WO2000077515A2 - Process for determining the polymer concentration in a spinning dope solution - Google Patents
Process for determining the polymer concentration in a spinning dope solution Download PDFInfo
- Publication number
- WO2000077515A2 WO2000077515A2 PCT/EP2000/004729 EP0004729W WO0077515A2 WO 2000077515 A2 WO2000077515 A2 WO 2000077515A2 EP 0004729 W EP0004729 W EP 0004729W WO 0077515 A2 WO0077515 A2 WO 0077515A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- solution
- spinning dope
- concentration
- dope solution
- polymer
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/30—Arrangements for calibrating or comparing, e.g. with standard objects
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/02—Analysing fluids
- G01N29/024—Analysing fluids by measuring propagation velocity or propagation time of acoustic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/022—Liquids
- G01N2291/0222—Binary liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/022—Liquids
- G01N2291/0224—Mixtures of three or more liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02809—Concentration of a compound, e.g. measured by a surface mass change
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02818—Density, viscosity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/10—Number of transducers
- G01N2291/102—Number of transducers one emitter, one receiver
Definitions
- the invention pertains to a process for determining the polymer concentration in a spinning dope solution.
- Fiber industry One area of technology that is a source and motivation for polymer research, particularly with respect to mechanical properties, is the fiber industry.
- the most widely used fiber-forming processes are melt spinning and solution spinning. In both processes, the polymer is extruded from the orifices of a spinneret. In melt spinning molten polymer is used, while in solution spinning a spinning dope solution is the source of the polymer.
- a small increase in the concentration could initiate the formation of a non-homogeneous or highly viscous spinning dope solution, which is unsuitable for the production of fibers with consistent properties and often also results in very inconvenient process equipment problems during production of the fibers. Therefore, it is important to determine the concentration as rapidly and accurately as possible.
- Several methods are known in the art for determining the polymer concentration in a solution, such as light scattering, density, conductivity, and refractive index measurement, and Infrared, Near Infrared, Raman, and UV spectroscopy.
- the polymer concentration in a spinning dope solution is determined by measuring the density of the solution. However, said measurement often is not accurate enough to bring fluctuations in the polymer concentration in a spinning dope solution to notice.
- devices for measuring the density of a spinning dope solution are difficult to clean. These disadvantages become even more important when the measurement is carried out in-line.
- the primary object of the present invention to provide a method to determine the polymer concentration in a spinning dope solution rapidly and accurately. Furthermore, the device used for this determination preferably is easier to clean than other presently commercially available devices.
- a process has been found that allows fast and accurate determination of the polymer concentration in a spinning dope solution.
- the process is characterized in that the determination is carried out by measuring the propagation velocity of ultrasonic sound in the solution.
- the process according to the invention can be applied using a spinning dope solution that is prepared either batch-wise or continuously by dissolving or dispersing any polymer in any solvent or any solution. Furthermore, a spinning dope solution with any polymer concentration can be used. Therefore, the process can be applied in the production of any fiber.
- a spinning dope solution with any polymer concentration can be used for the production of any fiber.
- the process is often required to use a spinning dope solution with a high polymer concentration in order to obtain the desired properties. Since the process is highly suitable for monitoring fluctuations, it can be applied advantageously in the production of said fibers.
- a high polymer concentration means a concentration of at least 70%, preferably at least 80% of the concentration at which a non-homogeneous spinning dope solution is formed, or at which the solution becomes too viscous to be used in a spinning process.
- This high concentration generally is between 10 and 25% by weight. If poly(p-phenylene terephthalamide) is used as the polymer in a sulfuhc acid (approx. 99.8% by weight) solution, then this high concentration is about 16 to 21% by weight.
- the spin dope concentration is not kept constant such high polymer concentration spinning dope solutions first of all pose problems in the production of fibers with consistent properties, and also lead to very inconvenient problems with the process equipment during production of the fibers.
- the determination of a polymer concentration according to the invention can be applied to spinning dope solutions and samples thereof, and can be carried out by measuring the propagation velocity of ultrasonic sound in the solution with an ultrasonic device comprising an emitter and a receiver for ultrasonic sound.
