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US 4,054,625 AGranted
Process for making fibers
AssigneeCrown Zellerbach Corporation
InventorsJohn H. Kozlowski, Paul C. Litzinger, Frank J. Steffes
Life of this patent
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Abstract
A process of manufacturing fibers by forming a mixture of a solvent, a polymer and water and flashing the mixture through a nozzle. Water is present as a discontinuous phase in the mixture. The polymer may be any polymer capable of forming fiber, preferably a crystalline or a partially crystalline polymer. The preferred polymers are crystalline or partially crystalline polyolefins, preferably polyethylene or polypropylene. The discrete fibers thus formed can be easily refined and used for making paper webs.
Claims24
A process of making discrete fibers comprising:
- A. forming a mixture comprising:
- 1. a polymer capable of forming fibers and of being swollen or dissolved by a solvent,
- 2. an organic solvent, in an amount at least greater by weight than said polymer, which is a solvent for said polymer at elevated temperatures and which is capable of forming therewith a phase which is substantially water immiscible and
- 3. water in an amount capable of forming a dispersed and non-continuous phase in said mixture in which the water is present as a dispersed phase and not as a continuous phase in the mixture;
- B. at a temperature sufficiently high that the polymer is present in at least a swollen state but below the critical temperature of the solvent and below the temperature at which the polymer decomposes and at autogeneous or higher pressure;
- C. agitating the mixture sufficiently to maintain the water as a dispersed and non-continuous phase therein;
- and
- D. passing the mixture through a nozzle into a zone of lower pressure which is at a temperature and pressure enabling said solvent to vaporize, thereby causing the formation of a fibrous product of discrete fibers.
5 more elements
A process of making discrete fibers comprising:
- A. forming a mixture comprising:
- (1) an at least partially crystalline polyolefin,
- (2) a substantially water immiscible organic solvent for the polyolefin in an amount between 70% and 98% of the combined weight of the polyolefin and solvent,
- (3) water in an amount greater than 1% but less than 70 volume percent of the mixture;
- in which the water is present as a dispersed and not as a continuous phase in the mixture;
- B. at a temperature above the melt dissolution temperature of the polyolefin but less than the critical temperature of the solvent and decomposition temperature of the polyolefin and at autogeneous pressure or higher;
- C. agitating the mixture sufficiently to maintain the water as a dispersed and non-continuous phase therein;
- and
- D. passing the mixture through a nozzle into a zone of lower pressure which is at a temperature and pressure enabling said solvent to vaporize, thereby causing the formation of a fibrous product of discrete fiber.
6 more elements
A process of forming discrete fibers comprising:
- A. forming a solution comprising:
- (1) an at least partially crystalline polyolefin and
- (2) a substantially water immiscible organic solvent for the polyolefin in an amount between 70% and 98% of the combined weight of the polyolefin and solvent at a temperature above the melt dissolution temperature of the polyolefin in the solvent;
- B. adding to said solution water, at a temperature above the melt dissolution temperature of said polyolefin and in an amount between 30% and 70% by volume of the mixture, while the solution is under sufficient agitation to disperse the water therein as a dispersed and non-continuous phase;
- C. maintaining the thus formed mixture under agitation at a temperature above said melt dissolution temperature but below the critical temperature of the solvent and below the temperature at which the polymer decomposes and at autogeneous pressure or higher;
- and
- D. passing the mixture through a nozzle into a zone of lower pressure which is at a temperature and pressure enabling said solvent to vaporize, thereby causing formation of a fibrous product of discrete fibers.
4 more elements
A process for preparing a fibrous synthetic polymer material, which comprises:
- mixing a diluent solution of 2-30 percent by weight of a hydrophobic polymer selected from the group consisting of polyethylene, polybutene, poly-methylpentene, polyamides, polyesters and polyacrylonitrile in a diluent of cyclohexane, hexane, octane, benzene, methylene chloride, alcohols or amides with an aqueous solution of polyvinyl alcohol and a surface active agent to form a water-in-oil emulsion, wherein the water to diluent ratio ranges from 1:10 to 1:1 by volume;
- heating said emulsion to a temperature above the melt dissolution point of said hydrophobic polymer under high pressure, and passing the heated emulsion through a nozzle into a lower pressure zone thereby volatilizing said diluent.
Dependencies are inferred from the claim text.