Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1998-06-30
2000-10-24
Copenheaver, Blaine
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
264 13, 264205, 26421114, 524466, 524473, D01D 511, D01F 632, C08J 309, C08L 2712
Patent
active
06136911&
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to fibers that are flash-spun from partially fluorinated hydrocarbon polymers and a solvent.
The art of flash-spinning strands of plexifilamentary film-fibrils from polymer in a solution or a dispersion is known in the art. The term "plexifilamentary" means a three-dimensional integral network of a multitude of thin, ribbon-like, film-fibril elements of random length and with a mean film thickness of less than about 4 microns and with a median fibril width of less than about 25 microns. In plexifilamentary structures, the film-fibril elements are generally coextensively aligned with the longitudinal axis of the structure and they intermittently unite and separate at irregular intervals in various places throughout the length, width and thickness of the structure to form a continuous three-dimensional network.
U.S. Pat. No. 3,227,784 to Blades et al. (assigned to E.I. du Pont de Nemours & Company ("DuPont")) describes a process wherein a polymer in solution is forwarded continuously to a spin orifice at a temperature above the boiling point of the solvent, and at autogenous pressure or greater, and is flash-spun into a zone of lower temperature and substantially lower pressure to generate a strand of plexifilamentary material. U.S. Pat. No. 5,192,468 to Coates et al. (assigned to DuPont) discloses another process for flash-spinning a plexifilamentary strand according to which a mechanically generated dispersion of melt-spinnable polymer, carbon dioxide and water under high pressure is flashed through a spin orifice into a zone of substantially lower temperature and pressure to form a plexifilamentary strand.
U.S. Pat. No. 3,227,794 to Anderson et al. (assigned to DuPont) teaches that plexifilamentary film-fibrils are best obtained from solution when fiber-forming polymer is dissolved in a solvent at a temperature and at a pressure above which two liquid phases form, which pressure is generally known as the cloud point pressure at the given temperature. This solution is passed to a pressure let-down chamber, where the pressure decreases below the cloud point pressure for the solution thereby causing phase separation. The resulting two phase dispersion of a solvent-rich phase in a polymer-rich phase is discharged through a spinneret orifice to form the plexifilamentary strand.
U.S. Pat. No. 3,484,899 to Smith (assigned to DuPont) discloses an apparatus with a horizontally oriented spin orifice through which a plexifilamentary strand can be flash-spun. The polymer strand is conventionally directed against a rotating lobed deflector baffle to spread the strand into a more planar web structure that the baffle alternately directs to the left and right as the web descends to a moving collection belt. The fibrous sheet formed on the belt has plexifilamentary film-fibril networks oriented in an overlapping multi-directional configuration.
Many improvements to the basic flash-spinning process have been reported or patented over the years. Flash-spinning of olefin polymers to produce non-woven sheets is practiced commercially and is the subject of numerous patents including U.S. Pat. No. 3,851,023 to Brethauer et al (assigned to DuPont). Flash-spinning of olefin polymers to produce pulp-like products from polymer solutions is disclosed in U.S. Pat. No. 5,279,776 to Shah (assigned to DuPont). Flash-spinning of olefin polymers to produce microcellular and ultra-microcellular foam products from polymer solutions is disclosed in U.S. Pat. Nos. 3,227,664 to Blades et al. and 3,584,090 to Parrish (assigned to DuPont).
The commercial application for flash-spinning has been primarily directed to the manufacture of polyolefin plexifilaments, especially of polyethylene and polypropylene. However, experimental work directed to the flash-spinning of other polymers, has been reported. For example, U.S. Pat. No. 3,227,784 to Blades et al. describes the flash-spinning of a solution of a perfluoroethylene/perfluoropropylene (90:10) copolymer from a solution in p-bis(trifluoromethyl)
REFERENCES:
patent: 3081519 (1963-03-01), Blades et al.
patent: 3227664 (1966-01-01), Blades et al.
patent: 3227784 (1966-01-01), Blades et al.
patent: 3484899 (1969-12-01), Smith
patent: 3584090 (1971-06-01), Parrish
patent: 3624250 (1971-11-01), Carlson
patent: 3851023 (1974-11-01), Brethauer et al.
patent: 3870689 (1975-03-01), Modena et al.
patent: 4054625 (1977-10-01), Kozlowski et al.
patent: 4608089 (1986-08-01), Gale et al.
patent: 4642262 (1987-02-01), Piotrowski et al.
patent: 4677175 (1987-06-01), Ihara et al.
patent: 5147586 (1992-09-01), Shin et al.
patent: 5192468 (1993-03-01), Coates et al.
patent: 5279776 (1994-01-01), Shah
patent: 5290846 (1994-03-01), Tuminello
patent: 5328946 (1994-07-01), Tuminello et al.
patent: 5364929 (1994-11-01), Dee et al.
patent: 5371810 (1994-12-01), Vaidyanathan
patent: 5816700 (1998-10-01), Starke, Sr. et al.
Armstrong John Edward
Shin Hyunkook
Waggoner James Ross
Copenheaver Blaine
E.I. Du Pont de Nemours and Company
Ruddock Ula C.
LandOfFree
Fibers flash-spun from partially fluorinated polymers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fibers flash-spun from partially fluorinated polymers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fibers flash-spun from partially fluorinated polymers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1964961