- the device generates ultrasonic sound waves at the emitter, measures the time it takes before such a wave from the emitter passing through the solution arrives at the receiver, and calculates the propagation velocity as the distance between the emitter and the receiver divided by this time.
- Ultrasonic sound with a frequency between 50 kHz and 100 MHz can be used.
- the polymer concentration in a spinning dope solution can be determined by comparing the propagation velocity of ultrasonic sound in this solution with reference propagation velocity values including graphs. These reference values have been measured in spinning dope solutions with known amounts of the polymer, by using the same solvent or solution for dispersing or dissolving the polymer as in the spinning dope solution where the concentration has to be determined.
- the propagation velocity (v) of ultrasonic sound in general depends on the density (d) and the adiabatic compressibility (c) of the solution according to the following equation:
- the ultrasonic device used for measuring the propagation velocity of ultrasonic sound comprises a temperature sensor in order to enable local adjustment of the temperature in the solution between the emitter and the receiver.
- the propagation velocity of ultrasonic sound in a spinning dope solution is also slightly dependent on the flow of the solution in which the measurement takes place.
- the propagation velocity is measured perpendicular to the flow direction.
- the distance between the emitter and the receiver also plays a role.
- a relatively large distance is preferred, providing the temperature and the pressure of the solution between the emitter and the receiver can be kept constant.
- a practical distance is between 1 and 10 cm, without it being the intention to limit the invention to this range. Most practical is a distance between 1 and 5 cm.
- the polymer is dissolved or dispersed homogeneously in the solution, secondly that the solution is free from air-bubbles, and finally that the length of any polymer or particle that may be present in the solution is smaller than half the wavelength of the ultrasonic sound used. Furthermore, a relatively large difference in density between the polymer and the solution used to dissolve or disperse this polymer is preferred, in order to attain enough sensitivity for determining the concentration of the polymer most accurately.
- In-line measuring means that the measurement is carried out continuously or with certain time intervals in a spinning dope solution or in any process stream consisting of this solution.
- the in-line measurement is carried out automatically, for example controlled by an electronic or computer system. Even more preferably, such an electronic or computer system is able to give signals or commands for correcting the polymer concentration in a spinning dope solution as soon as possible when necessary, thereby preventing fluctuations in this concentration as much as possible.
- an ultrasonic device measuring the propagation velocity of ultrasonic sound inline often can also be used for the qualitative monitoring of other irregularities in the solution, such as air-bubbles and non-dissolved particles. This monitoring will contribute further to the production of fibers of consistent composition and properties.
- Density measurements were carried out in-line using a density meter DIMF 2.0 (Bopp and Reuter), and propagation velocity measurements of ultrasonic sound with a frequency of about 1.5 MHz were carried out in-line using a LiquiSonicTM (SensoTech) as ultrasonic device.
- In-line in this example means, in a spinning dope solution that flows from a storage tank to a spinneret through a tube with a internal diameter of 16 mm.
- the emitter and the receiver of the ultrasonic device are arranged in such a way that the generated ultrasonic sound propagates perpendicular to the flow direction, and the distance between the emitter and the receiver is about 2 cm.
- Spinning dope solutions containing 18.04, 18.60, 19.03, 19.60, and 19.83% PPTA poly(p-phenylene terephthalamide) by weight, respectively, were prepared batch-wise by dispersing the required amount of PPTA in sulfuric acid (99.8% by weight) solutions.
