Codes: B01D 2239/0421 Rendering the filter material hydrophilic
• CPC Class Codes: B01D 2239/0471 Surface coating material
• CPC Class Codes: B01D 2239/06 Filter cloth, e.g. knitted, woven non-woven; self-supported material
• CPC Class Codes: B01D 2239/0622 Melt-blown
• CPC Class Codes: B01D 2239/064 The fibres being mixed
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material
• CPC Class Codes: B01D 2239/0681 The layers being joined by gluing
• CPC Class Codes: B01D 2239/10 Filtering material manufacturing
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/1291 Other parameters
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 71/34 Polyvinylidene fluoride
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0812 Bands; Tapes
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/12 Specific details about materials
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: D01D 5/0985 : by means of a flowing gas (e.g. melt-blowing)
• CPC Class Codes: D04H 1/43838 : Ultrafine fibres, e.g. microfibres
• CPC Class Codes: D04H 1/56 : in association with fibre formation, e.g. immediately following extrusion of staple fibres
• CPC Class Codes: Y10S 428/903 : Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10T 428/1307 : Bag or tubular film [e.g., pouch, flexible food casing, envelope, etc.]
• CPC Class Codes: Y10T 428/249953 : Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249978 : Voids specified as micro
• CPC Class Codes: Y10T 428/24998 : Composite has more than two layers
• CPC Class Codes: Y10T 428/249982 : With component specified as adhesive or bonding agent
• CPC Class Codes: Y10T 428/249987 : With nonvoid component of specified composition
• CPC Class Codes: Y10T 428/249995 : Constituent is in liquid form
• CPC Class Codes: Y10T 442/626 : Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/674 : Nonwoven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/676 : Vinyl polymer or copolymer sheet or film [e.g., polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, etc.]
• CPC Class Codes: Y10T 442/68 : Melt-blown nonwoven fabric

Abstract

Melt-blown fibrous webs having a uniform structure for use in processing biological fluids are disclosed.

Claims

1. A device for processing a biological fluid comprising:

at least one melt-blown fibrous web, wherein said web comprises fibers such that 90% of said fibers have a diameter ranging from a minimum fiber diameter to a maximum fiber diameter which is no more than about three times the minimum fiber diameter; and

a microporous membrane which is in fluid communication with said web.

2. The device of claim 1, further comprising a fibrous binding resin, wherein said binding resin binds the web to the membrane.

3. The device of claim 1, wherein said web has a critical wetting surface tension (CWST) of at least about 65 dynes/cm.

4. The device of claim 3, wherein the CWST is at least about 90 dynes/cm.

5. The device of claim 1, wherein said web has a basis weight in the range of about 1 g/ft² to about 50 g/ft².

6. The device of claim 1, wherein said web has a basis weight of about 20 g/ft² or less.

7. The device of claim 2, wherein the fibrous binding resin comprises polyethylene or PETG.

8. The device of claim 1, wherein the membrane comprises nylon or polyether sulfone.

9. The device of claim 2, wherein the membrane comprises a hydrophilic membrane.

10. The device of claim 9, wherein the web has a basis weight in the range of about 2 g/ft² to about 12 g/ft².

11. The device of claim 9 wherein said hydrophilic membrane comprises a polyether sulfone membrane, said device further comprising a nylon membrane downstream of the polyether sulfone membrane.

12. The device of claim 9, wherein the hydrophilic membrane comprises nylon.

13. The device of claim 9, wherein the hydrophilic membrane comprises polyether sulfone.

14. A device for processing a biological fluid comprising:

at least one melt-blown fibrous web, wherein said web comprises fibers such that 90% of said fibers have a diameter ranging from a minimum fiber diameter to a maximum fiber diameter which is no more than about three times the minimum fiber diameter;

a first microporous membrane which is in fluid communication with said web and is downstream of said web;

a fibrous binding resin, wherein said binding resin binds the web to the membrane; and

a second microporous membrane which is in fluid communication with the first microporous membrane and is downstream of the first microporous membrane.

15. The device of claim 14, wherein the first and second membranes comprise hydrophilic membranes.

16. The device of claim 14, wherein said web has a basis weight in the range of about 2 g/ft² to about 12 g/ft².

17. The device of claim 15, wherein said web has a critical wetting surface tension (CWST) of at least about 65 dynes/cm.

18. The device of claim 14, wherein a fibrous binding resin binds the second membrane to the first membrane.

19. A method for processing a biological fluid comprising:

passing a plasma-containing biological fluid through at least one melt-blown web, said web comprising fibers such that 90% of said fibers have a diameter ranging from a minimum fiber diameter to a maximum fiber diameter which is no more than about three times the minimum fiber diameter; and

passing plasma into a microporous membrane which is in fluid communication with said web.