Landscapes
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001503522A JP4582751B2 (en) | 1999-06-16 | 2000-05-23 | Method for producing fibers |
US10/009,804 US6672164B1 (en) | 1999-06-16 | 2000-05-23 | Process for determining the polymer concentration in a spinning dope solution |
AU59688/00A AU5968800A (en) | 1999-06-16 | 2000-05-23 | Process for determining the polymer concentration in a spinning dope solution |
GB0200404A GB2367363B (en) | 1999-06-16 | 2000-05-23 | Process for determining the polymer concentration in a spinning dope solution |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP99201907.5 | 1999-06-16 | ||
EP99201907 | 1999-06-16 | ||
US14560099P | 1999-07-26 | 1999-07-26 | |
US60/145,600 | 1999-07-26 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2000077515A2 true WO2000077515A2 (en) | 2000-12-21 |
WO2000077515A3 WO2000077515A3 (en) | 2001-02-08 |
Family
ID=26153331
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2000/004729 WO2000077515A2 (en) | 1999-06-16 | 2000-05-23 | Process for determining the polymer concentration in a spinning dope solution |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP4582751B2 (en) |
AU (1) | AU5968800A (en) |
GB (1) | GB2367363B (en) |
WO (1) | WO2000077515A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8309642B2 (en) | 2007-02-03 | 2012-11-13 | Teijin Aramid B.V. | Method for dissolving aramid polymer in sulfuric acid using a double shaft kneader |
CN107462630A (en) * | 2017-08-16 | 2017-12-12 | 中国石油化工股份有限公司 | A kind of polymer concentration detection method and equipment based on sound velocity method |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3420794A1 (en) * | 1983-06-10 | 1984-12-13 | Helmut Dr. Heimel | Device for investigating liquid properties |
US5433112A (en) * | 1992-09-15 | 1995-07-18 | Piche; Luc | Ultrasonic characterization of polymer melts under processing conditions |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63243330A (en) * | 1987-03-31 | 1988-10-11 | Asahi Chem Ind Co Ltd | Production of high-modulus fiber |
US5762798A (en) * | 1991-04-12 | 1998-06-09 | Minntech Corporation | Hollow fiber membranes and method of manufacture |
US5354524A (en) * | 1993-05-24 | 1994-10-11 | Alan Sellars | Monitoring concentration of dope in product manufacture |
DE69812946T2 (en) * | 1997-06-20 | 2003-12-18 | The Dow Chemical Co., Midland | ETHYLENE POLYMER COMPOSITIONS AND OBJECTS MADE THEREOF |
-
2000
- 2000-05-23 WO PCT/EP2000/004729 patent/WO2000077515A2/en active Application Filing
- 2000-05-23 JP JP2001503522A patent/JP4582751B2/en not_active Expired - Fee Related
- 2000-05-23 GB GB0200404A patent/GB2367363B/en not_active Expired - Fee Related
- 2000-05-23 AU AU59688/00A patent/AU5968800A/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3420794A1 (en) * | 1983-06-10 | 1984-12-13 | Helmut Dr. Heimel | Device for investigating liquid properties |
US5433112A (en) * | 1992-09-15 | 1995-07-18 | Piche; Luc | Ultrasonic characterization of polymer melts under processing conditions |
Non-Patent Citations (2)
Title |
---|
ANONYMOUS: "Ultrasonic measurement and control of polymer melt compositions" RESEARCH DISCLOSURE, vol. 263, 1986, page 127 XP002124943 gb * |
BEAR R S ET AL: "ULTRASONIC PULSE METHOD WITH NONLINEAR CALIBRATION FOR QUANTITATIVE MONITORING OF POLYMER BLENDS OVER A WIDE TEMPERATURE RANGE" ANALYTICAL CHEMISTRY,US,AMERICAN CHEMICAL SOCIETY. COLUMBUS, vol. 65, no. 9, 1993, page 1169-1173 XP000368536 ISSN: 0003-2700 cited in the application * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8309642B2 (en) | 2007-02-03 | 2012-11-13 | Teijin Aramid B.V. | Method for dissolving aramid polymer in sulfuric acid using a double shaft kneader |
CN107462630A (en) * | 2017-08-16 | 2017-12-12 | 中国石油化工股份有限公司 | A kind of polymer concentration detection method and equipment based on sound velocity method |
Also Published As
Publication number | Publication date |
---|---|
JP4582751B2 (en) | 2010-11-17 |
AU5968800A (en) | 2001-01-02 |
GB0200404D0 (en) | 2002-02-27 |
GB2367363A (en) | 2002-04-03 |
GB2367363B (en) | 2003-07-23 |
WO2000077515A3 (en) | 2001-02-08 |
JP2003502640A (en) | 2003-01-21 |
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